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Catecholaminergic Polymorphic Ventricular Tachycardia ( CPVT) is a highly lethal cardiac arrhythmia disease occurring during exercise or psychological stress. CPVT has an estimated prevalence of 1:10,000 and has mainly been associated with variants in calcium-regulating genes. Identification of potential false-positive pathogenic variants was conducted by searching the Exome Aggregation Consortium ( ExAC) database ( n = 60,706) for variants reported to be associated with CPVT. The pathogenicity of the interrogated variants was assessed using guidelines from the American College of Medical Genetics and Genomics ( ACMG) and in silico prediction tools. Of 246 variants 38 (15%) variants previously associated with CPVT were identified in the ExAC database. We predicted the CPVT prevalence to be 1:132. The ACMG standards classified 29% of ExAC variants as pathogenic or likely pathogenic. The in silico predictions showed a reduced probability of disease-causing effect for the variants identified in the exome database (p < 0.001). We have observed a large overrepresentation of previously CPVT-associated variants in a large exome database. Based on the frequency of CPVT in the general population, it is less likely that the previously proposed variants are associated with a highly penetrant monogenic form of the disease. [ABSTRACT FROM AUTHOR]

Objective: Prenatal exposure to maternal diabetes is associated with an increased risk of offspring heart defects. We evaluated associations with subtle infant cardiac changes., Research Design and Methods: In a cohort of 25,486 infants with transthoracic echocardiography within 60 days of birth, we investigated associations between maternal preexisting diabetes and gestational diabetes mellitus (GDM) and infant left ventricular (LV) structural and functional parameters, using linear regression to estimate adjusted mean differences (aMDs) between groups., Results: Infants exposed to maternal preexisting diabetes (n = 198) had thicker LV posterior walls (aMD 0.19 mm; 95% CI 0.11, 0.27), smaller LV internal diameters in systole (aMD -0.27 mm; 95% CI -0.45, -0.18) and diastole (aMD -0.37 mm; 95% CI -0.59, -0.09), reduced stroke volumes (aMD -0.36 mL; 95% CI -0.61, -0.11), and increased heart rates (aMD 3.14 bpm; 95% CI 1.10, 6.18) and mitral valve early peak velocities (aMD 2.17 cm/s; 95% CI 0.31, 4.04) than unexposed infants (n = 24,639). Infants born to mothers with GDM (n = 649) had significantly smaller LV internal diameters in systole (aMD -0.13 mm; 95% CI -0.22, -0.03) and similar structural and functional changes as children exposed to preexisting diabetes, albeit with smaller nonsignificant aMDs. Higher third-trimester HbA1c levels were associated with smaller LV internal diameters and stroke volumes in infants exposed to preexisting diabetes and with lower heart rates in infants exposed to GDM., Conclusions: Maternal preexisting diabetes and, to a lesser extent, GDM were associated with changes in infant LV structure and function., (© 2024 by the American Diabetes Association.)

Importance: Understanding of the genetics of accessory atrioventricular pathways (APs) and affiliated arrhythmias is limited., Objective: To investigate the genetics of APs and affiliated arrhythmias., Design, Setting, and Participants: This was a genome-wide association study (GWAS) of APs, defined by International Classification of Diseases (ICD) codes and/or confirmed by electrophysiology (EP) study. Genome-wide significant AP variants were tested for association with AP-affiliated arrhythmias: paroxysmal supraventricular tachycardia (PSVT), atrial fibrillation (AF), ventricular tachycardia, and cardiac arrest. AP variants were also tested in data on other heart diseases and measures of cardiac physiology. Individuals with APs and control individuals from Iceland (deCODE Genetics), Denmark (Copenhagen Hospital Biobank, Danish Blood Donor Study, and SupraGen/the Danish General Suburban Population Study [GESUS]), the US (Intermountain Healthcare), and the United Kingdom (UK Biobank) were included. Time of phenotype data collection ranged from January 1983 to December 2022. Data were analyzed from August 2022 to January 2024., Exposures: Sequence variants., Main Outcomes and Measures: Genome-wide significant association of sequence variants with APs., Results: The GWAS included 2310 individuals with APs (median [IQR] age, 43 [28-57] years; 1252 [54.2%] male and 1058 [45.8%] female) and 1 206 977 control individuals (median [IQR] year of birth, 1955 [1945-1970]; 632 888 [52.4%] female and 574 089 [47.6%] male). Of the individuals with APs, 909 had been confirmed in EP study. Three common missense variants were associated with APs, in the genes CCDC141 (p.Arg935Trp: adjusted odds ratio [aOR], 1.37; 95% CI, 1.24-1.52, and p.Ala141Val: aOR, 1.55; 95% CI 1.34-1.80) and SCN10A (p.Ala1073Val: OR, 1.22; 95% CI, 1.15-1.30). The 3 variants associated with PSVT and the SCN10A variant associated with AF, supporting an effect on AP-affiliated arrhythmias. All 3 AP risk alleles were associated with higher heart rate and shorter PR interval, and have reported associations with chronotropic response., Conclusions and Relevance: Associations were found between sequence variants and APs that were also associated with risk of PSVT, and thus likely atrioventricular reentrant tachycardia, but had allele-specific associations with AF and conduction disorders. Genetic variation in the modulation of heart rate, chronotropic response, and atrial or atrioventricular node conduction velocity may play a role in the risk of AP-affiliated arrhythmias. Further research into CCDC141 could provide insights for antiarrhythmic therapeutic targeting in the presence of an AP.

POPDC2 encodes for the Popeye domain-containing protein 2 which has an important role in cardiac pacemaking and conduction, due in part to its cAMP-dependent binding and regulation of TREK-1 potassium channels. Loss of Popdc2 in mice results in sinus pauses and bradycardia and morpholino knockdown of popdc2 in zebrafish results in atrioventricular (AV) block. We identified bi-allelic variants in POPDC2 in 4 families that presented with a phenotypic spectrum consisting of sinus node dysfunction, AV conduction defects and hypertrophic cardiomyopathy. Using homology modelling we show that the identified POPDC2 variants are predicted to diminish the ability of POPDC2 to bind cAMP. In in vitro electrophysiological studies we demonstrated that, while co-expression of wild-type POPDC2 with TREK-1 increased TREK-1 current density, POPDC2 variants found in the patients failed to increase TREK-1 current density. While patient muscle biopsy did not show clear myopathic disease, it showed significant reduction of the expression of both POPDC1 and POPDC2, suggesting that stability and/or membrane trafficking of the POPDC1-POPDC2 complex is impaired by pathogenic variants in any of the two proteins. Single-cell RNA sequencing from human hearts demonstrated that co-expression of POPDC1 and 2 was most prevalent in AV node, AV node pacemaker and AV bundle cells. Sinoatrial node cells expressed POPDC2 abundantly, but expression of POPDC1 was sparse. Together, these results concur with predisposition to AV node disease in humans with loss-of-function variants in POPDC1 and POPDC2 and presence of sinus node disease in POPDC2, but not in POPDC1 related disease in human. Using population-level genetic data of more than 1 million individuals we showed that none of the familial variants were associated with clinical outcomes in heterozygous state, suggesting that heterozygous family members are unlikely to develop clinical manifestations and therefore might not necessitate clinical follow-up. Our findings provide evidence for POPDC2 as the cause of a novel Mendelian autosomal recessive cardiac syndrome, consistent with previous work showing that mice and zebrafish deficient in functional POPDC2 display sinus and AV node dysfunction.

We report a multi-ancestry genome-wide association study on liver cirrhosis and its associated endophenotypes, alanine aminotransferase (ALT) and γ-glutamyl transferase. Using data from 12 cohorts, including 18,265 cases with cirrhosis, 1,782,047 controls, up to 1 million individuals with liver function tests and a validation cohort of 21,689 cases and 617,729 controls, we identify and validate 14 risk associations for cirrhosis. Many variants are located near genes involved in hepatic lipid metabolism. One of these, PNPLA3 p.Ile148Met, interacts with alcohol intake, obesity and diabetes on the risk of cirrhosis and hepatocellular carcinoma (HCC). We develop a polygenic risk score that associates with the progression from cirrhosis to HCC. By focusing on prioritized genes from common variant analyses, we find that rare coding variants in GPAM associate with lower ALT, supporting GPAM as a potential target for therapeutic inhibition. In conclusion, this study provides insights into the genetic underpinnings of cirrhosis., (© 2024. The Author(s).)

Background: Angioedema is a rare but potentially life-threatening adverse drug reaction in patients receiving angiotensin-converting enzyme inhibitors (ACEis). Research suggests that susceptibility to ACEi-induced angioedema (ACEi-AE) involves both genetic and nongenetic risk factors. Genome- and exome-wide studies of ACEi-AE have identified the first genetic risk loci. However, understanding of the underlying pathophysiology remains limited., Objective: We sought to identify further genetic factors of ACEi-AE to eventually gain a deeper understanding of its pathophysiology., Methods: By combining data from 8 cohorts, a genome-wide association study meta-analysis was performed in more than 1000 European patients with ACEi-AE. Secondary bioinformatic analyses were conducted to fine-map associated loci, identify relevant genes and pathways, and assess the genetic overlap between ACEi-AE and other traits. Finally, an exploratory cross-ancestry analysis was performed to assess shared genetic factors in European and African-American patients with ACEi-AE., Results: Three genome-wide significant risk loci were identified. One of these, located on chromosome 20q11.22, has not been implicated previously in ACEi-AE. Integrative secondary analyses highlighted previously reported genes (BDKRB2 [bradykinin receptor B2] and F5 [coagulation factor 5]) as well as biologically plausible novel candidate genes (PROCR [protein C receptor] and EDEM2 [endoplasmic reticulum degradation enhancing alpha-mannosidase like protein 2]). Lead variants at the risk loci were found with similar effect sizes and directions in an African-American cohort., Conclusions: The present results contributed to a deeper understanding of the pathophysiology of ACEi-AE by (1) providing further evidence for the involvement of bradykinin signaling and coagulation pathways and (2) suggesting, for the first time, the involvement of the fibrinolysis pathway in this adverse drug reaction. An exploratory cross-ancestry comparison implicated the relevance of the associated risk loci across diverse ancestries., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Importance: Recurrent pericarditis is a treatment challenge and often a debilitating condition. Drugs inhibiting interleukin 1 cytokines are a promising new treatment option, but their use is based on scarce biological evidence and clinical trials of modest sizes, and the contributions of innate and adaptive immune processes to the pathophysiology are incompletely understood., Objective: To use human genomics, transcriptomics, and proteomics to shed light on the pathogenesis of pericarditis., Design, Setting, and Participants: This was a meta-analysis of genome-wide association studies of pericarditis from 5 countries. Associations were examined between the pericarditis-associated variants and pericarditis subtypes (including recurrent pericarditis) and secondary phenotypes. To explore mechanisms, associations with messenger RNA expression (cis-eQTL), plasma protein levels (pQTL), and CpG methylation of DNA (ASM-QTL) were assessed. Data from Iceland (deCODE genetics, 1983-2020), Denmark (Copenhagen Hospital Biobank/Danish Blood Donor Study, 1977-2022), the UK (UK Biobank, 1953-2021), the US (Intermountain, 1996-2022), and Finland (FinnGen, 1970-2022) were included. Data were analyzed from September 2022 to August 2023., Exposure: Genotype., Main Outcomes and Measures: Pericarditis., Results: In this genome-wide association study of 4894 individuals with pericarditis (mean [SD] age at diagnosis, 51.4 [17.9] years, 2734 [67.6%] male, excluding the FinnGen cohort), associations were identified with 2 independent common intergenic variants at the interleukin 1 locus on chromosome 2q14. The lead variant was rs12992780 (T) (effect allele frequency [EAF], 31%-40%; odds ratio [OR], 0.83; 95% CI, 0.79-0.87; P = 6.67 × 10-16), downstream of IL1B and the secondary variant rs7575402 (A or T) (EAF, 45%-55%; adjusted OR, 0.89; 95% CI, 0.85-0.93; adjusted P = 9.6 × 10-8). The lead variant rs12992780 had a smaller odds ratio for recurrent pericarditis (0.76) than the acute form (0.86) (P for heterogeneity = .03) and rs7575402 was associated with CpG methylation overlapping binding sites of 4 transcription factors known to regulate interleukin 1 production: PU.1 (encoded by SPI1), STAT1, STAT3, and CCAAT/enhancer-binding protein β (encoded by CEBPB)., Conclusions and Relevance: This study found an association between pericarditis and 2 independent sequence variants at the interleukin 1 gene locus. This finding has the potential to contribute to development of more targeted and personalized therapy of pericarditis with interleukin 1-blocking drugs.

Many sequence variants have additive effects on blood lipid levels and, through that, on the risk of coronary artery disease (CAD). We show that variants also have non-additive effects and interact to affect lipid levels as well as affecting variance and correlations. Variance and correlation effects are often signatures of epistasis or gene-environmental interactions. These complex effects can translate into CAD risk. For example, Trp154Ter in FUT2 protects against CAD among subjects with the A1 blood group, whereas it associates with greater risk of CAD in others. His48Arg in ADH1B interacts with alcohol consumption to affect lipid levels and CAD. The effect of variants in TM6SF2 on blood lipids is greatest among those who never eat oily fish but absent from those who often do. This work demonstrates that variants that affect variance of quantitative traits can allow for the discovery of epistasis and interactions of variants with the environment., Competing Interests: Declaration of interests The authors affiliated with deCODE genetics/Amgen, Inc. are employed by the company., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background & Aims: Fatty liver disease has been associated with higher all-cause as well as liver-related, ischemic heart disease (IHD)-related and extrahepatic cancer-related mortality in observational epidemiological studies. We tested the hypothesis that fatty liver disease is a causal risk factor for higher mortality., Methods: We genotyped seven genetic variants known to be associated with fatty liver disease (in PNPLA3, TM6SF2, HSD17B13, MTARC1, MBOAT7, GCKR, and GPAM) in 110 913 individuals from the Danish general population. Hepatic steatosis was measured by hepatic computed tomography in n = 6965. Using a Mendelian randomization framework, we tested whether genetically proxied hepatic steatosis and/or elevated plasma alanine transaminase (ALT) was associated with liver-related mortality., Results: During a median follow-up of 9.5 years, 16 119 individuals died. In observational analyses, baseline elevated plasma ALT was associated with higher all-cause (1.26-fold), liver-related (9-fold), and extrahepatic cancer-related (1.25-fold) mortality. In genetic analyses, the risk alleles in PNPLA3, TM6SF2, and HSD17B13 were individually associated with higher liver-related mortality. The largest effects were seen for the PNPLA3 and TM6SF2 risk alleles, for which homozygous carriers had 3-fold and 6-fold, respectively, higher liver-related mortality than non-carriers. None of the risk alleles, individually or combined into risk scores, were robustly associated with all-cause, IHD-related, or extrahepatic cancer-related mortality. In instrumental variable analyses, genetically proxied hepatic steatosis and higher plasma ALT were associated with liver-related mortality., Conclusions: Human genetic data support that fatty liver disease is a causal driver of liver-related mortality., (© 2023 The Authors. Liver International published by John Wiley & Sons Ltd.)

Aims: Although highly heritable, the genetic etiology of calcific aortic stenosis (AS) remains incompletely understood. The aim of this study was to discover novel genetic contributors to AS and to integrate functional, expression, and cross-phenotype data to identify mechanisms of AS., Methods and Results: A genome-wide meta-analysis of 11.6 million variants in 10 cohorts involving 653 867 European ancestry participants (13 765 cases) was performed. Seventeen loci were associated with AS at P ≤ 5 × 10-8, of which 15 replicated in an independent cohort of 90 828 participants (7111 cases), including CELSR2-SORT1, NLRP6, and SMC2. A genetic risk score comprised of the index variants was associated with AS [odds ratio (OR) per standard deviation, 1.31; 95% confidence interval (CI), 1.26-1.35; P = 2.7 × 10-51] and aortic valve calcium (OR per standard deviation, 1.22; 95% CI, 1.08-1.37; P = 1.4 × 10-3), after adjustment for known risk factors. A phenome-wide association study indicated multiple associations with coronary artery disease, apolipoprotein B, and triglycerides. Mendelian randomization supported a causal role for apolipoprotein B-containing lipoprotein particles in AS (OR per g/L of apolipoprotein B, 3.85; 95% CI, 2.90-5.12; P = 2.1 × 10-20) and replicated previous findings of causality for lipoprotein(a) (OR per natural logarithm, 1.20; 95% CI, 1.17-1.23; P = 4.8 × 10-73) and body mass index (OR per kg/m2, 1.07; 95% CI, 1.05-1.9; P = 1.9 × 10-12). Colocalization analyses using the GTEx database identified a role for differential expression of the genes LPA, SORT1, ACTR2, NOTCH4, IL6R, and FADS., Conclusion: Dyslipidemia, inflammation, calcification, and adiposity play important roles in the etiology of AS, implicating novel treatments and prevention strategies., Competing Interests: Conflict of interest Scott M. Damrauer receives research support (to the University of Pennsylvania) from RenalytixAI and personal fees from Caico Ibs, both outside the scope of the present work. SMD is also named as a co-inventor on a government-owned US Patent application related to the use of genetic risk prediction for venous thromboembolic disease filed by the US Department of Veterans Affairs in accordance with Federal regulatory requirements. SMD is named as a co-inventor on a Government-owned US Patent application related to the use of PDE3B inhibition for preventing cardiovascular disease filed by the US Department of Veterans Affairs in accordance with Federal regulatory requirements. Stefan Söderberg has received speaker honoraria and consulting fees from Actelion Ltd. George Thanassoulis has received consulting fees from Ionis Pharmaceuticals and has participated in advisory boards for Amgen, Sanofi, Novartis, HLS Therapeutics and Silence. Morten Salling Olesen has received 5.000.000 dkrfra Sundhedsdonationer.Journalnr. 2022-0243. David O. Arnar has received travel support from Pfizer to attend the ESC 2022 Scientific Meeting in Barcelona and has stock options in Sidekick Health Digital Therapeutics. Henning Bundgaard has received lecture fees from Amgen, MSD, Sanofi-Avensis, BMS and grants from NordForsk, Innovation Fond, Denmark, The Capital Regions Research Foundation. Alex Hoerby Christensen—Novo Nordisk Foundation NNF20OC0065799. Romaine Capoulade has received an Honorarium for one lecture from Novartis. Robert Clarke has received support from BAYER (China Kadoorie Biobank). Unnur Thorsteinsdottir’s research is funded by deCODE genetics/Amgen. Daniel F. Gudbjartsson receives funds from deCODE Genetics/Amgen. Until 1 June 2022, Gudmundur Thorgeirsson was a part time employee of deCode Genetics that is owned by Amgen. Hilma Holm is an employee of deCODE genetics/Amgen Inc. Anna Helgadottir is an employee of deCODE genetics/Amgen Inc., (© The Author(s) 2023. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Objective: The association between common electrocardiogram (ECG) markers and Alzheimer's disease has been scarcely investigated, and it is unknown if ECG markers can improve risk prediction. Thus, we aimed to examine the association between common ECG markers and Alzheimer's disease in a large population., Methods: We studied the association between ECG markers and Alzheimer's disease using Cox models with adjustment for age, sex, and comorbidities using a large primary care population of patients aged 60 years or more., Results: We followed 172,236 subjects for a median of 7.5 years. Increased PR interval (hazard ratio for PR > 188 ms: 0.76 [95% confidence interval: 0.69-0.83, p < 0.001) and increased QTc interval (hazard ratio for QTc = [426;439]: 0.90 [0.83-0.98], p = 0.02) were associated with a decreased rate of Alzheimer's disease. A positive Sokolow-Lyon index >35 mm (1.22 [1.13-1.33], p < 0.001) and increased T-wave amplitude >4.1 mm (1.15 [1.04-1.27]) were associated with an increased rate of Alzheimer's disease. Upon addition of ECG markers to a reference model, 10-year prediction area under the receiver-operator characteristics curve (AUC) improved by 0.39 [0.06-0.67] %-points. The 10-year absolute risk of Alzheimer's disease was 6.5% and 5.2% for an 82-year old female and a male, respectively, with a favorable ECG, and 12% and 9.2%, respectively, with an unfavorable ECG, almost twice as high., Conclusions: We identified several common ECG markers which were associated with Alzheimer's disease, and which improved risk prediction for Alzheimer's disease., Competing Interests: Declaration of Competing Interest A.G.H. is an employee of Acesion Pharma. J.B·N is employed by Regeneron Pharmaceuticals, Inc. The remaining authors have no conflict of interests to declare., (Copyright © 2023. Published by Elsevier B.V.)

We report a genome-wide association study of venous thromboembolism (VTE) incorporating 81,190 cases and 1,419,671 controls sampled from six cohorts. We identify 93 risk loci, of which 62 are previously unreported. Many of the identified risk loci are at genes encoding proteins with functions converging on the coagulation cascade or platelet function. A VTE polygenic risk score (PRS) enabled effective identification of both high- and low-risk individuals. Individuals within the top 0.1% of PRS distribution had a VTE risk similar to homozygous or compound heterozygous carriers of the variants G20210A (c.*97 G > A) in F2 and p.R534Q in F5. We also document that F2 and F5 mutation carriers in the bottom 10% of the PRS distribution had a risk similar to that of the general population. We further show that PRS improved individual risk prediction beyond that of genetic and clinical risk factors. We investigated the extent to which venous and arterial thrombosis share clinical risk factors using Mendelian randomization, finding that some risk factors for arterial thrombosis were directionally concordant with VTE risk (for example, body mass index and smoking) whereas others were discordant (for example, systolic blood pressure and triglyceride levels)., (© 2023. The Author(s), under exclusive licence to Springer Nature America, Inc.)

Importance: An animal (mouse) study indicated that deficiency of proprotein convertase subtilisin/kexin type 9 (PCSK9) causes cardiac remodeling and heart failure (HF). Cardiac remodeling after PCSK9-inhibitor treatment is a concern for patients and for development of treatment directed against PCSK9., Objective: To determine whether genetic variants in the PCSK9 gene are associated with altered cardiac structure, cardiac function, and HF in humans., Design, Setting, Participants: This was a nested case-control study within the UK Biobank. Between March 13, 2006, and October 1, 2010, the UK Biobank enrolled 502 480 individuals aged 40 to 69 years. This study focused on a subset of those individuals, who completed cardiac magnetic resonance (CMR) imaging and had available genetic data. Analyses were conducted between November 2, 2021, and October 28, 2022., Exposures: Carrier status of predicted loss-of-function (pLoF) PCSK9 variants, R46L missense variant, and a genetic risk score (GRS)., Main Outcomes and Measures: A total of 11 CMR imaging measurements, generated using a machine learning algorithm, and HF diagnosis., Results: In up to 35 135 individuals with CMR images, 18 252 (52%) were female individuals, and mean (SD) age was 55.0 (7.4) years. No significant association between PCSK9 carrier status and CMR indices were found for left ventricular mass (pLoF: β = -1.01; 95% CI, -2.99 to 0.98; P = .32; R46L: β = -0.18; 95% CI, -0.55 to 0.19; P = .35; GRS: β = -0.19; 95% CI, -0.50 to 0.11; P = .22) and left ventricular ejection fraction (pLoF: β = 0.43; 95% CI, -1.32 to 2.18; P = .63; R46L: β = -0.19; 95% CI, -0.52 to 0.14; P = .26; GRS: β = -0.08; 95% CI, -0.35 to 0.20; P = .58) or HF (pLoF: odds ratio [OR], 1.14; 95% CI, 0.56-2.05; P = .69; R46L: OR, 0.99; 95% CI, 0.90-1.10; P = .91; GRS: OR, 1.04; 95% CI, 0.96-1.13; P = .32)., Conclusions and Relevance: Results of this case-control study suggest that there was no association between PCSK9 genetic variants and altered cardiac structure, cardiac function, or HF in humans.

Background and Aims: The causal contribution of apolipoprotein B (apoB) particles to coronary artery disease (CAD) is established. We examined whether this atherogenic contribution is better reflected by non-high-density lipoprotein cholesterol (non-HDL-C) or apoB particle concentration., Method and Results: We performed Mendelian randomization (MR) analysis using 235 variants as genetic instruments; testing the relationship between their effects on the exposures, non-HDL-C and apoB, and on the outcome CAD using weighted regression. Variant effect estimates on the exposures came from the UK Biobank (N = 376 336) and on the outcome from a meta-analysis of five CAD datasets (187 451 cases and 793 315 controls). Subsequently, we carried out sensitivity and replication analyses.In univariate MR analysis, both exposures associated with CAD (βnon-HDL-C = 0.40, P = 2.8 × 10-48 and βapoB = 0.38, P = 1.3 × 10-44). Adding effects on non-HDL-C into a model that already included those on apoB significantly improved the genetically predicted CAD effects (P = 3.9 × 10-5), while adding apoB into the model including non-HDL-C did not (P = 0.69). Thirty-five per cent (82/235) of the variants used as genetic instruments had discordant effects on the exposures, associating with non-HDL-C/apoB ratio at P < 2.1 × 10-4 (0.05/235). Fifty-one variants associated at genome-wide significance., Conclusion: Many sequence variants have discordant effects on non-HDL-C and apoB. These variants allowed us to show that the causal mechanism underlying the relationship between apolipoprotein B particles and CAD is more associated with non-HDL-C than apoB particle concentration., Competing Interests: Conflict of interest: The following authors affiliated with deCODE genetics/Amgen, Inc., are employed by the company: A.H., G.Th., A.S., L.S., G.S., V.T., E.B., V.S., S.G., H.H., J.S., P.S., D.O.A., G.T., U.T., D.F.G., K.S, and H.H., (© The Author(s) 2022. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Aims: To search for sequence variants associated with ACEi discontinuation and to test their association with ACEi-associated adverse drug reactions (ADRs)., Methods and Results: A genome-wide association study (GWAS) on ACEi discontinuation was conducted, including 33 959 ACEi-discontinuers and 44 041 controls. Cases were defined as persons who switched from an ACEi treatment to an angiotensin receptor blocker. Controls were defined as persons who continued ACEi treatment for at least 1 year. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were computed for ACEi discontinuation risk by mixed model regression analysis. Summary statistics from the individual cohorts were meta-analyzed with a fixed-effects model. To test for association with specific ACEi-associated ADRs, any genome-wide significant (P < 5 × 10-8) ACEi discontinuation variants was tested for association with ACEi-associated cough and angioedema. A polygenetic risk score (PRS) based on ACEi discontinuation GWAS data was constructed and tested for association with ACEi-associated cough and angioedema in two population-based samples. In total, seven genetic genome-wide loci were identified, of which six were previously unreported. The strongest association with ACEi discontinuation was at 20q13.3 (NTSR1; OR: 1.21; 95% CI: 1.17-1.24; P = 2.1 × 10-34). Five of seven lead variants were associated with ACEi-associated cough, whereas none were associated with ACEi-associated angioedema. The ACEi discontinuation PRS was associated with ACEi-associated cough in a dose-response manner but not with ACEi-associated angioedema. ACEi discontinuation was genetically correlated with important causes for cough, including gastro-esophageal reflux disease, allergic rhinitis, hay fever, and asthma, which indicates partly shared genetic underpinning between these traits., Conclusion: This study showed the advantage of using prescription patterns to discover genetic links with ADRs. In total, seven genetic loci that associated with ACEi discontinuation were identified. There was evidence of a strong association between our ADR phenotype and ACEi-associated cough. Taken together, these findings increase insight into the pathophysiological processes that underlie ACEi-associated ADRs., Competing Interests: Conflict of interest: The authors who are affiliated with deCODE genetics/Amgen Inc. declare competing financial interests as employees. C.T.P. reports grants from Bayer and grants from Novo Nordisk, outside the submitted work. L.K. reports personal fees and speakers honorarium for Novartis, AstraZeneca, and Boehringer, outside the submitted work. H.B. receives lecture fees from Bristol-Myers Squibb, Merch Sharp and Dohme. S.B. is a board member for Proscion A/S and Intomics A/S. All other authors declare that there is no conflict of interest., (© The Author(s) 2022. Published by Oxford University Press on behalf of European Society of Cardiology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: According to patterns of inheritance and incomplete penetrance, fewer than half of relatives to dilated cardiomyopathy probands will develop disease., Objectives: The purpose of this study was to investigate the prevalence and incidence, and to identify predictors of developing familial dilated cardiomyopathy (FDC) in relatives participating in family screening., Methods: The study was a retrospective, longitudinal cohort study of families screened and followed from 2006 to 2020 at a regional assembly of clinics for inherited cardiomyopathies., Results: In total, 211 families (563 relatives, 50% women) were included. At baseline, 124 relatives (22%) were diagnosed with FDC. Genetic sequencing identified the etiology in 37% of screened families and classified 101 (18%) relatives as unaffected carriers (n = 43) or noncarriers (ie, not at risk of FDC [n = 58]). The combined clinical and genetic baseline yield was 30%. During follow-up (2,313 person-years, median 5.0 years), 45 developed FDC (incidence rate of 2.0% per person-year; 95% CI: 1.4%-2.8%), increasing the overall yield to 34%. The incidence rate of FDC was high in relatives with baseline abnormalities on electrocardiogram or echocardiography compared with relatives with normal findings (4.7% vs 0.4% per person-year; HR: 12.9; P < 0.001). In total, baseline screening identified 326 (58%) relatives to be at low risk of FDC., Conclusions: Family screening identified a genetic predisposition to or overt FDC in 1 of 3 relatives at baseline. Genetic and clinical screening was normal in more than half of relatives, and these relatives had a low risk of developing FDC during follow-up. Thus, baseline screening identified a large proportion, in whom follow-up may safely be reduced, allowing focused follow-up of relatives at risk., Competing Interests: Funding Support and Author Disclosures The AP Møller Foundation (Dr Bundgaard), The Research Foundations at Rigshospitalet (Drs Vissing and Bundgaard), The Capital Region of Denmark (Dr Bundgaard), The Independent Research Fund Denmark (0134-00363B, Dr Christensen), The Novo Nordisk Foundation Denmark (NNF20OC0065799, Dr Christensen), the Innovation Fund Denmark (Dr Bundgaard), and NordForsk (through the funding to PM Heart [90580, Dr Bundgaard]) supported this study. The authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2022 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Objectives: To determine whether electrocardiogram (ECG) markers are associated with incident non-Alzheimer's dementia (non-AD) and whether these markers also improve risk prediction for non-AD., Materials and Methods: We retrospectively included 170,605 primary care patients aged 60 years or older referred for an ECG by their general practitioner and followed them for a median of 7.6 years. Using Cox regression, we reported hazard ratios (HRs) for electrocardiogram markers. Subsequently, we evaluated if addition of these electrocardiogram markers to a clinical model improved risk prediction for non-AD using change in area under the receiver-operator characteristics curve (AUC)., Results: The 5-year cumulative incidence of non-AD was 3.4 %. Increased heart rate (HR=1.06 pr. 10 bpm [95% confidence interval: 1.04-1.08], p<0.001), shorter QRS duration (HR=1.07 pr. 10 ms [1.05-1.09], p<0.001), elevated J-amplitude (HR=1.16 pr. mm [1.08-1.24], p<0.001), decreased T-peak amplitude (HR=1.02 pr. mm [1.01-1.04], p=0.002), and increased QTc (HR=1.08 pr. 20 ms [1.05-1.10], p<0.001) were associated with an increased rate of non-AD. Atrial fibrillation on the ECG (HR=1.18 [1.08-1.28], p<0.001) Sokolow-Lyon index > 35 mm (HR=1.31 [1.18-1.46], p<0.001) and borderline (HR=1.18 [1.11-1.26], p<0.001) or abnormal (HR=1.40 [1.27-1.55], p<0.001) QRS-T angle were also associated with an increased rate of non-AD. Upon addition of ECG markers to the Cox model, 5-year and 10-year C-statistic (AUC) improved significantly (delta-AUC, 0.36 [0.18-0.50] and 0.20 [0.03-0.35] %-points, respectively)., Conclusions: ECG markers typical of an elevated cardiovascular risk profile were associated with non-AD and improved both 5-year and 10-year risk predictions for non-AD., Competing Interests: Conflict of Interests A.G.H. is an employee of Acesion Pharma. J.B.N is employed by Regeneron Pharmaceuticals, Inc. The remaining authors have no conflict of interests to declare., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: Maternal hypertensive disorders of pregnancy (HDPs) are strongly associated with offspring congenital heart defects., Objectives: This study assessed whether infants exposed to maternal HDPs were also more likely to have subtle cardiac structural and functional abnormalities than unexposed infants., Methods: We used regression analyses to compare: 1) left ventricular parameters from conventional echocardiography performed in infants from the Copenhagen Baby Heart Study born to mothers with preeclampsia, gestational hypertension (GH), or no HDP; and 2) advanced echocardiographic parameters for 545 term infants born to mothers with preeclampsia and 545 matched infants not exposed to HDPs., Results: Compared with infants unexposed to HDPs (n = 17,384), infants exposed to preeclampsia (n = 754) had a thicker interventricular septum in end-diastole (adjusted mean difference [± SD] 0.05 [±0.02] mm; P  = 0.004), thicker left ventricular posterior wall (0.04 [±0.02] mm; P  = 0.009), larger left ventricular internal diameter (0.12 [±0.06] mm; P  = 0.04), and larger left ventricular volume (0.21 [±0.10] mL; P  = 0.03). Systolic function changes included increased fractional shortening (0.36% [±0.14%]; P  = 0.01) and stroke volume (0.18 [±0.07] mL; P  = 0.006), whereas diastolic function changes included lower transmitral early peak inflow velocity (-1.76 [±0.49] mL; P  = 0.0003), lower mitral annulus lateral wall a' (-0.21 [±0.09] cm/s; P  = 0.02), and smaller lateral E/e' (-1.06 [±0.38] cm/s; P  = 0.005). Conversely, there was little evidence of any association between maternal GH (n = 469) and offspring left ventricular parameters., Conclusions: Maternal preeclampsia, but not GH, was associated with subtle newborn cardiac morphological and functional alterations, including thickening of the left ventricular myocardium and altered systolic and diastolic function., Competing Interests: This Copenhagen Baby Heart sub-study was supported by the 10.13039/100007405Danish Heart Foundation, the 10.13039/501100003554Lundbeck Foundation, King Christian X's Foundation, Carl and Ellen Hertz' Foundation for Danish Medical and Natural Sciences, and the 10.13039/501100007438Hede Nielsen Family Foundation. Dr Boyd was supported by a grant from the 10.13039/501100009708Novo Nordisk Foundation. The funders played no role in the design of the study; in the collection, analysis, or interpretation of data; in the writing of manuscripts; or in decisions to publish results. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.PERSPECTIVESCOMPETENCY IN MEDICAL KNOWLEDGE: Not only do offspring exposed to maternal preeclampsia have increased risks of hypertension and cardiovascular disease in adulthood, they are also more likely to have subtle cardiac structural and functional abnormalities at birth than infants born to mothers without HDPs. TRANSLATIONAL OUTLOOK: Whether there is a link between disease in adult life and the subclinical alterations in cardiac structure and function already present at birth in children exposed to preeclampsia is unknown. Further research should explore the impact of exposure to maternal preeclampsia on cardiac health through childhood and young adulthood and determine whether these offspring would benefit from increased clinical attention starting in childhood., (© 2022 The Authors.)

Background Results from animal models and observational studies have raised concerns regarding the potential cataractogenic effects of statin treatment. We investigated whether common and rare genetic variants in HMGCR are associated with cataract risk, to gauge the likely long-term effects of statin treatment on lenticular opacities. Methods and Results We used genotyping data and exome sequencing data of unrelated European individuals in the UK Biobank to test the association between genetically proxied inhibition of HMGCR and cataract risk. First, we constructed an HMGCR genetic score consisting of 5 common variants weighted by their association with low-density lipoprotein cholesterol. Second, we analyzed exome sequencing data to identify carriers of predicted loss-of-function mutations in HMGCR . Common and rare variants in aggregate were then tested for association with cataract and cataract surgery. In an analysis of >402 000 individuals, a 38.7 mg/dL (1 mmol/L) reduction in low-density lipoprotein C by the HMGCR genetic score was associated with higher risk for cataract (odds ratio, 1.14 [95% CI, 1.00-1.39], P =0.045) and cataract surgery (odds ratio, 1.25 [95% CI, 1.06-1.48], P =0.009). Among 169 172 individuals with HMGCR sequencing data, we identified 32 participants (0.02%), who carried a rare HMGCR predicted loss-of-function variant. Compared with noncarriers, heterozygous carriers of HMGCR predicted loss-of-function had a higher risk of developing cataract (odds ratio, 4.54 [95% CI, 1.96-10.53], P =0.001) and cataract surgery (odds ratio, 5.27 [95% CI, 2.27-12.25] , P =5.37×10 -4 ). In exploratory analyses, we found no significant association between genetically proxied inhibition of PCSK9, NPC1L1 , or circulating low-density lipoprotein cholesterol levels ( P >0.05 for all) and cataract risk. Conclusions We found that genetically proxied inhibition of the HMGCR gene mimicking long-term statin treatment associated with higher risk of cataract. Clinical trials with longer follow-up are needed to confirm these findings.

Background: Fascicular heart blocks can progress to complete heart blocks, but this risk has not been evaluated in a large general population., Objective: The purpose of this study was to investigate the association between various types of fascicular blocks diagnosed by electrocardiographic (ECG) readings and the risk of incident higher degree atrioventricular block (AVB), syncope, pacemaker implantation, and death., Methods: We studied primary care patients referred for ECG recording between 2001 and 2015. Cox regression models were used to estimate hazard ratios (HRs) as well as absolute risks of cardiovascular outcomes., Results: Of 358,958 primary care patients (median age 54 years; 55% women), 13,636 (3.8%) had any type of fascicular block. Patients were followed up to 15.9 years. We found increasing HRs of incident syncope, pacemaker implantation, and third-degree AVB with increasing complexity of fascicular block. Compared with no block, isolated left anterior fascicular block (LAFB) was associated with 0%-2% increased 10-year risk of developing third-degree AVB (HR 1.6; 95% confidence interval [CI] 1.25-2.05), whereas right bundle branch block combined with LAFB and first-degree AVB was associated with up to 23% increased 10-year risk (HR 11.0; 95% CI 7.7-15.7), depending on age and sex group. Except for left posterior fascicular block (HR 2.09; 95% CI 1.87-2.32), we did not find any relevant associations between fascicular block and death., Conclusion: We found that higher degrees of fascicular blocks were associated with increasing risk of syncope, pacemaker implantation, and complete heart block, but the association with death was negligible., (Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Objective: To evaluate the association between PCSK9 predicted loss-of-function (pLoF) variants and glycemic traits, hepatobiliary function, and neurocognitive traits., Research Design and Methods: We identified carriers of PCSK9 pLoF variants in UK Biobank exome sequencing data. We assessed the aggregate effects of these variants on lipid and lipoprotein traits, which served as a positive control. Association of PCSK9 pLoF carrier status and glycemic traits, hepatobiliary function, and neurocognitive traits was then evaluated as a measure for adverse effects., Results: We identified 374 individuals carrying one of 41 unique PCSK9 pLoF variants. As expected, we found that PCSK9 pLoF carriers had significantly lower LDL cholesterol C levels (P = 7.4 × 10-55) and apolipoprotein B levels (P = 7.6 × 10-50) than did noncarriers. However, we found no significant associations between pLoF carrier status and glycemic traits, hepatobiliary function, and neurocognitive traits (P > 0.05)., Conclusions: Our results do not support adverse effects of PCSK9 pLoF variants on glycemic traits, hepatobiliary function, or neurocognitive traits., (© 2021 by the American Diabetes Association.)

Aims: Left atrial (LA) volume and function impose significant impact on cardiovascular pathogenesis if compromised. We aimed at investigating the genetic architecture of LA volume and function using cardiac magnetic resonance imaging data., Methods and Results: We used the UK Biobank, which is a large prospective population study with available phenotypic and genetic data. On a subset of 35 658 European individuals, we performed genome-wide association studies on five volumetric and functional LA variables, generated using a machine learning algorithm. In total, we identified 18 novel genetic loci, mapped to genes with known roles in cardiomyopathy (e.g. MYO18B, TTN, DSP, ANKRD1) and arrhythmia (e.g. TTN, CASQ2, MYO18B, C9orf3). We observed high genetic correlation between LA volume and function and stroke, which was most pronounced for LA passive emptying fraction (rg = 0.40, P = 4 × 10-6). To investigate whether the genetic risk of atrial fibrillation (AF) is associated with LA traits that precede overt AF, we produced a polygenetic risk score for AF. We found that polygenetic risk for AF is associated with increased LA volume and decreased LA function in participants without AF [LAmax 0.25 (mL/m2)/standard deviation (SD), 95% confidence interval (CI) (0.15; 0.36), P = 5.13 × 10-6; LAmin 0.21 (mL/m2)/SD, 95% CI (0.15; 0.28), P = 1.86 × 10-10; LA active emptying fraction -0.35%/SD, 95% CI (-0.43; -0.26), P = 3.14 × 10-14]., Conclusion: We report on 18 genetic loci associated with LA volume and function and show evidence for several plausible candidate genes important for LA structure., (© The Author(s) 2021. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Recent global developments underscore the prominent role big data have in modern medical science. But privacy issues constitute a prevalent problem for collecting and sharing data between researchers. However, synthetic data generated to represent real data carrying similar information and distribution may alleviate the privacy issue. In this study, we present generative adversarial networks (GANs) capable of generating realistic synthetic DeepFake 10-s 12-lead electrocardiograms (ECGs). We have developed and compared two methods, named WaveGAN* and Pulse2Pulse. We trained the GANs with 7,233 real normal ECGs to produce 121,977 DeepFake normal ECGs. By verifying the ECGs using a commercial ECG interpretation program (MUSE 12SL, GE Healthcare), we demonstrate that the Pulse2Pulse GAN was superior to the WaveGAN* to produce realistic ECGs. ECG intervals and amplitudes were similar between the DeepFake and real ECGs. Although these synthetic ECGs mimic the dataset used for creation, the ECGs are not linked to any individuals and may thus be used freely. The synthetic dataset will be available as open access for researchers at OSF.io and the DeepFake generator available at the Python Package Index (PyPI) for generating synthetic ECGs. In conclusion, we were able to generate realistic synthetic ECGs using generative adversarial neural networks on normal ECGs from two population studies, thereby addressing the relevant privacy issues in medical datasets., (© 2021. The Author(s).)

Aims: To determine the risk of major adverse cardiovascular events (MACE) and death, associated with an early large and rapid decline in glycated haemoglobin (HbA1C) following first time initiation of an oral antidiabetic drug (OAD)., Methods and Results: We included 10 518 primary care patients with type 2 diabetes, who initiated an OAD for the first time. For each individual, we measured a decline in HbA1C, as the difference between the pre-treatment HbA1C (within 3 months before OAD initiation) and the post-treatment HbA1C (within 1.5-4.5 months after OAD initiation), divided by the time between the two measurements. The decline was reported in mmol/mol change per 3 months in HbA1C and categorized by the median decline into levels of steep [≥9 mmol/mol (≥0.8%)] and flat decline [<9 mmol/mol per 3 months (<0.8%)]. Pre-treatment HbA1C was categorized by the median, into levels of low (48-62 mmol/mol) and high (>62 mmol/mol). Multiple Cox regression was used to study the effect of decline (steep vs. flat) on the outcome hazard rates separately for patients with low and high pre-treatment HbA1C. Analyses were adjusted for age, sex, traditional cardiovascular risk factors, severe comorbidities, and concomitant medication treatment. During a median follow-up time of 7.7 years, 1625 developed MACE and 2323 died. We found that a steep decline vs. a flat decline was significantly associated with a decreased hazard for MACE, both in individuals with high [hazard ratio (HR) 0.81; 95% confidence interval (CI) 0.69-0.94; P = 0.005] and low pre-treatment HbA1C (HR 0.79; 95% CI 0.66-0.96; P = 0.015). The hazard of MACE was more pronounced on the short-term vs. long-term in individuals with high pre-treatment HbA1C. We found no significant association between combinations of pre-treatment HbA1C and decline categories and hazard of all-cause mortality. However, a combination of a low pre-treatment HbA1C and steep decline was associated with increased 1-year mortality (HR 1.52; 95% CI 1.00-2.29; P = 0.048) and hypoglycaemia (HR 1.82; 95% CI 1.11-2.98; P = 0.017)., Conclusion: A combination of a high pre-treatment HbA1C and a steep decline in HbA1C was associated with a decreased short-term risk of MACE. A low pre-treatment HbA1C and a steep decline was associated with a long-term reduced risk of MACE, but a short-term increased risk of death and hypoglycaemia., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2020. For permissions, please email: journals.permissions@oup.com.)

Background: Angioedema is a rare but potentially life-threatening adverse reaction associated with angiotensin-converting enzyme (ACE) inhibitors. Identification of potential genetic factors related to this adverse event may help identify at-risk patients., Objectives: The aim of this study was to identify genetic factors associated with ACE inhibitor-associated angioedema., Methods: A genomewide association study involving patients of European descent, all taking ACE inhibitors, was conducted in a discovery cohort (Copenhagen Hospital Biobank), and associations were confirmed in a replication cohort (Swedegene). Cases were defined as subjects with angioedema events and filled prescriptions for ACE inhibitors ≤180 days before the events. Control subjects were defined as those with continuous treatment with ACE inhibitors without any history of angioedema. Odds ratios (ORs) and 95% confidence intervals (CIs) were computed for angioedema risk using logistic mixed model regression analysis. Summary statistics from the discovery and replication cohorts were analyzed using a fixed-effects meta-analysis model., Results: The discovery cohort consisted of 462 cases and 53,391 ACE inhibitor-treated control subjects. The replication cohort consisted of 142 cases and 1,345 ACE inhibitor-treated control subjects. In the discovery cohort, 1 locus, residing at chromosome 14q32.2, was identified that associated with angioedema at the genomewide significance level of P <5 × 10 -8 . The lead variant at this locus, rs34485356, is an intergenic variant located 60 kb upstream of BDKRB2 (OR: 1.62; 95% CI: 1.38 to 1.90; P = 4.3 × 10 -9 ). This variant was validated in our replication cohort with a similar direction and effect size (OR: 1.60; 95% CI: 1.13 to 2.25; P = 7.2 × 10 -3 ). We found that carriers of the risk allele had significantly lower systolic (-0.46 mm Hg per T allele; 95% CI: -0.83 to -0.10; P = 0.013) and diastolic (-0.26 mm Hg per T allele; 95% CI: -0.46 to -0.05; P = 0.013) blood pressure., Conclusions: In this genomewide association study involving individuals treated with ACE inhibitors, we found that common variants located in close proximity to the bradykinin receptor B 2 gene were associated with increased risk for ACE inhibitor-related angioedema., Competing Interests: Funding Support and Author Disclosures This work was supported by the John and Birthe Meyer Foundation, the Research Foundation at Rigshospitalet, the Innovation Fund Denmark (PM Heart), NordForsk, the Villadsen Family Foundation (Copenhagen, Denmark), the Arvid Nilsson Foundation (Copenhagen, Denmark), the Hallas-Møller Emerging Investigator Novo Nordisk (NNF17OC0031204; Copenhagen, Denmark), the Novo Nordisk Foundation (grants NNF17OC0027594 and NNF14CC0001; Copenhagen, Denmark), the Swedish Research Council (Medicine 521-2011-2440, 521-2014-3370, and 2018-03307; Uppsala, Sweden), the Swedish Heart and Lung Foundation (20120557, 20140291, and 20170711; Uppsala, Sweden), the Medical Products Agency (Uppsala, Sweden), Selander’s Foundation (Uppsala, Sweden), and Thureus’ Foundation and Clinical Research Support “Avtal om Läkarutbildning och Forskning” (Uppsala, Sweden). The Swedish Twin Registry is managed by Karolinska Institutet and receives funding through the Swedish Research Council under grant 2017-00641. The authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2021 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Deep learning-based tools may annotate and interpret medical data more quickly, consistently, and accurately than medical doctors. However, as medical doctors are ultimately responsible for clinical decision-making, any deep learning-based prediction should be accompanied by an explanation that a human can understand. We present an approach called electrocardiogram gradient class activation map (ECGradCAM), which is used to generate attention maps and explain the reasoning behind deep learning-based decision-making in ECG analysis. Attention maps may be used in the clinic to aid diagnosis, discover new medical knowledge, and identify novel features and characteristics of medical tests. In this paper, we showcase how ECGradCAM attention maps can unmask how a novel deep learning model measures both amplitudes and intervals in 12-lead electrocardiograms, and we show an example of how attention maps may be used to develop novel ECG features.

Background: Electrocardiographic T-wave morphology is used in drug safety studies as an adjunct to the QT c interval, but few measurements of T-wave morphology can be interpreted in clinical practice. Morphology combination score (MCS) is a combination of T-wave flatness/peakedness, asymmetry, and notching, enabling easy visual assessment of T-wave morphology. We aimed to test the association between T-wave morphology, quantified by MCS, and mortality., Methods: We included electrocardiograms recorded in 2001-2011 from 342,294 primary care patients. Using Cox regression, we evaluated the association between MCS, cardiovascular death, and all-cause mortality, adjusting for heart rate, QT c , QT-prolonging drugs, diabetes, ischemic heart disease, hypertension, and congestive heart failure., Results: 270,039 individuals (44% men, median age 55 [inter-quartile range: 42-67 years]) were included and followed for a median of 9.3 years, during which time 13,489 (5.0%) died from cardiovascular causes and 50,481 (18.7%) from any cause. High values of MCS (i.e. asymmetric, flattened, and/or notched T waves) were associated with an adjusted mortality Hazard Ratio of 1.75 (95% CI 1.62-1.89) and 1.61 (1.43-1.92) for women and men, respectively. Low values of MCS (i.e. peaked and symmetric T waves) were associated with a Hazard Ratio of 1.18 (1.08-1.28) and 1.71 (1.48-1.98) for women and men, respectively., Conclusions: In a large primary care population, we found that T-wave asymmetry, flatness, and notching provided prognostic information on mortality independent of heart rate, QTc, and baseline comorbidities., Competing Interests: Declaration of Competing Interest J.K.K. and C.G. are co-inventors of a patent regarding T-wave morphology. A.G.H. is an employee of Acesion Pharma. The remaining authors have nothing to declare., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Atrial fibrillation (AF) has traditionally been considered an electrical heart disease. However, genetic studies have revealed that the structural architecture of the heart also play a significant role. We evaluated the functional and structural consequences of harboring a titin-truncating variant (TTNtv) in AF patients, using cardiac magnetic resonance (CMR). Seventeen early-onset AF cases carrying a TTNtv, were matched 1:1 with non-AF controls and a replication cohort of early-onset AF cases without TTNtv, and underwent CMR. Cardiac volumes and left atrial late gadolinium enhancement (LA LGE), as a fibrosis proxy, were measured by a blinded operator. Results: AF cases with TTNtv had significantly reduced left ventricular ejection fraction (LVEF) compared with controls (57 ± 4 vs 64 ± 5%, P < 0.001). We obtained similar findings in early-onset AF patients without TTNtv compared with controls (61 ± 4 vs 64 ± 5%, P = 0.02). We furthermore found a statistically significant increase in LA LGE when comparing early-onset AF TTNtv cases with controls. Using state-of-the-art CMR, we found that early-onset AF patients, irrespective of TTNtv carrier status, had reduced LVEF, indicating that early-onset AF might not be as benign as previously thought.