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Objective: To identify common genetic variants associated with the presence of brain microbleeds (BMBs)., Methods: We performed genome-wide association studies in 11 population-based cohort studies and 3 case-control or case-only stroke cohorts. Genotypes were imputed to the Haplotype Reference Consortium or 1000 Genomes reference panel. BMBs were rated on susceptibility-weighted or T2*-weighted gradient echo MRI sequences, and further classified as lobar or mixed (including strictly deep and infratentorial, possibly with lobar BMB). In a subset, we assessed the effects of APOE ε2 and ε4 alleles on BMB counts. We also related previously identified cerebral small vessel disease variants to BMBs., Results: BMBs were detected in 3,556 of the 25,862 participants, of which 2,179 were strictly lobar and 1,293 mixed. One locus in the APOE region reached genome-wide significance for its association with BMB (lead single nucleotide polymorphism rs769449; odds ratio [OR] any BMB [95% confidence interval (CI)] 1.33 [1.21-1.45]; p = 2.5 × 10 -10 ). APOE ε4 alleles were associated with strictly lobar (OR [95% CI] 1.34 [1.19-1.50]; p = 1.0 × 10 -6 ) but not with mixed BMB counts (OR [95% CI] 1.04 [0.86-1.25]; p = 0.68). APOE ε2 alleles did not show associations with BMB counts. Variants previously related to deep intracerebral hemorrhage and lacunar stroke, and a risk score of cerebral white matter hyperintensity variants, were associated with BMB., Conclusions: Genetic variants in the APOE region are associated with the presence of BMB, most likely due to the APOE ε4 allele count related to a higher number of strictly lobar BMBs. Genetic predisposition to small vessel disease confers risk of BMB, indicating genetic overlap with other cerebral small vessel disease markers., (Copyright © 2020 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.)

Objective: To explore genetic and lifestyle risk factors of MRI-defined brain infarcts (BI) in large population-based cohorts., Methods: We performed meta-analyses of genome-wide association studies (GWAS) and examined associations of vascular risk factors and their genetic risk scores (GRS) with MRI-defined BI and a subset of BI, namely, small subcortical BI (SSBI), in 18 population-based cohorts (n = 20,949) from 5 ethnicities (3,726 with BI, 2,021 with SSBI). Top loci were followed up in 7 population-based cohorts (n = 6,862; 1,483 with BI, 630 with SBBI), and we tested associations with related phenotypes including ischemic stroke and pathologically defined BI., Results: The mean prevalence was 17.7% for BI and 10.5% for SSBI, steeply rising after age 65. Two loci showed genome-wide significant association with BI: FBN2, p = 1.77 × 10 -8 ; and LINC00539/ZDHHC20, p = 5.82 × 10 -9 . Both have been associated with blood pressure (BP)-related phenotypes, but did not replicate in the smaller follow-up sample or show associations with related phenotypes. Age- and sex-adjusted associations with BI and SSBI were observed for BP traits ( p value for BI, p [BI] = 9.38 × 10 -25 ; p [SSBI] = 5.23 × 10 -14 for hypertension), smoking ( p [BI] = 4.4 × 10 -10 ; p [SSBI] = 1.2 × 10 -4 ), diabetes ( p [BI] = 1.7 × 10 -8 ; p [SSBI] = 2.8 × 10 -3 ), previous cardiovascular disease ( p [BI] = 1.0 × 10 -18 ; p [SSBI] = 2.3 × 10 -7 ), stroke ( p [BI] = 3.9 × 10 -69 ; p [SSBI] = 3.2 × 10 -24 ), and MRI-defined white matter hyperintensity burden ( p [BI] = 1.43 × 10 -157 ; p [SSBI] = 3.16 × 10 -106 ), but not with body mass index or cholesterol. GRS of BP traits were associated with BI and SSBI ( p ≤ 0.0022), without indication of directional pleiotropy., Conclusion: In this multiethnic GWAS meta-analysis, including over 20,000 population-based participants, we identified genetic risk loci for BI requiring validation once additional large datasets become available. High BP, including genetically determined, was the most significant modifiable, causal risk factor for BI., (Copyright © 2019 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.)

Background and Purpose- White matter hyperintensities (WMH) on brain magnetic resonance imaging are typical signs of cerebral small vessel disease and may indicate various preclinical, age-related neurological disorders, such as stroke. Though WMH are highly heritable, known common variants explain a small proportion of the WMH variance. The contribution of low-frequency/rare coding variants to WMH burden has not been explored. Methods- In the discovery sample we recruited 20 719 stroke/dementia-free adults from 13 population-based cohort studies within the Cohorts for Heart and Aging Research in Genomic Epidemiology consortium, among which 17 790 were of European ancestry and 2929 of African ancestry. We genotyped these participants at ≈250 000 mostly exonic variants with Illumina HumanExome BeadChip arrays. We performed ethnicity-specific linear regression on rank-normalized WMH in each study separately, which were then combined in meta-analyses to test for association with single variants and genes aggregating the effects of putatively functional low-frequency/rare variants. We then sought replication of the top findings in 1192 adults (European ancestry) with whole exome/genome sequencing data from 2 independent studies. Results- At 17q25, we confirmed the association of multiple common variants in TRIM65, FBF1, and ACOX1 ( P<6×10 -7 ). We also identified a novel association with 2 low-frequency nonsynonymous variants in MRPL38 (lead, rs34136221; P EA =4.5×10 -8 ) partially independent of known common signal ( P EA(conditional) =1.4×10 -3 ). We further identified a locus at 2q33 containing common variants in NBEAL1, CARF, and WDR12 (lead, rs2351524; P all =1.9×10 -10 ). Although our novel findings were not replicated because of limited power and possible differences in study design, meta-analysis of the discovery and replication samples yielded stronger association for the 2 low-frequency MRPL38 variants ( P rs34136221 =2.8×10 -8 ). Conclusions- Both common and low-frequency/rare functional variants influence WMH. Larger replication and experimental follow-up are essential to confirm our findings and uncover the biological causal mechanisms of age-related WMH.

The average age of patients undergoing coronary artery bypass grafting (CABG) has increased. To determine influence of age on postoperative course, the authors reviewed the outcome of 199 consecutive patients who underwent primary, isolated, elective CABG. The 101 patients < 65 years (group I) and 98 patients > or = 65 years (group II) were similar in preoperative severity of symptoms, history of myocardial infarction, number of grafts received, and time on cardiopulmonary bypass. Comparison between the two groups revealed similar rates of operative mortality and morbidity. In group II patients, median rates of hospitalization and intensive or intermediate care unit stay were greater (P < 0.005), and there were significantly higher incidences of postoperative disorientation, transfusion of exogenous blood, and need for special discharge arrangements (P < 0.05). The authors conclude that CABG patients > or = 65 years of age have a longer and more complex postoperative course than younger patients and suggest that further nursing research be conducted to identify the specific needs of this patient population.