Search

Background: Although orthostatic hypotension (OH) is a well-recognized manifestation of neuropathy and hypovolemia, its contribution to cardiovascular disease (CVD) risk is controversial., Methods and Results: Participants with OH, defined as a decrease in blood pressure (systolic ≥20 mm Hg or diastolic ≥10 mm Hg) from the supine to standing position, were identified during the first visit of the ARIC (Atherosclerosis Risk in Communities) Study (1987-1989) within 2 minutes of standing. All participants were followed up for the development of myocardial infarction, heart failure, stroke, fatal coronary heart disease (CHD), any CHD (combination of silent, nonfatal, and fatal CHD or cardiac procedures), and all-cause mortality. Participants were assessed for carotid intimal thickness and plaque during the first visit. Detectable high-sensitivity troponin T (≥5 ng/L) and elevated NT-proBNP (N-terminal pro-B-type natriuretic peptide; ≥100 pg/mL) were determined in blood collected during the second visit (1990-1992). All associations were adjusted for known CVD risk factors. In 9139 participants (57% women; 23% black; mean age, 54±5.7 years), 3% had OH. During follow-up (median, 26 years), OH was associated with myocardial infarction (hazard ratio [HR], 1.88; 95% confidence interval [CI], 1.44-2.46), congestive heart failure (HR, 1.65; 95% CI, 1.34-2.04), stroke (HR, 1.83; 95% CI, 1.35-2.48), fatal CHD (HR, 2.77; 95% CI, 1.93-3.98), any CHD (HR, 2.00; 95% CI, 1.64-2.44), and all-cause mortality (HR, 1.68; 95% CI, 1.45-1.95). OH was also associated with carotid intimal thickness (β, 0.05 mm; 95% CI, 0.04-0.07 mm), carotid plaque (odds ratio, 1.51; 95% CI, 1.18-1.93), detectable high-sensitivity troponin T (odds ratio, 1.49; 95% CI, 1.16-1.93), and elevated NT-proBNP (odds ratio, 1.92; 95% CI, 1.48-2.49)., Conclusions: OH identified in community-dwelling middle-aged adults was associated with future CVD events and subclinical CVD. Further research is necessary to establish a causal role for OH in the pathogenesis of CVD., (© 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.)

Background: Sodium glucose co-transporter 2 inhibitors may reduce cardiovascular and heart failure risk in patients with type 2 diabetes mellitus (T2DM)., Objectives: The goal of this study was to examine the effects of canagliflozin on cardiovascular biomarkers in older patients with T2DM., Methods: In 666 T2DM patients randomized to receive canagliflozin 100 or 300 mg or placebo, the study assessed the median percent change in serum N-terminal pro-B-type natriuretic peptide (NT-proBNP), high-sensitivity troponin I (hsTnI), soluble (s)ST2, and galectin-3 from baseline to 26, 52, and 104 weeks., Results: Both serum NT-proBNP and serum hsTnI levels increased in placebo recipients, but they remained largely unchanged in those randomized to canagliflozin. Hodges-Lehmann estimates of the difference in median percent change between pooled canagliflozin and placebo were -15.0%, -16.1%, and -26.8% for NT-proBNP, and -8.3%, -11.9%, and -10.0% for hsTnI at weeks 26, 52, and 104, respectively (all p < 0.05). Serum sST2 was unchanged with canagliflozin and placebo over 104 weeks. Serum galectin-3 modestly increased from baseline with canagliflozin versus placebo, with significant differences observed at 26 and 52 weeks but not at 104 weeks. These results remained unchanged when only patients with complete samples were assessed., Conclusions: Compared with placebo, treatment with canagliflozin delayed the rise in serum NT-proBNP and hsTnI for over 2 years in older T2DM patients. These cardiac biomarker data provide support for the beneficial cardiovascular effect of sodium glucose co-transporter 2 inhibitors in T2DM. (A Safety and Efficacy Study of Canagliflozin in Older Patients [55 to 80 Years of Age] With Type 2 Diabetes Mellitus; NCT01106651)., (Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: The predictors of cardiovascular events in patients with chronic refractory angina are limited. High-sensitivity cardiac troponin T (hs-cTnT) assays are biomarkers that may be used to determine the prognosis of patients with stable coronary artery disease., Hypothesis: Hs-cTnT is a predictor of death and nonfatal myocardial infarction (MI) in patients with refractory angina., Methods: We prospectively enrolled 117 consecutive patients in this study. A heart team ruled out myocardial revascularization feasibility after assessing recent coronary angiograms; evidence of myocardial ischemia served as an inclusion criterion. Optimal medical therapy was encouraged via outpatient visits every 6 months; plasma hs-cTnT levels were determined at baseline. The primary endpoint was the composite incidence of death and nonfatal MI., Results: During a median follow-up period of 28.0 months (interquartile range, 18.0-47.5 months), an estimated 28.0-month cumulative event rate of 13.4% was determined via the Kaplan-Meier method. Univariate predictors of the composite endpoint were hs-cTnT levels and LV dysfunction. Following a multivariate analysis, only hs-cTnT was independently associated with the events in question, either as a continuous variable (hazard ratio per unit increase in the natural logarithm: 2.83, 95% confidence interval: 1.62-4.92, P < 0.001) or as a categorical variable (hazard ratio for concentrations above the 99th percentile: 5.14, 95% confidence interval: 2.05-12.91, P < 0.001)., Conclusions: In patients with chronic refractory angina, plasma concentration of hs-cTnT is the strongest predictor of death and nonfatal MI. Notably, none of the outcomes in question occurred in patients with baseline plasma levels <5.0 ng/L., (© 2016 Wiley Periodicals, Inc.)

Background: Patients with supraventricular tachycardia (SVT) and patients with coronary artery disease (CAD) often present with similar symptoms (chest pain, shortness of breath), similar electrocar¬diographic changes and elevated high-sensitivity troponin (Tn). It is not clear whether troponin reflects critical CAD or is elevated due to other causes in patients presenting with SVT. The aim of this study was to assess the role of elevated troponin in patients presenting with SVT., Methods: Patients undergoing radiofrequency ablation (RFA) for SVT and simultaneous coronary an¬giography at the Heart Centre Lucerne, Switzerland between January 2010 and October 2014 were in¬cluded in this analysis. Significant CAD was defined as diameter-stenosis ≥ 75% in vessels > 2.0 mm. The level of Tn was compared between patients with the presence or absence of CAD on coronary angi¬ography. A Tn value of ≥ 0.014 μg/L was considered as elevated., Results: During the study period a total of 473 patients underwent RFA for SVT. The study population consisted of 326 patients (69%, mean age 60 ± 12 years) who underwent invasive coronary angiogra¬phy during the same session. The prevalence of significant CAD was 14% (45/326 patients). The highest prevalence of CAD was found in patients with atrial flutter (35%, 18/45 patients). Tn was elevated in 83% (10/12 patients) with significant CAD and in 47% (26/55 patients) without CAD., Conclusions: The prevalence of CAD is low in patients with SVT, which questions the role of routine invasive coronary angiography during RFA. Tn measurement did not reliably exclude or confirm CAD in these patients.

Acute coronary syndrome (ACS) encompasses a pathophysiological spectrum of cardiovascular diseases, all of which have significant morbidity and mortality. ACS was once considered an acute condition; however, new treatment strategies and improvements in biomarker assays have led to ACS being an acute and chronic disease. Cardiac troponin is the preferred biomarker for the diagnosis of myocardial infarction, and there is considerable interest and efforts toward development and implementation of high-sensitivity cardiac troponin (hs-cTn) assays worldwide. Analytical and clinical performance characteristics of hs-cTn assays as well as testing limitations are important for laboratorians and clinicians to understand in order to utilize testing appropriately. Furthermore, expanding the clinical utility of hs-cTn into other cohorts such as asymptomatic community dwelling populations, heart failure, and chronic kidney disease populations supports novel opportunities for improved short- and long-term prognosis., (© 2017 Elsevier Inc. All rights reserved.)

Background: Physicians rely upon chest pain history to make management decisions in patients with suspected acute coronary syndromes, particularly where the diagnosis is not immediately apparent through electrocardiography and troponin testing. The objective of this study was to establish the discriminatory value of "typicality of chest pain" and the effect of clinician experience, for the prediction of acute myocardial infarction and presence of significant coronary artery disease.Methods: This prospective single-center observational study was undertaken in a UK General Hospital emergency department. We recruited consecutive adults with chest pain and a nondiagnostic electrocardiogram, for whom the treating physician determined that delayed troponin testing was necessary. Using their own clinical judgment, physicians recorded whether the chest pain described was typical or atypical for acute coronary syndrome. Physicians were defined as "experienced" or "novice" according to postgraduate experience. Acute myocardial infarction was adjudicated using a high-sensitivity troponin (hs-cTn) assay, whereas coronary artery disease was adjudicated angiographically.Results: Overall, 912 patients had typicality of chest pain assessed, of whom 114/912 (12.5%) had an acute myocardial infarction and 157/912 (17.2%) underwent angiography. In patients undergoing angiography, 90/157 (57.3%) had hs-cTn elevation, of whom 60 (66.7%) had significant coronary artery disease. Sixty-seven of 157 (42.7%) patients had angiography without hs-cTn elevation; of these, 31 (46.2%) had significant coronary artery disease. For the diagnosis of acute myocardial infarction, chest pain typicality had an area under the curve (AUC) of 0.54 (95% confidence interval [CI], 0.49-0.60). For the prediction of significant coronary artery disease with hs-cTn elevation AUC: 0.54 (95% CI, 0.40-0.67), and without hs-cTn elevation AUC: 0.45 (95% CI, 0.31-0.59). When assessed by experienced physicians, specificity for the diagnosis of acute myocardial infarction was higher at 65.8% (95% CI, 63.1%-68.7%) vs 55.4% (95% CI, 53.9%-56.8%) for novices.Conclusions: Subjective interpretation of "typicality of chest pain" is of limited discriminatory value in the assessment of suspected acute coronary syndromes, in the context of a nondiagnostic electrocardiogram. Greater clinical experience improves accuracy as a rule-in tool but does not improve overall discriminatory ability. [ABSTRACT FROM AUTHOR]

Purpose: Cardiac biomarkers including troponins are the cornerstone of the biological definition of acute myocardial infarction. New high-sensitivity cardiac assays determining troponin T (hs-cTnT) as well as I ((hs-cTnI) from Abbott and s-cTnI from Siemens) raise concerns because of their unclear kinetics following the peak., Aims: This study aims to compare kinetics of creatine kinases, hs-cTnT, hs-cTnI and s-cTnI in patients with ST-segment elevation myocardial infarction (STEMI) treated by percutaneous coronary intervention., Methods: We prospectively studied 106 consecutive patients admitted in our institution for STEMI and treated by percutaneous coronary intervention. We evaluated for all the patients simultaneously kinetics of creatine kinases, hs-cTnT (Roche) and two different cTnIs (hs-cTnI from Abbott and s-cTnI from Siemens). Modelling of kinetics was realized using mixed effects with cubic splines., Results: Kinetics of markers showed a first peak at 10.7h (8.0-12.0) for creatine kinases, 11.8h (10.4-13.3) for hs-cTnT (Roche); 11.8h (10.7-11.8) for hs-cTnI from Abbott and 10.2h (8.7-11.6) for s-cTnI from Siemens, respectively. This peak was followed by a nearly log linear decrease for hs-cTnI/s-cTnI and creatine kinases in contrast to hs-cTnT, which appeared with a biphasic shape curve marked by a second peak at 76.9h (69.5-82.8). The analysis of the decrease in percentage of the peak value at 77h showed that hs-cTnT follows a twice lower decrease than other markers., Conclusion: Kinetics of hs-cTnT, hs-cTnI and s-cTnI differ significantly with a linear decrease regarding both cTnI assays contrasting with a biphasic shape curve for hs-cTnT. This is of importance for clinical management of patients in routine settings especially in follow-up after STEMI including the suspicion of reinfarction., (© The European Society of Cardiology 2015.)

Abstract: Objective: The study objective was to compare the incidence and prognosis of acute myocardial infarction when using high-sensitivity cardiac troponin assays instead of a standard cardiac troponin assay for the diagnosis of acute myocardial infarction. Methods: In a prospective international multicenter study, we enrolled 1124 consecutive patients presenting with suspected acute myocardial infarction. Final diagnoses were adjudicated by 2 independent cardiologists 2 times using all available clinical information: first using standard cardiac troponin levels and second using high-sensitivity cardiac troponin T levels for adjudication. Patients were followed up for a mean of 19±9 months. Results: The use of high-sensitivity cardiac troponin T instead of standard cardiac troponin resulted in an increase in the incidence of acute myocardial infarction from 18% to 22% (242 vs 198 patients), a relative increase of 22%. Of the 44 additional acute myocardial infarctions, 35 were type 1 acute myocardial infarctions and 9 were type 2 acute myocardial infarctions. This was accompanied by a reciprocal decrease in the incidence of unstable angina (unstable angina, 11% vs 13%). The most pronounced increase was observed in patients adjudicated with cardiac symptoms of origin other than coronary artery disease with cardiomyocyte damage (83 vs 31 patients, relative increase of 268%). Cumulative 30-month mortality rates were 4.8% in patients without acute myocardial infarction, 16.4% in patients with a small acute myocardial infarction detected only by high-sensitivity cardiac troponin T but not standard cardiac troponin, and 23.9% in patients with a moderate/large acute myocardial infarction according to standard cardiac troponin assays and high-sensitivity cardiac troponin T (P <.001). Conclusions: The introduction of high-sensitivity cardiac troponin assays leads to only a modest increase in the incidence of acute myocardial infarction. The novel sensitive assays identify an additional high-risk group of patients with increased mortality, therefore appropriately classified with acute myocardial infarction (Advantageous Predictors of Acute Coronary Syndromes Evaluation; NCT00470587). [Copyright &y& Elsevier]

Laboratory testing for blood-based biomarkers of myocardial injury has steadily evolved over the past 60 years. Initial assays were cumbersome and were neither sensitive nor specific for myocardial necrosis. Major improvements have included the development of more cardiospecific markers, the introduction of random access immunoassays that facilitated near-real-time reporting of results, the development of rapid whole-blood point-of-care testing, and progressive improvements in assay design leading to modern high-sensitivity troponin assays that are now being introduced to the market. These new high-sensitivity assays will dramatically change the approach to patients presenting with acute coronary syndromes., (Copyright © 2014 Elsevier Inc. All rights reserved.)

High-sensitivity troponin (hsTn) assays are used clinically in most parts of the world and are expected to be approved by the US FDA for clinical use in the USA soon. Clinical use of hsTn leads to improvements in the detection of myocardial injury, shorter time to ruling out acute myocardial infarction, improved risk-stratification of patients with heart failure and atrial fibrillation among others. HsTn may also guide strategies for primary and secondary prevention of cardiovascular disease. However, unmet challenges remain, including distinguishing between acute and chronic hsTn elevations, distinguishing between type 1 and type 2 acute myocardial infarction and determining whether to use gender-neutral or gender-specific reference values.

Aims: Criteria for diagnosing myocardial infarction (MI) after coronary artery bypass grafting (CABG) are controversial. Uncertainties remain around the optimal threshold for biomarker elevation and the need for associated criteria. There are no studies of high-sensitivity troponin (hs-TnT) after CABG. We assessed whether using hs-TnT to define MI after CABG was associated with 30-day and medium-term mortality and evaluated the utility of adding to the troponin criteria new Q-waves or imaging evidence of new wall motion abnormality as suggested in the Universal Definition of MI., Methods: Isolated CABG was performed in 818 patients from July 2010 to June 2012 and hs-TnT was measured 12-24 hours after CABG. Patients with rising baseline or missing troponins (n=258) were excluded. Thresholds of 140 ng/l (10-times 99th percentile upper reference limit) and 500 ng/l (10-times coefficient of variation of 10% for fourth-generation troponin T applied to hs-TnT) were prespecified., Results: Mean follow up was 1.8±0.6 years. On multivariate analyses, isolated hs-TnT rise >140 ng/l (n=360) or >500 ng/l (n=162) were not associated with mortality. Additional ECG and/or echocardiographic criteria plus hs-TnT >140 ng/l was associated with 30-day mortality (hazard ratio, HR, 4.92, 95% CI 1.34-18.1; p=0.017) and medium-term mortality (HR 3.44, 95% CI 1.13-10.5; p=0.030), whereas ECG and/or echocardiographic abnormalities with hs-TnT >500 ng/l was not (p=0.281 and p=0.123 for 30-day and medium-term mortality, respectively)., Conclusions: A definition for MI following CABG using hs-TnT with a cut point of 10-times 99th percentile upper reference limit and ECG and/or echocardiographic criteria predicts 30-day and medium-term mortality. These findings validate the Third Universal Definition of type 5 MI.

Unlabelled: High-sensitivity troponin assays facilitate the rapid exclusion of acute myocardial infarction (AMI). However, elevated results are also seen in other conditions causing myocardial injury. Serial measurements increase the specificity for AMI, helping to rapidly identify patients for whom revascularisation may be appropriate. In this study, we explore a strategy for rapidly excluding AMI in symptomatic patients using serial high-sensitivity troponin measurements., Main Findings: (1) all patients presenting more than 3 h after symptom onset with a negative result had a second negative result; (2) AMI was excluded in all patients with two results falling below the lower limit of detection of a standard troponin assay by 8 h post-symptom onset.