Ischaemic stroke polygenic risk score and recurrent cardiac and cerebrovascular events after coronary artery revascularization.
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Biomedical subjects
Publications and source records attributed to Krishna G Aragam.
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IMPORTANCE: Dilated cardiomyopathy (DCM) is a major cause of heart failure that disproportionately affects individuals of African genetic ancestry (AFR), among whom familial clustering of disease is also more pronounced relative to those of European ancestry (EUR). However, established monogenic DCM genes, identified primarily in EUR populations, explain a smaller proportion of DCM cases in AFR populations. A recent study identified a common AFR-specific nonsense variant in CD36 that accounts for a substantial burden of DCM in AFR. How the risk and population impact of this variant compare with those of established genetic causes of DCM is unknown. OBJECTIVE: To compare the contribution of a CD36 nonsense variant to DCM risk with that of truncating variants in TTN and pathogenic or likely pathogenic (P/LP) variants in other established DCM genes. DESIGN SETTING AND PARTICIPANTS: Multicohort genetic association study including AFR and EUR participants with exome or genome sequence and DCM case status from four datasets: All of Us, Million Veteran Program, Penn Medicine Biobank, and the DCM Precision Medicine Study. EXPOSURE: Carrier status for TTN truncating variants, P/LP variants in 11 high confidence DCM genes, and the CD36 nonsense variant (Y325*; 0, 1, or 2 copies). MAIN OUTCOMES AND MEASURES: Odds of DCM; prevalence of risk-variant carriers among DCM cases; and population attributable fraction (PAF) for DCM. RESULTS: Among 82,623 AFR individuals across four studies, the mean age was 53.4 years and 1,625 had DCM. CD36 Y325* risk-allele homozygotes had 4.8-fold (95% CI, 3.1-7.3) increased odds of DCM, and CD36 Y325* heterozygotes had 1.4-fold (95% CI, 1.2-1.7) increased odds. TTN truncating variants also conferred elevated risk of DCM in AFR participants (OR, 8.46; 95% CI, 5.3-12.3). Among AFR DCM cases, 2.5% were CD36 homozygotes, second only to TTN truncating variants (4.3%) and exceeding all other high-confidence DCM genes combined (1.5%). In population-level analyses incorporating both heterozygous and homozygous CD36 Y325* carriers, the population-attributable fraction for CD36 (9.0%) surpassed that of TTN truncating variants (3.6%). CONCLUSIONS AND RELEVANCE: An ancestry-specific CD36 variant contributes more to DCM burden in AFR ancestry than established DCM genes, including TTN truncating variants, typically considered the most common genetic cause of DCM. These findings reshape the known genetic architecture of DCM in individuals of African ancestry and highlight the importance of representation in genomic research.
IMPORTANCE: Exercise may lead to disease progression and higher risk of sudden death in individuals with genetic cardiomyopathies, but the effects of exercise among individuals carrying a cardiomyopathy-associated variant without clinical manifestations (G+P-) are unclear. OBJECTIVE: To examine whether the effects of moderate to vigorous physical activity (MVPA) on cardiovascular (CV) outcomes, cardiac structure and function, and risk of developing overt cardiomyopathy and malignant ventricular arrhythmias (VAs) vary by G+P- status. DESIGN, SETTING, AND PARTICIPANTS: UK Biobank participants with whole-genome sequencing providing 1 week of accelerometer-based physical activity data and without prevalent heart failure (HF), atrial fibrillation (AF), cardiomyopathy, VAs, or implantable cardioverter-defibrillators were included in this cohort study. The study was conducted at 22 assessment centers throughout the UK from February 2013 to December 2015 with a median follow-up of 8 years. Data were analyzed from March 2024 to June 2025. EXPOSURE: Accelerometer-measured MVPA (minutes/week). MAIN OUTCOMES AND MEASURES: Associations were analyzed between MVPA volume and future incidence of adverse CV outcomes (AF, HF, myocardial infarction [MI], and stroke), cardiac magnetic resonance (CMR)-based measures of cardiac remodeling, and surrogates for clinical cardiomyopathy onset (cardiomyopathy and VA). Associations were compared between G+P- carriers and noncarriers. RESULTS: Among 84 699 individuals (mean [SD] age, 62 [8] years; 48 353 [57%] women; 3979 G+P- carriers), greater MVPA was associated with a lower risk of adverse CV outcomes over a median (IQR) 8.0 (7.5-8.5) years, irrespective of genotype. In multivariable models, higher MVPA was broadly associated with lower risk of incident CV disease in G+P- carriers (hazard ratio [HR] at optimal MVPA level vs zero [95% CI], AF: 0.68 [0.58-0.79]; HF: 0.58 [0.47-0.71]; MI: 0.49, [0.24-1.00]; stroke: 0.35 [0.12-0.99]). For G+P- carriers, MVPA in the range of 100 to 400 minutes per week was generally associated with lowest risk. Among individuals with CMR imaging, MVPA was associated with a similar pattern and extent of cardiac remodeling (eg, left ventricular dilation and left ventricular hypertrophy) in G+P- carriers vs noncarriers. Among G+P- carriers, higher MVPA was associated with lower risk of incident cardiomyopathy (HR at optimal MVPA vs 0, 0.03; 95% CI, 0.00-0.98) with no increase in risk of VA (eg, HR at 400 minutes of MVPA vs 0, 0.98; 95% CI, 0.83-1.14). Findings were generally consistent across variants associated with dilated cardiomyopathy, hypertrophic cardiomyopathy, or arrhythmogenic right ventricular cardiomyopathy, although precision of estimates for arrhythmogenic right ventricular cardiomyopathy were limited. CONCLUSIONS AND RELEVANCE: In this cohort study, MVPA within the general range of guideline-based recommendations was associated with lower risk of adverse CV outcomes and similar degrees of cardiac remodeling for G+P- carriers compared to noncarriers. Findings support the appropriateness of guideline-based MVPA recommendations for G+P- carriers.
IMPORTANCE: Rare monogenic variants linked to nonischemic dilated cardiomyopathy (DCM) are enriched among individuals with secondary cardiomyopathies, such as peripartum (PPCM), alcohol-induced (ACM), and cancer therapy-related (CCM) cardiomyopathies. However, it remains unclear whether a polygenic predisposition to DCM also contributes to these conditions. OBJECTIVE: To assess the association of a DCM polygenic score with PPCM, ACM, and CCM, and to evaluate the contributions of monogenic and polygenic susceptibilities to these secondary cardiomyopathies. DESIGN, SETTING, AND PARTICIPANTS: This was a retrospective genetic association analysis of data from the Mass General Brigham (MGB) Biobank (n = 42 137, 2008-2025), with replication in the UK Biobank (n = 295 160, 2005-2010), FinnGen (n = 417 950, 2017-2025), and the Veterans Affairs Million Veteran Program (n = 516 066, 2011-2025). In MGB Biobank, medical records were reviewed to ascertain secondary cardiomyopathy cases and antecedent clinical risk factors. EXPOSURES: DCM polygenic risk score and DCM monogenic variants. MAIN OUTCOMES AND MEASURES: The primary outcomes were the association of the DCM polygenic risk score with PPCM, ACM, and CCM and the prevalence of monogenic variants and a high polygenic score among individuals with cardiomyopathy. RESULTS: The mean (SD) age in the MGB Biobank was 55.7 (17.0) years at enrollment, and 24 551 (58.3%) were female. Across the 4 study cohorts, 3414 individuals with secondary cardiomyopathy were identified, including 70 with PPCM, 2281 with ACM, and 1063 with CCM. The DCM polygenic score was associated with PPCM (odds ratio [OR], 1.82 per SD; 95% CI, 1.43-2.30), ACM (OR, 1.56; 95% CI,1.34-1.82), and CCM (OR, 1.64; 95% CI,1.24-2.15) (all with P < .001). Monogenic variants were enriched but present in 7 of 113 individuals with medical record-reviewed cardiomyopathy in MGB, while 66 had a high polygenic score, which conferred an approximately 3-fold increased odds of cardiomyopathy. Most individuals with cardiomyopathy lacked antecedent clinical risk factors. CONCLUSIONS AND RELEVANCE: In this cohort study, individuals with PPCM, ACM, and CCM were enriched for monogenic DCM variants and a high DCM polygenic score, suggesting a shared genetic susceptibility influenced by distinct environmental precipitants. These findings support a shared genetic architecture between secondary cardiomyopathies and DCM, although additional work with larger numbers of individuals with cardiomyopathy is needed to confirm these findings.
Heart failure (HF) is a major contributor to global morbidity and mortality. While distinct clinical subtypes, defined by etiology and left ventricular ejection fraction, are well recognized, their genetic determinants remain inadequately understood. In this study, we report a genome-wide association study of HF and its subtypes in a sample of 1.9 million individuals. A total of 153,174 individuals had HF, of whom 44,012 had a nonischemic etiology (ni-HF). A subset of patients with ni-HF were stratified based on left ventricular systolic function, where data were available, identifying 5,406 individuals with reduced ejection fraction and 3,841 with preserved ejection fraction. We identify 66 genetic loci associated with HF and its subtypes, 37 of which have not previously been reported. Using functionally informed gene prioritization methods, we predict effector genes for each identified locus, and map these to etiologic disease clusters through phenome-wide association analysis, network analysis and colocalization. Through heritability enrichment analysis, we highlight the role of extracardiac tissues in disease etiology. We then examine the differential associations of upstream risk factors with HF subtypes using Mendelian randomization. These findings extend our understanding of the mechanisms underlying HF etiology and may inform future approaches to prevention and treatment.