Thomas, Kevin L.

Atrial fibrillation (AF) is one of the strongest risk factors for ischemic stroke, which is a leading cause of disability and death. Given the aging population, increasing prevalence of AF risk factors, and improved survival in those with cardiovascular disease, the number of individuals affected by AF will continue increasing over time. While multiple proven stroke prevention therapies exist, important questions remain about the optimal approach to stroke prevention at the population and individual patient levels. Our report summarizes the National Heart, Lung, and Blood Institute virtual workshop focused on identifying key research opportunities related to stroke prevention in AF. The workshop reviewed major knowledge gaps and identified targeted research opportunities to advance stroke prevention in AF in the following areas: (1) improving risk stratification tools for stroke and intracranial hemorrhage; (2) addressing challenges with oral anticoagulants; and (3) delineating the optimal roles of percutaneous left atrial appendage occlusion and surgical left atrial appendage closure/excision. This report aims to promote innovative, impactful research that will lead to more personalized, effective use of stroke prevention strategies in people with AF.

Importance Only modest attention has been paid to the contributions of social determinants of health to atrial fibrillation (AF) risk factors, diagnosis, symptoms, management, and outcomes. The diagnosis of AF provides unique challenges exacerbated by the arrhythmia’s often paroxysmal nature and individuals’ disparate access to health care and technologies that facilitate detection. Social determinants of health affect access to care and management decisions for AF, increasing the likelihood of adverse outcomes among individuals who experience systemic disadvantages. Developing effective approaches to address modifiable social determinants of health requires research to eliminate the substantive inequities in health care delivery and outcomes in AF. Observations The National Heart, Lung, and Blood Institute convened an expert panel to identify major knowledge gaps and research opportunities in the field of social determinants of AF. The workshop addressed the following social determinants: (1) socioeconomic status and access to care; (2) health literacy; (3) race, ethnicity, and racism; (4) sex and gender; (5) shared decision-making in systemically disadvantaged populations; and (6) place, including rurality, neighborhood, and community. Many individuals with AF have multiple adverse social determinants, which may cluster in the individual and in systemically disadvantaged places (eg, rural locations, urban neighborhoods). Cumulative disadvantages may accumulate over the life course and contribute to inequities in the diagnosis, management, and outcomes in AF. Conclusions and Relevance Workshop participants identified multiple critical research questions and approaches to catalyze social determinants of health research that address the distinctive aspects of AF. The long-term aspiration of this work is to eradicate the substantive inequities in AF diagnosis, management, and outcomes across populations.

Background The presence of valvular heart disease ( VHD ) may affect the risk of stroke and mortality in patients with atrial fibrillation ( AF ). Community‐based estimates of prevalence and outcomes of specific forms of VHD in patients with AF are lacking. Methods and Results We examined the prevalence of VHD , anticoagulation use, mortality, stroke/transient ischemic attack, and bleeding among a community cohort of patients with AF . Significant VHD was defined as follows: (1) moderate/severe mitral stenosis or mechanical valve; (2) bioprosthetic valve, surgical repair, or balloon valvuloplasty; and (3) moderate/severe aortic regurgitation or stenosis, mitral regurgitation, or tricuspid regurgitation. Proportional hazards models were performed to test the association between VHD groups and outcomes. Among 9748 patients with AF , 2705 (27.7%) had significant VHD . Anticoagulation use was highest among patients with mitral stenosis/mechanical valve (91.8%). Compared with individuals with no significant VHD , individuals with aortic regurgitation/aortic stenosis, mitral regurgitation, or tricuspid regurgitation (hazard ratio, 1.23; 95% confidence interval, 1.07–1.42) had the highest risk of death. There were no differences in stroke or transient ischemic attack and major bleeding among individuals with and without significant VHD . Patients with AF and aortic stenosis had the highest risk of death (hazard ratio, 1.32; 95% confidence interval, 1.08–1.62). Conclusions Significant VHD is common among patients with AF in community practice. In a community cohort of patients with AF and CHA 2 DS 2 ‐ VAS c score ≥2, most were anticoagulated. Individuals with AF and moderate‐to‐severe biological VHD have more comorbidities and a higher mortality risk; however, stroke and major bleeding are similar among those with and without significant VHD .

Background— QRS prolongation is associated with adverse outcomes in mostly white populations, but its clinical significance is not well established for other groups. We investigated the association between QRS duration and mortality in African Americans. Methods and Results— We analyzed data from 5146 African Americans in the Jackson Heart Study stratified by QRS duration on baseline 12-lead ECG. We defined QRS prolongation as QRS≥100 ms. We assessed the association between QRS duration and all-cause mortality using Cox proportional hazards models and reported the cumulative incidence of heart failure hospitalization. We identified factors associated with the development of QRS prolongation in patients with normal baseline QRS. At baseline, 30% (n=1528) of participants had QRS prolongation. The cumulative incidences of mortality and heart failure hospitalization were greater with versus without baseline QRS prolongation: 12.6% (95% confidence interval [CI], 11.0–14.4) versus 7.1% (95% CI, 6.3–8.0) and 8.2% (95% CI, 6.9–9.7) versus 4.4% (95% CI, 3.7–5.1), respectively. After risk adjustment, QRS prolongation was associated with increased mortality (hazard ratio, 1.27; 95% CI, 1.03–1.56; P =0.02). There was a linear relationship between QRS duration and mortality (hazard ratio per 10 ms increase, 1.06; 95% CI, 1.01–1.12). Older age, male sex, prior myocardial infarction, lower ejection fraction, left ventricular hypertrophy, and left ventricular dilatation were associated with the development of QRS prolongation. Conclusions— QRS prolongation in African Americans was associated with increased mortality and heart failure hospitalization. Factors associated with developing QRS prolongation included age, male sex, prior myocardial infarction, and left ventricular structural abnormalities.

Background— Prior studies have demonstrated low use of implantable cardioverter defibrillators (ICDs) as primary prevention, particularly among women and blacks. The degree to which the overall use of ICD therapy and disparities in use have changed is unclear. Methods and Results— We examined 11 880 unique patients with a history of heart failure and left ventricular ejection fraction ≤35% who were ≥65 years old and enrolled in the Get With the Guidelines–Heart Failure (GWTG-HF) program from January 2005 through December 2009. We determined the rate of ICD use by year for the overall population and for sex and race groups. From 2005 to 2007, overall ICD use increased from 30.2% to 42.4% and then remained unchanged in 2008 to 2009. After adjustment for potential confounders, ICD use increased significantly in the overall study population during 2005 to 2007 (odds ratio, 1.28; 95% confidence interval, 1.11–1.48 per year; P =0.0008) and in black women (odds ratio, 1.82; 95% confidence interval, 1.28–2.58 per year; P =0.0008), white women (odds ratio, 1.30; 95% confidence interval, 1.06–1.59 per year; P =0.010), black men (odds ratio, 1.54; 95% confidence interval, 1.19–1.99 per year; P =0.0009), and white men (odds ratio, 1.25; 95% confidence interval, 1.06–1.48 per year; P =0.0072). The increase in ICD use was greatest among blacks. Conclusions— In the GWTG-HF quality improvement program, a significant increase in ICD therapy use was observed over time in all sex and race groups. The previously described racial disparities in ICD use were no longer present by the end of the study period; however, sex differences persisted.