Greiner, Melissa A.

Introduction: Perceived discrimination is known to play a role in the development of cardiovascular (CV) risk factors such as hypertension, but the association with CV outcomes is less clear. A recent report from a multi-ethnic cohort study found a modestly increased risk of CV disease in participants reporting discrimination. We explored this association in an African American (AA) cohort. Hypothesis: Greater perceived discrimination is associated with a higher risk of CV disease Methods: We examined CV outcomes among 5085 AAs in the Jackson Heart Study enrolled in 2000-2004 and followed through December 31, 2012. We stratified participants by quartiles of perceived everyday discrimination and estimated the associations with CV outcomes (all-cause mortality, incident coronary heart disease [CHD], incident stroke, and heart failure [HF] hospitalization) using Cox models. Results: Greater perceived discrimination was more common in participants who were younger, male, had higher education and income, a lower perceived standing in the community, worse perceived healthcare access, and fewer comorbidities. Over a median follow-up of 9.8 years (8.0 years for HF), 573 deaths, 193 incident CHD, 156 incident strokes, and 348 HF hospitalizations occurred. Prior to adjustment, greater perceived discrimination was associated with a lower risk of death, incident CHD, stroke, and HF hospitalization (Table). After adjustment for potential confounders, we found no association of perceived discrimination with incident CHD, stroke or HF hospitalization; however, a decrease in all-cause mortality risk with higher perceived discrimination persisted. Conclusions: We found no independent association of perceived discrimination with risk of incident CV disease or HF hospitalization and a paradoxical negative association with mortality in this AA population. The unexpected finding of a lower risk of death with greater perceived discrimination requires further study.

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.