Ventricular Conduction and Long-Term Heart Failure Outcomes and Mortality in African Americans

Abstract

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 electrocardiogram. We defined QRS prolongation as QRS ≥ 100 msec. We assessed the association between QRS duration and all-cause mortality using Cox proportional hazards models, and reported the cumulative incidence of heart failure (HF) 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 HF hospitalization were greater with versus without baseline QRS prolongation: 12.6% (95% CI, 11.0–14.4) vs. 7.1% (95% CI, 6.3–8.0) and 8.2% (95% CI, 6.9–9.7) vs. 4.4% (95% CI, 3.7–5.1), respectively. After risk adjustment, QRS prolongation was associated with increased mortality (HR, 1.27; 95% CI, 1.03–1.56; P = .02). There was a linear relationship between QRS duration and mortality (HR per 10 msec 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 HF hospitalization. Factors associated with developing QRS prolongation included age, male sex, prior myocardial infarction, and left ventricular structural abnormalities.

Increased Proximal Aortic Diameter is Associated With Risk of Cardiovascular Events and All‐Cause Mortality in Blacks The Jackson Heart Study

“…HF hospitalizations in the JHS cohort were identified and adjudicated as previously described. 18 Study participants who did not develop cardiovascular events were censored by December 21, 2011. For the analysis of CHD, stroke, and HF hospitalization events, we excluded those with prevalent CHD for the analysis of CHD, those with prevalent stroke for the analysis of stroke, and those with prevalent HF for the analysis of HF hospitalization ( Figure 1).…”

“…In the JHS cohort, HF hospitalization surveillance began January 1, 2005. HF hospitalizations in the JHS cohort were identified and adjudicated as previously described 18. Study participants who did not develop cardiovascular events were censored by December 21, 2011.…”

Race and Sex Differences in QRS Interval and Associated Outcome Among Patients with Left Ventricular Systolic Dysfunction

“…Mentz et al analyzed a population of black study participants in Jackson, Mississippi, and found that QRS prolongation was associated with an increased risk of mortality across all spectrums of QRS duration. 35 Similarly, progressive QRS duration is typically associated with worse outcomes among HF patients. 24,25,28 Conversely, an observational study of 3471 HF patients (56% black, 41% white, and 3% other) found that mortality was lowest in participants with QRS duration ≥150 ms compared with <120 or 120 to 149 ms. 2 Similarly, Linde et al found no difference in mortality among women with LBBB compared with women whose QRS was <120 ms. 13 These inconsistencies in the data highlight the complexity of the relationship between QRS duration and mortality.…”

The Obesity and Heart Failure Epidemics Among African Americans: Insights From the Jackson Heart Study

“…Since HF history was not collected at the 3 clinical exams, we derived prevalent HF at each exam using the modified Gothenburg criteria developed and validated in the ARIC data set and as recently applied to the Jackson Heart Study cohort. [18, 19] Among participants without prevalent HF at exam 1, we assessed prevalent HF at exam 2 (median follow-up, 4.8 years from exam 1; range, 3.4–8.2 years) and prevalent HF at exam 3 (median follow-up, 8.0 years from exam 1; range, 6.4–12.2 years). We also assessed the cumulative incidence of HF hospitalization between 2005 and 2011 among study participants who survived to January 1, 2005, when HF hospitalization surveillance began.…”