Cardiac resynchronization therapy: A comparative analysis of mortality in African Americans and Caucasians.

BACKGROUND: Cardiac resynchronization therapy (CRT) is recommended in patients with heart failure, reduced left ventricular ejection fraction, and a prolonged QRS duration. African Americans are underrepresented in clinical trials and CRT is underutilized; consequently, the benefits and outcomes of CRT are not well-defined. METHODS: We evaluated 294 patients, determined survival using Kaplan-Meier analysis, and used Cox proportional hazards regression model to determine predictors of mortality. Propensity score-match analysis was applied to balance covariates in African Americans and Caucasians. RESULTS: The mean age for African Americans (n  =  131) and Caucasians (n  =  163) was 65 ± 12 and 70 ± 13 years (P  =  0.0003). Mortality in African Americans was 28% compared to 37% in Caucasians (P  =  0.14) over a median follow-up of 8.1 ± 0.6 years. Survival was significantly reduced in African Americans and Caucasians with a glomerular filtration rate (GFR) < 60 (6.7 ± 0.4, 95% confidence interval [CI]: 5.9-7.5 vs 8.6 ± 0.5 CI: 7.7-9.5 years, P  =  0.005), and those not treated with an aldosterone antagonist (7.1 ± 0.4, 95% CI: 6.5-7.9 vs 8.7 ± 0.6, 7.6-9.9 years, P  =  0.04), respectively. Independent predictors of mortality were a GFR <60 and low left ventricular ejection fraction. In African Americans, ischemic cardiomyopathy (ICM) and lack of therapy with an angiotensin-converting enzyme inhibitor (ACEI) or angiotensin II receptor blocker (ARB) were associated with increased mortality. CONCLUSIONS: Long-term survival benefit from CRT was similar in African Americans and Caucasians. A GFR < 60 and lack of therapy with an aldosterone antagonist were associated with decreased survival. Survival also was inversely related to the number of comorbidities. In African Americans, underutilization of an ACEI or ARB, and ICM were additional factors associated with increased mortality.

Association of elevated triglycerides and acute myocardial infarction in young Hispanics.

BACKGROUND: Previous studies have demonstrated that acute myocardial infarction (AMI) in young patients (age <45years) is associated with a high prevalence of smoking, obesity, hyperlipidemia and single vessel coronary artery disease (CAD). Hispanics represent the largest growing ethnic minority in the United States, yet features of AMI in young Hispanics have not been described. METHODS: Patients undergoing percutaneous coronary intervention for AMI at Los Angeles County + University of Southern California Medical Center and Keck Medical Center were studied. We compared young Hispanics (age<45, n=47) with older patients (Hispanics and non-Hispanics age ≥45, n=888) to identify unique features of AMI in young Hispanics. We also compared young Hispanics with young non-Hispanics (n=33) and older Hispanics (n=447) in regards to traditional CAD risk factors, laboratory values and in-hospital outcomes. Multivariable logistic regression was performed to identify variables independently associated with in-hospital mortality. RESULTS: Young Hispanics had higher triglyceride levels than young non-Hispanics and older patients (234.5±221.0mg/dL vs. 145.3±67.4mg/dL vs. 156±118.2mg/dL, p<0.0004); and higher triglyceride than older Hispanics (234.5±221.0 vs. 147.0±98.9mg/dL, p<0.02). Body mass index was independently associated with the logarithm (base10) of triglyceride levels (p<0.0001). Hispanic ethnicity and age<45years, however, were not independently associated with in-hospital mortality. CONCLUSIONS: Young Hispanics with AMI have higher triglyceride levels than young non-Hispanics and older Hispanics. The elevated triglyceride levels may be related to lifestyle changes experienced by a young immigrant population transitioning to life in the United States.