Mortality in African-Americans Following Cardiac Resynchronization Therapy: A Single Center Experience.

BACKGROUND: Cardiac resynchronization therapy (CRT) improves clinical outcomes and reduces mortality in heart failure patients who remain symptomatic despite optimal medical therapy. CRT trials have reported significant hemodynamic benefits, improvement in functional status, and reduced mortality and heart failure hospitalizations. However, African-American patient representation in these studies is limited thus the results may not be applicable to them. We described baseline clinical characteristics of African-American patients undergoing CRT and determined their outcomes relative to those reported in clinical trials. METHODS: We evaluated 131 African-American patients with New York Heart Association functional class II-IV heart failure undergoing CRT and determined predictors of all-cause mortality. Kaplan-Meier survival estimates and a Cox proportional hazards model determined mortality and risk of death. RESULTS: The mean age was 65 ± 12 years. Over a 6-year period, total mortality in African-Americans was 23% as compared with 29% in the MADIT-CRT trial. Increased mortality was associated with older age (hazard rate (HR) 1.04, 95% confidence interval (CI) 1.01-1.07, P=.01), ischemic cardiomyopathy (HR 2.86, 95% CI 1.36-6.04, P=.006), and absence of treatment with either an angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker (HR 2.75, 95% CI 1.30-5.80, P=.008), or beta-blocker (HR 2.56, 95% CI 0.98-6.69, P=.05). Hydralazine plus nitrate therapy was used in a small number of patients and did not influence mortality outcomes. CONCLUSION: African-Americans experience the same survival benefits from CRT as Caucasian patients reported in major clinical trials. Publication indices used to find publications listed in references: PubMed.

Biventricular paced QRS predictors of left ventricular lead locations in relation to mortality in cardiac resynchronization therapy.

BACKGROUND: Left ventricular (LV) lead location during cardiac resynchronization therapy (CRT) has influenced mortality and heart failure events; however the biventricular paced QRS morphology has not been established as a predictor of LV lead location or mortality. METHODS: We evaluated the biventricular paced QRS morphology in 306 patients undergoing CRT in relation to specific anatomic locations. A logistic regression model and Kaplan-Meier survival estimates were used to determine predictors of LV lead location and survival. RESULTS: The mean age was 68±13years. Predictors of LV lead location from anterior, lateral, and posterior segments were: absence of R in V1, QS in aVL; and R in aVL, respectively. Absence of an R in II, III, or aVF predicted an inferior site. A QS in V4-V6 differentiated apical from basal sites (p=0.01). LV pacing from sites along the middle cardiac vein revealed a higher mortality (34%), than lateral sites (20%, p=0.02). CONCLUSIONS: Biventricular paced QRS criteria were predictive of LV lead locations. The proposed algorithm enhanced the predictive accuracy of these criteria. LV pacing sites along the middle cardiac vein were associated with increased mortality.

T-cell responses induced in normal volunteers immunized with a DNA-based vaccine containing HIV-1 env and rev.

OBJECTIVE: An effective HIV-1 vaccine will likely need to induce strong cell-mediated immunity in humans. Therefore, we examined the ability of a DNA HIV-1 vaccine to induce a T-cell response in HIV-1 seronegative humans. DESIGN: Individuals were enrolled in a phase I clinical trial of safety and immune responses to an env/rev-containing plasmid at doses of 100, 300 or 1000 microg. Peripheral blood mononuclear cells (PBMC) samples were analyzed by standard lymphocyte proliferation, cytotoxic T lymphocyte (CTL) and ELISPOT techniques. RESULTS: PBMCs from subjects immunized with doses as low as 300 microg proliferated in vitro to env (four of six) or (three of six) proteins. Importantly, when the dose of vaccine was increased to 1000 microg of DNA, lymphocytes secreted IFN-gamma in an ELISPOT assay following in vitro stimulation with env (three of six) or rev (four of six) proteins. CONCLUSION: We observed HIV-1 DNA plasmid vaccines induce CD4 T-helper cell responses in humans. We observed a discrepancy in the CD4 versus CD8 response suggesting the importance of analyzing both compartments in clinical evaluation. Furthermore, this report demonstrates the high level of immunogenicity of and its importance as a component of a prophylactic vaccine for HIV-1.