Friday, 14 August 2009

HEART FAILURE AND CARDIOMIOPATHY

Data are inconclusive on the utility of anticoagulation to reduce thromboembolic events in patients with heart failure (HF) who are in sinus rhythm. The WATCH trial compared aspirin, clopidogrel and warfarin in adults in sinus rhythm with symptomatic heart failure and left ventricular ejection fraction ≤35 percent [9]. There were no significant differences among the three treatment arms for the primary end point of time to first occurrence of death, nonfatal myocardial infarction, or nonfatal stroke. Warfarin was associated with significantly fewer nonfatal strokes than clopidogrel or aspirin (0.2 versus 2.1 and 1.7 percent). However, this effect was no longer significant when central nervous system bleeds and fatal strokes were included.

The impact of exercise training in patients with heart failure was evaluated in the HF ACTION trial [10]. Patients with NYHA class II to IV HF (99 percent with class II or III symptoms) were randomly assigned to either a supervised exercise training program or usual care including recommendation of regular exercise [10]. There was a significant decrease in all-cause mortality and hospitalization for the exercise training program group after adjustment for major prognostic baseline factors, although there was no difference in the unadjusted analysis.

Limited data are available on the incidence of and risk factors for heart failure (HF) in young adults. A report from the CARDIA study of 5115 subjects aged 18 to 30 years who were prospectively followed for 20 years found that incident heart failure before 50 years of age is substantially more common among blacks than whites (1.1, 0.9, 0.08,and 0 percent in black women, black men, white women, and white men, respectively) [11]. Among blacks, independent predictors before age 30 years of subsequent early HF included higher diastolic blood pressure, high body-mass index, lower HDL cholesterol, kidney disease and left ventricular systolic dysfunction on echocardiogram at age ≤35 years.

Surgical anterior ventricular endocardial restoration (SAVER) excludes noncontracting segments of the dilated remodeled left ventricle after anterior myocardial infarction. The efficacy of this technique was evaluated in 1000 patients with ischemic cardiomyopathy were randomly assigned to either CABG alone or CABG with SAVER [12]. Entry criteria included coronary artery disease amenable to CABG, a left ventricular ejection fraction ≤35 percent, and an anterior akinetic or dyskinetic region of myocardium amenable to ventricular reconstruction. Most patients had symptomatic heart failure. Despite a significantly greater reduction in end-systolic volume index with CABG plus ventricular reconstruction compared to CABG alone, there was no significant difference at two-year follow-up in the rate of the primary outcome (death from any cause and hospitalization for cardiac causes).

Tissue changes in arrhythmogenic right ventricular cardiomyopathy (ARVC) are heterogeneous and patchy so biopsy results have limited accuracy. A preliminary report suggests that identification of reduction in plakoglobin signal (in the presence of preservation of N-cadherin signal) on immunohistochemical analysis of myocardial biopsy specimens is a sensitive and specific test for ARVC [13]. Further data are needed to determine the clinical utility of this technique.