Sex differences in outcome after implantable cardioverter defibrillator implantation in nonischemic cardiomyopathy.

BACKGROUND: Women have been underrepresented in randomized trials of implantable cardioverter defibrillator (ICD) therapy, and limited data suggest that women may not benefit from prophylactic ICD implantation to the same extent as men. In the Defibrillators in Non-Ischemic Cardiomyopathy Treatment Evaluation (DEFINITE) trial, a reduction in all-cause mortality was seen in men (P = .018) but not for women (P = .76). METHODS: Sex-specific cumulative probabilities of event-free survival from total, arrhythmic, and noncardiac mortality as well as appropriate shocks were calculated, and log-rank tests were performed. Interaction terms in multivariable Cox proportional hazards models were used to test the hypothesis that the effectiveness of the ICD differed between men and women. RESULTS: Among 458 patients (326 men and 132 women) with nonischemic cardiomyopathy enrolled in the DEFINITE trial, the test for an interaction between sex and ICD treatment on total mortality was not significant in unadjusted (P = .11) or in multivariable adjusted (P = .18) analyses. When we examined cause-specific mortality, we found no sex difference in the incidence of arrhythmic death. Instead, we documented a relative excess of noncardiac death among women randomized to the ICD (P = .02) as compared with women randomized to standard medical therapy. With respect to device use, there was a trend for women to have fewer appropriate ICD shocks after multivariable adjustment (P = .06). CONCLUSION: Among patients with nonischemic cardiomyopathy enrolled in DEFINITE, we found no conclusive evidence for a sex difference in the effectiveness of the ICD; however, the trial was not adequately powered to detect such interaction effects. Larger studies are required to definitively address whether the benefit of ICD therapy differs between men and women.

Prophylactic defibrillator implantation in patients with nonischemic dilated cardiomyopathy.

BACKGROUND: Patients with nonischemic dilated cardiomyopathy are at substantial risk for sudden death from cardiac causes. However, the value of prophylactic implantation of an implantable cardioverter-defibrillator (ICD) to prevent sudden death in such patients is unknown. METHODS: We enrolled 458 patients with nonischemic dilated cardiomyopathy, a left ventricular ejection fraction of less than 36 percent, and premature ventricular complexes or nonsustained ventricular tachycardia. A total of 229 patients were randomly assigned to receive standard medical therapy, and 229 to receive standard medical therapy plus a single-chamber ICD. RESULTS: Patients were followed for a mean (+/-SD) of 29.0+/-14.4 months. The mean left ventricular ejection fraction was 21 percent. The vast majority of patients were treated with angiotensin-converting-enzyme (ACE) inhibitors (86 percent) and beta-blockers (85 percent). There were 68 deaths: 28 in the ICD group, as compared with 40 in the standard-therapy group (hazard ratio, 0.65; 95 percent confidence interval, 0.40 to 1.06; P=0.08). The mortality rate at two years was 14.1 percent in the standard-therapy group (annual mortality rate, 7 percent) and 7.9 percent in the ICD group. There were 17 sudden deaths from arrhythmia: 3 in the ICD group, as compared with 14 in the standard-therapy group (hazard ratio, 0.20; 95 percent confidence interval, 0.06 to 0.71; P=0.006). CONCLUSIONS: In patients with severe, nonischemic dilated cardiomyopathy who were treated with ACE inhibitors and beta-blockers, the implantation of a cardioverter-defibrillator significantly reduced the risk of sudden death from arrhythmia and was associated with a nonsignificant reduction in the risk of death from any cause.

Short-term intravenous milrinone for acute exacerbation of chronic heart failure: a randomized controlled trial.

CONTEXT: Little randomized evidence is available to guide the in-hospital management of patients with an acute exacerbation of chronic heart failure. Although intravenous inotropic therapy usually produces beneficial hemodynamic effects and is labeled for use in the care of such patients, the effect of such therapy on intermediate-term clinical outcomes is uncertain. OBJECTIVE: To prospectively test whether a strategy that includes short-term use of milrinone in addition to standard therapy can improve clinical outcomes of patients hospitalized with an exacerbation of chronic heart failure. DESIGN: Prospective, randomized, double-blind, placebo-controlled trial conducted from July 1997 through November 1999. SETTING: Seventy-eight community and tertiary care hospitals in the United States. PARTICIPANTS: A total of 951 patients admitted with an exacerbation of systolic heart failure not requiring intravenous inotropic support (mean age, 65 years; 92% with baseline New York Heart Association class III or IV; mean left ventricular ejection fraction, 23%). INTERVENTION: Patients were randomly assigned to receive a 48-hour infusion of either milrinone, 0.5 microg/kg per minute initially (n = 477), or saline placebo (n = 472). MAIN OUTCOME MEASURE: Cumulative days of hospitalization for cardiovascular cause within 60 days following randomization. RESULTS: The median number of days hospitalized for cardiovascular causes within 60 days after randomization did not differ significantly between patients given milrinone (6 days) compared with placebo (7 days; P =.71). Sustained hypotension requiring intervention (10.7% vs 3.2%; P<.001) and new atrial arrhythmias (4.6% vs 1.5%; P =.004) occurred more frequently in patients who received milrinone. The milrinone and placebo groups did not differ significantly in in-hospital mortality (3.8% vs 2.3%; P =.19), 60-day mortality (10.3% vs 8.9%; P =.41), or the composite incidence of death or readmission (35.0% vs 35.3%; P =.92) CONCLUSION: These results do not support the routine use of intravenous milrinone as an adjunct to standard therapy in the treatment of patients hospitalized for an exacerbation of chronic heart failure.

Cardiopulmonary and Cardiovascular Physiology in Elderly Competitive Endurance Athletes.

Thirteen elderly male high intensity endurance athletes and 12 healthy age matched nonathletes were evaluated to determine differences in their cardiovascular physiology. Contrary to several pervious reports, this study did not demonstrate superiority of left ventricular (LV) systolic or diastolic function in athletes compared with controls, either at rest or immediately following exercise. Fasting serum lipids failed to demonstrate a favorable cholesterol profile in the athletes compared to inactive controls. Our results point to superior oxygen utilization (mean peak Vo2 44 vs. 27 mL/kg/min; athletes vs. controls) and the capacity to exercise both aerobically (mean duration 24 vs. 12 min; athletes vs. controls) and anaerobically (mean duration 10 vs. 4 min; athletes vs. controls) as distinguishing parameters between the two cohorts. Our study suggests that in senior athletes, enhanced LV diastolic function may not be as great a contributing factor to athletic performance as previously reported. (c)1999 by CVRR, Inc.