Normal cardiac output response to exercise predicted a significantly higher 1-year survival rate compared to a reduced response (95% vs 72%, P<0.0001) in patients with chronic heart failure.
Cohort (n=185)
Does direct measurement of cardiac output response to exercise predict 1-year survival in ambulatory patients with chronic heart failure referred for cardiac transplantation?
Direct measurement of cardiac output response to exercise, combined with peak VO2, provides strong independent prognostic information for selecting heart transplantation candidates.
Effect estimate: RR 4.3
Absolute Event Rate: 95% vs 72%
p-value: p=<0.0001
BACKGROUND: Peak exercise oxygen consumption (Vo2), a noninvasive index of peak exercise cardiac output (CO), is widely used to select candidates for heart transplantation. However, peak exercise Vo2 can be influenced by noncardiac factors such as deconditioning, motivation, or body composition and may yield misleading prognostic information. Direct measurement of the CO response to exercise may avoid this problem and more accurately predict prognosis. METHODS AND RESULTS: Hemodynamic and ventilatory responses to maximal treadmill exercise were measured in 185 ambulatory patients with chronic heart failure who had been referred for cardiac transplantation (mean left ventricular ejection fraction, 22 +/- 7%; mean peak Vo2, 12.9 +/- 3.0 mL. min-1.kg-1). CO response to exercise was normal in 83 patients and reduced in 102. By univariate analysis, patients with normal CO responses had a better 1-year survival rate (95%) than did those with reduced CO responses (72%) (P 14 mL.min-1.kg-1 (88%) was not different from that of patients with peak Vo2 of 10 mL.min-1.kg-1 (89%) (P < .0001). By Cox regression analysis, exercise CO response was the strongest independent predictor of survival (risk ratio, 4.3), with peak Vo2 dichotomized at 10 mL. min-1.kg-1 (risk ratio, 3.3) as the only other independent predictor. Patients with reduced CO responses and peak Vo2 of < or = 10 mL.min-1.kg-1 had an extremely poor 1-year survival rate (38%). CONCLUSIONS: Both CO response to exercise and peak exercise Vo2 provide valuable independent prognostic information in ambulatory patients with heart failure. These variables should be used in combination to select potential heart transplantation candidates.
Chomsky et al. (1996) conducted a cohort in Chronic heart failure (n=185). Normal cardiac output response to exercise vs. Reduced cardiac output response to exercise was evaluated on 1-year survival rate (RR 4.3, p=<0.0001). Normal cardiac output response to exercise predicted a significantly higher 1-year survival rate compared to a reduced response (95% vs 72%, P<0.0001) in patients with chronic heart failure.