Comparison of the long-term prognostic value of peak exercise oxygen pulse and peak oxygen uptake in patients with chronic heart failure.

OBJECTIVE To evaluate the ratio of peak oxygen consumption to peak heart rate (peak oxygen pulse) as a predictor of long term prognosis in chronic heart failure. PATIENTS AND SETTING 178 consecutive heart failure patients recruited to the cardiology department of a tertiary referral centre between 1986 and 1993. DESIGN Bicycle ergometry with measurement of respiratory exchange. Mean (SD) follow up was 32 (25) months. RESULTS Patients who died had a lower peak oxygen consumption (16.0 (5.5) v 18.0 (5.5) ml/min/kg, p = 0.05), lower indexed peak oxygen consumption (52 (14) v 60 (16)%, p = 0.006) but similar peak oxygen pulse (8.4 (2.6) v 8.4 (3.0) ml/beat, NS). The following variables were associated with a good long term prognosis: New York Heart Association class II, non-ischaemic heart failure, peak oxygen consumption > or = 17 ml/min/kg, indexed peak oxygen consumption > 63%. Peak oxygen pulse did not have predictive value. Only indexed peak oxygen consumption remained an independent predictor of survival in multivariate analysis. CONCLUSIONS Peak oxygen pulse has lower prognostic value than peak oxygen consumption, especially when the latter is indexed to predicted values.