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.