Peak exercise cardiac power output; a direct indicator of cardiac function strongly predictive of prognosis in chronic heart failure

• Published in: European heart journal Vol. 22; no. 16; pp. 1496 - 1503
• Main Authors: Williams, S.G, Cooke, G.A, Wright, D.J, Parsons, W.J, Riley, R.L, Marshall, P, Tan, L-B
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01.08.2001
• Subjects: Adult; Aged; Analysis of Variance; Biological and medical sciences; Blood Pressure - physiology; Cardiac Output - physiology; cardiac power output; Cardiology. Vascular system; Chronic heart failure; Exercise Test; Female; Follow-Up Studies; Heart; Heart Failure - mortality; Heart Failure - physiopathology; Heart failure, cardiogenic pulmonary edema, cardiac enlargement; Humans; Male; Medical sciences; Middle Aged; non-invasive cardiopulmonary exercise testing; Oxygen Consumption - physiology; prognosis; Survival Analysis; Human; Heart failure; Chronic; Maximum oxygen consumption; Prognosis; Follow up study; Heart disease; Cardiovascular disease; Exercise tolerance test; Hemodynamics; Survival
• ISSN: 0195-668X; 1522-9645
• DOI: 10.1053/euhj.2000.2547

Objectives This study assessed the prognostic value of peak cardiac power output, measured non-invasively during maximal cardiopulmonary exercise testing, against other exercise-derived haemodynamic variables in patients with chronic congestive heart failure. Method and Results Two hundred and nineteen unselected, consecutive patients with congestive heart failure (166 men, mean (±SD) age of 56±13 years) who underwent maximal symptom limited cardiopulmonary treadmill exercise testing with non-invasive estimation of cardiac output using carbon dioxide re-breathing techniques, were followed-up for a mean period of 4·64 (4·47–4·82, 95% CI) years. Cardiac power output was calculated from the product of cardiac output and mean arterial blood pressure. All cause mortality was 12·3% (27 deaths). Peak and resting cardiac power output, peak mean arterial blood pressure, peak and resting cardiac output and peak VO2were all predictive of outcome on univariate analyses. Peak cardiac power output, either entered continuously or categorically with a cut-off value of 1·96 watts, was the only independent predictor of mortality (P=0·0004 for values 1·96 watts and P=0·001 for continuous values) using multivariate analysis. A relative risk ratio of 5·08 (1·94–13·3, 95% CI) was obtained for a cardiac power output <1·96 watts. Conclusion Peak cardiac power output is an independent predictor of mortality that can be measured non-invasively using cardiopulmonary exercise testing. It can give further prognostic power to a peak VO2in the assessment of patients with congestive heart failure.