P6519Echo-derived peak cardiac power output-to-left ventricular mass with cardiopulmonary exercise testing predicts outcome in patients with heart failure and depressed systolic function

Background: Peak cardiac power output-to-mass (CPOM) represents a measure of the rate at which cardiac work is delivered with respect to the potential energy stored in left ventricle (LV) mass. Aim: To investigate the value of peak CPOM and cardiopulmonary exercise test (CPET) in risk stratification of patients with chronic heart failure (HF). Materials and methods: We studied 137 patients with chronic HF (mean LV ejection fraction 30%) undergoing CPET and exercise stress echocardiography. CPOM was calculated as the product of a constant (K=2.22 × 10–1) with cardiac output (CO) and the mean arterial pressure (MAP), divided by LV mass (M), and expressed in the unit of W/100 g: CPOM = [K × CO (l/min) × MAP (mmHg)]/M (g). Patients were followed-up for the primary end-point, that included all-cause death and VAD implantation and the composite end-point that comprised hospitalization for HF. Results: In multivariate Cox regression analyses, peak COPM was selected as the most powerful independent predictor of the end points (HR: 0.043, 95% CI: 0.004–0.044, p=0.008; HR: 0.011, 95% CI: 0.02–0.66, p=0.016). Five-year survival free from all-cause death or VAD implantation was 92% in those exhibiting VO2 >14 ml/min/kg and peak COPM >0.6 W/100 g (Fig. 1). Peak VO2 ≤14 ml/min/kg provided incremental prognostic value over demographic and clinical variables, BNP and resting echocardiographic parameters (chi-square: from 34.2 to 46.1; p=0.005), that was further increased by peak COPM ≤0.6 W/100 g (chi square: 52.2; p=0.026).