Impact of invasively determined cardiac power index on survival in patients with advanced chronic heart failure

Background: Hemodynamic parameters have recently emerged as tools for risk stratification of heart failure patients. Cardiac power output (CPO) is an indicator of cardiac performance. Cardiac power index (CPI) is calculated by indexing CPO to body surface area. The study aimed to demonstrate the prognostic role of resting CPI in advanced chronic heart failure patients. Methods: The study included patients with advanced chronic heart failure, ejection fraction below 30%, and classes III and IV functional capacity who had had right and left heart catheterization. A total of 99 patients were enrolled, with those having left ventricular assist device (LVAD) implantation or heart transplantation (HTx) excluded to determine LVAD- and HTx-free survival. Results: Of the 99 patients, 43 patients underwent LVAD and HTx surgery. Of the remaining 56 patients, 19 died (33.9%) over a period of 16 months (median). The value of CPI was associated with cardiac mortality (0.32 vs 0.42, p = 0.003). The cut-off level of CPI for mortality was 0.41 (89.5% sensitivity and 56.8% specificity). A diminished CPI (<0.41 W/m(2)) was also associated with high right atrial pressure (p = 0.016) and pulmonary vascular resistance (p = 0.012). A Kaplan-Meier survival analysis indicated that long-term survival was significantly reduced in patients with CPI <0.41. Conclusion: Cardiac power index at rest is associated with cardiac mortality in patients with advanced chronic heart failure.