CLINICAL, HEMODYNAMIC, AND CARDIOPULMONARY EXERCISE TEST DETERMINANTSOF SURVIVAL IN PATIENTS REFERRED FOR EVALUATION OF HEART-FAILURE

Background: Accurate prognosis in chronic heart failure has become inc reasingly important in assessing the efficacy of treatment and in appr opriately allocating scarce resources for transplantation. Previous st udies of severe heart failure have been limited by short follow-up per iods and few deaths. Objective: To establish clinical, hemodynamic, an d cardiopulmonary exercise test determinants of survival in patients w ith heart failure. Design: Retrospective study. Setting: Hospital-base d outpatient heart failure clinic. Participants: 644 patients referred for evaluation of heart failure over 10 years. Measurements: Age, cau se of heart failure, body surface area, cardiac index, ejection fracti on, pulmonary capillary wedge pressure, left ventricular dimensions, w atts achieved during exercise, heart rate, maximum systolic blood pres sure, a nd oxygen uptake ((V) over dot O-2) at the ventilatory thresho ld and at peak exercise were measured at baseline. Univariate and mult ivariate analyses were done for clinical, hemodynamic, and exercise te st predictors of death. A Cox hazards model was developed for time of death. Results: During a mean follow-up period of 4 years, 187 patient s (29%) died and 101 underwent transplantation. Actuarial 1-year and 5 -year survival rates were 90.5% and 73.4%, respectively. Resting systo lic blood pressure, watts achieved, peak (V) over dot O-2, (V) over do t O-2 at the ventilatory threshold, and peak heart rate were greater a mong survivors than among nonsurvivors. Cause of heart failure (corona ry artery disease or cardiomyopathy) was a strong determinant of death (relative risk for coronary artery disease, 1.73; P < 0.01). By multi variate analysis, only peak (V) over dot O-2 was a significant predict or of death. Stratification of peak (V) over dot O-2 above and below 1 2, 14, and 16 mL/kg per minute demonstrated significant differences in risk for death, but each cut-point predicted risk to a similar degree . Conclusions: Peak (V) over dot O-2 outperforms clinical variables, r ight-heart catheterization data, exercise time, and other exercise tes t variables in predicting outcome in severe chronic heart failure. Dir ect measurement of (V) over dot O-2 should be included when clinical o r surgical decisions are being made in patients referred for evaluatio n of heart failure or those considered for transplantation.