EXERCISE CAPACITY AFTER HEART-TRANSPLANTATION - INFLUENCE OF DONOR AND RECIPIENT CHARACTERISTICS

Background: For incompletely understood reasons, cardiac transplant re cipients achieve only 60% to 70% of predicted values for maximal exerc ise capacity. The objective was to determine the characteristics of ca rdiac transplant recipients that are predictive of exercise capacity. Methods: One hundred ten patients underwent maximal exercise testing u sing a modified Naughton protocol 26 +/- 1 months after transplantatio n. Recipient characteristics, resting hemodynamic variables and exerci se parameters were compared using univariate and multivariate analyses . Results: The average maximum heart rate was 85% of predicted, and th e average peak oxygen consumption (Vo(2)) was 17.7 +/- 0.3 ml/kg/min ( 64% of predicted). Pretransplant status, etiology of heart failure, is chemic time, degree of HLA disparity, cumulative corticosteroid exposu re, and number of rejection episodes failed to correlate with any exer cise parameter. Older recipient age and female gender were associated with greater values for the proportion of the predicted peak Vo(2) (p < 0.001 for age; p = 0.001 for gender). Older donor age was the strong est independent predictor of a decreased chronotropic response (p < 0. 001) and was a weak predictor of decreased peak Vo(2) (p = 0.014). Eve n in the multivariate analysis, maintenance prednisone dose negatively impacts exercise duration (p = 0.05), peak Vo(2) (p = 0.035) and perc ent of predicted peak Vo(2) (p = 0.032). Of all characteristics tested , pulmonary vascular resistance within 24 hours of exercise most power fully predicts exercise duration (p = 0.002) and peak Vo(2) (p = 0.001 ). Conclusions: Female recipients and older recipients have a lower ab solute exercise capacity, but achieve a greater proportion of their pr edicted capacity. Recipients of older donor hearts and those receiving chronic corticosteroids have decreased exercise capacity. Pulmonary v ascular resistance is inversely correlated with exercise capacity.