Is the transpulmonary pressure gradient a predictor for mortality after orthotopic cardiac transplantation?

Elevated pulmonary vascular resistance (PVR) is a well-known risk factor for right ventricular failure after orthotopic cardiac transplantation. The influence of preoperative transpulmonary pressure gradient (TPG) and PVR on post-transplant 30 days mortality was evaluated. To analyze the response of PVR and TPG to cardiac transplantation, we analyzed 718 adult patients undergoing primary cardiac transplantation. Indications for operation were: 35.2% ischemic cardiomyopathy (ICM), 61.2% idiopathic dilated cardiomyopathy (DCM), and 3.3% other diagnosis (e.g. hypertrophic cardiomyopathy). The mean age (51.9) and the mean ischemic time (169.7 min) were comparable between 30 days survivors and nonsurvivors. Student's t-tests and chi-square analysis were used to compare data from 30-day survivors and nonsurvivors. Statistical significance was defined as P < 0.05. Fisher's exact test and multiple logistic regression analysis was performed to evaluate the relationship between hemodynamic parameters and outcome after transplantation. Primary end-point was 30 days mortality and secondary end-point long-term survival of patient groups with different TPG and PVR values. In survivors the mean TPG was 10.3 +/- 5.1 (mean +/- SD) vs. 13 +/- 6.6 in patients who died after transplantation (P = 0.0012). The PVR was 2.6 +/- 1.4 vs. 3.5 +/- 2.2 (P = 0.0012). In multivariate logistic regression, the parameters TPG and PVR exhibit a significant influence between survivors and nonsurvivors after cardiac transplantation within 30 days (TPG: P = 0.0012; PVR: P = 0.0012). The mortality rates in patients with TPG > 11 mmHg and PVR < 2.8 Wood units or TPG < 11 mmHg and PVR > 2.8 Wood units were comparable to those with TPG < 11 mmHg and PVR < 2.8 mmHg. The TPG is an important predictor in nonrejection-related early mortality after orthotopic cardiac transplantation. The determination of TPG in combination with PVR is a more reliable predictor of early post-transplant survival than PVR alone.