Pulmonary Artery Hypertension as A Risk Factor for Long-Term Survival after Heart Transplantation

Abstract

Background: Heart failure is the most frequent cause of pulmonary artery hypertension (PAH) and its severity may predict the development of heart failure (HF) and is known to be a prognostic factor of poor outcome after heart transplant (HTx). The aim of this study was to investigate the impact of preoperative PAH related to left-sided HF on long-term survival after HTx and to identify the hemodynamic parameters of PAH that predict survival after HTx. Methods: A prospective observational trial was performed, and it included 44 patients subjected to heart transplantation. Patients were divided into two groups: The first one with the preoperative diagnosis of PAH and the second one without the PAH diagnosed prior to the HTx. The two groups were compared for baseline characteristics, operative characteristics, survival, and hemodynamic parameters obtained by right heart catheterization. Survival was analyzed using Kaplan Meyer analysis, and Cox regression analysis was performed to determine independent predictors of survival. Results: The median follow-up time was 637.4 days (1-2028 days). The median survival within the group of patients with preoperative PAH was 1144 days (95% CI 662.884-1625.116) and 1918.920 days (95% CI 1594.577-2243.263) within the group of patients without PAH (P = .023), HR 0.279 (95% [CI]: 0.086-0.910; P = .034. The 30-day mortality in patients within PAH group was significantly higher, six versus two patients in the non PAH group (χ2 = 5.103, P < .05), while the long-term outcome after this period did not differ between the groups. Patients with preoperative PAH had significantly higher values of MPAP, PCWP, TPG and PVRI, while CO and CI did not differ between the two groups. Mean PVRI was 359.1 ± 97.3 dyn·s·cm-5 in the group with preoperative PAH and 232.2 ± 22.75 dyn·s·cm-5 in the group without PAH, P < .001. TPG values were 11.95 ± 5.08 mmHg in the PAH group while patients without PAH had mean values of 5.16 ± 1.97 mmHg, P < .001. Cox regression analysis was done for the aforementioned parameters. Hazard ratio for worse survival after HTx for elevated values of PVRI was 1.006 (95% [CI]: 1.001-1.012; P = .018) TPG had a hazard ratio of 1.172 (95% [CI]: 1.032-1.233; P = .015). Conclusion: Pulmonary artery hypertension is an independent risk factor for higher 30-day mortality after HTx, while it does not affect the long-term outcome. Hemodynamic parameters obtained by right heart catheterization in heart transplant candidates could predict postoperative outcome. PVRI and TPG have been identified as independent predictors of higher 30-day postoperative mortality.