On the possibility to increase sensitivity of diagnostic tests for fixed pulmonary hypertension in heart transplant candidates

Abstract

Background: Fixed pulmonary hypertension (PH) in heart transplant candidates is a risk factor for right ventricular failure in the postoperative period and early mortality. Patients with fixed PH are not included in the waiting list. Thus, the correct assessment of the pulmonary circulation before the operation affects both clinical management and prognosis. Aim: To reduce the risk of incorrect patient non-inclusion to the waiting list by reduction of false negative test results for PH reversibility.Materials and methods: Fourteen heart transplant candidates were included in this retrospective cohort single center study. Fixed PH with pulmonary vascular resistance (PVR) exceeding 3.5 Wood's units was found in all these patients using right heart catheterization and pulmonary vasoreactivity tests. Initially, these patients had not been put into the waiting list. Pulmonary catheterization was performed in the intensive care unit with a Swan-Ganz catheter and pre-pulmonary thermodilution technique. To perform pulmonary vasoreactivity tests, inhaled iloprost (n = 12) or nitric oxide (n = 2) were used. Subsequently all patients received levosimendan infusion at a dose of 12.5 (0.05–0.2) mg/kg/min, with repeated pulmonary artery catheterization and pulmonary vasoreactivity tests at 72 hours after the infusion. Pulmonary vasoreactivity tests results allowed 13 patients to be included into the waiting list. Heart transplantation was performed in 8 recipients, with postoperative assessment of their hemodynamic and clinical parameters. Data are presented as median [25th percentile; 75th percentile].Results: After the levosimendan infusion, there was a decrease in the pulmonary artery mean pressure from 45 [36; 47] to 29.5 [23; 37] mm Hg (p < 0.01), and in PVR from 6.9 [4.9; 8.9] to 3.6 [2.9; 5.9] Wood's units (p <0.01). In 7 patients, PVR decreased to less than 3.5 Wood's units: the rest of the patients underwent pulmonary vasoreactivity tests. As a result, 13 of 14 patients showed reversible PH and were included into the waiting list. By the date of the manuscript submission, heart transplantation has been performed in 8 patients. Their PVR 6 hours after surgery was 2.2 [2; 3.1] Wood's units; there were no cases of fixed PH and right heart failure. There was a single death associated to a hemorrhagic stroke at day 6 after heart transplantation. The sensitivity of pre-operative pulmonary vasoreactivity tests with the use of levosimendan was 87.5%.Conclusion: Levosimendan infusion may increase the sensitivity of the pulmonary vasoreactivity tests before patients' inclusion into the waiting list for heart transplantation.