Risk Analysis of Perioperative Death in Lung Transplant Patients With Severe Idiopathic Pulmonary Hypertension

Abstract

ObjectiveTo investigate the risk factors for perioperative mortality in patients with severe idiopathic pulmonary hypertension (IPAH) undergoing lung transplantation (LTx). MethodsTwenty-two IPAH patients were included in the study and were divided 2 groups: a case group with early death post LTx (n = 5, 22.7%) and the remaining 17 recipients (87.3%), who did not die at perioperative time (the control group). All the preoperative clinical data and surgical procedures were analyzed using an independent t-test and Fisher's exact probability test. ResultsAll the patients had over class III heart function rated by World Health Organization classification. Both groups had significantly reduced capacity of 6-min walking distance (6 MWD), decreased oxygen saturation, increased N-terminal probrain natriuretic peptide (NT-proBNP), certain frequent syncope, hemoptysis, and lower extremity edema. In addition, cardiac catheterization examination demonstrated that all patients had elevated pulmonary artery systolic pressure, mean pulmonary artery systolic pressure, and right atrial pressure. Furthermore, reduced mixed venous oxygen saturation and partial pressure of oxygen were seen in oxygen inhalation in a dose of 5 L/min in both groups. Cardiovascular morphological changes in both groups by cardiac ultrasonography included dilated diameter of the right ventricle and the main pulmonary artery. However, the right ventricular ejection fraction and stroke volume were notedly dropped. Distended inferior vena cava and enhanced frequency of hypertensive tricuspid regurgitation velocity response to stress were seen, and pericardial effusion was developed in both groups of patients. Nevertheless, a paired t-test (n = 5 vs n = 17) showed no significance between groups (P > .05), while there was a significant difference in frequencies of brief loss of consciousness (P < .01). Serum sodium concentration, cardiac index (CI), inner diameter of the left ventricle at end diastolic phase, and inner diameter ratio of RV/LV were 116.80 ± 5.76 mmol/L vs 29.88 ± 7.28 mmol/L (P = .002), 1.30 ± 0.07 L/min/m2 vs 1.58 ± 0.26 L/min/m2 (P = .030), 28.80 ± 3.70 mm vs 34.76 ± 5.43 mm (P = .033) and 1.81 ± 0.28 mmol/L vs 1.43 ± 0.26 (P = .011) between case and control group, respectively. ConclusionsAll patients with IPAH waiting for lung transplantation were in critical condition. The highest death risks at perioperative time in IPAH patients were high frequencies of syncope, hyponatremia, lower CI, inner diameter of the left ventricle, and upward RV/LV ratio.