Risk factors of early death after lung transplantation in patients with idiopathic pulmonary fibrosis complicated with pulmonary arterial hypertension

Abstract

To investigate the risk factors of early death after lung transplantation in patients with idiopathic pulmonary fibrosis (IPF) complicated with pulmonary arterial hypertension (PAH). A retrospective cohort study was conducted. The clinical data of 134 patients with IPF and PAH who underwent lung transplantation at Wuxi People's Hospital Affiliated to Nanjing Medical University from January 2017 to December 2020 were collected. The donor's gender, age, duration of mechanical ventilation, and cold ischemia time, the recipient's gender, age, body mass index (BMI), smoking, history of hypertension and diabetes, preoperative usage of hormones, mean pulmonary arterial pressure (mPAP), cardiac echocardiography and cardiac function, serum creatinine (SCr), N-terminal pro-brain natriuretic peptide (NT-proBNP) as well as surgical type, extracorporeal membrane oxygenation (ECMO) treatment, duration of operation, and plasma and red blood cell infusion ratio were collected. The cumulative survival rates of patients at 30, 60, and 180 days after lung transplantation were calculated by Kaplan-Meier method. The univariate and multivariate Cox proportional hazards regression models were used to analyze the effects of donor, recipient, and surgical factors on early survival in donors after lung transplantation. The majority of donors were male (80.6%). There was 63.4% of the donors older than 35 years old, 80.6% of the donors had mechanical ventilation duration less than 10 days, and the median cold ischemia time was 465.00 (369.25, 556.25) minutes. The recipients were mainly males (83.6%). Most of the patients were younger than 65 years old (70.9%). Most of them had no hypertension (75.4%) or diabetes (67.9%). The median mPAP of recipients was 36 (30, 43) mmHg (1 mmHg ≈ 0.133 kPa). There were 73 patients with single lung transplantation (54.5%), and 61 with double lung transplantation (45.5%). The survival rates of 134 IPF patients with PAH at 30, 60, 180 days after lung transplantation were 81.3%, 76.9%, and 67.4%, respectively. Univariate Cox proportional risk regression analysis showed that recipient preoperative use of hormone [hazard ratio (HR) = 2.079, 95% confidence interval (95%CI) was 1.048-4.128], mPAP ≥ 35 mmHg (HR = 2.136, 95%CI was 1.129-4.044), NT-proBNP ≥ 300 ng/L (HR = 2.411, 95%CI was 1.323-4.392), New York Heart Association (NYHA) cardiac function classification III-IV (HR = 3.021, 95%CI was 1.652-5.523) were the risk factors of early postoperative death in patients with IPF complicated with PAH (all P < 0.05). In the multivariable Cox proportional risk regression analysis, recipient preoperative hormone usage (model 1: HR = 2.072, 95%CI was 1.044-4.114, P = 0.037; model 2: HR = 2.098, 95%CI was 1.057-4.165, P = 0.034), NT-proBNP ≥ 300 ng/L (HR = 2.246, 95%CI was 1.225-4.116, P = 0.009) and NYHA cardiac function classification III-IV (HR = 2.771, 95%CI was 1.495-5.134, P = 0.001) were independent risk factors of early postoperative death in patients with IPF. Preoperative hormone usage, NT-proBNP ≥ 300 ng/L, NYHA cardiac function classification III-IV are independent risk factors for early death in patients with IPF and PAH after lung transplantation. For these patients, attention should be paid to optimize their functional status before operation. Preoperative reduction of receptor hormone usage and improvement of cardiac function can improve the early survival rate of such patients after lung transplantation.