Methods: Between January 2011 and December 2020, a total of 173 patients (114 males, 59 females; mean age: 53.1±12.5 years; range, 18 to 77 years) who had advanced lung disease or pulmonary vascular disease and were included in the lung transplant list were retrospectively analyzed. Demographic characteristics, laboratory values, long-term mortality data, and clinical and cardiac catheterization data of the patients were compared using a TAPSE/PASP cut-off value of 0.55 mm/mmHg. The univariate and multivariate regression analyses were performed to identify the value of TAPSE/PASP ratio in predicting long-term mortality. The maximal selective rank test was carried out to determine the optimal cut-off value for TAPSE/PASP ratio.

Results: The univariate regression analysis revealed that the TAPSE/PASP ratio, six-minute walk distance, and albumin level were found to be predictors of mortality (hazard ratio [HR]=0.61, 95% confidence interval [CI]: 0.46-0.80, p=0.007; HR=0.72, 95% CI: 0.56-0.91, p=0.007; and HR=0.77, 95% CI: 0.59-0.99, p=0.04, respectively). In the multivariate regression analysis, the TAPSE/PASP ratio, body mass index, and six-minute walk distance were the predictors of mortality (HR=0.49, 95% CI: 0.34-0.70, p=0.004; HR=0.71, 95% CI: 0.51-0.97, p=0.03; and HR=0.71, 95% CI: 0.54-0.94, p=0.01, respectively).Through the maximal selective rank test, the optimal threshold value for TAPSE/PASP ratio was found to be 0.29 mm/mmHg. Patients with TAPSE/PASP >0.29 mm/ mmHg had an average life expectancy of 47.8 months, while the patients with TAPSE/PASP <0.29 mm/mmHg had an average life expectancy of 17.2 months.

Conclusion: Our study results suggest that a TAPSE/PASP ratio of <0.29 mm/mmHg is a poor prognostic factor for long-term mortality in patients on the waiting list for lung transplantation.