Association of hemodynamic and functional variables with pulmonary vasculopathy in lung transplant recipients living at high altitude: A retrospective study

Abstract

ObjectivePulmonary hypertension is a heterogeneous syndrome with diverse underlying etiologies. This study aimed to evaluate the association between preoperative hemodynamic parameters-assessed by right heart catheterization (RHC) and transthoracic echocardiography (TTE)-and histopathological findings in explanted lungs from transplant recipients residing at high altitude.MethodsWe conducted a retrospective analysis of lung transplant recipients with interstitial lung disease (ILD) who had available RHC and TTE data prior to transplantation. Clinical, functional, hemodynamic, and histopathological variables were collected to assess the presence and severity of pulmonary vasculopathy. Bivariate analyses, correlation tests, and internally validated predictive models were performed to explore these associations.ResultsA total of 38 patients were included (median age: 54 years). The median mean pulmonary artery pressure (mPAP) was 33 mmHg, and the pulmonary artery systolic pressure (PASP) was 42 mmHg. An inverse correlation was observed between vasculopathy grade and the ratio of tricuspid annular plane systolic excursion to PASP (TAPSE/PASP) (r = -0.49, p = 0.007). Trends toward significance were found for percent predicted forced vital capacity (FVC%) (r = -0.30, p = 0.074) and catheter-derived PASP (r = 0.30, p = 0.070). A moderate positive correlation was noted between vasculopathy grade and echocardiographic mPAP (r = 0.41, p = 0.003). Among all parameters evaluated, the product of TAPSE and FVC% demonstrated the highest discriminative ability for vasculopathy (area under the receiver operating characteristic curve [AUC] = 0.790), followed by FVC% (AUC = 0.689) and TAPSE (AUC = 0.678).ConclusionsNoninvasive measures-particularly the TAPSE/PASP ratio and composite indices incorporating FVC%-demonstrate moderate correlation with histopathological evidence of pulmonary vasculopathy in ILD patients living at high altitude. These findings highlight the potential utility of noninvasive tools in the preoperative evaluation of pulmonary vascular disease in this population.

Keywords: Pulmonary hypertension; echocardiography; heart catheterization; interstitial lung disease; lung transplantation; pulmonary vasculopathy.

Figure 1.

Grades of vasculopathy in pulmonary arterial hypertension.

Figure 2.

Distribution of patients based on the grades of vasculopathy.

Figure 3.

Bland–Altman plot of pulmonary artery systolic pressure agreement between echocardiography and catheterization.

Figure 4.

Receiver operating characteristic curves for predicting histopathological vasculopathy.