Background: Idiopathic pulmonary fibrosis (IPF) can lead to the development of pulmonary hypertension, which is associated with an increased risk of death. In pulmonary arterial hypertension, survival is directly related to the capacity of the right ventricle to adapt to elevated pulmonary vascular load. The relative importance of right ventricular function in IPF is not well understood. Our objective was to evaluate right ventricular echocardiographic and hemodynamic predictors of mortality in a cohort of patients with IPF referred for lung transplant evaluation.
Methods: We performed a retrospective cohort study of 135 patients who met 2011 American Thoracic Society/European Respiratory Society criteria for IPF and who were evaluated for lung transplantation at the Hospital of the University of Pennsylvania.
Results: Right ventricle:left ventricle diameter ratio (hazard ratio [HR], 4.5; 95% CI, 1.7-11.9), moderate to severe right atrial and right ventricular dilation (HR, 2.9; 95% CI, 1.4-5.9; and HR, 2.7; 95% CI, 1.4-5.4, respectively) and right ventricular dysfunction (HR, 5.5; 95% CI, 2.6-11.5) were associated with an increased risk of death. Higher pulmonary vascular resistance was also associated with increased mortality (HR per 1 Wood unit, 1.3; 95% CI, 1.1-1.5). These risk factors were independent of age, sex, race, height, weight, FVC, and lung transplantation status. Other hemodynamic indices, such as mean pulmonary artery pressure and cardiac index, were not associated with outcome.
Conclusions: Right-sided heart size and right ventricular dysfunction measured by echocardiography and higher pulmonary vascular resistance by invasive hemodynamic assessment predict mortality in patients with IPF evaluated for lung transplantation.