Indirect Echocardiographic Signs of Increased Right-sided Afterload in Progressive Pulmonary Fibrosis: Insights from a Multicentre Italian Study

Purpose: Pulmonary vascular involvement is a determinant of worse outcomes in fibrotic lung diseases. Its prevalence and prognostic relevance in patients with progressive pulmonary fibrosis (PPF) is unknown. The aim of this study was to assess the prevalence of indirect echocardiographic abnormalities in progressive pulmonary fibrosis before antifibrotic therapy, characterize a baseline high-risk cardiopulmonary functional profile, and assess 12-month clinical trajectories. Methods: Observational, retrospective, multicentre study. Results: 158 patients (median (IQR) age of 71 (65.2-77.0) years) with PPF were enrolled. Thirty (19.0%) had ≥ 1 echocardiographic indirect sign of increased right-sided afterload, 15 (9.5%) ≥ 2, 9 (5.7%) ≥ 3 and 1 (0.6%) all four. A shortened right ventricular outflow tract acceleration time (< 105 ms) was the most frequent alteration (12.7%), followed by right atrial dilation (10.8%). In univariable analysis, ≥1 sign was associated with male sex, a lower DLCO% predicted, a higher FVC%/DLCO% ratio and a shorter 6MWD; in the multivariable model only, male sex remained independently associated (aOR 3.45, 95% CI 0.99-12.07; p = 0.052). Twelve-month FVC trajectories did not differ by baseline echocardiographic status; nonetheless, ≥1 sign was associated with shorter time to acute exacerbation (log-rank p = 0.007) and all-cause hospitalisation (p = 0.001). Conclusions: Echocardiographic signs suggestive of increased right-sided afterload are present in a substantial proportion of PPF patients at the time of antifibrotic initiation. They identified patients at higher risk of acute exacerbation and hospitalisation, regardless of FVC decline. This higher-risk subgroup warrants specific pulmonary vascular evaluation and tighter clinical follow-up.