Cardiopulmonary exercise testing and echocardiography in the follow-up after acute pulmonary embolism

Abstract Background Echocardiography and cardiopulmonary exercise testing (CPET) can both provide prognostically relevant information during the follow-up after pulmonary embolism (PE). Objective To investigate the association of cardiopulmonary exercise limitation, as assessed by CPET, with the tricuspid regurgitation velocity (TRV) and probability of pulmonary hypertension (PH) as estimated by echocardiography after PE. Methods In a prospective cohort study, consecutive unselected survivors of acute PE underwent 3-month and 12-month follow-up, including echocardiography and CPET. We defined cardiopulmonary exercise limitation from CPET as at least one of VE/VCO2-slope ≥ 30 (≥ 36 for severe), or VE/VCO2-nadir ≥ 30 (≥ 36 for severe), peak O2 pulse < 80% of the predicted value (< 70% for severe). Echocardiographic probability of PH was defined according to the 2022 ESC/ERS PH Guidelines. Results Overall, 395 patients were included in the analysis. On CPET performed at 3 months, cardiopulmonary exercise limitation was found in 180/360 patients (50.0%; 34.7% mild/moderate; 15.3% severe), and at 12 months in 119/267 patients (44.5%; 28.8% mild/moderate; 15.7% severe). On echocardiography at 3 months, high probability was found in 13/360 patients (3.6%) and intermediate in 60/360 patients (16.7%); at 12 months, it was 10/267 (3.8%) and 36/267 (13.5%), respectively. TRV >2.8 m/s (Figure 1A) and high echocardiographic probability of PH (Figure 1B) were both significantly more prevalent among patients with severe cardiopulmonary limitation (both p <0.001 ). For patients who had measurable and quantified TRV values (n = 246 patients), TRV was significantly weakly/moderately associated with VE/VCO2 slope and VE/VCO2 nadir, but not associated with O2 pulse (Figure 2). Conclusion Abnormal exercise capacity of cardiopulmonary origin is frequent after PE and was associated with high echocardiographic probability of PH. Still, 67% of patients with severe cardiopulmonary limitation after PE exhibit low echocardiographic probability PH, thus supporting the argument to upgrade the role of CPET in the follow-up of patients after acute PE.Figure 1Figure 2