Abstract
BACKGROUND: Data on right ventricular (RV) exercise adaptation following acute intermediate and high-risk pulmonary embolism (PE) remain limited. This study aimed to evaluate the symptom burden, RV functional recovery during exercise and cardiopulmonary exercise parameters in survivors of intermediate and high-risk acute PE. METHODS: We prospectively recruited patients following acute intermediate and high-risk PE at four sites in Australia and UK. Study assessments included stress echocardiography, cardiopulmonary exercise testing (CPET) and ventilation-perfusion (VQ) scan at 3 months follow-up. RESULTS: Thirty patients were recruited and 24 (median age: 55 years, IQR: 22) completed follow-up. Reduced peak oxygen consumption (VO(2)) and workload was seen in 75.0% (n=18), with a persistent high symptom burden (mean PEmb-QoL Questionnaire 48.4±21.5 and emPHasis-10 score 22.4±8.8) reported at follow-up. All had improvement in RV-focused resting echocardiographic parameters. RV systolic dysfunction and RV to pulmonary artery (PA) uncoupling assessed by stress echocardiography was seen in 29.2% (n=7) patients and associated with increased ventilatory inefficiency (V̇E/V̇CO(2) slope 47.6 vs 32.4, p=0.03), peak exercise oxygen desaturation (93.2% vs 98.4%, p=0.01) and reduced peak oxygen pulse (p=0.036) compared with controls. Five out of seven patients with RV-PA uncoupling demonstrated persistent bilateral perfusion defects on VQ scintigraphy consistent with chronic thromboembolic pulmonary vascular disease. CONCLUSION: In our cohort, impaired RV adaptation on exercise was seen in almost one-third of patients. Combined stress echocardiography and CPET may enable more accurate phenotyping of patients with persistent symptoms following acute PE to allow timely detection of long-term complications.