Prognostic Relevance of Cardiopulmonary Exercise Testing for Patients with Chronic Thromboembolic Pulmonary Hypertension

Abstract

Background: Following acute pulmonary embolism (PE), a relevant number of patients experience decreased exercise capacity which can be associated with disturbed pulmonary perfusion. Cardiopulmonary exercise testing (CPET) shows several patterns typical for disturbed pulmonary perfusion. Research question: We aimed to examine whether CPET can also provide prognostic information in chronic thromboembolic pulmonary hypertension (CTEPH). Study Design and Methods: We performed a multicenter retrospective chart review in Germany between 2002 and 2020. Patients with CTEPH were included if they had ≥6 months of follow-up and complete CPET and hemodynamic data. Symptom-limited CPET was performed using a cycle ergometer (ramp or Jones protocol). The association of anthropometric data, comorbidities, symptoms, lung function, and echocardiographic, hemodynamic, and CPET parameters with survival was examined. Mortality prediction models were calculated by Cox regression with backward selection. Results: 345 patients (1532 person-years) were included; 138 underwent surgical treatment (pulmonary endarterectomy or balloon pulmonary angioplasty) and 207 received only non-surgical treatment. During follow-up (median 3.5 years), 78 patients died. The death rate per 1000 person-years was 24.9 and 74.2 in the surgical and non-surgical groups, respectively (p < 0.001). In age- and sex-adjusted Cox regression analyses, CPET parameters including peak oxygen uptake (VO2peak, reflecting cardiopulmonary exercise capacity) were prognostic in the non-surgical group but not in the surgical group. In mortality prediction models, age, sex, VO2peak (% predicted), and carbon monoxide transfer coefficient (% predicted) showed significant prognostic relevance in both the overall cohort and the non-surgical group. In the non-surgical group, Kaplan–Meier analysis showed that patients with VO2peak below 53.4% predicted (threshold identified by receiver operating characteristic analysis) had increased mortality (p = 0.007). Interpretation: The additional measurement of cardiopulmonary exercise capacity by CPET allows a more precise prognostic evaluation in patients with CTEPH. CPET might therefore be helpful for risk-adapted treatment of CTEPH.

Exercise Testing in Patients with Pulmonary Hypertension

“…In this prospective study of patients with acute PE, approximately 90% had evidence of ventilatory inefficiency and 30% had evidence of limited cardiocirculatory reserve. Importantly, the presence of ventilatory inefficiency following PE may speak to the development of chronic thromboembolic disease (CTED) and shed light on the potential role of follow-up imaging after PE and prognostication [19]. This has significant clinical implications, for this syndrome can often be treated with balloon pulmonary angioplasty (BPA) with improvements in CPET parameters includ-ing ventilatory insufficiency following this therapeutic intervention [20].…”

The association between O2-pulse slope ratio and functional severity of coronary stenosis: A combined cardiopulmonary exercise testing and quantitative flow ratio study

“…Cardiopulmonary exercise testing (CPET), a combination of exercise stress testing with ventilatory gas exchange measurements, has increasingly gained recognition for its utility in diagnosing the causes of unexplained dyspnea [7] , comprehensively assessing cardiac functions [8] , [9] , [10] , and predicting the prognosis of patients with heart disease [11] , [12] . More recently, CPET has gradually emerged as a widely used non-invasive evaluation method for myocardial ischemia in clinical practice.…”