Predictive Capability of Cardiopulmonary and Exercise Parameters From Day 1 to 6 Months After Acute Pulmonary Embolism

Performance-based outcome measures for assessing physical capacity in patients with pulmonary embolism: A scoping review

INTRODUCTION

Up to 50 % of patients surviving a pulmonary embolism (PE) report persisting shortness of breath, reduced physical capacity and psychological distress. As the PE population is heterogeneous compared to other cardiovascular patient groups, outcome measures for assessing physical capacity traditionally used in cardiac populations may not be reliable for the PE population as a whole. This scoping review aims to 1) map performance-based outcome measures (PBOMs) used for assessing physical capacity in PE research, and 2) to report the psychometric properties of the identified PBOMs in a PE population.

METHODS

The review was conducted according to the Joanna Briggs Institute framework for scoping reviews and reported according to the PRISMA-Extension for Scoping Reviews guideline.

RESULTS

The systematic search of five databases identified 4585 studies, of which 243 studies met the inclusion criteria. Of these, 185 studies focused on a subgroup of patients with chronic thromboembolic pulmonary hypertension. Ten different PBOMs were identified in the included studies. The 6-minute walk test (6MWT) and cardiopulmonary exercise test (CPET) were the most commonly used, followed by the (Modified) Bruce protocol and Incremental Shuttle Walk test. No studies reported psychometric properties of any of the identified PBOMs in a PE population.

CONCLUSIONS

Publication of studies measuring physical capacity within PE populations has increased significantly over the past 5-10 years. Still, not one study was identified, reporting the validity, reliability, or responsiveness for any of the identified PBOMs in a PE population. This should be a priority for future research in the field.

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

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.