'Post-Pulmonary Embolism Syndrome' after a First Episode of PE: Results of the E.L.O.P.E. Study

Background: Most pulmonary embolism (PE) research has focused on acute and short-term outcomes such as mortality and PE recurrence. Whether long-term morbidity such as exercise limitation, impaired quality of life (QOL) and persistent dyspnea occurs after PE is largely unstudied. To address this knowledge gap, we performed the ELOPE study, a prospective, observational, multicenter cohort study of long-term outcomes after acute PE (www.clinicaltrials.gov NCT01174628). Objectives: The objectives of the ELOPE (Evaluation of Long-term Outcomes after PE) Study were: (1) to describe and quantify degree of exercise limitation, QOL impairment and persistent dyspnea at 1 year after PE; and (2) to identify predictors of poor functional status at 1 year. Methods: Patients ≥18 years old with a 1st episode of acute PE diagnosed within the previous 10 days screened at 5 Canadian recruiting centers were potentially eligible to participate. Exclusion criteria were subsegmental-only PE, preexisting severe cardiopulmonary comorbidity, previous proximal DVT, contraindication to CT pulmonary angiography (CTPA), life expectancy After the Baseline (B) visit, patients attended follow-up (FU) visits at 1, 3, 6 and 12 months to measure QOL (SF-36, PEmbQoL), dyspnea (UCSD SOBQ), and 6-minute walk test (6MWT) [all FU visits]; undergo CTPA [B, 12], echocardiogram [B, 12], Q scan [6, 12], cardiopulmonary exercise testing (CPET) [1, 12] and pulmonary function tests [1, 12]; and measure biomarkers (BNP, ddimer, troponin) [B, 6]. The primary study outcome was maximal aerobic capacity defined by peak oxygen uptake (VO2) as a percent of predicted maximal VO2 (VO2max) on 1-year CPET, with For the present analysis, we summarized demographic and clinical characteristics of study subjects, the proportion of patients with VO2max Results: 984 patients were screened for participation; of these, 150 were eligible and 100 (67%) consented to participate. Mean (SD) age was 50 (15) years, 57% were male, 80% were outpatients and 33% had concomitant DVT. PE was provoked in 21% and unprovoked in 79%; none were cancer-related. At 1 year, 40/86 (46.5%) of patients had 80% predicted VO2max at 1 year. Independent baseline predictors of abnormal VO2max at 1 year included: male sex (relative risk (RR)= 3.2 [95% CI 1.3-8.1]; p=0.015), age (RR 0.98 [95% CI 0.96-0.99] per 1 year age increase; p=0.002), BMI (RR 1.1 [95% CI 1.01-1.2] per 1 kg/m2 BMI increase; p=0.023), and smoker (RR 1.8 [95% CI 1.1-2.9]; p=0.023). In addition, VO2max Conclusions: PE is a common and serious cardiovascular illness, yet clinically relevant information on characteristics and determinants of long-term outcome after PE have been lacking. Results of the ELOPE Study indicate that almost half of PE patients can be considered to have a "post-PE syndrome" characterized by exercise limitation at 1 year, which influences their QOL and degree of dyspnea. Predictors of this post-PE syndrome include male sex, younger age, higher BMI and smoking. CPET testing or 6MWT testing at 1 month may help to identify patients with a higher risk of post-PE syndrome at 1 year. Funding: Canadian Institutes of Health Research (MOP-93627) Disclosures Wells: Bayer: Honoraria; BMS/Pfizer: Research Funding.