Outpatient or inpatient treatment for acute pulmonary embolism: a retrospective cohort study of 439 consecutive patients

Current guidelines consider outpatient treatment as an option for low-risk pulmonary embolism (PE), and risk assessment tools such as the HESTIA criteria can be used to identify PE patients who could feasibly be treated in an outpatient setting. Little is known about what proportion of patients in daily care this would comprise, and, in these patients, outcome data outside of clinical trials are scarce. To assess the proportion of PE patients receiving outpatient early discharge or in-hospital therapy, evaluate differences in patient characteristics between these subgroups and to assess clinical outcomes at 6 months. Monocentric, retrospective cohort study in 439 consecutive patients undergoing outpatient, early-discharge or in-hospital treatment for PE. Outcome data on recurrent VTE, pulmonary hypertension or death were collected from routine follow-up visits 6 months after VTE diagnosis. PE patients were treated as outpatient (OP; n = 49; 11.2 %); early-discharge (ED; n = 62; 14.1 %) or in-hospital (IH; n = 328; 74.7 %). Median duration of hospital stay in the ED and IH groups were 1 (IQR: 1) day and 9 (IQR: 7) days, respectively. Outcome event rates at 6 months were 3.9 % for recurrent VTE (95 % CI 2.3-6.1, similar between groups), 5.2 % for pulmonary hypertension (95 % CI 3.3-7.8, similar between groups) and 10.7 % for mortality (95 % CI 8.0-14.0). Mortality was significantly higher in IH patients (14.0 %; 95 % CI 10.5-18.3) compared to OP (0 %; 95 % CI 0.0-7.3) or ED (1.6 %; 95 % CI 0.0-8.7) patients. Mortality risk factors were high-risk ESC category (OR: 5.7), paraneoplastic VTE (OR: 3.0), need for oxygen supplementation (OR: 5.2), diabetes (OR: 2.5), age (OR per additional year: 1.1) and elevated INR (OR per 0.1 point increase: 1.5). No difference in the treatment groups for pulmonary hypertension during follow-up was found. Independent risk factors were thrombophilia (OR: 8.43), signs of right ventricular strain in baseline ECG (OR: 6.64) or echocardiography (RVESP > 40 mmHg OR: 2.99). 32 % of the OP or ED patients had at least one criterion of the HESTIA score that would have excluded them from outpatient treatment. In daily care, treating PE in an almost exclusively outpatient setting seems feasible and safe for up to 25 % of all PE patients. The HESTIA criteria seem to exclude up to 30 % of patients for whom outpatient or early-discharge treatment seems feasible and safe.