Feasibility of Serial 6-min Walk Tests in Patients with Acute Heart Failure

Background: Functional status assessment is common in many cardiovascular diseases but it has undergone limited study in the setting of acute heart failure (AHF). Accordingly, we performed a pilot study of the feasibility of the six-minute walk test (6MWT) at the emergency department (ED) presentation and through the hospitalization in patients with AHF. Methods and Results: From November 2014 to February 2015, we conducted a multicenter, observational study of ED patients, aged 18–85 years, whose primary ED admission diagnosis was AHF. Other criteria for enrollment included a left ventricular ejection fraction ≤40%, systolic blood pressure between 90 and 170 mmHg, and verbal confirmation that the patient was able to walk >30 m at the baseline, prior to ED presentation. Study teams were uniformly trained to administer a 6MWT. Patients underwent a baseline 6MWT within 24 h of ED presentation (Day 1) and follow-up 6MWTs at 24 (Day 2), 48 (Day 3), and 120 h (Day 5). A total of 46 patients (65.2% male, 73.9% African American) had a day one mean walk distance of 137.3 ± 78 m, day 2 of 170.9 ± 100 m, and day 3 of 180.8 ± 98 m. The 6MWT demonstrated good reproducibility, as the distance walked on the first 6MWT on Day 3 was similar to the distance on the repeated 6MWT the same day. Conclusions: Our pilot study demonstrates the feasibility of the 6MWT as a functional status endpoint in AHF patients. A larger study in a more demographically diverse cohort of patients is necessary to confirm its utility and association with 30-day heart failure (HF) events.