Six-minute walking test and long term prognosis in patients with asymptomatic aortic valve stenosis.
Study Goal
The researchers aimed to determine whether the 6-minute walking test (6MWT) could predict all-cause and cardiovascular mortality in asymptomatic patients with aortic valve stenosis.
Results Summary
The study found that shorter walking distances (≤390m) during the 6MWT were associated with higher risks of all-cause and cardiovascular mortality, while longer distances (>465m) were linked to no cardiovascular deaths. Each additional 100m walked reduced all-cause mortality risk by 35%.
Population
Asymptomatic patients with aortic valve stenosis (peak velocity >2.5m/s and left ventricular ejection fraction >50%; 85 males; aged 72±8 years).
Effective Dosage
Not applicable (6MWT performance assessed, not a dosage).
Duration
Median follow-up of 5.5 years (IQR 4.5-6.3).
Interactions
None mentioned
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
6-minute walking test (6MWT) | increase | all-cause mortality | asymptomatic patients with aortic valve stenosis | - | is an independent predictor of | #1 |
6-minute walking test (6MWT) | increase | cardiovascular mortality | asymptomatic patients with aortic valve stenosis | - | is an independent predictor of | #2 |
short distance in 6MWT (≤390m) | increase | all-cause mortality | asymptomatic patients with aortic valve stenosis | HR: 2.44; 95% CI: 1.05-5.67; p=0.04 | were at higher risk of | #3 |
short distance in 6MWT (≤390m) | increase | cardiovascular mortality | asymptomatic patients with aortic valve stenosis | HR: 6.12; 95% CI: 1.18-31.83; p=0.03 | were at higher risk of | #4 |
every 100m covered in 6MWT | decrease | risk of all-cause mortality | asymptomatic patients with aortic valve stenosis | by 35% (HR: 0.65; 95% CI: 0.43-0.99; p=0.04) | decreased | #5 |
long distance in 6MWT (>465m) | no change | cardiovascular deaths | asymptomatic patients with aortic valve stenosis | - | did not experience | #6 |
6-minute walking test (6MWT) | neutral | echocardiographic evaluation | asymptomatic patients with aortic valve stenosis | - | is of incremental value to | #7 |
BACKGROUND: Management of asymptomatic patients with aortic valve stenosis is challenging due to the elusive relationship between symptomatic status and hemodynamic parameters in addition to the occurrence of cardiovascular death. The 6-minute walking test (6MWT) reflects overall hemodynamic function and could contribute to risk assessment in such patients. METHODS AND RESULTS: One hundred sixteen asymptomatic patients (peak velocity>2.5m/s and left ventricular ejection fraction >50% assessed by echocardiographic screening; 85 males; aged 72±8years) underwent clinical workup, transthoracic echocardiography and a 6MWT. The mean distance covered by patients able to perform the 6MWT (n=107) was 422±90m. Patients were grouped in tertiles according to distance covered in the 6MWT: Short, intermediate and long distance patients. During a median follow-up of 5.5years (IQR 4.5-6.3), 29 (25%) patients died, 10 (9%) from cardiovascular causes. Multivariate analysis revealed that short distance patients (≤390m) were at higher risk of all-cause mortality (HR: 2.44; 95% CI: 1.05-5.67; p=0.04) and cardiovascular mortality (HR: 6.12; 95% CI: 1.18-31.83; p=0.03). For every 100m covered, the risk of all-cause mortality decreased by 35% (HR: 0.65; 95% CI: 0.43-0.99; p=0.04). Long distance patients (>465m) did not experience cardiovascular deaths during follow-up. CONCLUSIONS: In asymptomatic patients with aortic valve stenosis, the 6MWT is an independent predictor of all-cause and cardiovascular mortality. It is of incremental value to the echocardiographic evaluation, suggesting that the 6MWT might be useful to guide clinical follow-up intervals and treatment strategy.