Usefulness of measuring maximal gait speed in conjunction with usual gait speed for risk stratification in patients with cardiovascular disease.

Abstract

Usual gait speed is a prognostic factor in cardiovascular disease (CVD) patients; however, given the aging population, there has been an increase in patients with CVD with slow usual gait speed. Even among patients with slow usual gait speed, some can walk with sufficient speed during maximal gait, while others cannot. This study aimed to investigate the relationship between maximal gait speed and prognosis, and the utility of evaluating maximal gait speed in conjunction with usual gait speed in risk stratification of prognosis in patients with CVD. We included 2951 CVD patients who underwent evaluation of both usual and maximal gait speeds. They were classified into the usual (+) group [usual gait speed ≥1.0m/s], usual (-) and maximal (+) group [usual gait speed <1.0m/s and maximal gait speed ≥1.0m/s], and usual (-) and maximal (-) group [usual gait speed <1.0m/s and maximal gait speed <1.0m/s]. Slower maximal gait speed was significantly associated with higher mortality in CVD patients. This association was consistent across various subgroups. Maximal gait speed provided additional prognostic information to that of pre-existing prognostic factors and usual gait speed (P=0.048). The usual (-) and maximal (-) group showed higher mortality (hazard ratio: 1.63; 95% confidence interval: 1.18-2.27; P=0.003) than the usual (-) and maximal (+) group. There was no significant difference in mortality between the usual (+) group and the usual (-) and maximal (+) group. Maximal gait speed was an independent prognostic predictor for CVD patients. Evaluating maximal gait speed in conjunction with usual gait speed was useful for further risk stratification of prognosis in CVD patients.