Moderate walking speed and survival association across 23-years follow-up in female patients with cardiovascular disease

Aims: To estimate the association between average walking speed (WS), determined using a moderate 1-km treadmill-walking test (1 k-TWT), and all-cause mortality in female patients with stable cardiovascular disease (CVD). Methods: A sample of 431 patients (age 67 [34-88] years), performed a 1 k-TWT and were followed for all-cause mortality for up to 23 years. Variables significantly associated with mortality were determined by Cox proportional hazard models. Based on average WS during the 1k_TWT the sample was subdivided into tertiles, and mortality risk was calculated. Receiver-operating-characteristic curves were constructed to assess the discriminatory accuracy of WS for estimating survival. Results: During a median follow-up of 10.4 years, a total of 135 deaths from any cause occurred, with an average mortality rate of 4.2%. The strongest predictor of mortality was WS (c-statistic for all-cause mortality 0.801, 95% confidence intervals: 0.51-1.11, p < 0.0001). Survival rate decreased from the fastest to the lowest tertile. Compared to the group with the lowest WS, the hazard ratios (95% confidence intervals) for the second and third tertiles were 0.73 (0.48-1.12) and 0.47 (0.25-0.91), respectively (p for trend <0.0001). Conclusion: Average WS maintained during a moderate treadmill-walk is inversely related to survival in female patients with CVD. The 1 k-TWT is a simple and useful tool for assessing progress and stratifying risk in women undergoing secondary prevention programs.