Abstract
AIMS: This study aimed to investigate the association between the time to achieve walkability after cardiac surgery and the risk of cardiovascular disease after hospital discharge. METHODS: We conducted a prospective cohort study involving 553 ambulatory patients aged 71.5 (range, 64.0-77.0) years who underwent cardiac surgery. All patients were divided into five groups based on the time to achieve walkability ≥100 m within 1, 2, 3, 4 or 5 days after cardiac surgery. We examined the risk of post-cardiovascular disease outcomes, including readmission due to heart failure, ischaemic heart disease and other cardiovascular disease, according to the time to achieve walkability with reference to 5 days using the Fine and Gray regression model, considering competing risks. RESULTS: In the survival curve analysis, we examined the time to experience post-cardiovascular disease incidence after hospital discharge. During a median of 3.3 years of follow-up, 118 patients developed cardiovascular disease. We observed a positive association between the time to achieve walkability and cardiovascular disease risk, particularly heart failure. The multivariate hazard ratios (95% confidence intervals) for heart failure readmission were N/A (not assessed due to the sample size being too small) for 1 day, 0.31 (0.10-0.99) for 2 days, 0.60 (0.21-1.79) for 3 days and 0.76 (0.22-2.72) for 4 days (P for trend = 0.032). CONCLUSIONS: The shorter walkability achievement time was associated with a lower risk of cardiovascular diseases, more specifically heart failure readmission, among patients who underwent cardiac surgery. The time required to achieve walkability is a useful predictor for cardiovascular diseases after hospital discharge.