AIMS: Individuals with cardiovascular disease (CVD) are more likely to become frail. However, no study has determined whether an incident CVD event alters frailty trajectories in older individuals. This study aims to determine the extent to which an incident CVD event modifies frailty trajectories and to identify factors that influence those changes. METHODS: 19,111 individuals (56.4%, women) ≥aged 65 years, who had no prior CVD event or other major health conditions at baseline, were followed for up to 11 years. Frailty was measured annually using the 64-item deficit-accumulation frailty index (FI) and Fried phenotype (Fried). Incident CVD events, including stroke, myocardial infarction and hospitalization for heart failure (HHF), were adjudicated by international experts. Linear mixed models were used to measure frailty changes. RESULTS: Over a median 8.3-year follow-up, frailty trajectories increased over time and 1934 incident CVD events occurred. Following a CVD event, individuals had a short-term increase in both FI (adjusted-betas: 3.65
95%CI, 3.34 to 3.96) and Fried (adjusted-beta: 0.32
95%CI, 0.26 to 0.38). Afterwards, only FI continued to increase over time (adjusted-beta: 0.41, 95%CI, 0.21 to 0.62). Among the CVD events, HHF and stroke were associated with the greatest increase in frailty. Of the factors examined, being >
80 years, women, living alone, or residing in regional/remote areas were associated with greater frailty burden. CONCLUSION: Our findings provide evidence that incident CVD event increases frailty burden, highlighting the need for targeted intervention to minimise frailty-related clinical complications for those most at risk.