Risk of Mortality Following Surgery in Patients With a Previous Cardiovascular Event

Importance There is a lack of consensus regarding the interval of time-dependent postoperative mortality risk following acute coronary syndrome or stroke. Objective To determine the magnitude and duration of risk associated with the time interval between a preoperative cardiovascular event and 30-day postoperative mortality. Design, Setting, and Participants This is a longitudinal retrospective population-based cohort study. This study linked data from the Hospital Episode Statistics for National Health Service England, Myocardial Ischaemia National Audit Project and the Office for National Statistics mortality registry. All adults undergoing a National Health Service-funded noncardiac, nonneurologic surgery in England between April 1, 2007, and March 31, 2018, registered in Hospital Episode Statistics Admitted Patient Care were included. Data were analyzed from July 2021 to July 2022. Exposure The time interval between a previous cardiovascular event (acute coronary syndrome or stroke) and surgery. Main Outcomes and Measures The primary outcome was 30-day all-cause mortality. Secondary outcomes were postoperative mortality at 60, 90, and 365 days. Multivariable logistic regression models with restricted cubic splines were used to estimate adjusted odds ratios. Results There were 877 430 patients with and 20 582 717 without a prior cardiovascular event (overall mean [SD] age, 53.4 [19.4] years; 11 577 157 [54%] female). Among patients with a previous cardiovascular event, the time interval associated with increased risk of postoperative mortality was surgery within 11.3 months (95% CI, 10.8-11.7), with subgroup risks of 14.2 months before elective surgery (95% CI, 13.3-15.3) and 7.3 months for emergency surgery (95% CI, 6.8-7.8). Heterogeneity in these timings was noted across many surgical specialties. The time-dependent risk intervals following stroke and myocardial infarction were similar, but the absolute risk was greater following a stroke. Regarding surgical urgency, the risk of 30-day mortality was higher in those with a prior cardiovascular event for emergency surgery (adjusted hazard ratio, 1.35; 95% CI, 1.34-1.37) and an elective procedure (adjusted hazard ratio, 1.83; 95% CI, 1.78-1.89) than those without a prior cardiovascular event. Conclusions and Relevance In this study, surgery within 1 year of an acute coronary syndrome or stroke was associated with increased postoperative mortality before reaching a new baseline, particularly for elective surgery. This information may help clinicians and patients balance deferring the potential benefits of the surgery against the desire to avoid increased mortality from overly expeditious surgery after a recent cardiovascular event.