Risk of mortality following surgery in patients with a previous cerebrovascular accident or acute coronary syndrome: a 10-year database linkage between Hospital Episode Statistics, Myocardial Infarction National Audit Project, and Office for National Statistics

Importance: There is a lack of consensus regarding the interval of time-dependent postoperative mortality risk following an 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: This is a longitudinal retrospective population-based cohort study.Setting: This study linked data from the Hospital Episode Statistics for NHS England, Myocardial Ischaemia National Audit Project and Office for National Statistics mortality registry.Participants: All adults undergoing a National Health Service-funded non-cardiac non-neurologic surgery in England between April 1, 2007, and March 31, 2018, registered in Hospital Episode Statistics Admitted Patient Care.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. The 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. Among patients with a previous cardiovascular event, the time interval associated with increased risk of postoperative mortality was surgery within 11.3 (95%CI 10.8-11.7) months, with subgroup risks of 14.2 (95%CI 13.3-15.3) months before elective surgery and 7.3 (95%CI 6.8-7.8) months for emergency surgery. Heterogeneity in these timings was noted across many surgical specialities. The time-dependent risk intervals following stroke and myocardial infarction were similar, but 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 (aHR = 1.35; 95%CI 1.34-1.37) and an elective procedure (aHR = 1.83; 95%CI 1.78-1.89) than ...