Time Elapsed After Ischemic Stroke and Risk of Adverse Cardiovascular Events and Mortality Following Elective Noncardiac Surgery

IMPORTANCE The timing of surgery in patients with recent ischemic stroke is an important and inadequately addressed issue. OBJECTIVE To assess the safety and importance of time elapsed between stroke and surgery in the risk of perioperative cardiovascular events and mortality. DESIGN, SETTING, AND PARTICIPANTS Danish nationwide cohort study (2005-2011) including all patients aged 20 years or older undergoing elective noncardiac surgeries (n = 481 183 surgeries). EXPOSURES Time elapsed between stroke and surgery in categories and as a continuous measure. MAIN OUTCOMES AND MEASURES Risk of major adverse cardiovascular events (MACE; including ischemic stroke, acutemyocardial infarction, and cardiovascular mortality) and all-cause mortality up to 30 days after surgery. Odds ratios (ORs) were calculated by multivariable logistic regression models. RESULTS Crude incidence rates ofMACE among patients with (n = 7137) and without (n = 474 046) prior stroke were 54.4 (95% CI, 49.1-59.9) vs 4.1 (95% CI, 3.9-4.2) per 1000 patients. Compared with patients without stroke, ORs forMACE were 14.23 (95% CI, 11.61-17.45) for stroke less than 3 months prior to surgery, 4.85 (95% CI, 3.32-7.08) for stroke 3 to less than 6 months prior, 3.04 (95% CI, 2.13-4.34) for stroke 6 to less than 12 months prior, and 2.47 (95% CI, 2.07-2.95) for stroke 12 months or more prior. MACE risks were at least as high for low-risk (OR, 9.96; 95% CI, 5.49-18.07 for stroke < 3 months) and intermediate-risk (OR, 17.12; 95% CI, 13.68-21.42 for stroke < 3 months) surgery compared with high-risk surgery (OR, 2.97; 95% CI, 0.98-9.01 for stroke < 3 months) (P =.003 for interaction). Similar patterns were found for 30-day mortality: ORs were 3.07 (95% CI, 2.30-4.09) for stroke less than 3 months prior, 1.97 (95% CI, 1.22-3.19) for stroke 3 to less than 6 months prior, 1.45 (95% CI, 0.95-2.20) for stroke 6 to less than 12 months prior, and 1.46 (95% CI, 1.21-1.77) for stroke 12 months or more prior to surgery compared with patients without stroke. Cubic regression splines performed on the stroke subgroup supported that risk leveled off after 9 months. CONCLUSIONS AND RELEVANCE A history of stroke was associated with adverse outcomes following surgery, in particular if time between stroke and surgery was less than 9 months. After 9 months, the associated risk appeared stable yet still increased compared with patients with no stroke. The time dependency of risk may warrant attention in future guidelines. Copyright 2014 American Medical Association. All rights reserved.