Association Between Preoperative Myocardial Perfusion Imaging and Cardiac Events after Elective Noncardiac Surgery

BackgroundThere remains a lack of robust evidence regarding the prognostic value of myocardial perfusion imaging (MPI) before noncardiac surgery in large and diverse patient populations. MethodsThis retrospective observational cohort study from single, tertiary, high surgical volume center in South Korea included 82,441 patients aged >40 years who underwent MPI using pharmacologic stress single photon emission computed tomography within 6 months before elective noncardiac surgery from January 2000 to December 2021. Results of MPI were classified as abnormal (any fixed or reversible perfusion defect) vs normal MPI before noncardiac surgery. The primary outcome was a composite of cardiac death or myocardial infarction within 30 days. ResultsAmong the 82441 patients (mean{+/-}standard deviation age, 65.7{+/-}9.6 years; 47417 [57.5%] men), 184 (0.2%) experienced cardiac death or myocardial infarction within 30 days after noncardiac surgery. MPI were abnormal in 5603 patients (6.8%). Compared with a normal MPI, an abnormal MPI had a higher risk of the primary outcome (crude incidence, 1.2% vs 0.1%; adjusted odds ratio, 4.64; 95% confidence interval, 3.29-6.50; P<.001). The presence of an abnormal MPI improved discrimination for the primary outcome (area under the receiver operating characteristic curve with MPI vs without MPI (0.77 vs 0.73; P<0.001)) and significantly increased net reclassification improvement (0.26; 95% confidence interval, 0.11-0.40; P<.001). Among patients with an abnormal MPI, 378 (6.7%) underwent pre-operative coronary revascularization; however, this was not associated with a lower risk of the primary outcome (P=.56). ConclusionAn abnormal myocardial perfusion imaging appeared to be an important risk factor for adverse postoperative events and provided additional prognostic value for patients undergoing noncardiac surgery. Nevertheless, preoperative MPI was limited by its low positive predictive value for postoperative cardiac events, leading to potentially unnecessary coronary revascularization procedures with unproven prognostic value. Clinical Perspectives What is new?This study included the largest population to date and included a broad spectrum of patient and surgical procedures compared with previous studies limited by relatively small sample sizes and low event rates. Preoperative abnormal MPI results were significantly associated with the postoperative risk of cardiac death and myocardial infarction in patients undergoing noncardiac surgery, and provided incremental prognostic value beyond clincial assement only. What are the clinical implications?O_LIur study suggested that MPI appears warranted, particularly for patients with a considerable surgical risk. C_LIO_LIHowever, its low positive predictive value, and unproven prognostic value of coronary revascularization triggered by MPI should be taken into account in the clincial practice. C_LI