Autonomic Vulnerability, Intraoperative Hypotension Burden, and Myocardial Injury after Noncardiac Surgery in Older Adults: A Propensity Score-Matched Retrospective Cohort Study

BACKGROUND:Myocardial injury after noncardiac surgery (MINS) is common and often clinically silent. Older adults with diabetes mellitus (DM) and/or hypertension (HTN) may have autonomic dysfunction that impairs hemodynamic compensation during surgical stress. We hypothesized that a preoperatively identifiable autonomic vulnerability phenotype would be associated with adjudicated ischemic MINS after major noncardiac surgery and that this association would be amplified at higher intraoperative hypotension (IOH) burden. METHODS:In this single-center retrospective cohort study, patients aged ≥65 years undergoing major noncardiac surgery with perioperative high-sensitivity cardiac troponin T (hs-cTnT) surveillance were analyzed. Autonomic vulnerability was defined as DM and/or HTN plus documented neuropathy, orthostatic hypotension or syncope/presyncope, or unexplained resting bradycardia/chronotropic incompetence. Propensity score matching (1:1) balanced measured confounders. The primary outcome was adjudicated ischemic MINS. Secondary outcomes included postoperative hs-cTnT elevation, 30-day major adverse cardiac events (MACE), 1-year all-cause mortality, and IOH effect modification. RESULTS:Among 2184 eligible patients, 612 matched pairs were analyzed. MINS occurred in 87 of 612 patients (14.2%) in the autonomic vulnerability group and 53 of 612 (8.7%) in the control group (odds ratio [OR], 1.75; 95% confidence interval [CI], 1.23-2.49; P = .002). Postoperative hs-cTnT elevation was also more frequent (27.1% vs 18.5%; OR, 1.63; 95% CI, 1.28-2.07; P < .001). Thirty-day MACE (hazard ratio [HR], 1.68; 95% CI, 1.12-2.51; P = .012) and 1-year mortality (HR, 1.54; 95% CI, 1.07-2.22; P = .020) were increased. IOH burden modified the autonomic vulnerability-MINS association (P for interaction = .018), with the highest excess risk in the highest IOH quartile (OR, 2.84; 95% CI, 1.62-4.97; P < .001). CONCLUSIONS:In older adults undergoing major noncardiac surgery, a preoperative electronic health record-based autonomic vulnerability phenotype was associated with higher risk of adjudicated ischemic MINS, and this association was stronger at higher IOH burden. These hypothesis-generating findings require external validation with formal autonomic testing.