Intraoperative Cardiac Events During Pediatric Cardiac Magnetic Resonance Imaging Under Anesthesia: A Retrospective Cohort Study.

BACKGROUND

Children with congenital heart disease (CHD) frequently undergo cardiac magnetic resonance imaging (MRI) under anesthesia. Although these procedures lack surgical stimulus, patients remain physiologically vulnerable, and the incidence of perioperative cardiovascular instability in this setting is poorly defined. We aimed to determine the incidence and predictors of intraoperative cardiac events during pediatric cardiac MRI using a recently proposed composite framework of intraoperative cardiovascular instability.

METHODS

This single-center retrospective cohort study analyzed patients ≤ 18 years undergoing cardiac MRI under anesthesia from 2013 to 2025. The primary outcome was intraoperative cardiac events, defined as ≥ 5 cumulative minutes with mean arterial pressure > 2 standard deviations below age- and sex-adjusted reference values, vasopressor administration, or severe adverse cardiac events. Multivariable logistic regression identified independent predictors. Thirty-day mortality was evaluated descriptively.

RESULTS

Among 330 cases, intraoperative cardiac events occurred in 29.7% (98/330). Hypotension was most common (24.2%), followed by vasopressor administration (9.7%); no severe adverse cardiac events were observed. Thirty-day mortality was 1.8% (6/330). Independent predictors included increasing age (OR 1.13 per year, 95% CI: 1.04-1.21), and higher-acuity preoperative location, including neonatal intensive care unit (ICU) (OR 4.42, 95% CI: 1.86-10.52) and pediatric ICU (OR 4.84, 95% CI: 1.91-12.26). Sensitivity analyses demonstrated consistent findings across model specifications.

CONCLUSIONS

Intraoperative cardiac events, primarily hypotension of unknown significance, were common during pediatric cardiac MRI under anesthesia; no severe adverse cardiac events occurred. Our findings highlight the physiologic complexity of this population and support the need for thoughtful perioperative risk stratification and management.