Patients undergoing cardiac surgery with intraoperative neuromonitoring had higher stroke and mortality rates in unmatched analyses, reflecting their elevated baseline risk profiles, but these differences were no longer statistically significant after adjusting for risk factors, according to a recent study.

In the observational cohort study, published in Open Heart, investigators evaluated the impact of intraoperative neuromonitoring (IONM) on stroke and mortality during coronary and valvular heart surgeries. They analyzed the data from 19,299 patients treated between 2010 and 2021, with 589 (3.1%) undergoing IONM, which utilized electroencephalography and somatosensory-evoked potentials for real-time neurologic monitoring.

Patients undergoing IONM were more likely to have preexisting cerebrovascular disease (60% vs 22%) and higher operative risks, reflected in unmatched analyses showing increased rates of stroke (4.9% vs 1.9%) and mortality (5.3% vs 2.5%). After propensity score matching to adjust for baseline risk factors, these differences were no longer statistically significant. Stroke occurred in 3.7% of the patients undergoing IONM compared with 5.4% of those without IONM, and operative mortality was 3.6% vs 5.3%, respectively. The long-term survival rates were similar between groups, with 5-year survival rates of 70.4% among the patients undergoing IONM and 71.9% among those without IONM (P = .419).

The findings suggested that IONM could serve as a potential biomarker for identifying patients at elevated neurologic risk rather than independently improving outcomes. In high-risk patients, IONM facilitated intraoperative interventions such as optimizing cerebral perfusion or repositioning bypass cannulas, which may have mitigated neurologic injury. While the study did not demonstrate improved outcomes directly attributable to IONM, the results underscored its utility in managing neurologic risks and highlighted the need for further prospective studies to validate its efficacy and establish standardized protocols.

Full disclosures can be found in the published study.