Delirium after Aortic Arch Surgery with Hypothermic Circulatory Arrest: Clinical and Neuroimaging Insights from the GOT ICE Randomized Trial.

Background

Postoperative delirium (POD) is a complication of arch surgery with hypothermic circulatory arrest (HCA) and may contribute to long-term cognitive decline, but prospective data are limited. We examined its incidence, predictors, and neurocognitive and neuroimaging correlates.

Methods

The Cognitive Effects of Body Temperature During Hypothermic Circulatory Arrest trial compared deep versus moderate hypothermia during elective arch repair. Delirium was assessed preoperatively and on postoperative days 1-3 using the Confusion Assessment Method. Thirty-day outcomes, cognition, quality of life, and resting-state functional magnetic resonance imaging at 4 weeks and 1 year were compared by POD status.

Results

Of 269 patients with complete assessments, POD occurred in 34.6% and did not differ significantly between hypothermia groups (p=0.45). Patients with POD had higher stroke rates (9.7% vs 0.6%; p<0.001), prolonged ventilation (3.2% vs. 0%; p=0.017), and longer hospitalization (8.5 vs. 5.9 days; p<0.001). Affected patients had worse cognition and quality of life (p<0.001) at 30 days, with partial recovery at 1 year. Baseline imaging demonstrated reduced thalamo-cerebellar connectivity in patients who developed POD (p<0.01, p-FWE<0.05), with persistent abnormalities at 1-year. Higher baseline cognition and ejection fraction were protective against POD (OR<1), whereas longer antegrade cerebral perfusion time increased risk (OR 1.03; 95% CI, 1.005-1.05; p=0.019).

Conclusions

POD affects >one-third of patients after arch surgery with HCA and is associated with worse 30-day and 1-year cognitive outcomes with enduring imaging abnormalities. Reduced preoperative thalamo-cerebellar connectivity suggests a preexisting neural vulnerability, indicating that delirium may unmask rather than cause long-term cognitive decline.