Hyperlipidemia and Postoperative Hallucinations After Cardiac Surgery: Insights from the VAACS Cohort Study

To evaluate the cumulative incidence and predictors of postoperative visual and auditory hallucinations among hyperlipidemic and normolipidemic patients undergoing cardiac surgery, with a particular focus on lipid indices, especially the low-density lipoprotein/high-density lipoprotein (LDL/HDL) ratio.

Multicenter, prospective cohort study with daily postoperative assessments from days 1-4 and follow-up to day 7, using Kaplan-Meier estimation and multivariable Cox proportional hazards regression.

Ten tertiary cardiac surgery centers across the West Bank of Palestine.

Adults (≥18 years) undergoing coronary artery bypass grafting or valve surgery (N = 1,332), stratified as hyperlipidemic (n = 448) or normolipidemic (n = 884) according to preoperative lipid profiles. Patients with incomplete records, cognitive impairment, language barriers, or psychiatric illness were excluded.

None (observational study).

Postoperative hallucinations were assessed using the validated Questionnaire for Psychotic Experiences. By day 7, visual hallucinations occurred in 11.2% of hyperlipidemic and 10.3% of normolipidemic patients, while auditory hallucinations occurred in 7.1% and 6.3%, respectively. The LDL/HDL ratio independently predicted both visual and auditory hallucinations in hyperlipidemic (visual: adjusted hazard ratio [aHR] 1.136, p = 0.016; auditory: aHR 1.146, p = 0.017) and normolipidemic (visual: aHR 1.123, p = 0.038; auditory: aHR 1.110, p = 0.047) cohorts. Longer aortic cross-clamp time increased visual hallucination risk (aHR 1.007; p = 0.015), while intraoperative fentanyl exposure reduced both visual (aHR 0.435; p = 0.011) and auditory (aHR 0.377; p = 0.023) hallucinations. A critical preoperative state predicted auditory hallucinations in hyperlipidemic patients (aHR 3.904; p = 0.001).

Elevated LDL/HDL ratio is a significant predictor of postoperative hallucinations. Integrating lipid profile evaluation into perioperative risk assessment may enhance neuropsychiatric outcomes following cardiac surgery.