Intraoperative hypotension did not have an impact on the development of adverse outcomes after off-pump coronary artery bypass grafting: a retrospective study.

PURPOSE: There are few reports on the relationship between intraoperative hypotension and adverse events after off-pump coronary artery bypass (OPCAB). We examined whether hypotension during OPCAB was associated with postoperative adverse events.

METHODS: This single-center retrospective observational study included adult patients who underwent OPCAB and entered the ICU. Vital signs including intraoperative blood pressure were extracted every minute from the electronic anesthesia record. Data on adverse events including AKI, delirium and new-onset atrial fibrillation occurring during the ICU stay and up to the fourth postoperative day were collected.

RESULTS: Sixty-three of 255 patients in the analysis developed postoperative adverse outcomes. Left ventricular ejection fraction (LVEF) was significantly lower in patients who experienced adverse events, and other patient background factors before surgery were not significantly different between the patients with and without postoperative adverse outcomes. Intraoperative data were comparable between the two groups. Univariate logistic regression analysis revealed that MAP < 55 mmHg for ≥ 6 min and MAP < 65 mmHg for ≥ 40 min were associated with postoperative adverse outcomes. However, the multivariate logistic regression analyses revealed that intraoperative MAP was not an independent explanatory factor for postoperative adverse events. LVEF < 50% and preoperative Hb < 14 g/dL were independent explanatory factors in the multivariate models.

CONCLUSIONS: Intraoperative hypotension during OPCAB was not associated with the development of postoperative adverse events, and preoperative LVEF and Hb level were associated with postoperative adverse events. Intraoperative low MAP reflected the case severity and patient vulnerability rather than acting as a mediator of postoperative complications.