Abstract 12257: Preinduction Heart Rate and In-hospital Mortality Following Coronary Artery Bypass Revascularization

Abstract

Background: This study reviews the effect of preoperative beta-blocker therapy to reduce the pre-induction heart rate in coronary artery bypass graft surgery (CABG).

Study Objectives: To examine patterns of use of preoperative beta-blockers in patients undergoing CABG and to determine if an association exists between lower preinduction heart rates and in-hospital mortality.

Design: Retrospective, multi-center, observational study using the STS National Adult Cardiac Surgery Database to assess preinduction heart rate and outcomes in patients who undergo elective primary CABG procedures between January 1, 2004 and December 31, 2007 (n=13,232) in 27 cardiac surgery centers located in the United States.

Methods: Data were collected on 13,232 CABG patients discharged between Jan. 1, 2004 and Dec. 31, 2007 at 27 hospitals located throughout the US. Data were divided into 5 groups according to patient's pre-induction heart rate category (HR 40–60, 61–70, 71–80, 81–90, >90). The mortality rates were adjusted by patient characteristics (age, sex, BSA), prior cardiac surgery, presence of COPD, diabetes, PVD, CHF, renal failure, LVEF and acuity of surgery. Logistic regression analysis was used to calculate the adjusted in-hospital mortality rates by pre-induction heart rate categories.

Data Analysis: Among 13,232 patients, there were 337 deaths (2.6%). Around 15.9% of patients had pre-induction heart rates greater than 80/bpm. Preoperative beta-blockade use declined by 15.5% across ordered preinduction heart rate groups. Crude mortality was significantly higher among patients with increased preinduction heart rate (p-trend = <0.001). After adjustment for baseline differences among patients, preinduction heart rate > or = 80 bpm remained associated with increased mortality (p-trend < 0.001). Further investigation concerning the effect of intraoperative treatment of increased heart rate with beta-adrenergic blockers on mortality after CABG surgery is warranted.

Conclusions: Decreased use of beta-blocker therapy and an increased pre-induction heart rate were associated with increased in- hospital mortality and this association persisted after adjustment for a variety of patient and disease characteristics.