The potential preventability of postoperative myocardial infarction: underuse of perioperative beta-adrenergic blockade.

BACKGROUND

Among selected patients undergoing major noncardiac surgery, beta-adrenergic blockade has been shown to reduce the risk for postoperative cardiac complications and mortality. We sought to determine how often postoperative MI might be considered preventable through appropriate use of these medications.

METHODS

We reviewed the medical records of patients who developed a postoperative MI between January 1, 1998, and October 31, 2001, at Baystate Medical Center, a 570-bed community-based teaching hospital in Springfield, Mass. We calculated a Revised Cardiac Risk Index score and used criteria from previous randomized trials to determine whether patients would have been candidates for perioperative beta-adrenergic blockade. Postoperative MI was considered potentially preventable if the patient appeared to have been an ideal candidate for beta-blocker therapy but did not receive it before the infarction. We compared the mortality of ideal candidates who did and did not receive beta-blockers before their infarction using multivariable logistic regression.

RESULTS

Seventy (97%) of the 72 patients who developed postoperative MI could have been identified as being at increased risk for cardiac complications, and 58 (81%) appeared to be ideal perioperative beta-blocker candidates. Thirty ideal candidates (52%) were treated with beta-blockers before the development of the infarction. Among ideal candidates, treatment with a beta-blocker before infarction was associated with an odds ratio of in-hospital mortality of 0.19 (95% confidence interval, 0.04-0.87).

CONCLUSIONS

A large percentage of the postoperative MIs at our institution might have been prevented if a beta-blocker had been administered to all ideal candidates around the time of surgery. Use of beta-blockers before infarction may reduces overall mortality, even among patients who go on to develop this complication.