Changing the Practice of Perioperative Cardioprotection

Beta-Blocker management in High-Risk Patients Presenting for Non-Cardiac Surgery: Before and after the POISE Trial

The POISE Trial was a randomised, placebo-controlled, double-blind study of the effectiveness of perioperative beta-blockade in preventing cardiac events including death in 8351 patients. Our hypothesis was that knowledge of the results of the POISE Trial would either increase or decrease the use of effective perioperative beta-blockade, depending on the result. Patients presenting for non-cardiac surgery and at risk of perioperative cardiac events were recruited in two cohorts before and after the release of the POISE Trial results. Effective perioperative beta-blockade was defined as heart rate <65 beats per minute for at least 80% of the perioperative period in patients prescribed beta-blockers. Effective perioperative beta-blockade was achieved in 22 (11.5%) of 191 patients prescribed perioperative beta-blockade in the first cohort (n=392) and seven (6%) of 118 patients in the second cohort (n=241) (P=0.10). Effective heart rate control was achieved in 29 (9%) patients prescribed perioperative beta-blockers compared with 10 (3%) patients not prescribed perioperative beta-blockers (P=0.001). The rate of implementation of effective beta-blockade was low before POISE and this did not change significantly after publication. Our finding does not provide reliable evidence of a change in practice as a result of the POISE Trial.

Vascular surgery patients prescribed preoperative β-blockers experienced a decrease in the maximal heart rate observed during induction of general anesthesia

OBJECTIVE

To investigate the association of preoperative β-blocker usage and maximal heart rates observed during the induction of general anesthesia.

DESIGN

Retrospective descriptive, univariate, and multivariate analyses of electronic hospital and anesthesia medical records.

SETTING

A tertiary-care medical center within the Veterans Health Administration.

PARTICIPANTS

Consecutive adult elective and emergent patients presenting for vascular surgery during calendar years 2005 to 2011.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of the 430 eligible cases, 218 were prescribed β-blockers, and 212 were not taking β-blockers. The two groups were comparable across baseline patient factors (ie, demographic, morphometric, surgical duration, and surgical procedures) and induction medication doses. The β-blocker group experienced a lower maximal heart rate during the induction of general anesthesia compared with the non-β-blocker group (105 ± 41 beats/min v 115 ± 45 beats/min, respectively; p < 0.01). Adjusted linear regression found a statistically significant association between lower maximal heart rate and the use of β-blockers (β = -11.1 beats/min, p < 0.01). There was no difference between groups in total intraoperative β-blocker administration.

CONCLUSIONS

Preoperative β-blockade of vascular surgery patients undergoing general anesthesia is associated with a lower maximal heart rate during anesthetic induction. There may be potential benefits in administering β-blockers to reduce physiologic stress in this surgical population at risk for perioperative cardiac morbidity. Future research should further explore intraoperative hemodynamic effects in light of existing practice guidelines for optimal medication selection, dosage, and heart rate control.

Statin use and postoperative atrial fibrillation after major noncardiac surgery

BACKGROUND

Although statin lipid-lowering medications likely reduce perioperative ischemic complications, few data exist to describe statins' effects on risk for and outcomes of atrial fibrillation following noncardiac surgery.

OBJECTIVE

To examine the association between treatment with statin medications and clinically significant postoperative atrial fibrillation (POAF) following major noncardiac surgery.

METHODS

A retrospective cohort study of patients aged 18 years or older who underwent major noncardiac surgery between January 1, 2008, and December 31, 2008. Cases of clinically significant POAF were selected by using a combination of International Classification of Diseases-9 codes and clinical variables. We defined statin users as those whose pharmacy data included a charge for a statin drug on the day of surgery, the day after surgery, or both.

RESULTS

Of 370,447 patients, 10,957 (3.0%) developed clinically significant POAF; overall, 79,871 (21.6%) received a perioperative statin. Patients receiving statins were generally older (68.8 vs 61.1 years; P <.001) and more likely to be receiving a beta-blocker (50.3% vs 21.6%; P < .001). Statin use was associated with a lower unadjusted rate of POAF (2.6% vs 3.0%; P < .001). After adjustment for patient risk factors and surgery type, odds for POAF remained significantly lower among statin-treated patients (adjusted odds ratio = 0.79; 95% confidence interval = 0.71-0.87; P < .001). Statin use was not associated with differences in cost, length of stay, or mortality among patients who developed POAF.

CONCLUSION

Treatment with statin agents appears to be associated with a lower risk for clinically significant POAF following major noncardiac surgery.

Cardiovascular problems in noncardiac surgery

PURPOSE OF REVIEW

Perioperative cardiac complications remain a major area of concern as our surgical population increases in volume, age and frequency of comorbidity. A variety of strategies can be used to optimize patients and potentially reduce the incidence of these serious complications.

RECENT FINDINGS

Recent literature suggests a trend towards less invasive testing for detection and quantification of coronary artery disease and greater interest in pharmacologic 'cardioprotection' using beta-blockers, statins and other agents targeting heart rate control and other mechanisms (e.g. reducing inflammatory responses). The recent Perioperative Ischemic Evaluation study has substantially altered this approach at least towards widespread application to lower/intermediate risk cohorts. Considerable attention has been focused on ensuring optimal standardized perioperative management of patients with a recent percutaneous coronary intervention, particularly those with an intracoronary stent. Widespread surveillance of postoperative troponin release and increasing recognition of the prognostic potential of elevated preoperative brain natriuretic peptides point towards changing strategies for long-term risk stratification.

SUMMARY

The complexity of a particular patient's physiologic responses to a wide variety of surgical procedures, which are undergoing constant technological refinement generally associated with lesser degrees of invasivity and stress make calculation of patients' perioperative risk very challenging. At the present time, adequate information is available for the clinician to screen patients with high-risk preoperative predictors, delay elective surgery for patients with recent intracoronary stents and continue chronic beta-blockade in appropriate patients. New large-scale database and subanalyses of major trials (e.g. Perioperative Ischemic Evaluation and Coronary Artery Revascularization Prophylaxis) should provide additional information to minimize perioperative cardiac risk.