Formal Preoperative Evaluation Is Associated with Higher Rates of Perioperative Beta‐ers in Noncardiac Surgery

Background:

Several randomized and observational trials in the past decade and the more recent ACC/AHA guidelines support the use of preoperative beta‐ers (PBB) in selected patients undergoing noncardiac surgery (NCS). National patient quality and safety groups continue to advocate this practice and measure its use as a marker of quality. The Internal Medicine Preoperative Assessment Consultation and Treatment (IMPACT) Center is a referral‐based clinic providing standardized preoperative evaluation by hospitalists at an academic tertiary care center in the Midwest. We sought to determine whether referral to the IMPACT Center increased the likelihood of administration of PBB.

Methods:

We performed a retrospective cohort study of 11,985 patients from January to December 2005 who underwent elective NCS requiring at least an overnight admission to the hospital. Patients were identified from the surgery scheduling system. A nonparsimonious propensity model was developed to predict IMPACT Center referral. Patient demographics, clinical laboratory values, comorbidities, type of surgery, surgical risk (using a 5‐point scale based on procedural bleed risk), anesthesia risk (using a 4‐point scale analogous to the ASA Physical Status classification derived from a computerized questionnaire consisting of 148 interactive questions), prescribed medications, and surgical history were included in the model. Multiple logistic regression stratified by the propensity for IMPACT referral was used to determine significant predictors of perioperative beta‐er use. Determinates of beta‐er eligibility were defined using a standardized assessment and treatment protocol.

Results:

Overall, 59.8% of patients were assessed in the IMPACT Center. The propensity model for IMPACT referral demonstrated strong predictive ability (c statistic = 0.856). The unadjusted odds ratio (OR) for IMPACT referral predicting PBB was 2.71 (P < .001). The OR for IMPACT referral remained a significant predictor of PBB (1.44, P < .001), even after rigorous adjustment for referral bias using propensity score methods and controlling for patient age (OR = 1.03 per year, P < .001), beta‐er eligibility (yes or no; OR = 2.24, P < .001), surgical risk (per unit on a 5‐point scale; OR = 1.39, P < .001), and anesthesia risk (per unit on 4‐point scale; OR = 1.12, P < .001).

Conclusions:

Preoperative patient assessment in the IMPACT center was associated with higher rates of perioperative beta‐er prescription, even after accounting for referral bias using propensity stratification. Further research is underway to investigate whether the higher use of PBB translated into improved perioperative cardiac outcomes in this cohort.

Author Disclosure:

B. J. Harte, None; E. Hixson, None; D. J. Brotman, None; B. Parker, None; A. Aneja, None; A. Jaffer, Prompte, consulting fees or other remuneration (payment); Society of Perioperative Assessment and Quality Improvement, nonremunerative positions of influence.