Cardiac Events after Noncardiac Surgery in Patients Undergoing Preoperative Dobutamine Stress Echocardiography: Findings From the Mayo Poce-DSE Investigators

Background

Current guidelines support the use of dobutamine stress echocardiography (DSE) prior to noncardiac surgery in higher-risk patients who are unable to perform at least 4 metabolic equivalents of physical activity. We evaluated postoperative outcomes of patients in different operative risk categories after preoperative DSE.

Methods

We collected data from the medical record on 4494 patients from January 1, 2006 to December 31, 2011 who had DSE up to 90 days prior to a noncardiac surgery. Patients were divided into low, intermediate, and high preoperative surgery-specific risk. Baseline demographic data and risk factors were abstracted from the medical record, as were postoperative cardiac events including myocardial infarction, cardiac arrest, and mortality within 30 days after surgery.

Results

There were 103 cardiac outcomes (2.3%), which included myocardial infarction (n = 57, 1.3%), resuscitated cardiac arrest (n = 26, 0.6%), and all-cause mortality (n = 40, 0.9%). Cardiac event rates were 0.0% (95% confidence interval CI], 0.0%-3.9%) in the low-surgical-risk group, 2.1% (95% CI, 1.6%-2.5%) in the intermediate-surgical-risk group, and 3.4% (95% CI, 2.0%-4.4%) in the high-risk group. Thirty-day postoperative mortality rates were 0%, 0.9%, and 0.8% for the low-risk, intermediate-risk, and high-risk surgical groups, respectively, and were not statistically different.

Conclusions

These findings demonstrate low cardiac event rates in patients who underwent a DSE prior to noncardiac surgery. The previously accepted construct of low-, intermediate-, and high-risk surgeries based on postoperative events of <1%, 1%-5%, and >5% overestimates the actual risk in contemporary settings.