Stress-only or stress/rest myocardial perfusion imaging in patients undergoing evaluation for bariatric surgery

Bariatric surgery for management of obesity is being used with increasing frequency. Stress testing with myocardial perfusion imaging is often employed as part of the workup prior to anticipated bariatric surgery. The incidence of clinically significant abnormalities on stress MPI performed for this indication, however, has not been established.

We retrospectively reviewed a series of 383 consecutive stress MPI studies performed on patients undergoing workup prior to planned bariatric surgery. The study population had a mean age 42 ± 10 years, and was 83% female, with a body mass index of 49 ± 8. The majority of patients (81%) were able to exercise using either the Bruce or Modified Bruce protocol, and 67% underwent stress-only imaging. Overall SPECT MPI findings were normal in 89% and equivocal in 6% of patients. The incidence of abnormal findings on MPI was 5% (3% mild and 2% moderate-to-severe abnormalities). At 1 year, overall survival was 99.5%, with no difference between those with and without MPI abnormalities. Similarly, the incidence of post-operative cardiac events was very low (2%), and mostly due to atrial arrhythmias or borderline elevations of troponin.

In a typical pre-bariatric surgery population, the incidence of abnormal stress MPI is low. The majority of patients were able to use a stress-only strategy for assessment of perfusion. At 1 year the incidence of adverse cardiovascular outcomes is very low. Additional studies should be focused on determining whether any subgroup of such patients may benefit more from pre-operative stress testing.