DENVER – Physicians making referrals for cardiac stress testing often underestimate their patients’ ability to exercise to target heart rate, according to Dr. Michael Ross.
Here’s what can happen as a result: In a prospective series of 120 consecutive patients referred for pharmacologic myocardial perfusion imaging stress testing by primary care physicians, surgeons, and cardiologists, 60% of the patients were able to mount the treadmill and exercise to 85% of their estimated maximum heart rate, he reported at the annual meeting of American Society of Nuclear Cardiology.
Primary care physicians were significantly more likely than were cardiologists or surgeons to order a pharmacologic stress test in patients who did not need one because they were able to complete the less costly exercise stress test.
Is that because primary care physicians don’t know their patients and their physical capacities as well as other physicians do? Highly unlikely. Instead, it appears they are more concerned that if they order an exercise stress test and a patient can’t complete it, they’ll have to reorder the test – this time using pharmacologic stress – with the attendant inconvenience and delay, according to Dr. Ross of Northwestern University, Chicago.
In a multivariate logistic regression analysis, the only independent predictors of failure to reach target heart rate were being on a beta-blocker and having diabetes.
Dr. Ross said he had no relevant financial disclosures.