Perspective:

This large database survey including over 500,000 patients in 224 hospitals demonstrated substantial variation in the use of noninvasive testing (predominately myocardial perfusion imaging) in patients presenting with symptoms for which myocardial ischemia was suspected. Within the limits of available data, the authors have modeled the likelihood of receiving cardiac imaging and demonstrating that 23% of the variations in rates of cardiac imaging are related to hospital-specific variation rather than clinical or patient-related variables. They further calculated that a pool of identical patients presenting at different hospitals could have as high as a two-fold difference in the likelihood of receiving noninvasive cardiac testing. Multiple previous studies have suggested an overutilization of cardiac noninvasive cardiac testing and have previously attributed it to hospital variation as well as practice variation. This large database study confirms an observation of a presumed excess of cardiovascular testing, but does not provide data to further elucidate the specific cause, with respect to further details of practice pattern, financial incentive, etc. The higher rates of angiography associated with higher rates of noninvasive testing with an actual drop in the percentage of patients requiring intervention, suggests that the lower threshold for cardiac testing resulted in more patients with low pretest likelihood being evaluated, which results in a subsequent higher rate of false-positive imaging results. While not addressed in this manuscript, an obvious next step would be to further find the characteristics of decision making in the low and high utilization hospitals with respect to specific guidelines, heterogeneity of practice patterns, and other factors.