MYOCARDIAL PERFUSION SCINTIGRAPHY - EFFECT ON DIAGNOSTIC AND CLINICALMANAGEMENT ALGORITHMS

Research has demonstrated that myocardial perfusion imaging increases the sensitivity and specificity of stress electrocardiography. However , the additional effect of the perfusion component of a stress study o n clinical management algorithms remains poorly defined. Methods: We p rospectively assessed the decision-making process in 518 patients, fro m 191 clinicians, undergoing stress myocardial perfusion imaging in ou r departments. Each clinician was asked, by telephone interview, to de fine the probability of reversible myocardial ischemia and their manag ement plan (i.e., no antianginal treatment, medical therapy or an inva sive intervention) in three stages: pretest, after the stress data was made available and after completion of the perfusion study. Results: The results of the stress data alone influenced the estimate of the pr obability of reversible ischemia in 149 of 518 patients, and managemen t strategy in 50 of 518 patients, The data from the perfusion componen t in isolation changed probability of reversible disease in 219 of 518 patients and altered clinical management in 77 of 518 patients. Of 10 3 patients in whom an invasive procedure was planned after the stress data, the availability of the perfusion data led to deferral of cathet erization in 48 cases (46.6%). Conversely, of the 415 patients triaged to a noninvasive plan after stress data, only 29 (7.0%) were changed to an invasive strategy. Of note, only 2.3% of women changed from a co nservative strategy as a consequence of the perfusion data, compared t o 9.1% of men. Conclusion: The perfusion component of a stress study h as a significant effect on both estimation of clinical probability and the definition of patient management strategy, Myocardial perfusion i maging reduced the number of catheterizations in patients initially tr iaged to an invasive management strategy. Conversely, the effect of st ress and perfusion data in patients triaged to conservative management on clinical grounds, especially women, remains less well defined.