Serial imaging and outcome prediction

The power of stress echocardiography and myocardial perfusion scintigraphy in predicting long-term outcome. Nothing lasts forever

“…If the population consisted initially of the latter group, it is likely that cardiac events will occur during longer-term follow-up due to progression of the disease that was not severe enough to cause abnormalities on earlier functional imaging; hence continued surveillance in individuals with higher clinical risk profile is warranted. 6 The recent development in hybrid imaging has particularly been useful in this situation. A low-dose CT used for attenuation correction applied with myocardial perfusion SPECT imaging in state-of-the-art laboratories can identify patients with a normal perfusion who may otherwise still be at high risk of cardiac events over the longer term in association with significant coronary artery calcifications.…”

“…The findings of this study of continued diversion of survival curves during the long-term followup among patients with abnormal stress test make the case for the need to repeat the test particularly in patients with initially mild to moderate abnormality as these patients appear to be at continued risk of cardiac events. The follow-up stress test may detect further increase in the severity and extent of functional abnormalities, 6 lower ischemic threshold, worsening of left ventricular function, adverse cardiac remodeling, and peri-infarct or remote ischemia in patients with predominantly fixed defects on initial study. These abnormalities may herald a status of higher risk than initially anticipated and may guide the physician in deciding to proceed with revascularization and or intensify medical therapy.…”

Serial cardiac SPECT studies: Technical issues and clinical implications

“…The intrinsic variability of MPI becomes important in interpreting serial tests in order to define a true change in a given patient and to guide clinical decision making. 7 It should be also noted that in trials using MPI to assess the effects of therapy, serial imaging would be stronger if at least moderate ischemia is an inclusion criterion, exceeding the variability of MPI, and thus assuring that the enrolled patients actually have ischemia. 6 Farzaneh-Far et al 8 identified 1425 consecutive patients with angiographically documented coronary artery disease who underwent two serial MPI scans within a 36-month time frame.…”