CT Angiography Plus CT Perfusion May Predict Cardiovascular Events

Noninvasive CT angiography and CT perfusion can help predict to major adverse cardiovascular events (MACE), according to a new study published in the journal Radiology. Researchers from Brazil and the United States undertook a study to compare the prognostic importance of combined CT angiography and CT myocardial stress perfusion imaging with that of combined invasive coronary angiography (ICA) and stress single photon emission CT myocardial perfusion imaging.  A total of 379 patients were evaluated for this study, which took place between November 2009 and July 2011. All participants, aged 45 to 85 years, had been referred for ICA. All images were analyzed in blinded independent core laboratories, and a panel of physicians adjudicated all adverse events. The researchers defined MACE as revascularization (more than 30 days after index ICA), myocardial infarction, or cardiac death; hospitalization for chest pain or congestive heart failure; or arrhythmia. Late MACE was defined similarly, except for patients who underwent revascularization within the first 182 days after ICA, who were excluded.  “Previous studies show that a lesion is hemodynamically significant if there is a significant blood pressure drop corresponding to a big reduction in blood flow across the stenosis,” co-author João A.C. Lima, MD, said in a release. “If plaque has those characteristics, the patient should be targeted for intervention, be it with a stent or downstream bypass surgery.” Lima is from Johns Hopkins Hospital and School of Medicine in Baltimore, Md. The results showed 51 of the 379 patients (13.5 percent) experienced at least one MACE: 49 revascularizations, five myocardial infarctions, one cardiac death, nine hospitalizations for chest pain or congestive heart failure, and one arrhythmia. The two-year MACE-free rates for combined CT angiography and CT perfusion findings were 94 percent negative for coronary artery disease (CAD) versus 82 percent positive for CAD and were similar to combined ICA/SPECT findings (93 percent negative for CAD versus 77 percent positive for CAD).  “The key finding of our study is that both techniques are equally effective in identifying which patients are going to have trouble down the road,” Lima said. “The noninvasive option should be a preferred or at least strongly considered option by cardiologists and radiologists managing these patients because it is safer and less expensive, and patients like it better.”