Researchers use noninvasive imaging to predict adverse cardiac events

New research has found that CT angiographies and stress tests could help predict when a patient is likely to suffer a heart attack or another serious cardiovascular event.

The study, published in the journal Radiology, examined if combined CT angiography and CT myocardial stress perfusion imaging could work just as well or better than invasive coronary angiography (ICA) and stress tests with single photon emission tomography (SPECT) in predicting if patients will have adverse cardiovascular events, such as a heart attack.

"Invasive angiography is generally safe, but it can cause vascular problems in a significant number of patients, most commonly at the site of the puncture," said João A.C. Lima, MD, the lead author on the study, who works at Johns Hopkins Hospital and School of Medicine in Baltimore. "In rare cases, it can cause strokes or heart attacks. These risks are not trivial."

The researchers compared invasive and noninvasive treatments in 379 patients who were advised to undergo ICA from November 2009 to July 2011 to assess the ability of techniques to predict heart attack, revascularization, arrhythmia or hospitalization for chest pain or congestive heart failure.

Results showed that 31.5 percent of patients experienced one or more cardiac events. They included 49 revascularizations, five myocardial infarctions, one cardiac death, nine hospitalizations and one arrhythmia. But before the events took place, both techniques showed similarly high values for predicting cardiac events. Two-year rates of cardiac events predicted with CT angiography and CT perfusion were 94 percent negative for coronary artery disease compared to 82 percent for it, which was consistent with the ICA/SPECT findings. Cardiac events predicted with ICA/SPECT were 93 percent negative.

"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."