Patients who were evaluated for CAD with cardiac hybrid imaging, which combined single-photon emission CT myocardial perfusion imaging with coronary CTA, had accurate predictions of long-term adverse cardiac events, according to a study published in Radiology.
“The strategy of direct referral to invasive coronary angiography without noninvasive imaging is obsolete,” Philipp A. Kaufmann, MD, professor and chair of nuclear medicine and director of cardiac imaging at University Hospital Zurich, said in a press release. “Even after documenting coronary artery disease with coronary CT angiography, we need further noninvasive evaluation before deciding upon revascularization vs. medication.”
Aju P. Pazhenkottil, MD, attending physician in the department of cardiology and nuclear medicine at University Hospital Zurich, and colleagues analyzed data from 428 patients who were referred for evaluation of suspected or known CAD with SPECT and coronary CTA between May 2005 and December 2008.
Patients and physicians were followed up through phone calls for hard events, including nonfatal MI and all-cause death, and a composite of major adverse cardiac events, defined as MI, death, coronary revascularization and unstable angina requiring hospitalization.
After patients underwent combined SPECT myocardial perfusion imaging with coronary CTA, they were categorized based on the findings:
Matched finding: a reversible SPECT myocardial perfusion imaging defect in an area that is subtended by a stenotic coronary artery.
Unmatched finding: SPECT or coronary CTA findings in unrelated territories.
Normal finding: any luminal narrowing less than 50 or normal coronary CTA findings and no defect at SPECT.
The final study population included 375 patients (mean age, 62 years; 35% women). During a median follow-up of 6.8 years, 160 major adverse cardiac events occurred in 29% of patients; 12% of the cohort died.
Patients with matched findings had the highest annual event rate (7%), whereas lower event rates were seen in patients with unmatched (3.7%) or normal findings (1.2%; P < .001).
The rate of major adverse cardiac events was 21.8% in the matched findings group, 9% in the unmatched findings group and 2.4% in the normal findings group (P < .001).
A matched finding was an independent predictor for hard events and major adverse cardiac events.
“To our knowledge, our study is the first to expand the proven predictive short-term value of cardiac hybrid imaging in a long-term period,” Pazhenkottil and colleagues wrote. – by Darlene Dobkowski
Disclosures: Kaufmann reports no relevant financial disclosures. Pazhenkottil reports he is on the speakers bureau for GE Healthcare. Please see the study for all other authors’ relevant financial disclosures.