ROME — Diagnostic techniques for guiding management of suspected coronary heart disease without angiography showed promise in studies presented here at the European Society of Cardiology (ESC) annual conference.
Both cardiac MRI and myocardial perfusion scintigraphy (MPS) appeared to perform better than a diagnostic protocol recommended in British guidelines, results of the CE-MARC 2 study suggested.
Compared to a guideline-first strategy, cardiac MRI yielded an almost 80% reduction in unnecessary angiography (7.5% versus 28.8% for guidelines; adjusted OR 0.21, 95% CI 0.12 to 0.34).
MPS fared just as well (7.5% for MRI versus 7.1% for MPS; adjusted OR 1.27, 95% CI 0.79 to 2.03), according to John P. Greenwood, MB ChB, PhD, of the University of Leeds in England.
CE-MARC 2 was simultaneously published online in the Journal of the American Medical Association.
There was no difference in the rate of positive angiography or major adverse cardiac events between the three strategies at 1 year.
Although the U.K.’s National Institute for Health and Clinical Excellence (NICE) guidelines recommend invasive imaging for higher-risk patients, Greenwood concluded that perhaps they “still drive more angiography than you need.”
And those guidelines can be very complicated to begin with, according to session discussant Udo Sechtem, MD, of Robert-Bosch Medical Center in Germany. “The question is whether we can go easier than the NICE protocol.”
Greenwood’s team randomized 1,202 symptomatic patients with suspected coronary heart disease to management directed by NICE guidelines (n=240), cardiac MRI (n=481), or MPS (n=481).
Angiography was deemed unnecessary if a patient’s fractional flow reserve was above 0.8 or if quantitative coronary angiography in coronary vessels at least 2.5 mm wide showed no diameter stenosis over 70% in one view (or 50% in two orthogonal views).
That 3-year adverse events never climbed above 4% in all groups showed that Greenwood was working with low-risk populations, Sechtem commented. “This is such a low risk cohort that symptomatic treatment combined with preventive medication, then followed by revascularization, should be the first step.”
The investigation could have tested coronary CT angiography as well, Sechtem suggested.
For that matter, what about cardiac positron emission tomography (PET)?
PET emerged as the winner in a head-to-head comparison with coronary CT angiography and single-photon emission computed tomography (SPECT) for catching myocardial ischemia, according to results of a study dubbed PACIFIC.
This modality had the highest overall scores for sensitivity (87%), specificity (84%), negative predictive value (89%), positive predictive value (81%), and accuracy (85%), Ibrahim Danad, MD, of VU University Medical Center in Amsterdam, told the audience at another ESC presentation.
Adding coronary CT angiography to PET, on the other hand, made several diagnostic metrics worse: sensitivity (74%), negative predictive value (82%), and accuracy (84%). Yet specificity and positive predictive value did improve to 92% and 88%, respectively, with this hybrid approach.
Danad’s single-center study included 208 patients with suspected coronary artery disease who had been referred for invasive coronary angiography.
CE-MARC 2 was sponsored by the British Heart Foundation.
Greenwood, Danad, and Sechtem reported no relevant conflicts of interest.
CE-MARC 2 co-authors disclosed assorted relationships with Siemens Healthcare, St. Jude Medical, Circle Cardiovascular Imaging, British Heart Foundation, and the National Institute for Health Research.
Journal of the American Medical Association
Greenwood JP, et al “Effect of care guided by cardiovascular magnetic resonance, myocardial perfusion scintigraphy, or NICE guidelines on subsequent unnecessary angiography rates: The CE-MARC 2 randomized clinical trial” JAMA 2016; DOI: 10.1001/jama.2016.12680.
European Society of Cardiology
Danad I, et al “Prospective comparison of cardiac PET/CT, SPECT/CT perfusion imaging and CT coronary angiography with invasive coronary angiography” ESC 2016.