Whether patients with stable coronary artery disease (CAD) were evaluated using cardiac MRI or coronary angiography had no impact on event rates over 3 years, according to a randomized trial from a German center, though researchers said that they couldn't show non-inferiority for the non-invasive strategy.
By 12 months:, cardiac death and non-fatal MI had reached 3.1% of patients who got coronary angiography and 4.2% of those who received cardiac MRI (P=0.72), observed researchers led by Dominik Buckert, MD, of Germany's University Hospital Ulm, reporting in the July issue of .
Events continued to accumulate over time such that at 3 years, the rates of cardiac death and MI were 4.1% and 9.4% in these groups, respectively (P=0.25). Non-inferiority was not demonstrated by the cardiac MRI group (P=0.88).
After screening 394 patients in 2012-2014, Buckert's group randomized 200 patients to diagnostic coronary angiography or adenosine stress cardiac MRI. The investigators noted that they had overestimated the number of events that would occur over the study period, which led to an underestimation of the sample size they needed.
The angiography arm saw 45.9% getting percutaneous coronary intervention (PCI) immediately (the rest receiving medical treatment alone); only 28.1% of the cardiac MRI arm were shown to have inducible ischemia and given PCI (except in the four cases where patients didn't show up for the procedure, had too small a target vessel, or didn't have CAD at coronary angiography).
Importantly, although the two arms started off with distinct rates of revascularization, their total revascularization count was no longer statistically different by the end of 3 years.
Improvements had also been noted for both study arms on the Seattle Angina Questionnaire. The cardiac MRI group did significantly better at 12 months in the physical limitation, treatment satisfaction, and quality of life scales, but again, this advantage had disappeared at the 3-year follow-up.
Study participants averaged 64.2 years old and were 64.8% men. The overall cohort presented with a Framingham 10-year risk score of 11.8%. Baseline characteristics were similar between groups except more people had diabetes and known CAD in the cardiac MRI group.
Cardiac MRI holds a Class Ia recommendation in the diagnostic workup of patients with symptomatic stable CAD, though few randomized studies have evaluated a patient management approach based on this modality, according to Buckert and colleagues.
Another trial of note was the "landmark" , which showed that noninvasive imaging with stress perfusion cardiac MRI was non-inferior to angiography and fractional flow reserve (FFR) as guiding strategy for the management of patients with known or suspected ischemic heart disease, recalled Colin Berry, MBChB, PhD, and colleagues of the British Heart Foundation Glasgow Cardiovascular Research Centre in Scotland.
In an editorial comment, Berry's group said that MR-INFORM and the current trial together "lend support to adoption of noninvasive myocardial imaging as an alternative reference strategy in patients with risk factors for ischemic heart disease."
"For now, invasive coronary angiography is the standard of care for decision making, but watch this space," they said, as noninvasive myocardial imaging will become more clinically useful as the technology advances.
FFR CT also holds promise given its unique integration of coronary anatomy and physiology, Berry and co-editorialists added.
Disclosures
The trial was partially funded by Guerbet.
Study authors and editorialists disclosed no relevant conflicts of interest.
Berry's institution holds research and consultancy agreements with Abbott Vascular, AstraZeneca, Coroventis, Corstem, GlaxoSmithKline, HeartFlow, Menarini, Neosoft, Novartis, Philips, and Siemens Healthcare.
Primary Source
JACC: Cardiovascular Imaging
Buckert D, et al "Comparing cardiac magnetic resonance-guided versus angiography-guided treatment of patients with stable coronary artery disease: results from a prospective randomized controlled trial" JACC Cardiovasc Imaging 2018; DOI: 10.1016/j.jcmg.2018.05.007.
Secondary Source
JACC: Cardiovascular Imaging
Berry C, et al "Magnetic resonance perfusion imaging to guide management of patients with stable ischemic heart disease" JACC Cardiovasc Imaging 2018; DOI: 10.1016/j.jcmg.2018.05.020.