July 2019

N Engl J Med, 2019 Jun 20;380(25):2418-2428. doi: 10.1056/NEJMoa1716734.

Magnetic Resonance Perfusion or Fractional Flow Reserve in Coronary Disease

Nagel E, Greenwood JP, McCann GP, Bettencourt N, Shah AM, Hussain ST, Perera D, Plein S, Bucciarelli-Ducci C, Paul M, Westwood MA, Marber M, Richter WS, Puntmann VO, Schwenke C, Schulz-Menger J, Das R, Wong J, Hausenloy DJ, Steen H1, Berry C; MR-INFORM Investigators

Guiding patients with stable chest pain non-invasively with perfusion cardiovascular magnetic resonance is non-inferior to invasive angiography and fractional flow reserve.

The management of patients with stable chest pain and intermediate to high pre-test likelihood for coronary artery disease can be safely done by a short, non-invasive stress perfusion test based on cardiovascular magnetic resonance (CMR). Outcome after one year is non-inferior to an invasive approach by coronary angiography including pressure measurements (fractional flow reserve).

Currently, patients with stable angina are frequently examined with invasive angiography to detect coronary artery stenosis. Guidelines recommend the proof of ischemia before revascularization, which can be done by fractional flow reserve (FFR). The use of FFR to decide on the need for revascularization has improved outcome of patients with coronary artery disease and is, thus considered the gold-standard.

The MR Perfusion Imaging to Guide Management of Patients with Stable Coronary Artery Disease (MR-INFORM) study randomly assigned 918 patients with typical stable chest pain, at least two risk factors for coronary artery disease or a positive exercise ECG to receive either an invasive coronary angiogram with FFR or perfusion CMR to assess if they needed revascularization or guideline directed medical therapy. All patients were followed-up for one year and major cardiac events, defined as death, myocardial infarction or target vessel revascularization were recorded.

In the CMR guided arm, less than half of the patients (40.5%) required an invasive angiography and about one third (35.7%) were revascularized. This was significantly less, than the revascularization rate of the invasive arm (45%, p<0.005). There were no differences in angina status between groups after one year. In both treatment arms patients had low event rates (3.9% in the angiography guided group and 3.3% in the perfusion CMR guided group) resulting in non-inferiority of perfusion CMR to angiography to guide patient management.

The results show, that perfusion CMR can be used as a first line test in patients with stable chest pain. This can reduce the number of invasive angiographies and revascularizations and provides identical outcomes on symptoms and event free survival. CMR is highly attractive for patients, as it is faster, does not require ionizing radiation and is non-invasive.