Little is known about combining diagnostic and therapeutic strategies to manage patients with suspected coronary artery disease. To bridge this gap two commonly used clinical management strategies were compared: myocardial-perfusion cardiovascular magnetic resonance imaging (MRI or CMR) and invasive angiography with measurement of fractional flow research (FFR).
An unblinded, multicenter, comparative-effectiveness noninferiority trial, MR-INFORM, was conducted. Patients (n=918) with typical angina must exhibit either two or more cardiovascular risk factors or a positive exercise treadmill test. Upon meeting this criterion, they were randomly assigned to a CMR-based strategy or an FFR-based strategy. The primary outcome was a major adverse cardiac event at one year.
Cardiovascular MRI is not inferior to FFR
In the CMR group, 184 of 454 patients (40.5%) met the criteria for revascularization as opposed to 213 of 464 patients (45.9%) in the FFR group (P=0.11). Fewer patients in the cardiovascular-MRI group underwent index revascularization than in the FFR group (162 [35.7%] vs. 2019 [45%], P=0.05]. With similar numbers of patients reaching the primary outcome in both groups, the noninferiority threshold was met. This included 15 of 421 patients (3.6%) in the cardiovascular group and 16 of 430 patients (3.7%) in the FFR group (risk difference, -0.2 percentage points; 95% confidence interview, -2.7 to 2.4).
Overall, CMR was noninferior to invasive coronary angiography combined with FFR. This was determined according to the number of major adverse cardiac events at 12 months. These methods are readily available and can be performed using standard MRI systems.
Author: Catherine Sorbara
Original Article: N Engl J Med. 2019. 380. 2418-28