Assessment of coronary arterial restenosis with phase-contrast magnetic resonance imaging measurements of coronary flow reserve

Background-After successful percutaneous coronary arterial revascularizatio n, 25% to 60% of subjects have restenosis, a recurrent coronary arterial na rrowing at the site of the intervention. At present, restenosis is usually detected invasively with contrast coronary angiography. This study was perf ormed to determine if phase-contrast MRT (PC-MRI) could be used to detect r estenosis noninvasively in patients with recurrent chest pain after percuta neous-revascularization. Methods and Results-Seventeen patients (15 men, 2 women, age 36 to 77 years ) with recurrent chest pain >3 months after successful percutaneous interve ntion underwent PC-MRI measurements of coronary artery flow reserve followe d by assessments of stenosis severity with computer-assisted quantitative c oronary angiography. The intervention was performed in the left anterior de scending coronary artery in 15 patients, one of its diagonal branches in 2 patients, and the right coronary artery in 1 patient. A PC-MRI coronary flo w reserve value less than or equal to 2.0 was 100% and 82% sensitive and 89 % and 100% specific for detecting a luminal diameter narrowing of greater t han or equal to 70% and greater than or equal to 50%, respectively. Conclusions-Assessments of coronary flow reserve with PC-MRI can be used to identify flow-limiting stenoses (luminal diameter narrowings >70%) in pati ents with recurrent chest pain in the months after a successful percutaneou s intervention.