Fractional flow reserve measurement modification with monorail pressure catheter.

A number of symptomatic patients with coronary artery disease undergo revascularization without definite evidence that particular coronary stenosis is responsible for their symptoms [1]. Currently, the borderline coronary artery stenoses are most commonly assessed by intravascular ultrasound and fractional flow reserve (FFR) alongside with quantitative coronary angiography [2]. FFR measurement, as performed by pressure wire (PW), requires its multiple removals during FFR and percutaneous coronary intervention (PCI), and results in a relatively high signal drift with loss of accuracy. The novel exchange microcatheter (RXi) was invented to assess FFR in a safer mode [3, 4]. A 61-year-old man was admitted to hospital with exertional stenocardia. The patient underwent myocardial infarction in 1988 and coronary artery bypass grafting operation in 1999. Angiography revealed total occlusion of the left anterior descending artery (LAD), as previously. In the right coronary artery (RCA) occurred disseminated, multi-segmental stenoses up to 40% with borderline stenosis of 60% in the distal portion (Fig. 1A). The aorto-marginal saphenous vein