Intraoperative measurement of fractional flow reserve in off-pump coronary artery bypass: A pilot study

Backgrounds Fractional flow reserve of myocardium (FFRmyo) is a functional study of significant coronary artery stenosis, defined as the ratio of the pressure distal to the stenosis (poststenosis) divided by the pressure of aortic root (prestenosis). Instead of cath laboratory, we could measure it in operating room for off-pump coronary artery bypass (OPCAB) surgery and here shared our methods in the pilot study. Methods and Results We used needles, catheters, and pressure tracing but without guidewires or fluoroscopy to measure FFRmyo during OPCAB. In February 2010, we conducted the pilot study and collected 32 anastomosis data from 10 patients. Without revising the anastomosis plans based on coronary angiographies, 24 FFRmyo of the 32 anastomoses (75%) were less than 0.75, which represented significant functional stenosis. The FFRmyo measurements did not lead to any adverse events. Conclusion The measurement of fractional flow reserve in OPCAB is safe and feasible. It can serve as a functional assessment of coronary artery stenosis in adjuvant to conventional coronary angiography.