Fractional flow reserve measured via left internal mammary artery after coronary artery bypass grafting:Two case reports

BACKGROUND The fractional flow reserve(FFR)has made the treatment of coronary heart disease more precise.However,there are few reports on the measurement of FFR via the left internal mammary artery(LIMA).Herein,we described the determination of further treatments by measuring FFR via the LIMA in 2 cases after coronary artery bypass grafting(CABG).CASE SUMMARY Case 1 was a 66-year-old male who was admitted due to“chest tightness after CABG.”The patient underwent CABG 7 years prior due to coronary heart disease.Coronary artery angiography showed complete occlusion of the left anterior descending artery(LAD),and subtotal occlusion of the third segment of the right coronary artery.On arterial angiography,there was 85%stenosis at the distal end of the anastomosis of the LIMA-LAD graft.FFR via LIMA was determined at 0.75.Thus,balloon dilation was performed in Case 1.FFR after balloon dilation was 0.94.Case 2 was a 60-year-old male who was admitted due to“chest tightness after CABG.”The patient underwent CABG 6 years prior due to coronary heart disease.There was 60%segmental stenosis in the middle segment of LAD and 75%anastomotic stenosis.FFR measured via LIMA was 0.83(negative);thus the intervention was not performed.Case 2 was given drug treatments.At the 3-mo follow-up,there was no recurrence of chest tightness or shortness of breath in both cases.They are currently under continual follow-up.CONCLUSION We provided evidence that FFR measurement via grafted blood vessels,especially LIMA,after CABG is a good method to determine the intervention course.