Evaluation of the relation between fractional flow reserve and midterm graft patency in CABG patients

Objectives: The severity of the stenosis in left anterior descending artery might be misdiagnosed in coronary angiography. Fractional flow reserve is an important tool in such patient group in order to determine the modality of the treatment; medical, percutaneous intervention or surgical revascularization. We proposed to evaluate the midterm outcome of patients with moderate left anterior descending artery stenosis, who under- went surgical revascularization with regard to fractional flow rate studies. Materials and Methods: Eleven patients were identified who were operated between 2005 and 2007. The mean age was 54.2 ±6.88 (range between 44 and 66). Our study group was composed of patients with mod- erate (50-60%) left anterior descending artery stenosis in whom a left anterior descending thoracic artery-left anterior descending artery anastomosis had been performed with the decision for surgical revascularization given with regard to fractional flow rate values. The symptomatic patients were evaluated with conventional angiography or three dimensional computed tomography, whereas asymptomatic patients were evaluated with Doppler ultrasonography. Results: All the patients had been operated under cardiopulmonary bypass with cross clamping of the aorta. The left anterior descending thoracic artery-left anterior descending artery anastomosis had been performed in all cases. Any mortality was not encountered. All the patients were evaluated within a mean interval of 2.4 years after the surgical revascularization. Five of the patients (45.5%) had left anterior descending thoracic artery flow, whereas 6 of the patients (54.5%) did not. Three dimensional computed tomography was per - formed in 5 of the asymptomatic patients, which demonstrated the 'string sign' of the left internal thoracic artery conduit as well as a left anterior descending artery without any significant stenotic lesion. The midterm (2-4 years) patency of left internal thoracic artery graft was found to be 54.5%. Conclusions: Our study demonstrates that when the patients with moderate left anterior descending artery stenosis undergo bypass surgery with regard to fractional flow rate measurement, graft stenosis might be en - countered in the follow up. This patient group may not be suitable for surgical revascularization.