Competitive Coronary Flow between the Native Left Anterior Descending Artery and Left Internal Mammary Artery Graft: Is It a Surrogate Angiographic Marker of Over-or-Unnecessary Revascularization Decision in Daily Practice?

Overdiagnosis and overtreatment are often thought of as relatively recent phenomena in modern medicine, influenced by a contemporary combination of technology, specialization, payment models, marketing, and supply-related demand. Several investigators have reported discrepancies between the angiographic and functional severity of coronary angiographic stenosis. However, the visual anatomic assessment of the coronary lesion severity continues in daily practice. We evaluated the consecutive all coronary angiograms performed between January 2015 and December 2015 and examined only patients who had previous coronary artery bypass grafting (CABG) to analyze the cases with regard to presence of the competitive flow (CF) between the native left anterior descending coronary artery (LAD) and left internal mammary artery (LIMA) graft. A total of 8,248 diagnostic coronary angiographies were performed between January 2015 and December 2015 at our facility. Of these, 886 coronary angiographies of CABG patients were detected. Whereas LIMA graft occlusion detected in 19 patient (2.1%), the LIMA-LAD CF rate was found in 86 (9.7%) CABG patients. The angiographic severity of the LAD stenosis in CF group evaluated as mild in 20 (25%), moderate in 61 (70%), and severe coronary artery disease in 4 (5%) patients. Our results showed that there is 9.7% rate of LIMA-LAD CF. Therefore, some unnecessary coronary stenting or CABG procedures might have been performed due to limited use of functional testing for clinical decision making. The functional angiography should play a more prominent role in catheterization laboratories as recommended by current revascularization guidelines to prevent overdiagnosis, misdiagnosis, or incorrect treatment decisions.