BACKGROUND: Approximately 90% of the patients submitted to coronary artery bypass graft surgery (CABG) receive a left internal thoracic artery (LITA) graft. Stenosis of the left subclavian artery can result in graft failure due to restricted coronary flow. The prevalence of stenosis of the left subclavian artery in patients with severe coronary atherosclerosis, deemed candidates to CABG, is not known. OBJECTIVE: To assess the prevalence of stenosis of left subclavian artery in CABG candidates, as well as the diagnostic effectiveness of clinical evaluation. METHODS: In a multicenter registry, selective angiography of the left subclavian artery was carried out in patients considered candidates to CABG during coronary cineangiography. Stenoses > 50% proximal to the origin of the LITA were considered significant. RESULTS: A total of 205 patients were included. Significant stenosis of the left subclavian artery was observed in 16 (7.8%) patients. Noninvasive differential arterial blood pressure measurement > 10 mmHg between both arms showed low sensitivity (37.5%) and low positive predictive value (13.3%) for stenosis identification. No clinical predictors of significant stenosis were identified by univariate analysis. CONCLUSION: Stenosis of the left subclavian artery is not uncommon in CABG candidates. Noninvasive blood pressure gradient between both arms has low diagnostic accuracy. Therefore, in patients candidates to CABG, selective angiography of the left subclavian artery should be considered, because of the risk of reduced flow and coronary-subclavian steal syndrome in patients with non-diagnosed stenosis of the subclavian artery who receive a LITA graft.
Atherosclerosis; Subclavian artery; Subclavian steal syndrome; Angiography
