Prevalência de estenose da artéria subclávia em pacientes candidatos a cirurgia de revascularização do miocárdio: registro multicêntrico / Prevalence of stenosis of the left subclavia artery in CABG candidates: a multicenter registry

RESUMO

Introdução: Aproximadamente 90 por cento dos pacientes submetidos a cirurgia de revascularização do miocárdio (CRM) recebem enxerto de artéria torácica interna esquerda. A ocorrência de estenose da artéria subclávia esquerda pode resultar em falência do enxerto por limitação de fluxo coronário. A prevalência de estenose da artéia subclávia esquerda em pacientes com aterosclerose coronária grave, considerados candidatos a CRM, não é conhecida. Objetivo: Determinar a prevalência e a eficácia da avaliação clínica para diagnóstico a estenose da artéria subclávia esquerda em candidatos a CRM. Método: Em um registro multicêntrico, realizou-se angiografia seletiva da artéria subclávia esquerda em pacientes com indicação de CRM na ocasião da cinecoronariografia. Estenoses maiores ou iguais a 50 por cento antes da origem da artéria torácica interna foram considerdas significativas. Resultados: Dos 205 pacientes estudados, 16 (7,8 por cento) apresentavam estenose significativa da artéria subclávia esquerda. A medida da pressão arterial não-invasiva diferencial entre...

ABSTRACT

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.