Review of coronary subclavian steal syndrome

Abstract

The clinical benefits of using the left internal mammary artery (LIMA) to bypass the left anterior descending artery are well established making it the most frequently used conduit for coronary artery bypass surgery (CABG). Coronary subclavian steal syndrome (CSSS) occurs during left arm exertion when (1) the LIMA is used during bypass surgery and (2) there is a high grade (≥75%) left subclavian artery stenosis or occlusion proximal to the ostia of the LIMA resulting in "stealing" of the myocardial blood supply via retrograde flow up the LIMA graft to maintain left upper extremity perfusion. Although CSSS was once thought to be a rare phenomenon, its prevalence has been underestimated and is becoming increasingly recognized as a serious threat to the success of CABG. Current guidelines are lacking on recommendations for screening of subclavian artery stenosis (SAS) pre- and post-CABG. We hope to provide an algorithm for SAS screening to prevent CSSS in internal mammary artery bypass recipients and review treatment options in the percutaneous era.

Coronary‐subclavian steal syndrome, an easily overlooked entity in interventional cardiology

“…First, it is common that SAS and accompanying CSSS is diagnosed incidentally as most patients remain asymptomatic due to slow disease progression enabling subclavian artery collateral circulation . The diagnosis can either be made on physical examination or by imaging study, including ultrasound, computed tomography angiography, magnetic resonance angiography, or (coronary) angiography . Suggestive signs on physical examination include a bruit, an interarm brachial blood pressure difference of >15 mmHg or an interradial pulse delay.…”

“…Second, CSSS can present itself indirectly with left ventricular systolic impairment and/or heart failure. Finally, CSSS can evidently induce the entire spectrum of ischemic heart disease from stable angina, acute coronary syndrome, and ventricular arrhythmias to sudden cardiac death …”

“…Interventional cardiologists performing coronary angiographies in patients after CABG with IMA grafting should actively screen for potential SAS. The gold standard remains selective subclavian artery angiography with pressure gradient recording . An angiographic 75% stenosis or a 50% stenosis with pressure gradient >10 mmHg are considered to be hemodynamically significant .…”

Síndrome Coronariana Aguda Como Apresentação Atípica Do Fenômeno De Roubo Subclávio

“…7 , é ocasionada por uma redução do calibre da artéria subclávia, levando à redução da pressão distal à lesão e comprometendo o fluxo sanguíneo regional, especialmente durante atividades realizadas com membros superiores 4 . A estenose da artéria subclávia é geralmente causada por aterosclerose, visto que o ângulo agudo entre a origem dessa artéria e a aorta ascendente aumenta o fluxo turbulento e o seu potencial aterogênico 8 , embora diversas outras condições possam comprometer o fluxo para esse vaso e causar roubo coronariano, tais como as arterites de Takayasu e de células gigantes. Além disso, há relatos de causas de RCS mesmo na ausência de estenose subclávia, como, por exemplo, o desenvolvimento de fluxo competitivo por fístula de hemodiálise 1 .…”

“…Outras modalidades diagnósticas são a ultrassonografia com Doppler antes e após exercício com membro superior, angiotomografia de tórax e ressonância magnética com angiografia. Entretanto, a mensuração bilateral da pressão arterial ainda permanece um método simples para rastreamento, embora alguns achados possam passar despercebidos, especialmente os pacientes que possuem estenose bilateral 8 . De qualquer formar, as diretrizes do American College of Cardiology/American Heart Association (ACCF/AHA) de 2011 e da European Society of Cardiology/European Association of Cardio-Thoracic Surgery ESC/EACTS de 2014 não apresentam nenhuma definição sobre o melhor método de rastreio 12,13 .…”