Why coronary artery bypass surgery is still the optimal treatment strategy for left main stem disease: an evidence-based review with a Malaysian surgical perspective

Left main stem (LMS) coronary artery disease (CAD) remains an important risk factor for increased mortality and morbidity at all stages of diagnosis and treatment of coronary artery disease. Anatomically, the LMS is a crucial vessel, as it provides two-thirds of the myocardial blood supply. Significant flow limiting stenosis usually results in low-tolerance angina and has prognostic implications. Historically, coronary artery bypass grafting (CABG) has been the treatment of choice for LMS revascularisation, but advances in percutaneous coronary intervention (PCI) have challenged this surgery-only paradigm. This article is a surgical appraisal of the current evidence regarding the optimal revascularisation strategy for LMS disease in terms of safety, efficacy and durability. LMS length is highly variable (2–40 mm) and does not appear to correlate with heart or patient size.1 LMS stenosis can be subdivided into three distinct lesions, ostial, body and bifurcation lesions, which have important therapeutic implications. LMS disease is a relatively common pathology, present in approximately 5–10% of patients undergoing coronary angiography. Prevalence is generally higher among Asians with over 20–30% of Malaysian CABG patients having significant LMS disease at surgery.2 Obstructive LMS disease is usually part of more widespread atherosclerotic CAD. Non-atherosclerotic causes of LMS lesions are rare and include tertiary syphilis-induced aortitis, Takayasu's arteritis and spontaneous dissection (most commonly in young women during the peripartum or early postpartum period). Iatrogenic causes include mediastinal radiation-induced fibrosis, and stenosis from traumatic surgical cannulation for delivery of antegrade cardioplegia, PCI intubation or malposition of an aortic-valve prosthesis.3 In Malaysia, in contrast to the West, premature CAD is a common finding; the reported mean age of patients undergoing PCI, is comparatively …