Obstructive unprotected left main coronary artery (ULMCA) disease is a high-risk condition with potentially poor clinical outcomes if not treated promptly. Coronary artery bypass grafting (CABG) has been the first-line treatment for several decades, relegating PCI to cases of high surgical risk. However, advances in PCI outcomes, coupled with technological and pharmacological progress, including new-generation drug-eluting stents, intracoronary imaging, and antithrombotic therapy, have progressively positioned PCI as a safe alternative to CABG in certain patient subgroups. Recent studies indicate CABG may be more favorable in younger patients, whereas PCI could be an equivalent option in older patients. Thus, this meta-analysis aimed to evaluate outcomes of PCI versus CABG in ULMCA disease based on patient age at presentation.

Fourteen studies (4 randomized controlled trials and 10 adjusted observational studies) involving a total of 24767 patients (7952 treated with PCI and 16779 with CABG) were included. The primary endpoint was all-cause mortality, with major adverse cardiovascular events (MACE), myocardial infarction, and repeat revascularization as secondary endpoints. The median follow-up was 4.6 years. For younger patients, CABG was associated with lower mortality and fewer repeat revascularizations compared to PCI. In older patients, no significant differences were observed in overall mortality, myocardial infarction, or repeat revascularization between the two approaches; however, a higher risk of MACE was noted after PCI. This is attributed by the authors to the use of a lower age threshold in most analyzed studies, leaving the elderly population underrepresented.

The study concludes that while myocardial revascularization remains the preferred treatment for ULMCA disease in younger patients, PCI can be a safe and effective alternative for older patients, highlighting the need for further studies focused on this age subgroup.

COMMENTARY:

This meta-analysis, which includes 14 studies, evaluates percutaneous versus surgical revascularization for LMCA disease stratified by age. However, most studies in the meta-analysis were not specifically designed to examine age effects, with insufficient representation of elderly patients. Additionally, the authors acknowledge data heterogeneity and lack of detailed procedural information, affecting the ability to draw definitive conclusions applicable to the elderly population. The inherent limitations of meta-analyses, including data heterogeneity and inadequate elderly representation, create uncertainty and emphasize the need for more targeted studies to make more precise clinical decisions in this subpopulation.

Left main coronary artery disease has historically resisted PCI as the last frontier. Until recently, major clinical trials and guidelines almost exclusively endorsed surgical revascularization for this condition. However, in the past 10 to 15 years, the rapid and significant advances with drug-eluting stents have spurred change. Randomized trials comparing both revascularization methods aim to elevate PCI to a level comparable to surgery across various patient groups (elderly, comorbidities, favorable PCI anatomy, etc.), as shown in this meta-analysis. European myocardial revascularization guidelines recommend both techniques with similar evidence levels (IA) when the SYNTAX score is low (≤ 22 points). For intermediate scores (22-32 points), the evidence level for PCI drops to IIaA, and it is not recommended at all (IIIB) for high SYNTAX scores (> 32 points). Nevertheless, following findings from the EXCEL study, EACTS withdrew support for these recommendations.

The growing interest among interventionalists in percutaneous approaches for LMCA is evident, and with the recent technological advances and the “TAVI phenomenon” as precedent, there are new challenges ahead. The results thus far endorse the effectiveness and superiority of the surgical approach. Studies like this should encourage surgeons to adopt less invasive procedures and pursue excellence in treating coronary artery disease. PCI also plays a key role in LMCA treatment, especially for favorable anatomies or when surgery poses high risk. Therefore, revascularization strategies should be individually tailored, guided by a multidisciplinary team to provide the best-suited option for each patient.

REFERENCE:

De Filippo O, Di Franco A, Boretto P, Bruno F, Cusenza V, Desalvo P, et al. Percutaneous coronary intervention versus coronary artery surgery for left main disease according to lesion site: A meta-analysis. J Thorac Cardiovasc Surg. 2023 Jul;166(1):120-132.e11. doi: 10.1016/j.jtcvs.2021.08.040.