Off-Pump Coronary Artery Bypass Grafting: Technical Evolution, Current Evidence, and Barriers to Universal Adoption

Off-pump coronary artery bypass grafting (OPCAB) represents one of the most significant technical innovations in contemporary cardiac surgery. Developed as an alternative to conventional on-pump coronary artery bypass grafting (ONCAB), OPCAB avoids cardiopulmonary bypass and its associated systemic inflammatory response, aiming to reduce perioperative morbidity and improve recovery. Over the past three decades, advances in stabilization devices, intracoronary shunts, anesthetic management, and surgical training have refined the procedure, making it safer and more reproducible. Despite these developments, OPCAB adoption remains inconsistent worldwide, reflecting ongoing debate about its relative benefits and limitations. Evidence from randomized controlled trials, meta-analyses, and large registries suggests that OPCAB achieves comparable early mortality to ONCAB, with potential advantages in reducing renal dysfunction, neurocognitive decline, and perioperative bleeding. These benefits appear most pronounced in high-risk subgroups, including elderly patients and those with significant comorbidities. However, concerns persist regarding long-term graft patency, completeness of revascularization, and variability in outcomes depending on surgeon experience and institutional expertise. Cost-effectiveness analyses have suggested potential resource savings, but these are offset by training requirements and the technical complexity of the procedure. Global practice variation highlights the influence of surgical culture, guideline ambiguity, and institutional resources. Barriers to universal adoption include technical challenges, inconsistent long-term outcomes, and limited exposure in training programs. In the future, robotic and minimally invasive OPCAB, as well as hybrid revascularization strategies, may expand its role. This review synthesizes current evidence, explores barriers to widespread implementation, and outlines future directions for integrating OPCAB into balanced, evidence-based clinical practice.