Despite dramatic advances in the diagnosis and treatment of cardiovascular disease, one cannot help but note the remarkable durability of coronary artery bypass grafting (CABG) as a reliable therapeutic option in the treatment of patients with coronary artery disease. The impressive decline in cardiovascular mortality over the past two decades is currently threatened by an epidemic of obesity and its attendant increase in diabetes. Indeed, adults with diabetes are 2–4 times more likely to have cardiovascular disease than are those without it, and at least 65% will die of it. Therefore, cardiovascular disease remains the leading killer of men and women in the United States and much of the world. It may not be surprising that CABG remains the most common operation performed by cardiac surgeons. Nor has an investigational interest in the procedure waned, as recent inquiry of “coronary artery bypass graft” in Pubmed yielded over 73,000 publications with a sustained interest over the past two decades.
Despite an increasing patient risk profile, mortality and morbidity have declined over this time and currently hovers around a 2.0% operative mortality and 1.3% rate of stroke. That said, the surgical community has been diligent in its efforts to reduce morbidity and improve patient outcomes. And that diligence and interest were well reflected in the CABG sessions at the recent 101st Annual Meeting of the American Association of Thoracic Surgery.
The recognition that the use of cardiopulmonary bypass and cardioplegic arrest, despite providing surgeons with a bloodless motionless field superbly suited for surgical precision, also subjects patients to a systemic inflammatory response, possible reperfusion injury, and obligate manipulation of a sometimes diseased aorta inspired the development of “off-pump” techniques. Now, after over 100 prospective randomized trials and 60 meta-analyses on the question of on- vs. off-pump CABG, the discussion has moved from “which technique is better” to “which technique is specifically better suited for which patient.” The role of operator experience and expertise appears foundational to achieving outcomes with the off-pump approach that can rival the graft patency and long-term survival of the on-pump approach while potentially providing lower morbidity in high-risk patients. With a declining volume of off-pump cases in American centers, questions regarding the adequacy of training sufficient to achieve that high level of expertise remains challenging.
The addition of an “anaortic” approach, which minimizes or eliminates the need for aortic manipulation (arterial grafts and “Y” or “T” grafts that do not need a proximal graft to the aorta), may further diminish the incidence of stroke. This approach, of course, raises the other major issue capturing surgical interest — the potential benefit for multi-arterial grafting. In the face of nearly overwhelming retrospective data favoring the long-term survival for a multi-arterial approach, the negative results of the controversial and somewhat flawed ART trial have certainly fueled the controversy. With less than 10% of American patients receiving multi-arterial grafting, there remains a discrepancy between current practice and the experience of professional opinion leaders — a gap that is progressively being filled with a higher level of emerging evidence.
Certainly, with CABG remaining a reliable therapy, especially for patients with complex coronary disease, diabetes, and reduced ventricular function, the relentless professional pursuit of improved results that have emerged from this and similar meetings bodes well for the persistently large population of patients with advanced coronary artery disease.