Can the off-pump coronary artery bypass debate shed light on postoperative right heart dysfunction?

The debate over the relative merits of off-pump coronary artery bypass grafting (OPCAB) and conventional onpump coronary artery bypass grafting (CABG) continues unabated and remains an area of great controversy. Given the known effects of cardiopulmonary bypass (CPB) on the inflammatory and coagulation cascades, as well as a suggestion of adverse neurological sequelae, there has been a logical argument to perform surgical revascularizations without its use. Proponents of OPCAB have cited advantages in terms of neurological outcomes, renal function, blood use, cost, length of stay, arrhythmias, infections, and ventricular function.1–3 Critics assert that OPCAB is more technically demanding than conventional CABG, and, moreover, that consistent data showing sustained benefits have been lacking and that some existing data suggest inferior revascularization.4,5 At present, analyses of randomized controlled trials have generally shown that OPCAB results in outcomes equivalent to those of conventional CABG in terms of mortality, long-term neurological function, and revascularization while reducing rates of blood use, renal impairment, and cost.3,6–8 Given the steep learning curve of OPCAB and lack of clear long-term cardiovascular or neurological benefit, however, many surgeons have reverted to or continued to favor conventional CABG as their strategy of choice. One criticism leveled at OPCAB is that the results reported usually come from surgeons and centers that are exceptionally experienced in the technique. Given the significantly higher technical demands of OPCAB, results equivalent to conventional CABG may not be applicable to most practicing surgeons. The implication, though unproven, is that the average cardiac surgeon might experience worse outcomes when using OPCAB than with conventional CABG. Indeed, this may explain the relatively low penetration of this technique, despite some demonstrable advantages. Thus, despite high expectations and initial enthusiasm for OPCAB, only about 20% to 25% of surgical coronary revascularizations in the United States are currently performed without the use of CPB.