The great singer Whitney Houston posed a question over 25 years ago that many still ponder today. “Where,” she asked, “do broken hearts go?”
Of course, her classic song asks us to imagine a destination for the pain wrought by the dissolution of love. Physicians, however, have more concrete possibilities in mind when asking where to take the hurting center of our emotional and physiologic lives: the cardiac catheterization lab versus the operating room. That is, for patients with multi-vessel coronary artery disease (CAD) who require revascularization, should first-line treatment be PCI or CABG?
Current guidelines suggest that CABG is the revascularization strategy of choice, but the studies that formed the basis for those recommendations compared CABG to PCI using first-generation stents. The development of second-generation stents has renewed the debate about whether PCI might be just as effective as surgery.
Two studies, now published in NEJM, seek to answer this question. The data from both suggest that while the answer is complicated, CABG seems to maintain its edge when it comes to long-term cardiovascular outcomes.
The first study is a prospective trial conducted in 27 sites in Asia. Designed to enroll 1800 adults with angiographically confirmed multi-vessel CAD who were deemed to be candidates for either intervention, the trial ultimately included only 880 participants due to slow enrollment. Participants were randomly assigned to PCI with everolimus-eluting stents or to CABG. Patients with clinically-significant left main disease were excluded from the trial.
The second study, an observational registry analysis, used similar criteria to define multi-vessel CAD. The investigators analyzed 18,000 patients included in a New York state database to compare outcomes between patients who had received everolimus-eluting stents and those who underwent CABG.
In the trial done in Asia, at a median follow-up of 4.6 years, the composite endpoint of death, MI, or target vessel revascularization occurred in 15.3% of patients in the PCI group versus 10.6% in the CABG arm (P = 0.04). There were no significant between-group differences in death or stroke, but there were significantly more spontaneous MIs and repeat revascularizations in the PCI arm.
In the New York registry study, at a mean follow-up of 2.9 years, the PCI group, as compared with CABG, had a higher risk of MI (1.9% per year vs 1.1% P<0.001) and repeat revascularization (7.2% per year vs 3.1% P<0.001), but PCI was associated with a lower risk of stroke (0.7% per year vs 1% P<0.001). As in the Asian trial, there was no significant difference in mortality between groups.
In an accompanying editorial, Stanford cardiologist Dr. Robert Harrington describes the limitations of an undersized randomized trial and the possible confounding inherent to an observational registry study. He concludes, “To the extent that the data from these two studies can be relied on, there are clearly trade-offs between the two revascularization strategies that need to be discussed with patients as part of the shared decision-making process. The early hazard of CABG (the risk of stroke) may be unacceptable to some patients, whereas others might want to avoid the later hazards of PCI (the risk of needing a repeat PCI procedure or having a myocardial infarction).”
NEJM Deputy Editor John Jarcho agrees, noting that together these studies “offer physicians new data to help weigh the benefits of improved long-term cardiovascular outcomes associated with CABG against the possible harms of undergoing major surgery.” These studies, then, offer some new knowledge and still leave the door open for continued debate about the best way to help patients (and their hearts) to find their way home.