Safety concerns still linger about using drug-eluting stents (DES) in patients with diabetes, but complications could result from the individual’s condition and not from the stent itself.
Diabetes currently afflicts 171 million people globally, including 23.6 million Americans—and these figures are expected to double by 2030. The adverse vascular consequences of diabetes are well documented, along with the increased incidence of atherosclerosis. Research suggests that the representation of coronary artery disease in patients with diabetes varies widely and the decision whether to perform PCI or CABG is not so clear cut.
“That decision needs to be tailored to the individual patient,” says Suresh R. Mulukutla, MD, an interventional cardiologist from the Cardiovascular Institute at the University of Pittsburgh Medical Center.
|Peter B. Berger, MD, director of the Center for Clinical Studies at Geisinger Health System in Danville, Pa.|
A diabetic patient who is typically a good surgical candidate has left main disease, or one or two bifurcation lesions, or mild to moderate left anterior descending artery disease with a single severe stenosis. PCI would be preferred if the atherosclerotic state is relatively straightforward—one or no bifurcation, no significant left main involvement and little diffused disease.
Recently, some confusion arose over the BARI 2D trial and its accompanying editorial (NEJM 2009;360(24):2503-2515/2570-2572). BARI 2D, which enrolled more than 2,000 diabetics, was misinterpreted as having been powered to compare CABG with PCI. “It was not a CABG versus PCI study, but rather a medical therapy versus revascularization study. The choice of revascularization, which included both angioplasty and CABG, was left up to the treating physician. It was not a randomized comparison of the two,” Mulukutla explains.
However, BARI 2D led to some over-reaching interpretations that revascularization (whether PCI or bypass) is in many ways equivalent to medical therapy. In the accompanying editorial, Boden et al wrote that BARI 2D “reinforces other current scientific evidence supporting the benefits of CABG over PCI, especially in patients with diabetes.” In response, Peter B. Berger, MD, director of the Center for Clinical Studies at Geisinger Health System in Danville, Pa., says, “I couldn’t disagree more strongly with that statement, as the BARI 2D trial does not only not support CABG over PCI—it doesn’t even address the issue.”
DES vs. BMS
Recent clinical data have trended toward DES over bare-metal stents (BMS) for diabetics. At the 2008American Heart Association scientific sessions, Mauri et al presented results on 5,051 diabetics in the nonrandomized Mass-DAC Registry, which found that the risk-adjusted mortality at three years was 17.5 percent for DES versus 20.7 percent for BMS, with no excess adverse events.
Yet, some questions still remain about whether insulin-treated diabetics will respond differently to either a DES or BMS. Mulukutla et al sought to answer this concern in an analysis of the one-year outcomes in the NHLBI Dynamic Registry, which involved insulin-treated and noninsulin-treated diabetics who underwent PCI with either DES or BMS (JACC Intv 2008;1:139-147). They found that DES were associated with a lower risk for repeat revascularization compared with BMS in either group. Also, DES use was not associated with any significant increased safety risk compared with BMS.
The authors concluded that DES should be the “preferred strategy for diabetic patients.” Mulukutla adds that while “study after study has shown stronger efficacy data with DES over BMS, our study shows that they are at least as safe as BMS in this patient population. In fact, there appears to be no safety concerns with the use of DES in the diabetic population.”
Mulukutla says the only exceptions are patients with whom there will be dual-antiplatelet compliance issues, such as those who have scheduled surgery. He estimates that about 85 to 90 percent of the diabetic population are being treated with DES. In an accompanying editorial, Steven Marso wrote that despite the improved vessel patency and acceptable safety profile with DES, there is neither a neutralization of restenosis risk nor an optimal DES platform ideally suited for diabetics (JACC Intv 2008;1:148-149).
Likewise, Berger says he does not