Guidelines Notwithstanding, More Diabetics with Multivessel CAD Receive PCI Than CABG

Despite current society guidelines that recommend CABG over PCI for diabetic patients with multivessel disease, only about one-third of them actually undergo surgery in the setting of NSTEMI, according to new registry data. What’s more, the proportion of this population who receive PCI has increased over the last several years.

In 2011, the American College of Cardiology and the American Heart Association decided that CABG should be the preferred revascularization option for patients with multivessel disease and diabetes. Even though this recommendation was based on data from randomized control trials of mostly stable patients, a subgroup analysis of the FREEDOM trial confirmed the superiority of surgery over PCI in diabetic patients with multivessel disease who were enrolled after an ACS event.

To address the “implementation gap between the available evidence base and routine medical practice,” Ambarish Pandey, MD (UT Southwestern Medical Center, Dallas, TX), and colleagues looked at revascularization methods in 29,769 NSTEMI patients with diabetes and multivessel disease enrolled in the ACTION Registry-Get With the Guidelines from July 2008 to December 2014.

Overall, 36.4% were treated with CABG, 46.2% received PCI (77.2% with at least one DES), and 17.3% were treated with no revascularization. The proportion of patients receiving any revascularization increased from 81.1% to 83.6% over the course of the study (P < 0.0001 for trend), driven entirely by increasing PCI rates (45% to 48.9%; P = 0.0002 for trend). Rates of CABG remained stable over time (36.1% to 34.7%; P = 0.88 for trend).

Moreover, among the 312 hospitals that treated at least 25 patients throughout the study period, hospital-level use of CABG ranged from zero to 78% and PCI ranged from 22% to 100%. While no hospital-level characteristics predicted whether a patient would receive PCI or CABG, patient-level predictors included:

• Anatomical severity of disease
• Early treatment of adenosine diphosphate receptor antagonists
• Age
• Sex
• History of heart failure

Evidence Base Not Applicable for NSTEMI

The results “provide an insight into the contemporary patterns of revascularization” among diabetics with multivessel disease and NSTEMI, Pandey and colleagues write. Rather than basing their revascularization decisions on the guidelines, most practitioners are instead “particularly influenced by the severity of underlying CAD,” they add.

The wide ranging hospital variation among both CABG and PCI is likely related to “a lack of clinical consensus among physicians regarding the optimal [strategy],” the authors write, “rather than a lack of awareness regarding the evidence base.” Some physicians might not even consider the available evidence base applicable in the setting of NSTEMI, they add, and “the provider’s preferences may also bias the patients to align toward less [the] invasive option.”

Commenting to TCTMD, Sripal Bangalore, MD (NYU Langone Medical Center, New York, NY), said he is “not really” concerned over the discrepancy between the proportion of patients receiving CABG and the guidelines because past evidence mostly comes from patients with stable ischemic heart disease. “Although the FREEDOM trial included stable ACS patients, and the results of superiority of CABG over PCI was seen in this subset, we have to bear in mind that the FREEDOM trial used first-generation DES,” he said in an email. “It is reassuring to see that a [third] of patients undergo CABG and the proportion increase[s] with increasing CAD complexity.”

In fact, FREEDOM co-investigator Michael Farkouh, MD (Mount Sinai Hospital, New York, NY), who was not involved in this study, told TCTMD that he was impressed by the CABG rate. “I don’t think it’s inappropriately low. I’m surprised that it is even 30% because of the way we practice,” he said. “We practice ACS by going after the culprit vessel and then making a decision later about bypass.”

Likewise, Ajay Kirtane, MD (Columbia University Medical Center, New York, NY), told TCTMD he would be “more concerned if these findings were that way in a stable population. But with true no-STEMI, the urgency goes up.” More troubling, however, was the relatively high rate of patients in this study who received no revascularization, he said.

“These are people who would clearly merit revascularization as a whole, and maybe some of them are elderly or have other reasons, but [their rate] seemed a little bit high,” Kirtane commented.

But Farkouh said he was not concerned with this metric. “That’s an interesting phenomenon probably related to the fact that there were enzyme rises but that patients didn’t have any lesions to be revascularized,” he explained. “That’s not unusual either because the lesions that cause events are not always greater than 50%, so that didn’t surprise me. I think you are going to have a subset treated medically either by choice or by anatomy.”

Going forward, Bangalore called for randomized studies to determine an “optimal treatment strategy” for patients with multivessel disease and NSTEMI. “The driver for decision between PCI and CABG should be based on ability to completely revascularize patients, as we have shown in a number of studies from the New York State registry,” he added.

What is really needed are outcomes data, Farkouh said. “How do these . . . FREEDOM-like patients do if they have bypass instead of PCI? That’s a question we really don’t know,” he observed. “That’s probably an interesting twist on it all. Because when you have and MI and you do bypass, they are higher risk patients because they’ve had a heart attack and you are doing surgery on them.”

Related Stories:

• Over the Long-term, EES Match CABG for Diabetic Patients With Multivessel Disease
• FREEDOM: CABG Superior to PCI in Diabetic Patients with Multivessel Disease
• Early QOL Advantage of CABG Over PCI for Diabetic Patients Disappears After 2 Years