AHA: CABG bests PCI for diabetics with multivessel disease, but not for stroke

For diabetic patients with multivessel disease, CABG was superior to PCI in that it significantly reduced rates of death and MI, but had a higher risk of stroke, based on the late-breaking FREEDOM trial. However, there are patient-oriented considerations, particularly with stroke risk, which may make the decision to favor CABG over PCI less clear-cut, Ajay J. Kirtane, MD, told Cardiovascular Business.

The trial was presented Nov. 4 at the 2012 American Heart Association (AHA) Scientific Sessions in Los Angeles.

In the U.S., approximately 700,000 patients undergo multivessel coronary revascularization annually, wrote the FREEDOM investigators in the study that was simultaneously published Nov. 4 in the New England Journal of Medicine. Of these patients, approximately 25 percent have diabetes (Circulation 2012;125[1]:e2-e220).

In the trial, Michael E. Farkouh, MD, of the Mount Sinai Hospital in New York City, and his colleagues randomly assigned patients with multivessel coronary artery disease to undergo either PCI with drug-eluting stents or CABG. The patients were followed for a minimum of two years (median among survivors, 3.8 years). The primary outcome was a composite of death from any cause, nonfatal MI or nonfatal stroke.

From 2005 through 2010, they enrolled 1,900 patients (mean age, 63.1 years, 29 percent women and 83 percent had three-vessel disease) at 140 international centers. After five years, the CABG group had a lower combined rate of strokes, MIs and deaths (18.7 percent) than the PCI group (26.6 percent).

Strokes, a well-known risk of bypass surgery, occurred more often in the CABG group (5.2 percent) than in the PCI group (2.4 percent). However, more people died from any cause in the PCI group (16.3 percent) than in the CABG group (10.9 percent). The survival advantage of CABG over PCI was consistent regardless of race, gender, number of blocked vessels or disease severity, according to the authors.

The finding of increased stroke with CABG “has been observed in virtually every comparative trial of the treatment strategies,” wrote the study authors.  

“If you were to look solely at death and MI, CABG is clearly superior in this trial, but the two procedures are clearly different from a patient-oriented perspective, particularly with regards to the invasive nature of the two procedures and the increased stroke risk, especially within 30 days,” said Kirtane, of New York-Presbyterian and Columbia University Medical Center in New York City. “This study reaffirms the heart team strategy. For the past five years in our practice, if we are presented with a diabetic patient with multivessel disease, interventionalists take the patient off the cath lab table to consult with a surgeon.”

With regards to the mortality benefit, Mark A. Hlatky, MD, of Stanford University School of Medicine in Stanford, Calif., in the accompanying NEJM editorial, wrote that mortality has been consistently reduced by CABG compared with PCI, in more than 4,000 patients with diabetes who have been evaluated in 13 clinical trials. "The controversy should finally be settled,” he wrote.

However, Hlatky concurred with Kirtane that informed decision-making is necessary for the patients and the specialists. He added there is “little time for informed discussion about alternative treatment options … Well-informed patients might choose any of those options on the basis of their concerns about the various outcomes of treatments, such as survival, stroke, MI, angina and recovery time.”

Hlatky added that these discussions should begin before coronary angiography “to provide enough time for the patient to digest the information, discuss it with family members and members of the heart team, and come to an informed decision.”

Yet, Kirtane stressed that interventionalists need to get comfortable taking patients off the cath lab table, once they’ve undergone a diagnostic catheterization, to have these conversations, even though that has not been the traditional pathway for interventionalists and may cause some questions from patients. “Interventionalists are there to make a diagnosis first, not necessarily intervene on a patient,” he said. “In order to truly assess the patient, you need to perform a diagnostic catheterization.”

Regardless of when the conversation occurs, there is agreement that the discussion should take place. And Kirtane added that the stroke findings may be “more compelling for patients than the late MI or even the mortality findings.”

While the study authors and Hlatky stressed the importance of patient selection, there isn’t a clear-cut way to mitigate for stroke risk. “There are physicians who would perform off-pump surgery or screen patients ahead of time with carotid Doppler, but those methods would be exploratory,” Kirtane pointed out. “It’s not just for stroke risk, but also all the neurocognitive complications that accompany bypass surgery, which leads many patients to opt for stenting first.”            

As Hlatky wrote in his editorial, “This is a complicated decision, and clinical guidelines in the U.S. and Europe now emphasize the importance of more deliberate decision-making about coronary revascularization, including discussions with a multidisciplinary heart team.”

The National Heart, Lung and Blood Institute partially funded the trial.