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CABG surpasses PCI for diabetics out to 7.5 years

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Further evidence shows CABG usually better for diabetics

These extended results from the FREEDOM trial that followed many patients for 10 years or longer add to the consistent evidence base that supports coronary artery bypass grafting (CABG) as the preferred revascularization strategy for patients with diabetes and multivessel coronary disease. The new findings support existing society guidelines that recommend CABG over percutaneous coronary intervention in these patients, most recently in the revascularization guidelines from the European Society of Cardiology (Eur Heart J. 2018 Aug 25. doi: 10.1093/eurheartj/ehy394). An update to the U.S. guidelines should appear in 2019.

Dr. Alice K. Jacobs, professor of medicine, Boston University MItchel L. Zoler/MDedge News

Dr. Alice K. Jacobs

An important limitation of the extended follow-up analysis reported by Dr. Fuster was that it included half of the patients originally enrolled in FREEDOM. This introduced a potential bias and also underpowered the study, but the 89% follow-up of patients at centers that opted to participate in the longer-term phase helps mitigate the potential for bias.

Continued improvement of revascularization techniques, hardware, and medical management of patients with diabetes and multivessel coronary artery disease makes it challenging to apply the results of studies run in earlier eras to today’s practice. It is possible that continued evolution of coronary stent technology may reduce the differences in outcomes between bypass surgery and percutaneous coronary interventions, although this is less likely if much of CABG’s success relates to the protection it gives against new disease. Future comparisons of different approaches with revascularization will need to take into account the potential contribution of other procedures, other adverse outcomes aside from mortality during long-term follow-up, the consequences of incomplete revascularization, and the impact of new medications for treating diabetes that have been recently shown to also have cardiovascular disease effects. All these factors in concert will define the optimal approach to managing these patients.

Alice K. Jacobs, MD , is director of the cardiac catheterization laboratory at Boston Medical Center and a professor of medicine at Boston University. She has received research support from Abbott Vascular. She made these comments as designated discussant for the study.


 

REPORTING FROM THE AHA SCIENTIFIC SESSIONS

– Patients with diabetes who underwent coronary artery bypass grafting had significantly better survival than patients with diabetes who underwent percutaneous coronary intervention after a median 7.5 years of follow-up.

Dr. Valentin Fuster, professor of medicine, Icahn Medical School at Mount Sinai, New York MItchel L. Zoler/MDedge News

Dr. Valentin Fuster

Those patients comprised about half the patients enrolled in the FREEDOM randomized trial.

Long-term follow-up was only possible for just under half the 1,900 patients with diabetes and multivessel coronary disease originally enrolled in FREEDOM, but when researchers combined the long-term results with the data collected in the original study that had a median 3.8-year follow-up, they found all-cause mortality occurred in 18.3% of the patients who underwent coronary artery bypass grafting (CABG) and in 24.3% of patients treated with percutaneous coronary intervention (PCI), a 6% absolute between-group difference that was statistically significant, Valentin Fuster, MD, said at the American Heart Association scientific sessions. This fully jibed with the primary FREEDOM results, which found after 5 years a statistically significant reduction in all-cause death with CABG, compared with PCI, and also a significant reduction in the study’s primary endpoint (a combination of all-cause death, MI, and stroke), which occurred in 18.7% of patients randomized to CABG and in 26.6% of those randomized to PCI (N Engl J Med. 2012 Dec 20;367[25]:2375-84).

The extended follow-up finding lent additional support to existing society recommendations that CABG is the preferred revascularization strategy for patients with diabetes and multivessel coronary disease, most recently from the European Society of Cardiology (Eur Heart J. 2018 Aug 25. doi: 10.1093/eurheartj/ehy394), said Dr. Fuster, professor of medicine at the Icahn School of Medicine at Mount Sinai and director of Mount Sinai Heart in New York. A subgroup analysis of the extended follow-up also suggested that the survival benefit from CABG, compared with PCI, was especially strong among patients at or below the study’s median age of 63 years. In the younger subgroup survival among patients treated with CABG was twice as good as it was among patients treated with PCI.

Dr. Fuster noted that few data have been previously reported for survival rates beyond 5 years after revascularization. “This was a difficult study. Following patients for more than 5 years is hard,” he said. Concurrently with his report at the meeting the results also appeared online (J Am Coll Cardiol. 2018 Nov 11. doi: 10.1016/j.jacc.2018.11.001).

The FREEDOM (Future Revascularization Evaluation in Patients with Diabetes Mellitus: Optimal Management of Multivessel Disease) trial enrolled patients at 140 participating centers during 2005-2010. A total of 25 sites agreed to participate in the extended follow-up and could track 943 patients, 50% of the starting cohort of 1,900 and 89% of the patients originally enrolled at these 25 centers. Dr. Fuster stressed that the 957 patients not included in the follow-up had not been lost, but rather had been managed at sites that declined to participate in this additional study.

Dr. Fuster acknowledged that methods and hardware for PCI have changed since the study ran a decade ago, as have options for medical management. He also highlighted that the long-term follow-up results had no data on rates of MIs and strokes.

FREEDOM had no commercial funding. Dr. Fuster reported no relevant disclosures.

SOURCE: Fuster V et al. AHA 2018, Abstract 18609.

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