Extended long term follow up confirms that coronary artery bypass grafting (CABG) is superior to percutaneous coronary intervention (PCI) with drug eluting stents (DES) for revascularisation in patients with type 2 diabetes and multivessel disease.
The final report from the FREEDOM trial, which originally compared outcomes of the two strategies at four years, has now been released with median follow up of eight years showing a 32% lower all-cause mortality for CABG than with PCI-DES.
Almost half the patients involved in the original study (943 of 190) were followed up for an extended period of up to 13 years (median 7.5) after being randomised to CABG or PCI with sirolimus or paclitaxel eluting stents and a background of optimal medical therapy.
Results from the follow-on trial showed that the significant reduction in death seen for CABG compared to PCI was maintained (18.7% vs 23.7%).
Writing in the Journal of the American College of Cardiology, the researchers said the findings allowed a number needed to treat (NNT) of 21 to be calculated for mortality at 7.5 years of follow-up for CABG over PCI.
However the higher rate of stroke seen in the original study with CABG represented a number needed to harm (NNH) for stroke at 3.8 years of follow-up for CABG over PCI.
Overall there was a 2.7 ratio of likelihood to be helped or harmed for CABG over PCI “supporting current recommendations by national and international guideline committees to consider CABG over PCI in patients with diabetes and multivessel disease,” they concluded.
An accompanying commentary by US cardiologists Sripal Bangalore and Marco A. Zenati of the New York University School of Medicine said there was a question of whether the benefits of CABG over PCI would be maintained in the modern era of novel hypoglycaemic agents such as SGLT2 inhibitors and improvements in drug eluting stents.
They said new trials such as the ISCHEMIA study were now comparing CABG, PCI and conservative strategies of medical therapy alone in patients with T2D.
Nevertheless, they said it would be foolish to ignore the results from the FREEDOM trial and the “compelling” evidence for CABG in patients with diabetes.
“Patients are presumably diagnosed with diabetes prior to the coronary angiography and a discussion indicating survival benefit with CABG should be initiated in advance of the diagnostic procedure, in order to allow enough time for the patient and family members to digest the information and make a decision that fits the individual preferences and lifestyle needs,” they wrote.