The new 2021 coronary revascularization guidelines are spurring controversy, as surgical associations raise concerns about the interpretation of the evidence behind key recommendations and the makeup of the writing committee.
The guideline was published in December by the American College of Cardiology, American Heart Association, and Society for Cardiovascular Angiography and Interventions (ACC/AHA/SCAI), and replaces the 2011 coronary artery bypass surgery (CABG) and the 2011 and 2015 percutaneous coronary intervention (PCI) guidelines.
Dr. Joseph Sabik III
The American Association for Thoracic Surgery (AATS) and Society of Thoracic Surgeons (STS) were part of the development of the document but have withdrawn their support, citing three areas of concern in a recent editorial in Annals of Thoracic Surgery.
“I do have to emphasize this is not just the AATS and STS – the European societies, Latin American societies, Asian societies, and even cardiologists are all coming out against these guidelines,” Joseph F. Sabik III, MD, University Hospitals Cleveland Medical Center, lead author of the editorial, said in an interview. “So, I think that tells us that something didn’t go right here.”
The main objection is the downgrading of CABG surgery from a class 1 to weak 2b recommendation to improve survival in patients with three-vessel coronary artery disease (CAD) and normal left ventricular function.
The ISCHEMIA trial was used to support this two-level downgrade and a class 1 to 2a downgrade for CABG in three-vessel CAD with mild to moderate left ventricular dysfunction. But the trial wasn’t powered for survival, only 20% of patients underwent CABG as the initial invasive strategy, and patients were followed for less than 5 years, the editorialists observed.
At the same time, there’s plenty of observational and randomized studies such as SYNTAX, EXCEL, and FAME 3 showing a clear survival benefit of CABG over PCI, Dr. Sabik said. “The criticism is that these are old studies and aren’t applicable today, but we don’t understand downgrading without any evidence suggesting it [CABG] isn’t effective anymore.”
CABG and PCI treated as equal
AATS and STS also object to the new guidelines treating PCI and CABG as equivalent revascularization strategies in decreasing ischemic events. Both were given a 2b recommendation for survival with triple-vessel disease, but randomized trials have demonstrated not only lower mortality with surgery but fewer reinterventions and myocardial infarctions.
“None of that gets acknowledged in the guidelines; they are treated equally,” Dr. Sabik said. “So if you’re going to say that CABG isn’t any better than medical therapy, in our mind, you have to say that PCI is worse than medical therapy. And we don’t believe that, I want you to know. We just think that the logic doesn’t make any sense. The committee used what it wanted to but didn’t use many things that committees have used in the past to give CABG a level 1 recommendation.”
The downgrade is also at odds with the 2018 European Society of Cardiology (ESC)/ European Association for Cardio-Thoracic Surgery (EACTS) guidelines, which give CABG a class 1 recommendation in three-vessel CAD as well as one- or two-vessel CAD with proximal left atrial descending artery stenosis.
In a Dec. 14 letter to the ACC/AHA Joint Committee, the Latin American Association of Cardiac and Endovascular Surgery (LACES) also called out the guideline committee for the 2b class of recommendation (COR) for PCI and CABG, saying it contradicts the text, which “clearly considers” the need to give a weaker endorsement for PCI than for CABG in patients with multivessel CAD.
“Considering that this section has the most significant impact due to the prevalence of stable ischemic heart disease in patients with multivessel CAD, such a contradiction may affect the lives and survival of millions of patients worldwide and have a major socioeconomic impact,” the letter states.
“Therefore, LACES respectfully but vehemently believes the Task Force should seriously reconsider the wording and recommendations in this specific large group of patients.”