The CABANA Trial: Results Not as Disappointing as Reaction by Non-EPs

On May 10, Dr. Doug Packer presented the results of the long-awaited CABANA trial at Heart Rhythm 2018. This trial compared catheter ablation to drugs for patients with new-onset or untreated atrial fibrillation (AF). Patients could have either paroxysmal or persistent AF, but had to be either over age 65 years or have a history of prior stroke, and had to be eligible for both ablation and antiarrhythmic drug therapy. Ablation was not superior to drug therapy for the primary endpoint of death, disabling stroke, serious bleeding, or cardiac arrest at 5 years (8% vs 9.2%, respectively; P=0.3).

Currently, we perform ablation on patients with symptomatic, drug-refractory AF using FDA-approved ablation tools that have been proven in randomized controlled trials to be safe and effective in preventing AF recurrence. This is associated with a class I recommendation in societal guidelines for patients with paroxysmal AF. The goal is to prevent AF recurrence in patients who are most likely to benefit, and to do it safely. Our focus has been finding the best approaches to prevent recurrent AF. It would have been nice if the CABANA trial showed that AF ablation is helpful as first-line therapy or also reduced mortality, but that would just be an added benefit. Not all cardiovascular interventions need to reduce mortality for them to be useful, as long as the intervention has been studied using objective endpoints that are meaningful to patients. 

One cannot ignore the enormous impact that the AF epidemic has had on patients and their families. One also cannot ignore the list of trials, including randomized trials, which have demonstrated the benefits of AF ablation in these patients. Just as important is the impact that ablation can have on an individual. For example, take the data from a patient shown in Figure 1. The pacemaker diagnostics in this patient with recurrent, medically-refractory paroxysmal AF who underwent ablation in February 2012 show a dramatic reduction in her AF burden after the procedure. She also had a dramatic improvement in her quality of life. This is not a placebo effect. This is a hard endpoint. Those who are jumping on social media after CABANA demanding a sham-controlled AF ablation trial are ignorant of the last 20 years of data, and have clearly not spent time with enough patients who have benefited from an AF ablation procedure.

The biggest disappointment from the CABANA trial is the comments from our non-EP cardiology colleagues who seem to have been poised to pounce. One can be critical of the study design, or of the overemphasis on secondary endpoints and on-treatment analyses that looked more favorable, but there is no place for other physicians, particularly cardiologists, to suggest that electrophysiologists are performing AF ablation in the absence of evidence and are only doing so for the money. In an opinion piece in the New York Times, a cardiology fellow wrote, “Doctors are rewarded on a fee-for-service basis, meaning the more that they do, the more they are paid. This is especially true of doctors performing procedures such as catheter ablation. Last year, five cardiologists at Ohio State University made almost $2 million (twice what the Buckeyes’ president made). In this environment, despite their best intentions, physicians cannot be expected to be completely disinterested stewards for their patients.”¹ Who is teaching this fellow that productivity-based physician compensation models inherently lead to impartiality and unethical non-evidenced based behavior? Why does a cardiology trainee think it is okay to come after electrophysiologists this way? Maybe it is because senior cardiologists, such as Dr. Milton Packer, think it is. As a vocal heart failure specialist, he wrote, “For most, performing catheter ablations has become a major source of revenue; it is currently estimated to be a $4.5-billion industry. Undoubtedly, if catheter ablations were found to be unhelpful, the annual salaries of the electrophysiologists would plummet.”² Now that is a disappointment.

Catheter ablation for heart rhythm disorders changes lives, including the lives of patients with medically-refractory symptomatic AF. There is no dispute about this, and the results of the CABANA trial do not change this.

References

1. Warraich H. Don’t Put That in My Heart Until You’re Sure It Really Works. New York Times. Published May 20, 2018. Available at https://nyti.ms/2IAn0AK. Accessed May 22, 2018. 
2. Packer M. Unbelievable! Electrophysiologists Embrace ‘Alternative Facts’. MedPage Today. Published May 16, 2018. Available at https://bit.ly/2ItSc4s. Accessed May 22, 2018.