Ablation for atrial fibrillation — author’s reply

In my post about the recent NEJM article on ablation for atrial fibrillation, I commented that “… it is not clear to me how exactly to evaluate a comparison of an ejection fraction in atrial fibrillation (the baseline) with one obtained in normal sinus rhythm…”

The corresponding author of this article, Dr. Pierre Jais, has emailed me this reply:

I would like to thank you for your comments and interesting web site.

I just would like to emphasize that the baseline echographic EF was acquired just after the ablation procedure, in sinus rhythm, to overcome the
limititation you pointed out.

Best regards.

Pierre Jais

I went back to the article, to see if I had misunderstood or misstated the methods. The description of the echocardiographic determination of ejection fraction at baseline is as follows:

Patients were routinely admitted two days before the ablation procedure for baseline evaluation. Treatment with oral anticoagulants, taken by all the patients, was stopped on admission, and treatment with all antiarrhythmic drugs, except amiodarone, was stopped for an appropriate period before ablation. Heart rate and rhythm were monitored with the use of 48-hour ambulatory electrocardiography. Transesophageal echocardiography was performed to rule out atrial thrombi, and transthoracic echocardiography was performed to evaluate cardiac structure and function. Echocardiographic measurement of the left ventricular ejection fraction was standardized with the use of Simpson’s biplane method for all patients during the initial hospitalization and subsequent visits.

From the above description, I don’t think it was unreasonable to assume that the initial EF was determined while the patients were still in atrial fibrillation.

Thus, the author’s reply represents a significant clarification.