Complications, rehospitalizations not uncommon post-AF ablation

Reed Miller

January 05, 2012

Stanford, CA - The risk of an atrial-fibrillation ablation patient suffering a complication or needing to be rehospitalized soon after the procedure depends on the treating center's procedure volume as well as patient factors, a new "real-world" study shows[1].

Dr Rashme Shah (Cedars-Sinai Medical Center, Los Angeles, CA) and colleagues analyzed administrative data from 4156 AF ablation cases in the Healthcare Utilization Project California State Inpatient Database in order to provide a more realistic picture of complication rates in contemporary practice, she told heartwire . "Most of the data we have now are from the clinical trials in highly selective populations," she said. "This investigation really incorporates a broader population that in the real world can be getting this procedure."

"There's a bit of a knowledge gap with regards to short-term and longer-term complication rates after atrial-fibrillation ablation," study coauthor Dr James V Freeman (Stanford University, CA) told heart wire . The procedural complication rates reported in past trials range from 1% to 8% in experienced academic hospitals and from 7% to 10% in Medicare beneficiaries. "There's a real divergence between the two sources of data regarding what the true complication rates are. The academic centers tend to have a great deal of experience and are very specialized and not representative of the general experience. Medicare patients are older than 65 years of age. Patients 65 years and older are not really representative of the general patients who are being treated for atrial fibrillation with ablation out in the community."

The average age of patients in the study by Shah et al, published in the January 10, 2012 issue of the Journal of the American College of Cardiology, was 61.7 years, and the recent hospital procedure experience during the preceding year ranged from seven procedures in the lowest quartile to 137 in the highest quartile. Commenting on the study, Dr Lluis Mont (Universitat de Barcelona, Spain) told heart wire that "the results are not surprising and are quite in line with what has been published. This is really robust data because they do not come from very specialized centers. This is real practice and the real world."

Study affirms experience with women, older and sicker patients

The study found that 5.1% of patients undergoing an initial AF ablation had a complication, and 9.4% of patients had to be readmitted to the hospital within 30 days of their AF ablation. Older age, female sex, and prior AF hospitalizations were the patient factors associated with higher risk of complications and 30-day readmission. Less hospital experience with AF ablation was also associated with a higher adjusted risk of complications and/or 30-day readmissions.

"It was helpful to get a sense—and to reaffirm what has been shown with other procedures—that there are particular groups, like women, that we need to be particularly careful about with regard to how we anticoagulate them and how closely they're watched for complications and readmissions," Freeman said.

Mont said, "Most of the risk factors are [already] well-recognized. For example, women are more fragile for many cardiovascular procedures, and age is important, as is concomitant disease." Mont also pointed out that the study confirms that AF ablation is a relatively safe procedure, since most of the complications are not severe.

Bleeding and AF recurrence are common

The most common complications (52.1% of patients who had at least one complication) were vascular, usually bleeding. About 44% of patients with a complication showed a hematoma or hemorrhage, and 49.3% had a perforation or tamponade. Only one death and 10 strokes were related to procedural complications. Shah said that the bleeding rates were "not surprising with the procedure, because you use a huge catheter and much blood thinner." Unfortunately, the details of the one death are unknown based on the administrative data in the study, she said.

The most common cause of rehospitalization was AF or atrial flutter, appearing in 105 (26.9%) of the 390 rehospitalized patients. There were nine deaths (2.3%) and 19 (4.9%) acute strokes within 30 days of the ablation procedure. The rate of all-cause hospitalization was 38.5% at one year, and the rate of readmission for recurrent AF, atrial flutter, and/or repeat ablation was 21.7% by one year and 29.6% by two years.

Freeman said, "Those numbers appear, at first look, to be relatively high" and are relatively high for an elective procedure, but they are "within range" of other interventional procedures. The authors cite studies of Medicare data showing that the 30-day readmission rate for Medicare PCI patients is 14.6% and the readmission rate of Medicare beneficiaries with heart failure is 20.1%.

The AF recurrence rate "wasn't incredibly high compared with the published data, but these are hospitalizations, and hospitalizations aren't cheap," so a registry study collecting more detailed clinical data from the patients "might be a next step to understanding who are getting complications and get a better idea of how to prevent [them] and avoid these expensive hospitalizations," Shah said.

Mont agreed that "what is lacking is [information] on the type of patients who are included. When we talk about atrial fibrillation, there are many different stages of the disease. So that's a limitation [of the study]—that you had to put all of these together, and you may have very advanced disease with a very bad result and very young patients with very nice results.

"If you really want to know what you can offer patients, you have to separate the patients with a small atrium and better conditions from patients with very advanced disease," he explained.

The importance of experience

In an accompanying editorial[2], Dr David E Haines (Beaumont Health System, Royal Oak, MI) emphasizes the correlation between experience and procedural results that was demonstrated in Shah et al's study. "It is problematic that complex procedures continue to be performed at very low-volume centers in the US medical system," he argues. "As long as a hospital is able to profit from supporting interventional procedures by its physicians, there will be a tendency to set a low bar for granting privileges to any doctor who claims proficiency.

"It is imperative that any center that commits to establishing an AF-ablation program initiate robust quality-assurance methodology that tracks the long-term outcomes after intervention," Haines insists. "Until this is done, it is impossible to understand whether the individual operators and the hospital team are providing acceptable service to their patients."

Neither the authors nor the editorialist report any conflicts of interest.



Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.