Author + information
- Chance M. Witt, MD and
- Abhishek J. Deshmukh, MBBS∗ ()
- ↵∗Address for correspondence:
Dr. Abhishek J. Deshmukh, Department of Cardiovascular Medicine, Mayo Clinic, 200 First Street Southwest, Rochester, Minnesota 55905.
Atrial fibrillation (AF) is a major burden in the United States affecting millions of people, with numbers only expected to increase. Along with this growing epidemic, we have seen improvements in catheter ablation techniques over time that have led to the most recent guidelines in 2014 suggesting that ablation is a reasonable first-line option and a class 1 treatment option for many patients after failing antiarrhythmic drugs (1). With millions of patients dealing with AF, it has been necessary for more electrophysiologists around the country to begin performing these procedures to keep up with the growing demand for treatment of this disease. There is a clear procedural endpoint, isolation of the pulmonary veins, and this should be accomplished in the safest possible manner. Therefore, once the basics of how to isolate the pulmonary vein are understood, much of the focus of the procedure is on developing a “muscle memory” and preventing complications.
Concerningly, it was found in a prior analysis of the Nationwide Inpatient Sample that complication rates were not improving and even showed a trend toward an increase in complications (2). This study also showed an inverse association between operator volume and complication rate. During this period, technology and experience of many physicians was improving, so the increase in complications likely related to the physicians just beginning to perform pulmonary vein isolation ablations. As with any procedure or surgery, there is a learning curve and success rates and complication rates tend to improve over time. Therefore, during the period where a wave of physicians new to the procedure was starting up AF ablation programs, we saw increasing complication rates.
If this increase in complications is explained by the surge in entry of new and low-volume proceduralists, then there might be a different result if we only focused on an individual practice where the technological advances and increasing experience were the primary forces over time. In this issue of JACC: Clinical Electrophysiology, Rehman et al. (3) provide this type of analysis. They demonstrate that over a 16-year period of the early 2000s, the gains in experience, technology, and ideal best practices at their high-volume, tertiary care center led to decreases in many life-threatening complications. Not only did the rates of complications improve, but the overall rates were extremely low, <1%, with 0 deaths seen in over 10,000 patients undergoing ablation for AF.
This study provides us with several important pieces of data. First, it shows that with the correct tools and continuous quality improvement, AF ablation with pulmonary vein isolation can be a fairly low-risk procedure with an extremely low, or in this case 0, risk of mortality. It also demonstrates that when life-threatening complications do occur, as happened to 100 patients in this study, expert management by a well-equipped team of physicians and staff can save the patient from death and morbidity.
Several specific complications in this study deserve to be highlighted. Pericardial effusion was the most common potentially life-threatening complication, but it can often be handled effectively with pericardiocentesis, a skill with which many electrophysiologists have become increasingly comfortable. It also shows the rare but crucial need for surgical backup. Rehman et al. (3) note a decrease in this complication over time, which they temporally correlate with the introduction of contact force–sensing catheters.
The next most common complication in their study, and the one with the most long-term negative effect on patients, was stroke. This highlights that although they are rare, strokes continue to occur with these procedures and typically leave the patients with significant long-term deficits. On the positive side, they note that the rate of stroke incidence also decreased over the study period, which they correlate with changes in technology, the introduction of irrigated catheters, and changes in practice, performing procedures on uninterrupted anticoagulation.
Lastly, there were no atrioesophageal fistulas seen in the entire cohort of over 10,000 patients. This is an intriguing finding as prior studies have suggested that this occurs rarely but probably much more often than 1 in 10,000 patients, so even with ideal techniques, at least a single case would be expected (4). Although these procedures were performed at a tertiary referral center where follow-up can often be incomplete, atrioesophageal fistula frequently leads to death, which would have been captured in the death statistic. Furthermore, the patients were called at 3 months, which should cover the typical time course of this complication. Atrioesophageal fistula has been notoriously difficult to predict and study systematically due to the rare occurrence. Perhaps continuing with the practices we think should be beneficial, such as paying careful attention to the esophageal temperature probe, and reviewing our experiences, is the only option for information on how to prevent this devastating occurrence.
This leads into the most important aspect of this report. It provides a “how-to” guide for new and inexperienced operators. Although it may be ideal for all patients to undergo their AF ablation procedures at a high-volume tertiary care referral center, that is not a feasible option. There are too many patients with the disease and the cost and time associated with travel makes the widespread adoption of the procedure a necessity. Therefore, it is important that large, experienced centers continue to try and identify the ideal procedural management and techniques and share this information with other physicians around the country. Rehman et al. (3) provide a great example of how that is done. They demonstrate that they have a very low, acceptable rate of life-threatening complications and then highlight which specific procedure-related issues they feel contributed to this result. This is not a randomized trial or even case-control study, but it provides highly valuable information so that others can emulate what they have done. They even provide a useful appendix with practices they thought improved the safety of their procedures. Two major improvements noted in this table, which we would highlight, include the use of intracardiac echocardiography throughout the procedure and ultrasound for vascular access. Both of these are simple and important for preventing complications and the former is very helpful for early identification of complications. It is probably accurate to say that many physicians performing enough of these procedures will begin to identify these best practices on their own, but when patient’s lives are at stake, it is important to learn from others rather than “burn and learn.”
Fortunately, a more contemporary analysis of the National Inpatient Sample showed that the complication rate and mortality rate with inpatient AF ablation in the years 2011 to 2014 was significantly lower than the prior study of the years 2000 to 2010 (5). This was seen despite the likelihood that the trend of increasing outpatient procedures has led to a sicker cohort undergoing inpatient procedures. Therefore, we may be making some progress with the safety of AF ablation. Unfortunately, this same study showed an increasing complication rate within the 2011 to 2014 period, so a large experience such as the one provided by Rehman et al. (3) continues to be important to provide a blueprint for how to perform a safe AF ablation.
With high volumes of cases, use of 3-dimensional mapping, steerable sheaths, contact force catheters, balloon-based technologies, and endless other options, AF ablation has really changed from “this is how it is done” to “this is how I do it.” Furthermore, it is not uncommon to hear rumblings about personal records for high numbers of cases per day, short time per procedure, or relegating AF ablation to “just another pulmonary vein isolation,” all of which may be associated with suboptimal safety profiles. One apt analogy to consider, which is often quoted in relation to professional racing drivers on normal roads and why they have more crashes and get more fines: “At their level of skill, driving like an average driver may be intolerably boring. Imagine being a master of Beethoven and all you are allowed to play is Twinkle, Twinkle, Little Star!
Safety is defined and measured more by an absence than a presence. We urge caution for the bravados as not only are lives at stake, but in the foreseeable future, there is likely a chance of public reporting of data on efficacy and safety of procedures. For a shining example of how to perform this procedure with a goal of safety in mind, this experience from the Cleveland Clinic is truly aspirational!
↵∗ Editorials published in JACC: Clinical Electrophysiology reflect the views of the authors and do not necessarily represent the views of JACC: Clinical Electrophysiology or the American College of Cardiology.
Both authors have reported that they have no relationships relevant to the contents of this paper to disclose.
All authors attest they are in compliance with human studies committees and animal welfare regulations of the authors’ institutions and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the JACC: Clinical Electrophysiology author instructions page.
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