Author + information
- Published online May 21, 2018.
- Luke K. Kim, MD∗ (, )
- Ilhwan Yeo, MD,
- Jim Cheung, MD,
- Dmitriy N. Feldman, MD,
- Rajesh V. Swaminathan, MD and
- Hooman Kamel, MD
- ↵∗Division of Cardiology, Department of Medicine, Weill Cornell Medical College, 520 East 70th Street, Starr Pavilion 4, New York, New York 10021
The burden on the health care system due to atrial fibrillation (AF) continues to grow (1). Catheter ablation of AF has been used as an effective tool to treat symptomatic AF, and its application has continued to expand. A recent study based on National Inpatient Sample (NIS) data identified an overall increase in complication rates over a 10-year period (1). However, the impact of changing demographics on outcomes has not been established. Therefore, we sought to examine the association of evolving comorbidities of patients undergoing catheter ablation of AF with procedural adverse events using real-world data.
Using NIS files between 2003 and 2013, we identified patients with a principal diagnosis of AF using an International Classification of Diseases-9th Revision-Clinical Modification code as done in prior analyses (1). We analyzed the impact of comorbidities including: age, hypertension, diabetes mellitus (DM), anemia, collagen vascular disease, coagulopathy, peripheral vascular disease (PVD), chronic renal failure (CRF), chronic obstructive pulmonary disease (COPD), obesity, coronary artery disease (CAD), congestive heart failure (CHF), smoking, dyslipidemia, HIV, alcohol use, drug abuse, hypothyroidism, liver disease, electrolyte disorder, valvular disease, and pulmonary circulation disorder. We examined several in-hospital post-procedural outcomes including all-cause mortality, vascular complications, cardiac complications (including myocardial infarction and pericardial complications), conversion to open heart surgery, respiratory complications, and infectious complications (1).
From 2003 to 2013, there were complications in 8,533 of 111,670 cases (7.6%). The majority were due to vascular complications (4.3%), cardiac complications (2.5%), and respiratory complications (1.2%). Other complications included post-procedural stroke (0.4%), infectious complications (0.2%), and complications requiring open heart surgery (0.1%). Patients with CAD, anemia, COPD, coagulopathy, DM with complications, electrolyte disorder, obesity, PVD, obesity, and CRF were more likely to have complications. Similar to prior studies, there was a significant increase in post-procedural complications over time (from 7.2% in 2003 to 8.8% in 2013, p for trend = 0.01) (1). There was a significant increase in trends of blood loss requiring transfusion (0.1% in 2003 to 0.9% in 2013; p for trend = 0.01), pericardial complications (2.6% in 2003 to 1.9% in 2013; p for trend = 0.05), respiratory complications (0.7% in 2003 to 1.7% in 2013; p for trend = 0.004), and infectious complications (0% in 2003 to 0.4% in 2013; p for trend = 0.001).
In terms of comorbidities, the mean age of patients steadily increased during the study period (61.1 years in 2003 to 64.5 years in 2013; p for trend <0.001). Rates of cardiac comorbidities including CAD, CHF, and PVD increased by 60%, 33%, and 88%, respectively, from 2003 to 2013. Rates of other significant comorbidities, such as anemia, COPD, DM without complications, hypertension, obesity, and CRF, also showed continual growth (with an increase of 83%, 18%, 73%, 60%, 298%, and 344%, respectively, from 2003 to 2013). Although the crude odds ratio of overall post-procedural complication increased steadily from 2003 to 2013 (p for trend = 0.01), adjusted odds ratio, accounting for changing patient characteristics, showed that there was no significant change in trends of complication rates from 2003 to 2013 (Figure 1). Among individual complications, increasing trends were no longer observed for post-procedural hemorrhage requiring transfusion, pericardial complications, and respiratory complications after adjusting for patient comorbidities (p for trend = 0.34, p for trend = 0.67, and p for trend = 0.12, respectively).
The impact of comorbidities on complication rate trends has been seen in large population-based studies of other cardiovascular procedures (2). It is possible that cases requiring catheter ablation for AF are becoming more complex because many comorbidities are also risk factors for developing AF (3). However, the trends toward increased disease burden among patients undergoing catheter ablation for AF are likely explained not only by demographic changes of an aging population but also by changes in physician practice patterns. We identified a 30% increase in CHF among patients undergoing catheter ablation of AF between 2003 and 2013. CHF is a disease process that is associated not only with AF but numerous other comorbidities. Recent studies have shown an increasing role for catheter ablation in the treatment of patients with AF and CHF (4,5). The increasing prevalence of CHF among the general population as well as a growing acceptance of catheter ablation as an important therapy for these patients may partially explain the changes in patient demographics found in our study. With expanding indications for catheter ablation of AF, it is likely that catheter ablation for AF is being performed on sicker patients as operators become more comfortable with improving technology and experience. Our estimates were derived from a 20% sample of U.S. hospitals, and it is possible that the volume was either underrepresented or overrepresented by the sample. Furthermore, our study does not provide follow-up data, including freedom from AF. However, our study is the first to show that in-hospital outcomes remain unchanged despite the evolving complexity in patients undergoing catheter ablation for AF.
Please note: This work was supported by grants from the Michael Wolk Heart Foundation and the New York Cardiac Center, Inc. (New York, New York). The Michael Wolk Heart Foundation and the New York Cardiac Center, Inc. had no role in the design and conduct of the study; in the collection, analysis, and interpretation of the data; or in the preparation, review, or approval of the manuscript. The authors have reported that they have no relationships relevant to the contents of this paper to disclose. Dr. Cheung has received consulting fees from Biosense Webster. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
The authors attest they are in compliance with human studies committees and animal welfare regulations of the authors’ institution and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the JACC: Clinical Electrophysiology author instructions page.
- 2018 American College of Cardiology Foundation
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