Major Complications of Implantable Cardioverter-Defibrillators
Abstract & Commentary
By John P. DiMarco, MD, PhD, Professor of Medicine, Division of Cardiology, University of Virginia, Charlottesville. Dr. DiMarco is a consultant for Novartis, and does research for Medtronic and Guidant.
Synopsis: In fiscal 2003, 10.8% of Medicare patients undergoing cardioverter-defibrillator implantation experienced one or more early complications, associated with significant increases in LOS and costs.
Source: Reynolds MR, et al. The Frequency and Incremental Cost of Major Complications Among Medicare Beneficiaries Receiving Implantable Cardioverter-Defibrillators. J Am Coll Cardiol. 2006;47:2493-2497.
Reynolds and colleagues analyzed data on ICD implants from the Medicare Provider Analysis and Review (MedPAR) database for fiscal year 2003. All Medicare beneficiaries who underwent ICD implantation, with or without a left ventricular lead for resynchronization therapy, between October, 2002 and September, 2003, were identified in MedPAR by the appropriate ICD-9-CM code (37.94 or 00.51). Only procedures performed on an inpatient basis were included. Initially, 53,936 cases were identified, but 22,952 patients underwent one or more additional cardiovascular procedures during the same hospital admission and were excluded from analysis. Complications identified with ICD implant were then analyzed in the remaining 30,984 cases. The database was searched for the complications related to the procedure, which included the following: in-hospital deaths: implant related infections, pocket hematoma or hemorrhage, mechanical complication of the ICD, pneumothorax, cardiac perforation with pericardial effusion or tamponade, and acute renal failure with new onset hemodialysis. Other variables analyzed included length of stay and total cost for the implant hospitalization. Length of stay was defined as the number of days from admission to hospital discharge. Hospital cost was estimated by multiplying total charges submitted to CMS by each hospital's cost-to-charge ratio. Physician fees were not included.
In fiscal 2003, 30,984 Medicare patients underwent in-patient implantation of a single- or dual-chamber ICD (74.6%) or a cardiac resynchronization therapy—defibrillator (CRT-D) (25.4%) without other major cardiovascular procedures during the admission. Implantations were performed at 1122 hospitals, with the median hospital implant volume being 15. The mean (+SD) hospital course cost per admission was $42,184 ± $23,199, and the mean length of stay was 4.7 ± 6 days. Complications were identified in 10.8% of all procedures. Of interest, the overall complication rate was slightly higher for single- and dual-chamber ICD implants compared to CRT-D implants (11.0% vs 10.5%). The most common complications were mechanical complications (4.8% ICD, 3.8% CRT-D), hematomas (2.5% ICD, 3.4% CRT-D), infection (1.4% ICD, 0.7% CRT-D), and pneumothorax (1.0% ICD, 1.2% CRT-D). Death occurred before hospital discharge in 0.9% of cases. Of these patients who died, 33% had one or more procedure-related complications. Baseline characteristics of patients with and without complications were also analyzed. Patients who experienced complications were slightly more frequently women and nonwhite, and more likely to have acute myocardial infarction, ventricular fibrillation, cardiac arrest, and chronic pulmonary or renal disease compared to patients without complications. However, all of these clinical differences were relatively small. Patients with any complication generated $8769 in excess hospital cost and an increase of 4.3 days in length of stay.
Reynolds et al conclude that complications with ICD implants are more frequent in Medicare beneficiaries than had been previously estimated from published data from clinical trials or single-center experiences. ICD-related complications significantly increase the cost of therapy, and efforts to reduce these complications would have significant clinical and financial benefits.
Commentary
The data from this study show that the rate of complication with ICD implantation in Medicare beneficiaries is higher than previous estimates in the literature. These prior estimates had been based on data either from large clinical trials or observational data from single centers. There are several possible reasons why the complication rate is higher in a real world experience like that reported in this analysis of the Medicare database. Clinical trials are usually performed in high volume, highly experienced centers. Many of the centers will implant hundreds of ICDs per year. In this study, the mean number of implants per year per hospital was only 15. Clearly, increased experience should decrease the risk of complications. This possible explanation is also supported by the fact that the implant complication rate was essentially the same for both ICD and CRT-D implants. The latter are presumably performed by more experienced implanters. As a result, even though the CRT-D procedure is more difficult and complex, the observed complication rate was not higher. Another possible explanation is the fact that patients in clinical trials may not have the same clinical characteristics as the total Medicare population. Patients with serious co-morbid conditions or the very elderly are frequently excluded from clinical trials, but may meet criteria for an ICD or CRT-D, and go on to receive an implantable device. These patients are likely to experience a higher rate of complications. Finally, the patients reported here were all in-patients. At the present time, in my, and in most, electrophysiology laboratories, most ICD implants are done on an outpatient basis. Since these patients would not be included in the MedPAR database unless they were hospitalized for a complication, the complication rate for an in-patient only group, will be higher than the total experience.
In fiscal 2003, 10.8% of Medicare patients undergoing cardioverter-defibrillator implantation experienced one or more early complications, associated with significant increases in LOS and costs.You have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
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