May 14th, 2013
Study Questions Role of Dual-Chamber ICDs for Primary Prevention
The majority of patients who receive an ICD for primary prevention without a pacing indication have a dual-chamber ICD implanted. Although there are a number of theoretical advantages with dual-chamber devices, they are more likely to cause complications than single-chamber devices. Although CMS requires providers to justify the medical necessity of dual-chamber devices, current guidelines from the AHA/ACC and HRS do not specify a single-chamber device.
In a new study published in JAMA, Pamela Peterson and colleagues analyzed data from 32,000 patients enrolled in the National Cardiovascular Data Registry (NCDR) who received an ICD for primary prevention without a pacing indication. Of these, 38% received a single-chamber device and 62% received a dual-chamber device. At 1 year there were no significant differences in mortality, all-cause hospitalization, or heart failure hospitalization between the two groups. However, patients in the dual-chamber group had a higher risk of complications, including a highly significant increase in the 90-day risk of mechanical complications requiring re-operation (1.43% in the single-chamber group versus 2.02% in the dual-chamber group, p<0.001). A very similar pattern emerged when the investigators performed an analysis that matched patients in the two groups with a propensity model. The analysis suggested “that the choice of a dual-chamber device is relatively random with respect to patient characteristics…”
In their discussion the authors noted that dual-chamber devices are more expensive than single-chamber devices and are also likely to increase costs through more complications and a greater risk of generator depletion. “Our study does not provide evidence that would support the more costly and more morbid device for patients receiving an ICD for primary prevention,” they wrote.
The authors concluded:
“Many patients receiving primary prevention ICDs receive dual-chamber devices. Dual-chamber devices do not appear to offer any clinical benefit over single-chamber devices with regard to death, all-cause readmission, or heart failure readmission in the year following implant. However, dual-chamber ICDs are associated with higher rates of complications. Therefore, among patients without clear pacing indications, the decision to implant a dual-chamber ICD for primary prevention should be considered carefully.”