Correspondence

Testing New ICD Technology

N Engl J Med 2008; 359:2610December 11, 2008

Article

To the Editor:

In their Perspective article in this issue of the Journal, Hauser and Almquist1 discuss issues involved in the testing of implantable cardioverter–defibrillators (ICDs). The authors contend that “the decision by the FDA [Food and Drug Administration] and industry to forgo premarketing clinical testing of the [new quadripolar,2 or IS-4] connector is not in the best interest of patients.” This is an incorrect description of the position of the FDA.

The FDA has made no absolute decision that all implantable leads with IS-4 connectors will not require new clinical data. When we are evaluating an application for a modification of a device, our questions are sometimes best answered by appropriate engineering analyses and often through the use of clinical data. Clinical experience with similar models of the device can provide insight into a new device's expected clinical performance.

Sometimes, nonclinical studies can be more informative than clinical evaluation with regard to device safety and effectiveness. For example, during clinical evaluation of implantable leads with IS-4 connectors, there may be few spontaneous shocks, whereas during in vivo studies in animals, a higher number of shocks can be intentionally delivered in a way that permits better evaluation of connector performance and allows for device and histologic assessment.

When preclinical studies and existing clinical data support approval and expected long-term failure rates are low, postapproval studies may provide an appropriate means for verifying long-term device performance. Ensuring device safety does not necessarily require that every device be clinically evaluated before marketing. Approval of some implantable leads with IS-4 connectors may be appropriate without new clinical data. The FDA decides what information is needed to support an approval on the basis of its review of an individual application. This is a scientifically sound approach to protecting public health.

Mitchell J. Shein, M.S.
Daniel G. Schultz, M.D.
Food and Drug Administration, Rockville, MD 20857

2 References

1. 1

   Hauser RG, Almquist AK. Learning from our mistakes? Testing new ICD technology. N Engl J Med 2008;359:2517-2519
   Full Text | Web of Science | Medline

2. 2

   AAMI/CDV-2 27186 — active implantable medical devices: four-pole connector system for implantable cardiac rhythm management devices: dimensional and test requirements. Arlington, VA: Association for the Advancement of Medical Instrumentation, June 20, 2008.
   

Citing Articles (1)

Citing Articles

1. 1

   Hauser, Robert G., Almquist, Adrian K., . (2008) Learning from Our Mistakes? Testing New ICD Technology. New England Journal of Medicine 359:24, 2517-2519
   Full Text