Permanent pacemakers and implantable cardioverter-defibrillators (ICDs) are essential and well established treatments for heart rhythm disorders. Device malfunctions and component failures have been an issue since implantable devices came into medical use. In particular, the year 2005 has seen an unprecedented amount of attention paid to ICD and pacemaker and malfunction and recalls. However, the overall safety history of cardiac devices is excellent. In this article, we provide a brief overview of the year’s events, as well as describe how our lab has handled recall notification.

Summary of Recent Advisories
       Medtronic, Inc. (Minneapolis, MN) issued a physician advisory letter in February 2005 regarding an increased risk of sudden battery failure in some of its ICDs in the Marquis family. This involved a shorting mechanism attributed to a specific battery design. Some devices were explanted, but the majority was followed closely. The initial response of the medical community was to exchange these devices; however, more patients were likely harmed by the explantation approach than helped by it. In our practice, two patients were referred from other centers for device infection after generator exchanges, for ICD and lead removal. A follow-up analysis showed an anode grid short rate of 0.01–0.07% during the first half of battery life.
       After a 21-year-old patient with hypertrophic cardiomyopathy died of a cardiac arrest because his ICD failed to respond,¹ device malfunctions became a highly publicized issue. On June 17, 2005, Guidant Corporation (St. Paul, MN) issued an advisory letter warning of this potential deterioration of a wire insulator, which causes the ICD to short-circuit and fail to deliver life-saving shocks. Arcing during attempted shock delivery caused electrical overstress, damaging the integrated circuitry.
       Following this, Guidant issued a recall on about 50,000 ICD and cardiac resynchronization therapy-defibrillator (CRT-D) devices, primarily based on the risk of this short circuit that might prevent appropriate shocks. Reports of two deaths were received by the FDA. Affected models were the VENTAK PRIZM 2 DR (Model 1861) (one death), CONTAK RENEWAL (Model H135) and CONTAK RENEWAL 2 (Model H155) (one death). The projected risk was < 0.2%. Also recalled were the VENTAK PRIZM AVT, VITALITY AVT, RENEWAL 3 AVT, and RENEWAL 4 AVT, for the risk of a memory error that might affect available therapy. The projected risk was 0.01% of these devices.
       On June 23, 2005, Guidant issued another safety warning regarding a magnetic switch that can become stuck in a closed position, preventing the device from reacting appropriately to a tachyarrhythmia, and affecting battery longevity. This involved the CONTAK RENEWAL 3, CONTAK RENEWAL 4, and RENEWAL RF. Reprogramming (Enable Magnet Use to OFF) was recommended to address this issue.
       On July 1, 2005, the U.S. Food and Drug Administration (FDA) gave a Class I designation to the Guidant recall of the VENTAK PRIZM 2 DR (Model 1861), CONTAK RENEWAL (Model H135) and CONTAK RENEWAL 2 (Model H155) devices. This implies a reasonable probability of serious adverse health consequences or death. There are no tests for or signs of impending device failure. The agency still left the decision on whether to replace the devices up to patients and physicians. The recalls based on the memory error and magnetic switch problems received a Class II recall designation, since the probability of serious health consequences was determined to be remote.
       Continuing in the vein of full disclosure, Guidant issued a safety advisory affecting 28,000 pacemakers worldwide on July 18, 2005. A hermetic sealing component had degraded in some cases, which could lead to premature battery depletion. Guidant initiated a voluntary recall of the PULSAR® Max, PULSAR, DISCOVERY®, MERIDIAN®, PULSAR MAX II, DISCOVERY II, VIRTUS PLUS® II, INTELIS II, and CONTAK® TR. The deterioration in this case would occur gradually. Nonetheless, on July 22, 2005, the FDA classified Guidant’s action as a Class I pacemaker recall.
       On September 22, 2005, Guidant issued an advisory affecting almost 170,000 pacemakers in the INSIGNIA® and NEXUS® lines, because foreign material within a crystal timing component may lead to device failure. Verifying pacemaker operation in the packaging prior to implantation would pick up this problem. A failure rate of 0.017% to 0.037% is predicted for active devices over the remaining device lifetime, in the first failure mode.
       On October 6, 2005, St. Jude Medical issued a physician advisory regarding a memory chip component which can be affected by background cosmic radiation. This can cause a temporary loss of pacing and a permanent loss of defibrillation support. To date, only 60 out of 36,000 devices (0.00167) have been found to be affected. Affected models are the Photon DR (Model V-230HV) (certain serial numbers), Photon Micro VR/DR (Models V-194/V-232), and Atlas VR/DR (Models V-199/V-240).

Regulatory Implications
       In June 2005, the Heart Rhythm Society (HRS) formed a task force to develop guidelines on ICD recalls. The primary goal was to draft uniform notification standards to inform physicians and patients about safety alerts and recalls. A press statement of June 23, 2005, concurred with the FDA’s recommendation that patients affected by the recalls speak with their heart rhythm specialists regarding treatment options. In addition, it conveyed the fact that the benefits of ICDs in preventing sudden cardiac arrest outweigh the risk of device failure. On September 16, a policy conference on pacemaker and ICD performance was convened by HRS — recommendations are forthcoming at the time of this writing. The conference sought to develop an improved device surveillance system. A summary proceedings document is expected on the HRS website in mid-October.
       A recent article by Maisel² describes the evolution of device regulation, and recommends further monitoring and public disclosure of malfunctions in these increasingly complex devices. Our primary clinical response to the above alerts and recalls has been immediate patient notification and close follow-up. One affected ICD was exchanged, as were three affected pacemakers.
       The FDA conducted a study on the 2.25 million pacemakers and the 416,000 ICDs implanted between 1990 and 2002 in the U.S. The annual malfunction rate was 20.7/1000 for ICDs, compared to 4.6/1000 for pacemakers. Over the course of the study, pacemaker malfunctions declined and ICD malfunctions increased. This was presented at the HRS Policy Conference on Pacemaker and ICD Performance on September 16, 2005.

Device Clinic Recommendations
       Pacemakers and ICDs will continue to become more complex as new technology becomes available. With rising complexity of cardiac devices, the threat of future alerts and recalls exist. Device clinics share responsibility for ensuring that patients are promptly notified of alerts and recalls issued by the manufacturing companies. Established policies and procedures are necessary to communicate this vital information in a timely manner.
       A database that maintains the patient device model, leads, serial numbers and contact information is essential. This database provides a means by which to readily identify and initiate contact with the respective patient. Upon receipt of an alert or recall notice from the manufacturer, all patients should be notified within an established time frame. At Carle Clinic, patients are typically notified within 48 hours of receiving notification. An alternative means of communicating this information is necessary for patients that are not available by phone, such as a certified letter. The nature of the recall or alert should be reviewed with the patient, along with its potential impact. This information should be shared in a manner in which the patient and their significant others understand. The patient then should be scheduled to come into the clinic to have their device interrogated and to allow for review of the alert or recall information, and any programming changes. It is important to ensure adequate time is allowed at the appointment to review the alert or recall information, the implications, treatment options, and any questions.
       With heightened media coverage of recent alerts and recalls, many patients have contacted the office questioning if their device is implicated. These questions range from “I have been reading…is my device one of those?” to “Will my device work if I need it?” Although the alerts affect only a select number of patients in the clinic, it is important to reassure all patients that procedures are in place to provide alert information and that any necessary actions will be promptly taken to ensure their safety. Device support groups or newsletters provide a means by which to communicate this type of information to all patients followed in the clinic. At our most recent support group meeting, multiple questions were raised regarding the recent alerts. Patients and their significant others expressed a broad range of questions, with device failure being their greatest concern. By initiating the discussion regarding the alerts and addressing all questions, a significant amount of the expressed fear and anxiety was alleviated.

Conclusions
       We see concern on the part of patients and physicians regarding these recalls and advisories. It is important to note, though, that despite potential malfunctions, ICDs save lives,³ and pacemakers certainly improve quality of life. Device malfunctions should be reported to the FDA for post-market surveillance. The Manufacturer and User Facility Device Experience (MAUDE) database contains these reports and is publicly available.
       With continued advancing technology, devices will continue to evolve in efforts to better treat patients with rhythm disturbances and heart failure. Device clinics must maintain timely methods to address alerts and ensure the safety of their patients.