FDA safety alerts flag cardiac devices

Editor's Note

The US Food and Drug Administration (FDA) issued early alerts August 6 for three medical devices due to safety concerns: Medline ReNewal’s reprocessed St. Jude Medical electrophysiology catheters, Boston Scientific’s ENDOTAK RELIANCE defibrillation leads with ePTFE-coated coils, and Boston Scientific's WATCHMAN Access Systems.

The Medline alert involves specific lots of reprocessed St. Jude Medical Response Diagnostic and Supreme Electrophysiology Catheters. According to the FDA, residual particulates may be present on patient-contacting surfaces. Use of these devices could pose a potential risk of inflammatory response or systemic infection. If particulates dislodge during use and contact circulating blood or the heart, this may lead to granulomatous reaction or thrombus formation, which could result in cerebral or pulmonary embolism or deep vein thrombosis. No serious injuries or deaths had been reported as of July 29.

The FDA instructs facilities to quarantine affected catheter lots immediately and notify any recipients. Additional instructions and contact information are provided in the full FDA announcement.

According to the FDA, Boston Scientific has identified a pattern of gradually rising low-voltage shock impedance (LVSI) linked to calcification of the ePTFE-coated defibrillator lead coils. This calcification can encapsulate and electrically insulate the shock coil, potentially reducing the effectiveness of delivered shocks. As of July 24, Boston Scientific reported 386 serious injuries and 16 patient deaths associated with this issue. The most common harm was early lead replacement, and the most serious was death or need for cardiac resuscitation due to failed arrhythmia conversion.

Boston Scientific found that leads implanted for eight or more years were more likely to exhibit this calcification pattern, particularly when programmed for reversed (RV+) polarity. RV+ shocks were 4.5 times more likely to trigger a high shock impedance alert and were associated with lower defibrillator-determined shock success rates. The FDA advises clinicians to continue routine monitoring and assess LVSI and HVSI values during follow-up. If replacement is being considered, providers should weigh the risks of extraction versus abandonment. Detailed clinical guidance is available in the full FDA announcement.

The third alert is reportedly due to use of Boston Scientific’s WATCHMAN Access Systems resulting in higher likelihood of air embolism events when procedures are performed without positive pressure-controlled ventilation.  As of July 30, the manufacturer has reported 120 serious injuries and 17 patient deaths related to this issue.

According to the FDA alert, procedures involving transseptal access to the left atrium carry approximately a threefold higher risk of negative left atrial pressure and air ingress when performed under conscious or deep sedation. The risk is particularly elevated in patients with low left atrial pressure, hypovolemia, or partial upper airway collapse. Resulting air embolisms may lead to arrhythmia, stroke, hemodynamic collapse, or other ischemic organ failure. These risks are limited to the duration of the implant procedure and do not apply to patients with previously implanted WATCHMAN devices.

Guidance for responding to the recall, contact details, and other information is available in the full FDA announcement.