A new study has linked St. Jude Riata leads to 22 deaths, according to researchers. St. Jude’s defective Riata defibrillator leads were recalled in December over possible risks of injury or death, leaving the 76,000 Americans implanted with the defective devices patients with difficult options.
Implantable defibrillators are meant to keep the heart beating regularly and to shock the heart back to proper rhythm should the heart stop. The defibrillator lead, a thin wire attached to the heart wall, delivers an electrical impulse by way of the defibrillator. Should the wire perforate the heart wall, the heart can bleed into its pericardial sac, a lethal condition known as cardiac tamponade, in which pressure builds around the heart preventing it from beating effectively.
A review of the U.S. Food and Drug Administration’s (FDA) safety database revealed 133 deaths linked to St. Jude’s Riata or Medtronic Inc. Quattro Secure leads, according to the report from Robert Hauser, said Bloomberg Businessweek. Hauser is a cardiologist at the Minneapolis Heart Institute. Of those, 22 deaths were the result of failed wires used to connect Riata and Riata ST to the heart and were, for the most part, the result of short circuits between high-voltage components, according to the study, said Businessweek. Five deaths were linked to Medtronic’s Quattro Secure lead, according to the report.
Also, according to the study, the deaths were not a result of a flaw known as externalized conductors. According to Hauser, both the Riata and Riata ST wires “are prone to high-voltage failures that have resulted in death.” The study appears in the journal Heart Rhythm, which was obtained by Bloomberg News and confirmed by Hauser. “These failures appear to be caused by insulation defects that resulted in short- circuiting between high-voltage components,” said Hauser.
Abrasion-related issues with defibrillator wires like Riata are insulated with silicone and known to cause failure and patient harm, said a St. Jude spokeswoman, Amy Jo Meyer, in an email to Businessweek. The risk has been documented in medical literature and is linked to a 3-10% failure rate, said Meyer.
In response, St. Jude stopped selling silicone-only defibrillator leads and began utilizing a new insulation—Optim—said Meyer. “We continue to study the performance of our older generation silicone leads through the Riata Lead Evaluation Study that was initiated at the end of last year and will communicate the findings from this study as soon as they become available,” Meyer said, wrote Businessweek.
St. Jude announced that it just appointed the Population Health Research Institute, an academic health science research institute, to look at performance information from three registries concerning the newer Riata ST Optim and Durata, said Businessweek.
The analysis, said Businessweek, is a broader review of the review Hauser just released that revealed that the failed leads suffered from a number of defects. Worse, the surgery to remove the wires may, in some cases, pose greater risks than keeping them, according to U.S. regulators. This leaves physicians and their patients with three options: Leave the lead connected and conduct regular monitoring; disconnect, but leave the lead in place and insert new wires next to it; or remove and replace the entire device.