St. Jude QuickSite and QuickFlex CRT Lead Problems Identified

After identifying additional problems with the small wires used to connect their cardiac resynchronization therapy (CRT) devices to the heart, St. Jude Medical, Inc. has announced that it is halting sales of two more types of leads. 

On April 4, St. Jude indicated that they will stop selling QuickSite and QuickFlex left-ventricular leads, which are used in defibrillators known as cardiac resynchronization therapy (CRT) devices.

The manufacturer indicates that the defibrillator leads have insulation problems, which is almost exactly the same problem that led to a St. Jude Riata lead recall about four months ago.

At least 39 confirmed reports have been identified where the conducting material inside the St. Jude QuickSite and QuickFlex CRT lead wires have been seen poking through the insulation. Although there have been no reports of patient injuries or of patients losing therapy due to the defective leads, this poses a serious safety concern.

More than 171,000 QuickSite and QuickFlex leads have been sold worldwide. Although the incident rate is only 0.023, the problems are likely underreported because the leads often continue to work. In a letter to physicians, the company estimated that the problem affects 3% to 4% of all QuickSite and QuickFlex leads.

In late November, St. Jude sent another Physician Advisory Letter to warn doctors about similar problems with their Riata and Riata ST leads, which also had problems with conductors poking through the leads’ insulation. The FDA reported at at that time that at least two patient deaths and one serious injury had been linked to the externalized conductor problem. The rate of incidence with the Riata and Riata ST leads appears to have been much higher, affecting about 19% of all patients.

Earlier this month, research presented at the American College of Cardiology meeting in Chicago found that the St. Jude Riata leads were actually failing in multiple ways that could cause problems for consumers. After looking at 105 reports of lead wire failures, researchers found that two-thirds suffered from more than the wires poking through the insulation, but in some cases they produced static noise that could cause unnecessary shocks or drain power needed for life-saving heart stimulation.

The internal defibrillators are designed to be implanted near a patient’s heart, monitor the heart rhythms and give life-saving electrical shocks if necessary. The defibrillator leads, which deliver the electrical charge, are supposed to remain covered by insulation once implanted. However, in some cases it appears that the leads have penetrated the insulation and parts of those leads are bare and uncovered inside patients’ bodies.

The recalled leads pose a serious health concern, as it is largely impractical for patients to have the small lead wires removed, leaving patients with more frequent medical follow ups and the need to hope that they do not experience any of the problems associated with the small wires that connect their implanted defibrillator to their heart.