Largest study to date of Boston Scientific's S-ICD 'leadless' defibrillator released

The largest study yet of Boston Scientific's S-ICD "leadless" defibrillator shows that its safety and performance match standard, transvenous devices.

A new study of the so-called "leadless" defibrillator made by Boston Scientific [1] (NYSE:BSX [2]) shows that the device matches the safety and performance of standard defibrillators, which use leads threaded through blood vessels to deliver shocks to the heart.

The S-ICD device, which Boston Scientific acquired when it bought Cameron Health earlier this year, won pre-market approval from the FDA this week. Instead of transvenous leads, the S-ICD uses leads that are implanted subcutaneously. The shock therapy is delivered through the sternum to the heart.

The Effortless real-world study showed a rate of inappropriate shocks for the S-ICD of nearly 7%, about ½ that of the 330-patient investigational device exemption trial behind the FDA approval [3]. Nearly 90% of ventricular fibrillation episodes were converted with the S-ICD, versus 90.8% for the control arm of the trial, according to heartwire [4]. Complications rates were low and also comparable, according to the website.