Bos Sci's S-ICD Passes Muster in the Real World

Posted by amanda.pedersen on May 11, 2017

S-ICD system demonstrates high effectiveness, and low complication rate in largest prospective study of real-world patients.

Amanda Pedersen

The Emblem MRI S-ICD, Boston Scientific's latest-generation S-ICD system, is being evaluated in the company's recently-initiated MADIT S-ICD study.


It’s one thing when a device performs well during a carefully-controlled clinical trial with a select group of patients, but what happens after it makes it into the actual clinical setting? Both FDA and physicians are increasingly looking for real-world evidence to fill in the knowledge gap, and to find out if the device passes muster when used in patients who don’t necessarily meet the specific enrollment criteria of a randomized clinical trial.

Boston Scientific had to put its subcutaneous implantable defibrillator (S-ICD) system to the real-world test in a U.S. post-market approval study, and so far at least, the device has passed with flying colors.

According to data presented at Heart Rhythm Society’s annual meeting in Chicago, the therapy effectively terminated heart arrhythmias in 98.7% of evaluated patients, and had a complication-free rate of 96.2% at 30 days post-procedure.  

Marlborough, MA-based Boston Scientific noted that this is the largest S-ICD study to date (1,637 patients implanted with the device at 86 U.S. centers), and that physicians are implanting the device largely for patients typically treated with transvenous implantable cardioverter defibrillators (TV-ICD), as well as for sicker patients.

The results suggest that the technology serves as an alternative treatment to T-ICDs, according to the study investigators. They also noted that the population studied is more similar to T-ICD populations compared to previous S-ICD studies, reinforcing that the device can be used in a broad population of ICD-indicated patients.

FDA approved the device in 2012. Nearly two-thirds of the patients evaluated in the post-approval study were primary prevention patients with a low ejection fraction, which represents the highest proportion of patients that are implanted with ICD devices, according to the company. Additionally, more than half of the patients had comorbidities such as heart failure and hypertension, and more than 13% were on dialysis for end-stage renal disease.

“Beyond the positive clinical outcomes, we are also seeing advancements in procedural techniques as physician experience and confidence continue to build,” said Kenneth Stein, MD, Boston Scientific’s senior vice president and chief medical officer of global health policy and rhythm management. “Physicians are implanting over half of the devices with two surgical incisions rather than the standard three incisions and avoiding use of general anesthesia in more than one-third of patients.”

Last month the company initiated a worldwide study, the Multicenter Automatic Defibrillator Implantation Trial with Subcutaneous Implantable Cardioverter Defibrillator (MADIT S-ICD) to evaluate the survival benefit of patients treated with the Emblem MRI S-ICD, which is its latest generation S-ICD system. MADIT S-ICD is enrolling patients who are 65 and older with a history of prior heart attack, diabetes, and moderately reduced left ventricular ejection fraction.

Amanda Pedersen is Qmed's news editor. Contact her at


[Image credit: Boston Scientific Corp.]