Dive Brief:

• In three Medtronic-backed analyses using electronic health records data from UnitedHealth Group's Optum unit, researchers examined various populations and found implantable cardioverter defibrillators (ICDs) and cardiac resynchronization therapy (CRT) devices were underutilized in patients medically indicated for the treatments. 
• Emergent patterns from the studies included: Only half of ICD-indicated patients were referred to an electrophysiologist; devices were implanted more frequently in men than in women; and men and women of color received the devices at lower rates than white men.
• Separately, the company released initial pilot study data on its investigational extravascular ICD system, while competitor Boston Scientific presented new data on its subcutaneous ICD system, which some analysts said is taking ICD market share from Medtronic.

Dive Insight:

Implantable cardioverter defibrillators are an established treatment for fast or irregular heartbeats. The devices deliver a shock or pacing to restore the heart to normal rhythm. Cardiac resynchronization therapy is a treatment for heart failure that uses a CRT-pacemaker (CRT-P) or CRT-defibrillator (CRT-D) to improve the pumping efficiency of the heart.

And, according to findings Medtronic presented at last week's annual meeting of the Heart Rhythm Society, not enough implantable cardiac devices are getting to patients who could benefit from them. 

In an analysis of EHR data from more than one million patients, Medtronic said its devices were implanted in 16.7% of indicated men and 12.7% of indicated women and were significantly underused in all patient populations. Both women and men of color and white women received devices at lower rates than white men.

Medtronic also looked at utilization of ICDs and CRT-Ds compared to other cardiovascular interventions, such as imaging, drug therapies and coronary procedures, in a group of more than 100,000 patients. That analysis found consistent underutilization trends across five years, from 2012 through 2016, with 32.3% of eligible patients receiving CRT and 11.0% getting ICDs.

Medtronic's cardiac rhythm and heart failure unit eked out sales growth of 0.3% in the second quarter as the introduction of longer-lasting implants over the past several years has meant fewer sales of replacement CRT-D devices in particular. 

In a third study examining referral patterns, just 50.5% of ICD-indicated patients were referred to an electrophysiologist, Medtronic said. Of those who got referrals, 44.3% received a device, compared with 8.8% who did not see an electrophysiologist.

Medtronic is developing an extravascular ICD, which the company said entails a lead placed outside of the heart and veins to deliver defibrillation and anti-tachycardia pacing therapy in a single system, while remaining the same size as traditional, transvenous ICDs. Medtronic Saturday released findings from a 21-patient pilot study of the device, showing the system terminated induced ventricular arrhythmias in 89.5% of tested patients and pacing capture was achieved in more than 95% of patients. The device also detected and treated ventricular tachycardia in one patient outside the hospital setting.

And rival Boston Scientific presented its own ICD data Friday for its Emblem subcutaneous implantable defibrillator (S-ICD) system, which is designed to prevent sudden cardiac death in patients with a left ventricular ejection fraction 35% or less, a population whose function is severely below normal and is more likely to be considered for the therapy, according to the Cleveland Clinic.

Recipients of the therapy in the 1,116-patient study had a complication-free rate of 95.8% at 30 days post-procedure and conversion efficacy of induced ventricular fibrillation of 99.2%.

"We found that the complication rate within this primary prevention population was as low as in prior S-ICD registries, despite the patients having much lower LVEF, more hypertension, and diabetes – underscoring that sicker patients do well with this device for the prevention of sudden death," said principal investigator Lucas V.A. Boersma in a statement.

Analysts at Needham & Co. said Boston Scientific will be a tough competitor for Medtronic in the ICD space.

"[Medtronic] has been losing share in the ICD market due partly to its lack of a non-transvenous ICD to compete with [Boston Scientific's] S-ICD. MDT is seeking to address this product gap with its extravascular ICD (EV-ICD). Unlike BSX's S-ICD which runs a lead outside of the sternum, MDT's EV-ICD runs a lead just below the sternum," Needham & Co. analysts wrote in a note to investors following the Heart Rhythm Society's annual meeting last week.

While Medtronic's EV-ICD is probably a few years from reaching the market, they think it could be "a meaningful revenue growth driver," the Needham analysts said. Medtronic management expects to begin the U.S. pivotal trial in the first half of fiscal 2020 with a possible launch beyond fiscal year 2020, the analysts said.

Maria Rachal contributed to this story.