MINNEAPOLIS — Switching candidates for implantable cardioverter-defibrillator (ICD) implantation to a dual-function device that also modulates cardiac contractility was associated with successful defibrillation and symptom stabilization or improvement in a majority of participants with heart failure with reduced ejection fraction at 6 months.

These latest results from the Integra-D trial also revealed no unexpected complications at 1 month after implantation of the Optimizer Smart device (Impulse Dynamics), which received FDA approval in 2019 to deliver cardiac contractility therapy to people with moderate-to-severe heart failure. The study also included a 25% smaller and 33% lighter next-generation Optimizer Smart Mini-System. Each device is designed as a cardiac contractility modulation defibrillator (CCM-D).

The data were presented at the Heart Failure Society of America (HFSA) 2025 Annual Scientific Meeting.

“As a clinician, we all know when we put in an ICD, it is a warranty. When we can put in a CCM-D, it is also a warranty, together, for treating heart failure,” Nir Uriel, MD, director of Advanced Heart Failure and Cardiac Transplantation at Columbia-Presbyterian Medical Group in New York City, said during a late-breaking research session.

Implantation involves pectoral generator placement and DF-4 and IS-1 leads in the right ventricle. All trial participants were candidates for de novo ICD implantation without cardiac resynchronization therapy (CRT), had stage C or D heart failure, were taking guideline-directed medical therapy, and had a left ventricular ejection fraction (LVEF) of 40% or less. 

Mean age was 63 years, 29% were women, and mean LVEF was 30%. Comorbidities were prevalent: 81% had hypertension, 79% had dyslipidemia, 48% had diabetes, and 25% had stage 3 or greater chronic kidney disease. Primary prevention ICD was indicated in 98%. Forty-six percent had New York Heart Association (NYHA) class II disease, 48% had NYHA class III disease, and 1% had class IV disease.

“It important to emphasize that 54% had at least triple therapy and 36% were receiving quadruple therapy,” said Uriel, co-principal investigator for the study.

Of the 101 study participants, one failed to induce during acute defibrillation testing and was excluded from further analysis. Successful acute defibrillation in 100 participants included 94 who responded to a first shock of 26J and six others who responded to a second shock of 36J from the device during testing.

30-Day Results and Complications

There were no inappropriate CCMs during ventricular arrhythmias or CCM events that led to inappropriate ICD oversensing, Uriel said. 

Eighty-nine percent of participants were taking a recommended therapeutic dose at 30 days, defined as at least 70% of the CCM programmed setting. In addition, the study protocol required participants to recharge one of the device’s batteries for 60 minutes once a week. The rechargeable battery delivers daily CCM therapy while the non-rechargeable battery delivers high-voltage ICD therapy and anti-tachycardia pacing, postshock bradycardia pacing, and emergent bradycardia pacing (ventricular backup pacing at 40 beats per minute). 

At 30 days, 91% of participants were fully compliant with charging protocol, defined as at least 60 minutes of charging per 10-day period. 

Five complications were reported at 30 days. One participant had a lead displacement that required revision; one experienced a pocket infection that was treated with antibiotics only; and one experienced worsening heart failure. One participant experienced chest pain/pericarditis and another experienced hypotension that was not related to heart failure. 

“So defibrillation is good; safety is also good,” Uriel said. 

Participants with complications were treated with programming adjustments or seen in an outpatient setting without an invasive intervention or major medical intervention, the researchers noted. 

Improved NYHA Class at 6 Months

Compared to baseline, 88% of participants improved or remained stable in terms of NYHA classification at 6 months. This group included 7% who improved by two NYHA classes during this time. 

Class III patients experienced the most significant improvements, compared with class II patients who had modest improvements. The researchers noted a ceiling effect was possible.

“The main theme is the majority improved,” Uriel said. “This is very important — 55% of all the patients with class III or class IV improved, and this is very similar to CRT, which was 57%.”

Of the 11 participants whose NYHA class worsened, six had frequent charging noncompliance events or adverse events near the time of the 6-month follow-up.

These posttransplant findings from the Integra-D trial demonstrate it is possible to successfully defibrillate patients undergoing efficacy testing with this combination device, according to Uriel. He added that the device successfully performed ICD functions and delivered appropriate CCM therapy without any inappropriate interactions between the CCM and ICD components. The RV septal lead positioning used in the trial also demonstrated reliable defibrillation efficacy.

Preliminary 6-month data show that heart failure symptoms improved or remained stable in the majority of patients.

“CCM-D provides an integrated therapy for heart failure with reduced fraction patients, offering both symptom relief and sudden cardiac death prevention,” Uriel said. “After these 100 patients, we will continue to enroll up to 300 patients, who will not need efficacy testing.”

‘A Useful Device’

Session co-moderator Laura Cohen, MD, cardiologist at Massachusetts General Hospital in Boston, said that “moving the needle further” and making a difference for some patients shows the device can be “clinically useful.”

“It's absolutely going to be a game-changing device in terms of the fact that it’s integrating two machines into one. Patients will be excited about the idea of a single implant,” she told Medscape Medical News. 

Cohen also highlighted the benefits of having a device that is comparable to CRT.

“We have lots of patients who don’t qualify for CRT based on not having a left bundle or the specific requirements for CRT, who would still benefit from the CCM device. The fact that it improves your current NYHA class on par with CRT could be beneficial for many patients,” she said. 

“The question of cost is certainly there. I think it’ll depend on how the company costs out the device,” Cohen added. “My overall impression is that it seems like a useful device.”

The study was sponsored by Impulse Dynamics. Uriel and Cohen reported having no relevant conflicts of interest.