An Implantable Defibrillator to Treat Dangerous Heart Rhythms

By Jeemin Kwon

The S-ICD is an FDA-approved device that can prevent sudden cardiac arrest; this trial is testing it in people with diabetes who’ve had prior heart attacks with relatively preserved heart function​

Clinical Trials Identifier: NCT02787785

Trial name: Multicenter Automatic Defibrillator Implantation Trial with Subcutaneous Implantable Cardioverter Defibrillator (MADIT S-ICD)

Diabetes type: Type 1 and type 2 diabetes

What the trial is testing: The trial is testing whether a device called a subcutaneous implantable cardioverter defibrillator (S-ICD) can help people with diabetes who have had a heart attack and relatively preserved heart function (measured by a term called “ejection fraction”). The S-ICD is an FDA-approved device that works to treat life-threatening heart rhythms and prevent cardiac arrest in patients with reduced heart function. The S-ICD is not yet approved for use in this trial population – people with relatively preserved heart function. The device, which is implanted underneath the skin on the left side of the chest, constantly monitors heart rhythms. If it detects a fast, life-threatening abnormal heart rhythm, it sends out an electrical shock to correct it (similar to an external defibrillator). See here for more information about the S-ICD.

What the trial is measuring: Trial participants will be randomly divided into two groups: one group will receive the S-ICD device and the other will not. The trial will track the number of deaths (from any cause) to see if the S-ICD will save lives compared to conventional medical therapy in this trial population.

Why is this new/important? People with diabetes, especially following a heart attack, are at greater risk for cardiac arrest than people without diabetes. Studies suggest that people with diabetes in relatively good heart health (ejection fraction of 36-50%) have a similar risk for death and cardiac arrest as people without diabetes who have poor heart health. Because people with diabetes face increased risk, the S-ICD may be useful to treat abnormal heart rhythms and improve health outcomes.   

Trial length: There is no set end date to the trial, but the estimate is a 2.5-year follow-up.

Trial locations: This study will be active at approximately 100 locations across the United States, Europe, and Israel. Click here for a detailed list and contacts specific to each location. 

Do you qualify? Select inclusion criteria include:

• Age 65 or greater

• Diabetes diagnosis with management plan that includes oral (pill) medication, non-insulin injections, or insulin

• Left ventricular ejection fraction (LVEF) of 36-50% – this requires imaging tests normally done after a heart attack

• Have experienced one or more heart attacks (myocardial infarctions) more than three months before joining trial

Exclusion criteria include:

• LVEF greater than 50% or less than 36%

• Already have an implanted ICD, CRT, or pacemaker device

• On dialysis

• BMI greater than 45 kg/m² (calculate BMI here)

• Active infection when joining trial

Click here for the full list of inclusion and exclusion criteria.

Where to get more information: For more information about this trial, see the clinical trial page. Click here for contacts specific to each trial location.