Study information

Recruiting status

Study completed

Recruitment start





Clinical Trials Registration



Guideline relevant study

DZHK Funding

DZHK-assoziierte Studie (keine finanzielle Förderung)

Operative contact: Professor Frank Edelmann, MD

Evaluation of the safety and efficacy of the OPTIMIZER ® system in subjects with moderate-to-severe heart failure (FIX-HF-5C)

The OPTIMIZER® IVs is a device which is implanted like a pacemaker close to the heart in a minimally invasive procedure. It is used to treat patients with chronic heart failure. The device transmits electrical impulses without causing the heart muscle to contract. The impulse brings about a positive change in the function of protein components of the myocardial cells (post-translational modification). This technique is also referred to as cardiac contractility modulation or CCM.

In Germany, the device carries a CE mark. In the USA, however, it has not yet been approved. The manufacturer, Impulse Dynamics, is currently conducting a study to confirm proof of efficacy of the method and to meet the regulatory objectives of the US Food and Drug Administration (FDA) so that the product can be approved for the US market as well.

The study was designed to examine the system’s safety and efficacy in patients with moderate to severe heart failure. During the 24-week study phase the researchers will analyse any complications and test the efficacy of the system by cardiopulmonary stress testing, comparing the changes in maximal oxygen consumption between treatment group and control group.


A Randomized Controlled Trial to Evaluate the Safety and Efficacy of Cardiac Contractility Modulation. William T. Abraham et al. J Am Coll Cardiol HF. 2018 Oct, 6 (10) 874-883.

More publications of the trial can be found here: FIX-HF-5C publications

Principal Investigators

Gerd Hasenfuß (Göttingen)

Press releases and news

DZHK study on heart failure and iron deficiency kicks off

Iron deficiency is common in patients suffering from heart failure. A clinical study of the German...