CCM

Question 1

What is CCM?

Answer 1

CCM stands for cardiac contractility modulation

Question 2

What is CCM therapy?

Answer 2

Electrical impulses delivered during the absolute refractory period (ARP) of the action potential, around 30ms after onset of QRS complex.

Biphasic, bipolar signals administered for a duration of 20ms, with energy levels that are 50-100 fold that of a standard pacemaker impulse

Question 3

How long is CCM therapy administered for?

Answer 3

Administered for 5-12 hours on a daily basis. The shorter duration appears comparable in effectiveness, is more efficacious in reducing battery drain and enables eligibility of patients with frequent ectopy burden who may otherwise be excluded.

Question 4

What do impulses do in CCM therapy?

Answer 4

Impulses do not elicit a new action potential and the electro-mechanical impulse is unaffected (i.e. ‘non-excitatory’).

Question 5

Does CCM increase myocardial oxygen demand?

Answer 5

No

Question 6

How is CCM placed?

Answer 6

CCM therapy is provided by a pacemaker-like generator (OPTIMIZER III, IMPULSE Dynamics) that is attached to two standard active fixation leads. These are placed along the mid-septal wall with an anatomical separation distance of at least 2cm. A separate right atrial lead is positioned via active fixation to sequence with atrial activation.

Question 7

Cellular mechanisms of CCM therapy?

Answer 7

CCM has been shown to upregulate L-type calcium channels resulting in augmentation of intracellular calcium influx during the subsequent membrane depolarisation. There is also concurrent uptake into the sarcoplasmic reticulum via sarcoplasmic reticulum calcium-ATPase 2a (SERCA2a) receptors, thus improving calcium-triggered calcium release via ryanodine receptors (RyR2)

Question 8

First CCM study and it’s results?

Answer 8

FIX-HF3 was the first study to assess clinical effectiveness of CCM therapy, though it was unblinded and observational.

In patients with drug-refractory New York Heart Association (NYHA) class III CHF and narrow QRS duration, improvements were observed at 2 month follow-up in LVEF, 6-minute walk, NYHA functional class and QoL scores as measured by the Minnesota Living with Heart Failure Questionnaire (MLWHFQ).