Cardiac Contractility Modulation in Heart Failure: A Win but Perhaps Not a Knockout

Cardiac contractility modulation (CCM; under expedited FDA review at the time of this writing) is a technique of pacing the right ventricle at two sites with nonexcitatory stimuli during the absolute refractory period. The technique is reported to increase cardiac contractility despite an obscure mechanism of action. In a relatively large, randomized trial of this device, subgroup analysis showed treatment benefit in patients with left ventricular ejection fractions (LVEFs) of 25% to 45%. In a new, randomized, controlled, manufacturer-funded trial (NCT01381172), researchers studied the CCM device in patients with this range of LVEF, QRS of <130 ms, and New York Heart Association (NYHA) heart failure class of III to IV.

In the study, 86 patie…