Cardiac contractility modulation as bailout in a patient with phospholamban p.Arg14del related cardiomyopathy intolerant to medication: a case report.

Background: Cardiac contractility modulation (CCM) is a novel device-based therapeutic option in patients with heart failure with reduced ejection fraction who are not eligible for cardiac resynchronization therapy. Cardiac contractility modulation enhances cardiac contractility by delivering high-voltage non-excitatory electrical impulses during the absolute refractory period. Cardiac contractility modulation is known to improve left ventricular ejection fraction (LVEF), quality of life, and exercise capacity in heart failure (HF) patients.

Case Summary: We present a case of a 77-years-old woman with a cardiomyopathy associated with a pathogenic variant [p.(Arg14del), Dutch founder mutation]. Due to progressive deterioration of LVEF (25%) despite maximally tolerated guideline-directed medical therapy (GDMT), a CCM device was implanted. After implantation, the patient experienced a sharp thoracic and interscapular pain after stimulation of one of the two leads. This lead was turned-off and the output on the other lead was increased to maximal output of 7,5 V. After 3 months, there were less signs and symptoms of HF. New York Heart Association class improved from class III to II and the patient was free of thoracic pain. Echocardiography demonstrated further improvement of LVEF to 44% and a decrease in end-diastolic pressures.

Discussion: We describe a case of CCM therapy in a patient with HF related to a genetic cardiomyopathy due to a pathogenic variant in phospholamban , persistent symptoms despite maximally tolerated GDMT. Although it was necessary to deactivate one of the both leads due to thoracic pain, LVEF and HF symptoms significantly improved. Further research is needed to elaborate on the potential role of CCM therapy in genetic cardiomyopathies.