Improvement of cardiac function with device‐based diaphragmatic stimulation in chronic heart failure patients: the randomized, open‐label, crossover Epiphrenic II Pilot Trial

Abstract

AimsDevice-based pacing-induced diaphragmatic stimulation (PIDS) may have therapeutic potential for chronic heart failure (HF) patients. We studied the effects of PIDS on cardiac function and functional outcomes. Methods and resultsIn 24 chronic HF patients with CRT, an additional electrode was attached to the left diaphragm. Randomized into two groups, patients received the following PIDS modes for 3 weeks in a different sequence: (i) PIDS off (control group); (ii) PIDS 0 ms mode (PIDS simultaneously with ventricular CRT pulse); or (iii) PIDS optimized mode (PIDS with optimized delay to ventricular CRT pulse). For PIDS optimization, acoustic cardiography was used. Effects of each PIDS mode on dyspnoea, power during exercise testing, and LVEF were assessed. Dyspnoea improved with the PIDS 0 ms mode (P = 0.057) and the PIDS optimized mode (P = 0.034) as compared with the control group. Maximal power increased from median 100.5 W in the control group to 104.0 W in the PIDS 0 ms mode (P = 0.092) and 109.5 W in the PIDS optimized mode (P = 0.022). Median LVEF was 33.5% in the control group, 33.0% in the PIDS 0 ms mode, and 37.0% in the PIDS optimized mode (P = 0.763 and P = 0.009 as compared with the control group, respectively).

Diaphragm Involvement in Heart Failure: Mere Consequence of Hypoperfusion or Mediated by HF-Related Pro-inflammatory Cytokine Storms?

“…Inspiratory muscle training in HFrEF patients has been shown to have favorable effects on dyspnea and functional capactiy (Bosnak-Guclu et al, 2011; Marco et al, 2013; Beeler et al, 2014). Plus, it has recently been elegantly reviewed that inspiratory dysfunction in HF is unaffected by acute decompensation of heart failure and is not reversed by heart transplant (Kelley and Ferreira, 2017).…”

Synchronized Diaphragmatic Stimulation for the Treatment of Symptomatic Heart Failure

“…When applied at the right time in the cardiac cycle, SDS can improve cardiac filling, cardiovascular pressure conditions, and systolic cardiac performance. 2 SDS modulates the intrathoracic pressure through a localized contraction of the diaphragm facilitated by stimulating the diaphragmatic muscle in concert with the cardiac cycle. Because the stimulation is not targeting the phrenic nerve but rather the slow responding type-I diaphragmic muscle fibers, the corresponding diaphragmatic “twitch” is clinically impactful yet does not affect respiration and is also not perceptible to the patient.…”

“…Because the stimulation is not targeting the phrenic nerve but rather the slow responding type-I diaphragmic muscle fibers, the corresponding diaphragmatic “twitch” is clinically impactful yet does not affect respiration and is also not perceptible to the patient. 2 , 3 …”

“…The SDS concept has been validated through a series of preclinical studies and human pilot studies. In humans, SDS has been investigated in the acute setting 3 of post coronary artery bypass graft surgery and in the chronic setting of CRT, where Beeler et al 2 reported on a small, randomized crossover trial that used a CRT device to deliver diaphragmatic stimulation synchronized to atrioventricular delay optimized and simultaneous biventricular pacing. Three weeks of diaphragmatic pacing improved breathlessness, exercise capacity, and left ventricular ejection fraction (LVEF) over CRT therapy alone.…”

Functional electrical stimulation of lower limb muscles as an alternative mode of exercise training in chronic heart failure: practical considerations and proposed algorithm

“…In addition to conventional physical exercise, alternative modes of training have been studied in CHF patients . In this context, neuromuscular or functional electrical stimulation (FES) of leg muscles offers an alternative mode of training and represents an attractive option for CHF patients who are unable, non‐adherent or unwilling to exercise.…”