The RECOVER HF pilot is a feasibility study for evaluating a randomized, doubled-blinded study design to determine the benefits and risks of chronically delivering Synchronized Diaphragmatic Stimulation (SDS) in Heart Failure patients on GDMT with NYHA II/III, EF<=40% and QRSd,=130ms.

Symptomatic Diaphragmatic Stimulation (SDS) is a novel approach designed to improve cardiac function, symptoms, and, ultimately, outcomes for patients who are symptomatic for heart failure.

Elevated intracardiac pressures are the hallmark of heart failure (HF) and a key pathological driver of disease progression and limited exertional capacity. The degree of cardiac pressure elevation is determined by preload, afterload, and pericardial restraint. The pericardium restrains the heart, and the degree of restraint is determined by the pericardial structure itself and the intrathoracic pressure. This aspect of HF pathophysiology is among the fundamental drivers behind the SDS therapy concept. SDS induces a temporal modulation of intrathoracic pressure with a resultant reduction in pericardial restraint, leading to improved cardiac filling and reduced afterload. When applied at the right time in the cardiac cycle, SDS can improve cardiac filling, cardiovascular pressure conditions, and systolic cardiac performance.

Encouraged by the results of the VisONE HF study pilot (NCT03484780), SDS shall now be further valuated in a randomized controlled trial (RCT) pilot. This RCT pilot has three objectives: two semi-acute items (15-30 days) verification of sensing function using the modified input filters and improved usability based on increased automaticity of the user-interface; and one chronic result (6 months) to reproduce similar efficacy endpoints. The herein described study is a pilot trial for a larger RCT trial.

Inclusion Criteria:

• NYHA classes II/III on optimal Guideline Directed Medical Therapy
• QRS duration ≤ 130 ms
• LVEF < 40%
• Willing and able to comply with protocol requirements, including attending all required visits
• Wiling to participate in the study and able to sign an informed consent form

Exclusion Criteria:

• Baseline 6-minute walk test > 500 meters or < 200 meters
• NT-proBNP< 250 if on loop diuretics, or NT-proBNP < 500 if not on loop diuretics
• Supine resting heart rate > 140 bpm
• Systolic blood pressure < 80 mmHg or > 170 mmHg
• Serum creatinine > 2.5 mg/dL
• Serum hepatic function 3x ULN
• Unstable angina, AMI, CABG, PTCA, CVA/TIA, persistent AF, NSVT or DCCV within 3 months
• Intermittent IV inotropic drug treatment
• Arrhythmias present during screening (profound ectopy, bradycardia, profound prevalence of ectopy, NSVT, VF, AF*, SVT or AFLT) - * see enrollment exception allowing for 10 patients in AF for a separate subgroup analysis
• Reversible non-ischemic cardiomyopathy
• Primary valvular disease
• Severe primary pulmonary disease, including pulmonary arterial hypertension. PAP sys >70 mmHg at rest
• Severe COPD, other respiratory or lung diseases where FEV < 50%
• Pericardial disease
• Diabetic neuropathy
• Existing diaphragmatic stimulation for respiration assist
• LVAD or other mechanical cardiac assist devices
• Contraindications to laparoscopic access to the diaphragm, as determined by the implanting physician
• Known intra-abdominal pathology which could increase the risk of laparoscopic access to the diaphragm.
• Previous open laparotomy within 1 year
• Previous thoracic or abdominal organ transplant
• Drug induced immuno-suppression
• Body mass index > 40
• Enrollment in a concurrent investigation / clinical study
• Having a life expectancy of <1 year due to any condition
• Pregnant or planning a pregnancy during the study period

Investigator blinded to device programming, therapy imperceptible to patient