Better Respiratory Function in Heart Failure Patients With Use of Central-Acting Therapeutics

Background

Diaphragm atrophy can contribute to dyspnea in patients with heart failure (HF) with its link to central neurohormonal overactivation. HF medications that cross the blood-brain barrier could act centrally and improve respiratory function, potentially alleviating diaphragmatic atrophy. Therefore, we compared the benefit of central- vs peripheral-acting HF drugs on respiratory function, as assessed by a single cardiopulmonary exercise test (CPET) and outcomes in HF patients.

Methods

A retrospective study was conducted of 624 ambulatory adult HF patients (80% male) with reduced left ventricular ejection fraction ≤ 40% and a complete CPET, followed at a single institution between 2001 and 2017. CPET parameters, and the outcomes all-cause death, a composite endpoint (all-cause death, need for left ventricular assist device, heart transplantation), and all-cause and/or HF hospitalizations, were compared in patients receiving central-acting (n = 550) vs peripheral-acting (n = 74) drugs.

Results

Compared to patients who receive peripheral-acting drugs, patients who receive central-acting drugs had better respiratory function (peak breath-by breath oxygen uptake [VO2], P = 0.020; forced expiratory volume in 1 second [FEV1], P = 0.007), and ventilatory efficiency (minute ventilation / carbon dioxide production [VE/VCO2], P < 0.001; end-tidal carbon dioxide tension [PETCO2], P = 0.015; and trend for forced vital capacity [FVC], P = 0.056). Many of the associations between the CPET parameters and drug type remained significant after multivariate adjustment. Moreover, patients receiving central-acting drugs had fewer composite events (P = 0.023), and HF hospitalizations (P = 0.044), although significance after multivariant correction was not achieved, despite the hazard ratio being 0.664 and 0.757, respectively.

Conclusions

Central-acting drugs were associated with better respiratory function as measured by CPET parameters in HF patients. This could extend to clinically meaningful composite outcomes and hospitalizations but required more power to be definitive in linking to drug effect. Central-acting HF drugs show a role in mitigating diaphragm weakness.

Modern Approaches for the Treatment of Heart Failure: Recent Advances and Future Perspectives

Heart failure (HF) is a progressively deteriorating medical condition that significantly reduces both the patients’ life expectancy and quality of life. Even though real progress was made in the past decades in the discovery of novel pharmacological treatments for HF, the prevention of premature deaths has only been marginally alleviated. Despite the availability of a plethora of pharmaceutical approaches, proper management of HF is still challenging. Thus, a myriad of experimental and clinical studies focusing on the discovery of new and provocative underlying mechanisms of HF physiopathology pave the way for the development of novel HF therapeutic approaches. Furthermore, recent technological advances made possible the development of various interventional techniques and device-based approaches for the treatment of HF. Since many of these modern approaches interfere with various well-known pathological mechanisms in HF, they have a real ability to complement and or increase the efficiency of existing medications and thus improve the prognosis and survival rate of HF patients. Their promising and encouraging results reported to date compel the extension of heart failure treatment beyond the classical view. The aim of this review was to summarize modern approaches, new perspectives, and future directions for the treatment of HF.

Novel Therapeutic Devices in Heart Failure

Heart failure (HF) constitutes a significant clinical problem and is associated with a sizeable burden for the healthcare system. Numerous novel techniques, including device interventions, are investigated to improve clinical outcome. A review of the most notable currently studied devices targeting pathophysiological processes in HF was performed. Interventions regarding autonomic nervous system imbalance, i.e., baroreflex activation therapy; vagus, splanchnic and cardiopulmonary nerves modulation; respiratory disturbances, i.e., phrenic nerve stimulation and synchronized diaphragmatic therapy; decongestion management, i.e., the Reprieve system, transcatheter renal venous decongestion system, Doraya, preCardia, WhiteSwell and Aquapass, are presented. Each segment is divided into subsections: potential pathophysiological target, existing evidence and weaknesses or unexplained issues. Novel therapeutic devices represent great potential in HF therapy management; however, further evidence is necessary to fully evaluate their utility.

Synchronized diaphragmatic stimulation for heart failure using the VisONE system: a first-in-patient study

Aims

Synchronized diaphragmatic stimulation (SDS) modulates intrathoracic and intra‐abdominal pressures with favourable effects on cardiac function for patients with a reduced left ventricular ejection fraction (LVEF) and heart failure (HFrEF). VisONE‐HF is a first‐in‐patient, observational study assessing the feasibility and 1 year effects of a novel, minimally invasive SDS device.

Methods and results

The SDS system comprises a pulse generator and two laparoscopically delivered, bipolar, active‐fixation leads on the inferior diaphragmatic surface. Fifteen symptomatic men with HFrEF and ischaemic heart disease receiving guideline‐recommended therapy were enrolled (age 60 [56, 67] years, New York Heart Association class II [53%] /III [47%], LVEF 27 [23, 33] %, QRSd 117 [100, 125] ms, & N terminal pro brain natriuretic peptide [NT‐proBNP] 1779 [911, 2,072] pg/mL). Implant success was 100%. Patients were evaluated at 3, 6, and 12 months for device‐related or lead‐related complications, quality of life (SF‐36 QOL), 6 min hall walk distance (6MHWd), and by echocardiography. No implant procedure or SDS‐related adverse event occurred, and patients were unaware of diaphragmatic stimulation. By 12 months, left ventricular end‐systolic volume decreased (136 [123, 170] mL to 98 [89, 106] mL; P = 0.05), 6MHWd increased (315 [300, 330] m to 340 [315, 368] m; P = 0.004), and SF‐36 QOL improved (physical scale 0 [0, 0] to 25 [0, 50], P = 0.006; emotional scale 0 [0, 33] to 33 [33, 67], P = 0.001). Although neither reached statistical significance, LVEF decreased (28 [23, 40]% vs. 34 [29, 38]%; P = ns) and NT‐proBNP was lower (1784 [920, 2540] pg/mL vs. 1492 [879, 2028] pg/mL; P = ns).

Conclusions

These data demonstrate the feasibility of laparoscopic implantation and delivery of SDS without raising safety concerns. These encouraging findings should be investigated further in adequately powered randomized trials.

Synchronized diaphragmatic stimulation: a case report of a novel extra-cardiac intervention for chronic heart failure

Synchronized diaphragmatic stimulation (SDS) is a novel extra‐cardiac device‐based therapy for symptomatic heart failure with reduced ejection fraction. SDS provides imperceptible chronic stimulation of the diaphragm through a laparoscopically implanted system consisting of an implantable pulse generator and two sensing/stimulating leads affixed to the inferior surface of the diaphragm delivering imperceptible R‐wave gaited pulses that alter intrathoracic pressure improving ventricular filling and cardiac output. We describe, in a man with a history of myocardial infarctions resulting in heart failure and persistent New York Heart Association Class III symptoms despite standard therapies, the successful implantation of SDS resulting in improved quality of life, N‐terminal pro brain natriuretic peptide, cardiac function, and exercise tolerance through 12 months of follow‐up. Randomized trials are now required to validate these findings.