Restoring respiratory sinus arrhythmia in heart failure

A CiC award will enable Eva Sammut to test the safety and feasibility of a novel device to reinstate RSA in dyssynchronous heart failure.

Confidence in Concept (CiC) awards fund proof of concept studies, which provide robust evidence of the feasibility of a proposed solution to a clinical need.

Dr Eva Sammut, NIHR-funded academic clinical lecturer in Cardiology at the BHI, received a £100K Elizabeth Blackwell Institute MRC CiC award in January to look at the feasibility, safety and effectiveness of a novel device to restore respiratory sinus arrhythmia in patients with heart failure.

Q: Why is your research significant?

Heart failure is a global clinical pandemic with clear unmet clinical need. Despite some advancements in therapy, prognosis remains poor with a 50 per cent five-year mortality representing a significant societal and healthcare burden.

Respiratory sinus arrhythmia (RSA) is a physiological phenomenon of a subtle increase of heart rate during inspiration and the converse during expiration. RSA is a major component of physiological heart rate  variability, a sign of good cardiac health, and is known to be lost in patients with heart failure. Loss of RSA is associated with increased ventricular  arrhythmia and sudden cardiac death. Restoring RSA in heart failure patients could improve their life  expectancy and markedly reduce hospitalisation costs. Existing preclinical models are inadequate to validate the safety of new treatments in this priority area.

Q: What are you developing?

Our group have developed a novel device which is able to reinstate RSA. Our preliminary results are very promising and demonstrate feasibility. Further proof of concept data from an advanced preclinical model is now pivotal to ensure the safety, feasibility and applicability of the new device to  progress it toward bedside to benefit patients.

This project will test the safety and feasibility of this new technology in the setting of dyssynchronous HF. This is a complex form of heart failure that responds poorly to the best available current treatment –  a specialised pacemaker named cardiac  resynchronisation therapy.

This study will be performed at the University’s Translational Biomedical Research Centre facility. We will develop an advanced preclinical model of dyssynchronous heart failure with balloon catheter myocardial infarction and superimposed pacemaker-induced ventricular dyssynchrony. Next, we will use this model to test this novel pacemaker approach to reinstating respiratory sinus arrhythmia in addition to cardiac resynchronisation therapy.

Q: Who are you working with?

A unique multidisciplinary team has been assembled including Professors Julian Paton, Raimondo Ascione and Alain Nogaret, and Drs Tom Johnson, Ed Duncan and Vito Domenico Bruno, who are co-applicants supporting this project.

We are also working in collaboration with Ceryx Medical, a spin out company formed by the universities of Bristol, Bath and Auckland.

Q: What next?

We are delighted to receive this funding to be able to take this exciting new technology to the next  developmental stage. This project is critical to ensure safety, feasibility and applicability of the new device in this setting. If positive results are demonstrated this would pave the way for larger, efficacy translational studies, with a view to reach patients in the NHS  within the next five to six years.

This post first appeared in the March 2021 BHI Newsletter

First use of ROB2 in Cochrane Review of Exercise Interventions for CHD

Graham Stuart and Guido Pieles collaborated with Craig Williams at the University of Exeter to publish a Cochrane Review, which gathered evidence for the effectiveness of physical activity interventions for people with congenital heart disease.

The Review compared three types of interventions from 15 trials, including programmes designed to increase physical activity, aerobic fitness and health-related quality of life. It found some evidence for increased physical fitness and physical activity, although there are no data yet to suggest this results in fewer hospital visits.

Read the Review in the Cochrane Library

Graham says:

Exercise used to be discouraged in patients with CHD. This was poor advice and led to an increase in cardiovascular and psychosocial morbidity.

Our Cochrane Review has shown that there is a need for further research to demonstrate why  exercise benefits disordered cardiovascular  physiology and to establish whether the  multiple theoretical benefits of exercise training  can translate into improved clinical outcomes.

All authors of Cochrane systematic reviews are now expected to use the Cochrane Risk of Bias tool (ROB2) to assess the risk of bias in any  randomized controlled trials they identify, to help people understand the trustworthiness of the findings. This was the first Cochrane Review to use ROB2 methodology.

Read the Cochrane editorial on ROB2

This post first appeared in the March 2021 BHI Newsletter