Summary: Pacemakers are implanted to help the heart beat in the correct rhythm. Traditionally, pacemakers were paced with right ventricular (RV) pacing. However, there have since been advancements to modern pacing strategies that increase cardiac activation, decrease symptoms, and improve quality of life. Despite these benefits, thousands of patients who had a traditional RV pacemaker implanted are not upgraded to modern pacing, with pacemakers simply being replaced like-for-like at the end of their life. This study aims to establish whether upgrading these existing pacemakers improves quality of life for these patients, a finding that hopes to inform future policy for pacemaker management.

When an individual has issues with their heart rhythm, they may be fitted with a pacemaker. A pacemaker is a small device implanted under the skin that compensates for the heart’s inability to regulate its own rhythm. For people who have pacemakers implanted today, they receive novel so-called “pacing” strategies that help the heart to beat correctly. Historically however, these modern pacing strategies were not used, and pacemakers instead relied on traditional right ventricular (RV) pacing. RV pacing activates the heart’s main pumping chambers in a slow, abnormal sequence.

There is significant evidence to suggest that modern pacing strategies produce more efficient cardiac activation, reduce injury to the heart muscle and ultimately improve quality of life and survival. Despite that, for those people who originally had a traditional pacemaker implanted, they are not upgraded to the more modern option. Even at the end of the pacemaker’s battery life, the pacemaker is simply replaced like-for-like, and upgrades to modern pacing strategies are only ever made once cardiac function is severely impaired. This means that despite the advancements in pacing made in the last decades, over a million UK patients still have pacemakers with RV pacing.

It is therefore theorised that there are potentially tens of thousands of patients suffering unnecessary symptoms and potentially even death because of the current practice of replacing pacemakers like-for-like rather than upgrading them.

Dr Keene and his team therefore aim to explore whether these patients experience less symptoms and better quality of life if changed to a modern pacing strategy. In order to test this, each patient will receive a new pacemaker which can be paced by either RV or modern pacing and can electronically be switched from one to the other. Each participant will undergo 1-month in each pacing strategy, in a random blinded order. They will document symptoms weekly on a smartphone. At the end of each month, they will undergo measurements of their heart, a walking test and quality of life questionnaires. After 2 months, they will review their own recorded symptoms and decide if one month was clearly better than the other. Many will settle at that stage on one strategy as distinctly better, completing the trial there. Any patients who are unsure will proceed for longer (2 x 6-month) periods with each strategy in case the effect takes longer to materialise. They will again document their symptoms and review them at the end.

If it can be established that a modern pacing upgrade for these patients decreases symptoms and improves quality of life, it will provide grounds for a major policy change with regard to pacemaker management.