Preventing recurrent blackouts with upfront pacemaker implantation

Seven research projects were recently awarded funding thanks to our partnership with Equity Trustees. This collaboration recognises high impact research projects that directly benefit children and those suffering with cancer, heart disease and depression. The following highlights one of the funded projects: The syncope-stopper study: Comparison of upfront pacing with standard care for high-risk patients with unexplained syncope. We spoke to project lead, Associate Professor Aleksandr Voskoboinik, about the project.


What is your project addressing?

The study is a randomised multicentre trial of 200 patients presenting with unexplained syncope (blackouts). We have developed a novel risk score (‘DROP score’) that we think may identify patients at high risk of bradycardias (slow heart rhythm disturbances) that would benefit from upfront pacemaker insertion (rather than waiting for further recurrent blackouts and injury and documentation of heart rhythm slowing). Fifty per cent of enrolled patients with a DROP score of 2 or higher will be randomised to pacemaker insertion and 50% will be randomised to a more ‘conservative’ approach (await documentation of heart rhythm slowing).

Ultimately, we hope to show that we can identify high risk patients based on this score and can prevent recurrent blackouts, injury and hospitalisation by upfront pacemaker implantation.

Is there a need for this particular project?

Unexplained syncope poses a significant diagnostic challenge to clinicians. While syncope accounts for approximately 20,000 emergency department presentations in Victoria, about half of patients admitted for investigation of syncope are subsequently discharged without a clear diagnosis. Recurrent syncope is associated with increased risk of serious injury from recurrent syncope as well as higher mortality. Up to 20% of patients with implantable loop recorders (ILR) for unexplained syncope require subsequent permanent pacemaker (PPM) insertion for bradyarrhythmia. While ILRs are frequently inserted for further diagnostic evaluation, they are costly (approximately $4,000 each – more than pacemakers) and are unable to prevent further syncopal episodes.

Several scores have been developed for use in the emergency department for identifying patients with syncope at risk of ‘adverse events’. However, these scores have not been validated for use beyond the emergency department and are cumbersome, while also including variables (e.g. haematocrit, breathlessness, hypotension) that are unable to guide cardiologists evaluating the potential for future bradyarrhythmia and ultimately the utility of pacemaker implantation.


What is the aim of the project?

To demonstrate utility of a novel risk score (DROP score) which identifies patients at highest risk of bradycardic syncope and similarly can identify low risk patients where earlier discharge may be appropriate.

It will also demonstrate that upfront pacing in high-risk patients (based on the DROP score) is the most cost-effective and safest strategy for management of unexplained syncope.


What stage is the project at? 

Recruitment has commenced at the Alfred and are looking to roll out the study at Cabrini and Western Health next.


What outcomes will the project see?

We hope to show that upfront pacing reduces the incidence of cardiovascular death, recurrent syncope and recurrent cardiovascular hospitalisation (and hence also improves quality of life). We also hope to show that this strategy will reduce cost and healthcare utilisation.


What impact will this project have?

(1) Mainstream use of this novel DROP score that identifies patients at highest risk of bradycardic syncope (and similarly can identify low risk patients).

(2) Demonstration that upfront pacing in high-risk patients is the most cost-effective and safest strategy for management of unexplained syncope.

(3) If positive, the study would be incorporated into major society guidelines for syncope with potential for high impact publication.


Watch this space for future project developments.