Clinical Trials Day: Our Favourite Recent Studies in Cardiac Rhythm Management

On May 20, 1747, James Lind conducted what’s thought to be the world’s first clinical trial on board Britain’s HMS Salisbury. More than 200 years after Lind experimented with citrus fruits as a way to fight scurvy in sailors, we mark May 20 as Clinical Trials Day. The day spotlights and celebrates advances in clinical research. From COVID-19 vaccine trials to telemedicine and digital health studies, the last few years have been particularly important for clinical data that’s changing the way patients who have cardiovascular conditions are treated. Here’s a few of our recent highlights.

TRUST Study Update: What Future Does Remote Monitoring Have?

At the beginning of the COVID-19 pandemic, the European Society of Cardiology (ESC) observed a 50 percent decrease in hospital admissions for heart attacks. The ESC hypothesized that wasn’t because there were fewer heart attacks happening than normal, but that patients were staying away from emergency rooms because they were afraid to catch the virus.

While still urging patients not to delay necessary visits to the emergency room, heart rhythm societies around the world issued a  joint practice update recommending that physicians follow their arrhythmia patients remotely except in emergencies. Eventually, a 2021 update of the TRUST study1 started being discussed from a new perspective – how to help strained hospitals manage pandemic workloads, and finding out whether device patients could be kept safely at home for follow-up care.

Exclusive RPM (3 to 15 Months) Compared With Conventional Care

TRUST Principal Investigator Dr. Niraj Varma sought to see if continuous and automatic remote monitoring, such as that provided by BIOTRONIK Home Monitoring, could combine with centralized analytics to reduce nonactionable, in-patient evaluations, while also maintaining risk-event detection. Simply: could remote monitoring keep patients safe at home if their scheduled follow-ups didn’t involve their physician having to address an emergency event? And, if it could, were cases requiring urgent in-person intervention still detected in time?

After a new analysis of over 900 patients in a remote patient monitoring (RPM) group, and around 400 in a conventional follow-up group, researchers found they could reduce unnecessary clinic visits by 81% in the RPM group without compromising the ability to safely detect and address emergency events.

In the longer term, this research may help provide a base of data to allow for more routine follow-ups to be done remotely, reducing clinical workloads and costs for both patients and payers, as well as making care more convenient for the patient.


Charting and Addressing Syncope in Pacemaker Patients: The SYNCOPACED Registry and BIOSync Trial

Syncope, characterized by fainting episodes, remains one of the most debilitating bradyarrhythmia symptoms. Some of these episodes even persist in patients who have an implanted pacemaker — and often there is no evidence of any pacemaker malfunction. That motivated Palmisano et al. to set up the SYNCOPACED registry2. Enrolling more than 1,300 pacemaker patients and following them over four years, researchers wanted to find out if they could explain the causes of recurring syncope in patients who already had pacemakers. Around 15% of patients experienced at least one syncope episode after getting their pacemaker implant. Researchers also found that pacemaker malfunctions, tachyarrhythmias and structural cardiac diseases were rare causes. Orthostatic hypotension and reflex syncope were far more common. Around a fifth of cases had unexplained causes.

Survival free of syncope recurrence for CLS-paced patients versus placebo

If, as SYNCOPACED registry results suggest, some pacemaker patients are still potentially prone to syncope, what treatment options might physicians be able to turn to for these patients? The BioSync CLS trial3 enrolled 127 patients who experienced severe reflex syncope, where alternate therapies had failed. Half were given a placebo, and half were given a pacemaker with Closed Loop Stimulation (CLS), an algorithm unique to BIOTRONIK pacemakers that also adapts to mental stress, rather than simply physical stress. The CLS group saw a 77% reduction in recurring syncope after two years, suggesting a way forward for patients who haven’t responded to previous syncope treatments.



1 Varma, N. et al. Alert-Based ICD Follow-Up: A Model of Digitally Driven Remote Patient Monitoring, JACC: Clinical Electrophysiology, 2021. DOI: https://doi.org/10.1016/j.jacep.2021.01.008.

2 Palmisano, P et al. Causes of syncopal recurrences in patients treated with permanent pacing for bradyarrhythmic syncope: Findings from the SYNCOPACED registry. Heart Rhythm. 2021 May;18(5):770-777. DOI: 10.1016/j.hrthm.2021.01.010.

3 Brignole, M et al. Cardiac pacing in severe recurrent reflex syncope and tilt-induced asystole, European Heart Journal, Volume 42, Issue 5, 1 February 2021, Pages 508–516. DOI: 10.1093/eurheartj/ehaa936.