BERLIN, Germany,

BIOTRONIK CLS Technology Shown to Reduce Fainting in Syncope Patients by Sevenfold

Robustly Positive Results of SPAIN Study Published in Journal of American College of Cardiology

BIOTRONIK’s exclusive rate responsive technology, Closed Loop Stimulation (CLS) has shown to reduce fainting in pacemaker patients with vasovagal syncope up to sevenfold. Results from the SPAIN study, the first prospective double-blind placebo-controlled trial, have now been published in the Journal of the American College of Cardiology.

“The remarkable benefits of BIOTRONIK CLS pacemakers for patients suffering from dangerous recurrent syncope are gaining recognition among physicians, but this is the first time that this technology has been proven by a clinical trial,” said the study’s primary investigator, Dr. Gonzalo Baron-Esquivias, Hospital Virgen del Rocio, Seville, Spain. “If the findings are confirmed by larger studies, like the ongoing BioSync CLS trial, it could spell a change in international guidelines to recommend CLS pacing in this patient group.”

In the SPAIN study, 54 patients aged 40 or older were recruited from 11 medical centers in Spain and Canada. All had experienced more than five episodes of syncope in their lifetimes and furthermore had more than two episodes in the previous year. Half were randomly assigned to receive DDD-CLS pacing for 12 months and the other half control pseudo-DDI pacing. After 12 months, patients were crossed over to the other pacing program. If a patient in either group had more than three episodes of syncope in one month, their pacing assignment was switched.

The primary endpoint of a greater than 50 percent reduction of syncopal episodes compared with the previous year was met. During the trial, four patients experienced syncope while receiving CLS pacing, compared with 21 patients who fainted during pseudo DDI pacing. Among patients initially assigned CLS, 72.2 percent had a reduction of more than 50 percent in syncope episodes within the first year. However syncope recurred after they crossed over to the DDI group. Patients who crossed over to DDD-CLS after a year of placebo pacing saw a reduction of more than 50 percent in syncopal episodes during the second year.

“At BIOTRONIK we focus on patient safety and quality of life. The SPAIN study demonstrated marked clinical improvement in syncope patients, a challenging patient population with no other treatment options currently available. There is also a lack of clear consensus among the medical community on how to treat this group,” stated Albert Panzeri, Vice President at BIOTRONIK. “With the BIOSync CLS trial, BIOTRONIK is doing its part to gather further clinical evidence with the potential to make a significant difference in these patients’ lives.”



1 Baron-Esquivias G et al. Journal of the American College of Cardiology. 2017, October 3.


At BIOTRONIK, patient well-being is our top priority and has been for 60 years. BIOTRONIK is a leading global medical technology company with products and services that save and improve the lives of millions suffering from heart and blood vessel diseases. Driven by a purpose to perfectly match technology with the human body, we are dedicated innovators who develop trusted cardiovascular and endovascular solutions. BIOTRONIK is headquartered in Berlin, Germany, and is represented in over 100 countries.