A sequential algorithm, which includes carotid sinus massage, tilt testing and implantable loop recorder implantation, helps to reduce syncope recurrence to 9% at one year in old patients with severe recurrent syncopes, according to results from the Syncope unit project 2 (SUP 2) study.
SUP 2 identified that nearly 50% of patients aged 70 years or older without prodromes had an asystolic reflex for which cardiac pacing was well-suited.
The study, presented by lead investigator Michele Brignole (Arrhythmology Centre, Department of Cardiology, Ospedali del Tigullio, Lavagna, Italy) at EHRA EUROPACE – CARDIOSTIM (21-24 June, Milan, Italy), has been published in the European Heart Journal.
“Opinions differ regarding the effectiveness of cardiac pacing in patients affected by reflex syncope,” write Brignole et al. Therefore, the primary objective of SUP 2 was to assess the effectiveness of a standardised guideline-based algorithm and to assess the reduction in syncopal recurrences after dual-chamber pacemaker therapy in patients affected by any form of reflex syncope diagnosed by means of carotid sinus massage, tilt testing or implantable loop recorder.
A secondary objective, Brignole et al note, was to compare the rate of syncope recurrence after pacemaker implantation with that observed in a group of patients (N=124) with non-diagnostic tests who had received and implantable loop recorder.
The prospective, multicentre, observational study enrolled 253 patients aged 40 or older (mean age 70±12 years) affected by severe, unpredictable, recurrent, certain or suspected reflex syncope at 10 structured syncope units in Italy. The patients had a median of 4 (3-6) syncopes, 89% without or with short prodromes.
In the algorithm, which was designed in accordance with the recommendations of the European Society of Cardiology’s guidelines on syncope, Brignole noted at EHRA EUROPACE – CARDIOSTIM, all patients underwent a sequential protocol.
Initially patients went through carotid sinus massage followed by tilt testing if coronary sinus massage was negative, followed by implantation of implantable loop recorder if tilt testing was negative. “Patients who had an asystolic response to one of these tests received a dual-chamber pacemaker,” Brignole said.
In total, 47% (N=120) of the patients received a pacemaker (65 cases came from coronary sinus massage testing, 32 from tilt table testing and 23 from implantable loop recorder information). During a mean follow-up 13±7 months (106 cases), Brignole noted, syncope recurred in 9% of patients (95% confidence interval (CI), 6-12). At two years, syncope recurred in 15% of cases (95% CI, 10-20). A year before pacemaker implantation, overall pacemaker patients had 200 syncopal episodes, excluding the index episode, and 11 episodes a year after implantation. The recurrence of syncope was “not different among the three subgroups of pacemaker patients” but was “significantly lower” than that observed in the group of 124 patients with non-diagnostic test who had received an implantable loop recorder (22%, 95% CI, 18-26 at one year and 37%, 95% CI, 30-43 at two years).
There were no deaths during the observation period and no traumas related to syncope recurrence, Brignole highlighted.
According to the results of this study, Brignole said: “The typical patient who is expected to benefit from cardiac pacing is around the age of 70 years and has a history of unpredictable syncopes, which start in advanced age-mostly after the age of 40”.
Jean-Claude Deharo (Hôpital de la Timone, Marseille, France), discussant of the SUP 2 study results at EHRA EUROPACE – CARDIOSTIM said: “This pragmatic trial is easy to translate into clinical practice; however, we still need to stick to the inclusion criteria.”
