Prevention of Syncope by Cardiac Pacing in Patients With Bifascicular Block (PRESS)

Study Objective The purpose of this study is to evaluate the efficacy of bradycardia pacing with respect to patient symptoms in patients with bifascicular block and syncope of unexplained origin.

Primary endpoint First occurrence of a composite of Syncope of any origin OR Presyncopal episode with documented cardioinhibitory origin OR Atrioventricular block of any degree; all associated with patient symptoms Design: Randomized, prospective, single blinded, two parallel arms Treatment group : DDD60 - programmed in DDD mode / 60 lower limit Control Group: DDI30 - programmed in DDI mode / 30 lower limit Randomization type: block randomization: Block size: 4, allocation ratio 1:1 Sample: 100 patients Population Patients with bifascicular block with at least one syncopal episode within the last 6 months preceding enrollment. Patients should be negative to a series of pre-enrollment screening in order to exclude: Brady-tachy syndrome, vasovagal syncope or carotid sinus syndrome, atrial fibrillation, inducible AV block Ejection fraction >=40% Mean nocturnal heart rate >=35 bpm

pacing in DDD60 is supposed to prevent events of syncope, presyncope of cardioinhibitory origin and symptom associated to av block

pacing in DDDI30 is supposed to act as a safety backup upfront to episodes of syncope, presyncope or AV block, but not supposed to reduce symptoms.

Combined Endpoint Defined as First Occurrence Among the Following Events 1)Syncope Episode of Any Origin; 2)Presyncopal Episode With Documented Cardioinhibitory Origin 3) Atrioventricular Block of Any Degree Associated With Patient Symptoms

Number of participants experiencing syncope episodes, symptomatic pre-syncopal episodes associated with a device intervention (ventricular pacing) and symptomatic episodes associated with documentation of intermittent or permanent atrio-ventricular block

patients presenting with at least one episode of atrial fibrillation during the 2 years follow up period

Inclusion Criteria: Evidence of Bifascicular block At least one episode of syncope during last 6 months from the enrollment Exclusion Criteria: Patients with Brady-tachy syndrome that needs of pacemaker to prevent the symptomatic bradycardia o symptomatic tachycardia arrhythmia Patients with vasovagal syndrome by positive TTT or carotid sinus syndrome Patients with Chronic Atrial Fibrillation Patients with Atrial Ventricular Block induces at EPS

Brignole M, Donateo P, Tomaino M, Massa R, Iori M, Beiras X, Moya A, Kus T, Deharo JC, Giuli S, Gentili A, Sutton R; International Study on Syncope of Uncertain Etiology 3 (ISSUE-3) Investigators. Benefit of pacemaker therapy in patients with presumed neurally mediated syncope and documented asystole is greater when tilt test is negative: an analysis from the third International Study on Syncope of Uncertain Etiology (ISSUE-3). Circ Arrhythm Electrophysiol. 2014 Feb;7(1):10-6. doi: 10.1161/CIRCEP.113.001103. Epub 2013 Dec 12.

Santini M, Castro A, Giada F, Ricci R, Inama G, Gaggioli G, Calo L, Orazi S, Viscusi M, Chiodi L, Bartoletti A, Foglia-Manzillo G, Ammirati F, Loricchio ML, Pedrinazzi C, Turreni F, Gasparini G, Accardi F, Raciti G, Raviele A. Prevention of syncope through permanent cardiac pacing in patients with bifascicular block and syncope of unexplained origin: the PRESS study. Circ Arrhythm Electrophysiol. 2013 Feb;6(1):101-7. doi: 10.1161/CIRCEP.112.975102. Epub 2013 Feb 6.