title: Standardized algorithm for cardiac pacing in older patients affected by severe unpredictable reflex syncope: 3-year insights from the Syncope Unit Project 2 (SUP 2) study.
abstract: OBJECTIVE
  The aim of this study was to determine the long-term effects and determinants of success of cardiac pacing in patients affected by reflex syncope enrolled in the Syncope Unit Project 2 (SUP 2) study. Initial results have validated the effectiveness of a standardized guideline-based algorithm which can be used in clinical practice in order to select suitable candidates for cardiac pacing.
  
  
  RESULTS
  In this prospective, multicentre, observational study, patients aged >40 years, affected by severe unpredictable recurrent reflex syncope, underwent carotid sinus massage (CSM), followed by tilt testing (TT) if CSM was negative, followed by implantation of an implantable loop recorder (ILR) if TT was negative. Those who had an asystolic response to one of these tests received a dual-chamber pacemaker. Of 281 patients who met the inclusion criteria, 137 (49%) received a pacemaker and were followed up for a mean of 26 ± 11 months: syncope recurred in 25 (18%) of them. At 3 years, the actuarial syncope recurrence rate was 20% [95% confidence interval (CI) 12-30] and was significantly lower than in 142 patients who did not receive a pacemaker and were observed by means of an ILR [43% (95% CI 29-57), P = 0.01]. The 3-year recurrence rate was not different among 78 CSM+, 38 TT+, and 21 ILR+ patients, whereas it was lower in 20 patients with negative TT [5% (95% CI 0-15)] than in 61 patients with positive TT [24% (95% CI 10-38)].
  
  
  CONCLUSIONS
  The benefit of cardiac pacing is maintained at 3 years, irrespective of the index diagnostic test, and is maximum in patients with negative TT.
  
  
  BACKGROUND
  URL: http://www.clinicaltrials.gov. Unique identifier: NCT01509534.
authors.affiliation: Arrhythmologic Centre, Department of Cardiology, Ospedali del Tigullio, Lavagna 16033, Italy mbrignole@ASL4.liguria.it.
authors.forename: Michele
authors.initials: M
authors.lastname: Brignole
authors.affiliation: Ospedale Pugliese Ciaccio, Catanzaro, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Arabia
authors.affiliation: Ospedale 'GB Grassi', Ostia, Italy.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Ammirati
authors.affiliation: Ospedale Generale Regionale, Bolzano, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Tomaino
authors.affiliation: Arcispedale S. Maria Nuova, Reggio Emilia, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Quartieri
authors.affiliation: Ospedale Careggi, Firenze, Italy.
authors.forename: Martina
authors.initials: M
authors.lastname: Rafanelli
authors.affiliation: Ospedale S. Giuseppe, Empoli, Italy.
authors.forename: Attilio
authors.initials: A
authors.lastname: Del Rosso
authors.affiliation: Ospedale Niguarda Ca' Granda, Milano, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Rita Vecchi
authors.affiliation: Ospedale SS. Annunziata, Taranto, Italy.
authors.forename: Vitantonio
authors.initials: V
authors.lastname: Russo
authors.affiliation: Ospedale Villa Scassi, Genova, Italy.
authors.forename: Germano
authors.initials: G
authors.lastname: Gaggioli
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects / Q000379:methods*; D002346:Carotid Sinus / Q000294:innervation*; D004867:Equipment Design; D005260:Female; D006801:Humans; D007558:Italy; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D018579:Patient Selection; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012008:Recurrence; D012018:Reflex; D012720:Severity of Illness Index; D019462:Syncope, Vasovagal / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D018667:Tilt-Table Test; D013997:Time Factors; D016896:Treatment Outcome
keywords: Cardiac pacing; Carotid sinus syndrome; Implantable loop recorder; Neurally mediated syncope; Reflex syncope; Syncope; Tilt testing