Table 3

Randomized Trials Comparing Atrium-Based Pacing With Ventricular Pacing

CharacteristicsDanish Study (281)PASE (23)CTOPP (282,284,285)MOST (22,31,48,49,286,287)UK-PACE (283)
Pacing indicationSNDSND and AVBSND and AVBSNDAVB
No. of patients randomized2254072,5682,0102,021
Mean follow-up (years)5.51.56.42.83
Pacing modesAAI vs VVIDDDR* vs VVIR*DDD/AAI vs VVI(R)DDDR vs VVIR*DDD(R) vs VVI(R)
Atrium-based pacing superior with respect to:
 Quality of life or functional statusNA
  • SND patients: yes

  • AVB patients: no

NoYesNA
 Heart failureYesNoNoMarginalNo
 Atrial fibrillationYesNoYesYesNo
 Stroke or thromboembolismYesNoNoNoNo
 MortalityYesNoNoNoNo
 Cross-over or pacing dropout
  • VVI to AAI/DDD: 4%

  • AAI to DDD: 5%

  • AAI to VVI: 10%

VVIR* to DDDR*: 26%
  • VVI(R) dropout: 7%

  • DDD/AAI dropout: 25%

VVIR* to DDDR*: 37.6%
  • VVI(R) to DDD(R): 3.1%

  • DDD(R) dropout: 8.3%

R* added to pacing mode designation indicates rate-responsive pacemakers implanted in all patients. (R) added to pacing mode designation indicates rate-responsive pacemakers implanted in some patients.

AAI indicates atrial demand; AVB, atrioventricular block; CTOPP, Canadian Trial of Physiologic Pacing; DDD, fully automatic; MOST, Mode Selection Trial; PASE, Pacemaker Selection in the Elderly; SND, sinus node dysfunction; UK-PACE, United Kingdom Pacing and Cardiovascular Events; and VVI, ventricular demand.