Long-term clinical effects of ventricular pacing reduction with a changeover mode to minimize ventricular pacing in a general pacemaker population

Abstract

AimRight ventricular pacing (VP) has been hypothesized to increase the risk in heart failure (HF) and atrial fibrillation (AF). The ANSWER study evaluated, whether an AAI-DDD changeover mode to minimize VP (SafeR) improves outcome compared with DDD in a general dual-chamber pacemaker population.Methods and resultsANSWER was a randomized controlled multicentre trial assessing SafeR vs. standard DDD in sinus node disease (SND) or AV block (AVB) patients. After a 1-month run-in period, they were randomized (1 : 1) and followed for 3 years. Pre-specified co-primary end-points were VP and the composite of hospitalization for HF, AF, or cardioversion. Pre-specified secondary end-points were cardiac death or HF hospitalizations and cardiovascular hospitalizations. ANSWER enrolled 650 patients (52.0% SND, 48% AVB) at 43 European centres and randomized in SafeR (n = 314) or DDD (n = 318). The SafeR mode showed a significant decrease in VP compared with DDD (11.5 vs. 93.6%, P < 0.0001 at 3 years). Deaths and syncope did not differ between randomization arms. No significant difference between groups [HR = 0.78; 95% CI (0.48–1.25); P = 0.30] was found in the time to event of the co-primary composite of hospitalization for HF, AF, or cardioversion, nor in the individual components. SafeR showed a 51% risk reduction (RR) in experiencing cardiac death or HF hospitalization [HR = 0.49; 95% CI (0.27–0.90); P = 0.02] and 30% RR in experiencing cardiovascular hospitalizations [HR = 0.70; 95% CI (0.49–1.00); P = 0.05].ConclusionSafeR safely and significantly reduced VP in a general pacemaker population though had no effect on hospitalization for HF, AF, or cardioversion, when compared with DDD.

Influence of Patient’s Exercise Tolerance on Exercise Heart Rate in Closed Loop Stimulation vs. Accelerometer-based Rate Adaptive Pacing

“…In pooled data for all patients, worsening of echo parameters over 2 years was negligible. The low progression of heart failure is likely the consequence of a preserved LVEF (≥50%) in 83% and no AHA/ACC stage C in 68% of patients at baseline, and a moderate percentage of right ventricular pacing during the study (mean ~50%) [12]. The mean LVEF (60%) was at the upper edge of the range reported from larger pacemaker studies (47%-58%) [1,12].…”

“…The low progression of heart failure is likely the consequence of a preserved LVEF (≥50%) in 83% and no AHA/ACC stage C in 68% of patients at baseline, and a moderate percentage of right ventricular pacing during the study (mean ~50%) [12]. The mean LVEF (60%) was at the upper edge of the range reported from larger pacemaker studies (47%-58%) [1,12]. Deleterious long-term effects of rateadaptive pacing are more likely in patients with poor baseline cardiac condition [13].…”

Reducing Ventricular Pacing Frequency in Patients With Atrioventricular Block

“…These aspects have been investigated in CAN-SAVE R (Canadian Multi-Centre Randomised StudySpontaneous Atrioventricular Conduction Preservation) 15,16 and in ANSWER (Evaluation of the SafeR™ Mode in Patients With Dual-Chamber Pacemaker Indication). 13,14 The CAN-SAVE R study 15,16 included 373 patients with indications for DDD pacemakers in 10 Canadian centers. Patients were randomized 1:1 to SafeR TM or DDD pacing with a long AV delay (250 ms); SND was present in 73% (81% of whom had no concomitant AVB) and AVB in 41% (66% of whom had no concomitant SND).…”

“…The ANSWER study 13,14 enrolled 650 consecutive patients with a pacemaker indication at 43 European centers and randomized them to programming either the SafeR algorithm or conventional DDD pacing. Approximately half of the population had SND (52%) or AVB (48%); the vast majority of patients with AVB had an intermittent AVB.…”

“…Because the most common indication for permanent pacing is intermittent or persistent complete atrioventricular block (AVB) 7 (Web Table 3-ESC GDL 2013); the value of reducing VP has not been tested adequately in this patient group until recently (Table 1). [9][10][11][12][13][14][15][16][17][18][19][20][21][22] New studies have evaluated the use of an algorithm limiting the frequency of VP in patients with advanced or complete AVB (Table 1). The purpose of the present review is to report the recent apparently contradictory data suggesting more aggressively adopting algorithms that reduce the frequency of ventricular pacing in patients with AVB-a population for whom we have typically programmed continuous and uninterrupted ventricular pacing.…”