NCA - Cardiac Pacemakers: Single-Chamber and Dual-Chamber Permanent Cardiac Pacemakers (CAG-00063R3) - Decision Memo

Nielsen and colleagues reported the results of a randomized trial to compare single-chamber atrial (AAI) and dual-chamber (DDD) pacing in patients with sick sinus syndrome (SSS).  Inclusion criteria were symptomatic bradycardia < 40 bpm or symptomatic QRS pauses of more than two seconds.  Exclusion criteria included AVB, chronic AF and bundle branch block.  Primary outcomes were changes in left atrial (LA) size and left ventricular (LV) size and function as measured by M-mode echocardiography.  Secondary outcomes included death, stroke and AF.  From December 1994 to March 1999, 177 consecutive patients were randomized to one of three rate-adaptive pacemakers: single chamber atrial (AAIR; n = 54), dual chamber (DDDR-s with a short AV delay; n = 60) or dual chamber (DDDR-l with a fixed long AV delay; n = 63).  Mean age was 75 years.  Men comprised 41 percent of the study population.  Mean follow-up was three years.The authors reported: DDDR pacing causes increased LA diameter, and DDDR pacing with a short atrioventricular delay also causes decreased LVFS [left ventricular fractional shortening].  No changes occur in LA or LV diameters or LVFS during AAIR pacing.  Atrial fibrillation is significantly less common during AAIR pacing.  No significant differences in mortality, stroke and heart failure were detected between groups.Nielsen JC, Thomsen PE, Hjberg S, Mller M, Vesterlund T, Dalsgaard D, Mortensen LS, Nielsen T, Asklund M, Friis EV, Christensen PD, Simonsen EH, Eriksen UH, Jensen GV, Svendsen JH, Toff WD, Healey JS, Andersen HR; DANPACE Investigators. A comparison of single-lead atrial pacing with dual-chamber pacing in sick sinus syndrome. Eur Heart J. 2011 Mar;32(6):686-96. doi: 10.1093/eurheartj/ehr022. Epub 2011 Feb 7.Nielsen and colleagues reported the results of a randomized trial to compare single lead atrial pacing (AAIR) and dual chamber pacing (DDDR) in patients with SSS (DANPACE:  The Danish Multicenter Randomized Trial on Single Lead Atrial Pacing versus Dual Chamber Pacing in Sick Sinus Syndrome).  Inclusion criteria were symptomatic bradycardia, documented sino-atrial block or sinus-arrest with pauses > 2 seconds or sinus bradycardia < 40 bpm for more than one minute while awake, PR interval  0.22 seconds if aged 1870 years or PR interval  0.26 seconds if aged  70 years and QRS width < 0.12 seconds.  Exclusion criteria included AVB, bundle branch block, long-standing persistent AF (> 12 months), AF with ventricular rate < 40 bpm for  1 minute or pauses > 3 seconds, a positive test for carotid sinus hypersensitivity, planned cardiac surgery, or a life-expectancy shorter than one year.  Primary outcome was death from any cause.  Secondary outcomes included paroxysmal AF, chronic AF, stroke, peripheral embolism, heart failure and pacemaker re-operation.  From March 1999 to June 2008, 1415 patients were randomly assigned to AAIR (n = 707) or DDDR (n = 708).  Mean age was 73 years. Men comprised 35 percent of the study population.  Mean follow-up was five years.The authors did not detect significant differences in death (29.6% vs. 27.3%), chronic AF (11.2% vs. 10.7%), stroke (5.5% vs. 4.8%) or heart failure.  They concluded: In patients with sick sinus syndrome, there is no statistically significant difference in death from any cause between AAIR pacing and DDDR pacing.  AAIR pacing is associated with a higher incidence of paroxysmal atrial fibrillation and a two-fold increased risk of pacemaker reoperation.  These findings support the routine use of DDDR pacing in these patients.Toff WD, Camm AJ, Skehan JD; United Kingdom Pacing and Cardiovascular Events Trial Investigators. Single-chamber versus dual-chamber pacing for high-grade atrioventricular block. N Engl J Med. 2005 Jul 14;353(2):145-55.Toff and colleagues reported the results of a randomized trial to compare the clinical benefits of single chamber ventricular pacing and dual chamber pacing in elderly patients with AVB.  Patients were 70 years of age or older and were scheduled to receive their first pacemakers for high-grade (second-degree or complete) AVB.  Exclusion criteria were chronic established atrial fibrillation, or newly diagnosed ischemic heart disease, and myocardial infarction.  Primary outcome was death from all causes.  Secondary outcomes included atrial fibrillation (defined as an episode, with or without symptoms, lasting 15 minutes or more and verified by electrocardiography), new or significantly worsening heart failure, a composite of stroke, transient ischemic attack, or other thromboembolism, revision of the pacing system, new-onset angina or newly diagnosed ischemic heart disease, and myocardial infarction.From August 1995 to September 1999, 2021 patients were enrolled and randomly assigned to single-chamber ventricular pacing (fixed rate: n = 504 and adaptive: n = 505) and to dual-chamber pacing (n = 1012).  Mean age was 80 years.  Men comprised 57 percent of the study population.  Mean follow-up was 4.6 years for death and 3 years for other cardiovascular events.  The authors reported: The mean annual mortality rate was 7.2 percent in the single-chamber group and 7.4 percent in the dual-chamber group (hazard ratio, 0.96; 95 percent confidence interval, 0.83 to 1.11).  We found no significant differences between the group with single-chamber pacing and that with dual-chamber pacing in the rates of atrial fibrillation, heart failure, or a composite of stroke, transient ischemic attack, or other thromboembolism.  They concluded: In elderly patients with high-grade atrioventricular block, the pacing mode does not influence the rate of death from all causes during the first five years or the incidence of cardiovascular events during the first three years after implantation of a pacemaker.3.  Medicare Evidence Development & Coverage Advisory Committee (MEDCAC)The MEDCAC was not convened for this review.4. Evidence-based guidelinesEpstein AE, Dimarco JP, Ellenbogen KA, Estes NA 3rd, Freedman RA, Gettes LS, Gillinov AM, Gregoratos G, Hammill SC, Hayes DL, Hlatky MA, Newby LK, Page RL, Schoenfeld MH, Silka MJ, Stevenson LW, Sweeney MO; American College of Cardiology; American Heart Association Task Force on Practice Guidelines; American Association for Thoracic Surgery; Society of Thoracic Surgeons. ACC/AHA/HRS 2008 Guidelines for device-based therapy of cardiac rhythm abnormalities. Heart Rhythm. 2008 Jun;5(6):e1-62. doi: 10.1016/j.hrthm.2008.04.014. Epub 2008 May 21.Epstein AE, DiMarco JP, Ellenbogen KA, Estes NAM III, Freedman RA, Gettes LS, Gillinov AM, Gregoratos G, Hammill SC, Hayes DL, Hlatky MA, Newby LK, Page RL, Schoenfeld MH, Silka MJ, Stevenson LW, Sweeney MO. ACC/AHA/HRS 2008 guidelines for device-based therapy of cardiac rhythm abnormalities: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the ACC/AHA/NASPE 2002 Guideline Update for Implantation of Cardiac Pacemakers and Antiarrhythmia Devices). Heart Rhythm 2008;5:e1e62.In 2008, ACC, AHA, and HRS published evidence-based guidelines on device-based therapy for arrhythmias.  Recommendations were reported for arrhythmias as well as device selection.  Table 2 (reproduced below) presented indications for single chamber and dual chamber pacemakers.