Pacing Mode Choice (Mixed)

Title of Trial
Pacemaker Selection in the Elderly (PASE) study

Date and Citation of Primary Publication(s) or References
Lamas GA, Orav EJ, Stambler BS, et al. Quality of life and clinical outcomes in elderly patients treated with ventricular pacing as compared to with dual chamber pacing. Pacemaker Selection in the Elderly Investigators. N Eng J Med 1998; 338: 1097-1104.

Purpose of the Trial
Evaluate the effects of pacing mode choice in elderly patients with bradycardia.

Study Category
Pacing

Patient Population
Inclusion Criteria
Patients older than 65 years, in sinus rhythm, who required a pacemaker for bradycardia.

Exclusion Criteria
Patients who could not participate in quality of life evaluations, patients with clinically overt congestive heart failure at implantation, patients with permanent atrial fibrillation (no episodes of sinus rhythm for six months), patients with a serious noncardiac illness, and patients with inadequate atrial capture or sensing thresholds.

Study Design
Single blind randomized controlled comparison. Patients were randomized to the VVIR or DDDR pacing mode at enrollment.

Primary Endpoints
Health related quality-of-life (SF-36).

Secondary Endpoints
Death from all causes, first nonfatal stroke or death, first hospitalization for heart failure, development of atrial fibrillation, development of pacemaker syndrome.

Baseline Characteristics
Patient number: 407 patients
Mean Age: 76 years (range: 65-96 years)
Gender: 40% female
Other characteristics:
Indications for permanent pacing: Atrioventricular block: 49%, sinus node dysfunction: 43%, other: 8%. Ventriculoatrial conduction was present in 29% at time of implantation. Other problems included 29% with a history of supraventricular tachycardia (including atrial fibrillation), 27% with a history of heart failure, and baseline cerebrovascular disease in 13%.

Time to Follow-up
Quality of life evaluation at 3, 9, and 18 months.

Results
Quality-of-life improved with both pacing modes compared to baseline. No differences in quality-of-life were noted between the two pacing modes. A 26% crossover rate due to development of pacemaker syndrome was observed. No differences in clinical outcomes were detected between the pacing modes: Death (VVIR: 17% vs. DDDR: 16%, p = 0.95), Stroke, heart failure hospitalization, and death (VVIR: 27% vs. DDDR: 22%; p = 0.18), and development of atrial fibrillation (VVIR: 19% vs. DDDR: 17%; p = 0.80). In the prespecified subgroup analysis, sinus node dysfunction patients were evaluated separately. In this subgroup dual chamber pacing was associated with mild improvements in the role-emotional and social function subscales. In addition, dual chamber pacing was also associated with borderline but non-significant improvement in clinical endpoints: Death (VVIR: 20% vs. DDDR: 12%, p = 0.09), the combined endpoint of stroke, heart failure hospitalization, and death (VVIR: 31% vs. DDDR: 20%; p = 0.07), and development of atrial fibrillation (VVIR: 28% vs. DDDR: 19%; p = 0.06). For patients with atrioventricular block no differences in the clinical endpoints or quality-of-life could be detected between the VVIR and DDDR pacing modes.

Overall population

Endpoint	VVIR (n=204)	DDDR (n=203)	P
All cause mortality	17%	16%	0.95
Stroke or death	19%	17%	0.75
Stroke or death or hospitalization for heart failure	27%	22%	0.18
Atrial fibrillation	19%	17%	0.80

Sinus node dysfunction

Endpoint	VVIR  (n=85)	DDDR  (n=90)	P
All cause mortality	20%	12%	0.09
Stroke or death	22%	13%	0.11
Stroke or death or hospitalization for heart failure	31%	20%	0.07
Atrial fibrillation	28%	19%	0.06

Atrioventricular block

Endpoint	VVIR (n=204)	DDDR (n=203)	P
All cause mortality	15%	17%	0.41
Stroke or death	18%	18%	0.68
Stroke or death or hospitalization for heart failure	26%	21%	0.49
Atrial fibrillation	11%	16%	0.26

Sponsor
Intermedics

Trial Status:  Completed