Approximately 130,000 pacemakers were implanted in the United States in 1993, at a cost of well over $1 billion. Pacemaker recipients may have single chamber ventricular or dual chamber pacemakers implanted. Dual chamber pacemakers are more expensive and less long-lived, but more physiologic, than single chamber pacemakers. The purpose of this 5 year mode Selection Trial (MOST) is to determine whether dual chamber rate modulated pacing (DDDR) in patients with sick sinus syndrome: improves event-free survival; leads to superior quality of life and functional status; is more cost-effective than rate modulated single chamber (VVIR) pacing. The primary endpoint of MOST is a composite endpoint consisting of all cause mortality or stroke. The study is designed with a 90% power to detect a 25% difference between groups (p=0.05, 2 tailed). Secondary endpoints include health status and cost-effectiveness, total mortality, cardiovascular mortality, development of atrial fibrillation, development of pacemaker syndrome, and a combined clinical endpoint of non-fatal stroke, heart failure hospitalization, or death. Eligible, consenting patients with sick sinus syndrome will undergo DDDR pacemaker implantation and be randomly and noninvasively programmed to DDDR pacemaker implantation and be randomly and noninvasively programmed to DDDR or to VVIR. Enrollment will take place over 3 years, and follow-up will vary from 1.5 years to 4.5 years. Clinical and electrocardiographic data will be assessed by semi-annual visits, and quality of life will be assessed in a 1400 patient subset by yearly telephone interviews. Health care expenditures also will be assessed. Thus, this study will assess the patient benefits (clinical endpoints and health status), and societal benefits (cost effectiveness) of pacing mode selection in sinus node dysfunction.

National Institute of Health (NIH)
National Heart, Lung, and Blood Institute (NHLBI)
Research Project--Cooperative Agreements (U01)
Project #
Application #
Study Section
Special Emphasis Panel (ZHL1-CCT-G (F1))
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Mount Sinai Medical Center (Miami Beach)
Miami Beach
United States
Zip Code
Peguero, Julio G; Arenas, Ivan; Lamas, Gervasio A (2014) Chelation therapy and cardiovascular disease: connecting scientific silos to benefit cardiac patients. Trends Cardiovasc Med 24:232-40
Solenkova, Natalia V; Newman, Jonathan D; Berger, Jeffrey S et al. (2014) Metal pollutants and cardiovascular disease: mechanisms and consequences of exposure. Am Heart J 168:812-22
Holmqvist, Fredrik; Hellkamp, Anne S; Lee, Kerry L et al. (2014) Adverse effects of first-degree AV-block in patients with sinus node dysfunction: data from the mode selection trial. Pacing Clin Electrophysiol 37:1111-9
Fleischmann, Kirsten E; Orav, E John; Lamas, Gervasio A et al. (2009) Atrial fibrillation and quality of life after pacemaker implantation for sick sinus syndrome: data from the Mode Selection Trial (MOST). Am Heart J 158:78-83.e2
Fleischmann, Kirsten E; Orav, E John; Lamas, Gervasio A et al. (2006) Pacemaker implantation and quality of life in the Mode Selection Trial (MOST). Heart Rhythm 3:653-9
Lewis, Eldrin F; Hellkamp, Anne S; Pfeffer, Marc A et al. (2006) The association of the heart failure score with mortality and heart failure hospitalizations in elderly patients: insights from the Mode Selection Trial (MOST). Am Heart J 151:699-705
Hellkamp, Anne S; Lee, Kerry L; Sweeney, Michael O et al. (2006) Treatment crossovers did not affect randomized treatment comparisons in the Mode Selection Trial (MOST). J Am Coll Cardiol 47:2260-6
Sweeney, Michael O; Hellkamp, Anne S (2006) Heart failure during cardiac pacing. Circulation 113:2082-8
Shukla, Himanshu H; Hellkamp, Anne S; James, Erskine A et al. (2005) Heart failure hospitalization is more common in pacemaker patients with sinus node dysfunction and a prolonged paced QRS duration. Heart Rhythm 2:245-51
Sweeney, Michael O; Hellkamp, Anne S; Lee, Kerry L et al. (2005) Association of prolonged QRS duration with death in a clinical trial of pacemaker therapy for sinus node dysfunction. Circulation 111:2418-23

Showing the most recent 10 out of 18 publications