Heart Disease :: Dual-chamber pacemakers reduce rates of atrial fibrillation

More expensive pacemakers that pace the heart?s upper and lower chambers are worth the extra cost because they can reduce the risk of hospitalization and disability in patients with heart disease, according to a study published in Circulation: Journal of the American Heart Association.

The dual-chamber devices significantly reduced the rates of atrial fibrillation and heart failure hospitalizations, which over the long term results in a highly favorable cost-effectiveness ratio, said David J. Cohen, M.D., M.Sc., an associate professor of medicine at Harvard Medical School in Boston. Atrial fibrillation is a type of irregular heartbeat associated with an increased risk of stroke and heart failure.

Single-chamber or right-ventricular pacemakers pace a ventricle, one of the heart?s two large, lower pumping chambers. Dual-chamber devices also pace one of the atria (the smaller, upper chambers), which is considered a more natural synchronization.

Cohen, the senior author of the study, said that during the first four years after implant the dual-chamber devices had a cost-effectiveness ratio of $53,000 per quality adjusted year of life gained.

In the U.S. healthcare system, cost-effectiveness ratios between $50,000 and $100,000 per quality adjusted year of life gained are generally considered to be in the gray zone of attractiveness as health care expenditures, he said. But when we used a computer simulation model to estimate lifetime costs and benefits, the dual-chamber devices were associated with an average cost-effectiveness ratio of $6,000 to $7,000 cost per quality-adjusted life year gained compared with single-chamber pacing. That is very favorable.

The four-year, 2010-patient Mode Selection in Sinus Node Dysfunction (MOST) study randomized 1,014 patients to dual-chamber devices and 996 to right-ventricular (single-chamber) pacing devices. The median age of patients was 74; 48 percent were women. The National Heart, Lung and Blood Institute sponsored the trial.

All of the patients had sick sinus syndrome, meaning they had very slow heartbeats along with symptoms such as lightheadedness, dizziness, fainting or general fatigue. The condition is diagnosed by electrocardiogram, Cohen said.

Since the dual-chamber devices didn?t reduce mortality, the favorable cost-effectiveness observed in the study was derived mainly from improved quality of life – fewer hospitalizations, less disability, Cohen said.

Patients who received the dual-chamber devices were less likely to develop atrial fibrillation, or to be hospitalized for heart failure, than those who received single-chamber pacemakers. Patients receiving the dual-chamber devices also had a slightly lower risk of death or stroke, had better results on a heart failure score, and relatively small, but significantly better results on several measures of health-related quality of life.

Although dual-chamber pacemakers cost about $3,000 more than single-chamber devices (including the cost of implantation) during the first four years, the cumulative cost for a patient with a dual-chamber device was $27,441. The cumulative cost for someone with a single-chamber device was $26,760. When cost data from the first four years were fed into a computer model that estimated lifetime costs, the dual-chamber pacemaker had a discounted lifetime cost of $59,104, while the discounted lifetime cost for the ventricular pacemaker was estimated at $58,160.

Included in the analysis were the costs of pacemaker implantation (hardware, hospital fees, professional fees), outpatient follow-up (emergency department visits, unscheduled outpatient visits, and half of scheduled visits during the trial), medication, and rehospitalization for cardiovascular events (atrial fibrillation, heart failure, stroke). Time costs and out-of pocket costs were not included as the authors expected these to be very small compared with medical care costs.

The authors concluded that compared with ventricular pacemakers, the dual-chamber devices have a projected gain of 0.17 quality-adjusted life years compared with single-chamber devices. Although this increase in quality-adjusted years of life may seem modest, it compares favorably with other medical advances including r-tPA vs. streptokinase for suspected acute myocardial infarction (about 0.06 to 0.29 years of life), beta-blockers for low-risk survivors of heart attack (about 0.10 years of life), and stenting vs. balloon angioplasty for single-vessel coronary revascularization (about 0.03 quality-adjusted years of life), the authors wrote.


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