Abstract
The objective of this study was to compare the cost of intravenous adenosine and intravenous dipyridamole in positron emission tomography (PET) in patients with coronary artery disease. A retrospective, open-label, case-control, cost-effectiveness analysis was performed in the outpatient nuclear medicine department of a university hospital. Thirty-six patients underwent dipyridamole PET, and 72 matched patients underwent adenosine PET. A cost-effectiveness analysis was conducted using a direct cost accounting approach to estimate institutional costs. Key costs evaluated included acquisition cost, administration cost, monitoring cost, cost of management of side effects, and cost of follow-up care. The total cost of adenosine PET and dipyridamole PET was divided by their respective predictive accuracies to provide a total cost adjusted for efficacy. Adenosine increased heart rate and lowered systolic blood pressure to a significantly greater extent than dipyridamole. The number of patients experiencing adverse drug reactions was significantly greater for adenosine (82%) than for dipyridamole (67%), but the frequency of prolonged (>5 minutes) and late-onset side effects was significantly greater for dipyridamole than for adenosine. The frequency of side effects requiring medical intervention was also significantly greater for dipyridamole (53%) than for adenosine (6%). Although adenosine had a significantly greater acquisition cost than dipyridamole, costs of monitoring, management of side effects, and follow-up care were significantly less for adenosine than for dipyridamole. As a result, the total cost of using dipyridamole is significantly greater ($928.00 per patient) than the total cost of using adenosine ($672.00 per patient). Based on these results, adenosine may be the drug of choice for pharmacologic vasodilation for PET.