Background: The presence of calcified deposits in the coronary arteries has become established as a marker of coronary atherosclerosis.
Design and Setting: Single medical center observational study.
Study objective: 1) To determine the sensitivity and specificity of coronary calcium by cinefluoroscopy (CF) and to validate the reliability of CF in the angiographic detection of > 50% coronary artery stenosis. 2) To assess the financial benefit of adding CF-determined coronary calcium into the self-paid executive physical examination items. 3) To evaluate whether an algorithm using CF to assess coronary calcium has potential as an initial cost-effective testing pathway for diagnosis of > 50% coronary artery stenosis.
Methods: Between November 1, 2004 and April 25, 2005, 333 patients who underwent angiography for diagnosis of and determine the extent of coronary artery disease were enrolled in the study. All patients received CF to determine presence or absence of calcium in the coronary artery system prior to selective angiography. Sensitivity and specificity were then obtained to confirm CF as a reliable non-invasive test for diagnosing > 50% coronary artery stenosis. Direct cost, total cost and estimated profit were calculated with and without the cost of cardiac catheterization laboratory at Chang Gung Memorial Hospital, which has an average of 475 patients/month who undergo self-paid executive physical examinations. Direct cost, total cost and estimated loss of coronary calcium by electron beam computed tomography (EBCT) were calculated for the acquisition of an EBCT machine by Chang Gung Memorial Hospital. A test model was applied to examine the costs and cost-effectiveness of the following diagnostic modalities: the traditional treadmill exercise (TMET); stress thallium and positron emission tomography (THALLIUM); coronary calcium by EBCT calcium score > 0 and > 168; and, coronary calcium by CF for diagnosis of obstructive coronary artery disease (CAD) as a function of pretest likelihood (i.e., prevalence) of disease.
Results: Two hundred fifty three men and 80 women were enrolled in this study (mean age, 63.9+11.4 years; age range, 35-90 years). Sensitivity and specificity of CF in the detection of patients with angiographically coronary artery stenosis >50% were 96% and 86%, respectively. The profit accrued from implementing the CF test at Chang Gung Memorial Hospital, including the cost of the cardiac catheterization laboratory, was NT$329/patient. At 475 patients per month, this test will produce revenue of NT$156,275/month or NT$1,875,300/year. The profit achieved by implementing the CF test at Chang Gung Memorial Hospital, excluding the cost of the cardiac catheterization laboratory was NT$838.7/patient, or NT$398,382.5/month and NT$4,780,590/year. Conversely, implementing the EBCT test will cost Chang Gung Memorial Hospital NT$ 1,124,990/month or NT$ 13,499,880/year. With disease prevalence at < 0.7, CF examination was the most cost-efficient initial diagnostic testing pathway. However, for the group with prevalence at 1.0, the highest group, initial angiography with no prior non-invasive testing was the most cost-effective strategy for diagnosis of obstructive coronary artery disease.
Conclusion: 1) Calcium detection with CF is a highly sensitive and moderately specific test, and a simple, inexpensive, and safe technique for identifying CAD. 2) Instituting CF as a screening test for self-paid executive physical examinations would result in considerable profit for the hospital. Conversely, establishing an EBCT program will produce a substantial financial loss. 3) For patients evaluated for obstructive CAD, a test pathway utilizing CF to detect coronary artery calcium as an initial non-invasive test minimized direct costs and maximized cost-effectiveness. Cinefluoroscopy has been neglected as a noninvasive technique for diagnosis of coronary stenosis and is sufficiently promising to warrant increased clinical use.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0731105-152748 |
| Date | 31 July 2005 |
| Creators | Hang, Chi-Ling |
| Contributors | Hsueh-Wen Chang, Ming-rea Kao, NONE, NONE |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0731105-152748 |
| Rights | unrestricted, Copyright information available at source archive |
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