Thesis (S.M.)--Harvard-MIT Division of Health Sciences and Technology, 2010. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 35-38). / Background: The optimal long-term antiplatelet therapy (APT) that balances the benefit of preventing myocardial infarction (MI) with the risk of severe bleeding is unknown in patients greater than one year after drug-eluting stent (DES) placement. Methods: We modeled life expectancy (LE) using published data by building a Markov model to compare several APT strategies composed of aspirin and clopidogrel, both as monotherapy and in various clinically plausible combinations. The base case examined a 65-year old person treated with a DES then continuous aspirin plus clopidogrel (Dual-Rx) for one year without complications. We considered risk of mortality from myocardial infarction and severe bleeding. We used a lifetime horizon and projected LE without quality-adjustment. Results: In the base-case analysis, APT yielding greatest LE was a toss-up between Dual-Rx indefinitely (LE of 13.48 years), clopidogrel indefinitely (LE of 13.45 years), and aspirin indefinitely (LE of 13.42 years); of the strategies considered, no APT was least preferred (LE of 13.36 years). All parameters were varied over plausible ranges in sensitivity analyses, including the duration of future treatment with clopidogrel (base-case, life long). The choice of APT remained a toss-up unless: the annual probability of MI fell below 0.0087 (base-case, 0.013) or the relative risk of systemic bleeding exceeded 1.52 (base case, 1.00), in which case clopidogrel indefinitely was preferred; or the efficacy of clopidogrel to prevent MI fell below 0.09 (base case, 0.20) or the relative risk of clopidogrel for severe gastrointestinal hemorrhage exceeded 3.33 (base case, 2.01), in which case aspirin indefinitely was preferred. Conclusions: For patients with a drug-eluting stent placed greater than one year ago, the antiplatelet therapy which yields the greatest life expectancy is a toss-up between dual antiplatelet therapy (clopidogrel plus aspirin indefinitely), clopidogrel indefinitely, and aspirin indefinitely. However, additional research (including a clinical trial, subgroup analysis, and modeling) is needed. / by J. Stewart Evans. / S.M.
| Identifer | oai:union.ndltd.org:MIT/oai:dspace.mit.edu:1721.1/63226 |
| Date | January 2010 |
| Creators | Evans, J. Stewart (James Stewart) |
| Contributors | Alexa T. McCray, Stephen G. Pauker and John B. Wong., Harvard University--MIT Division of Health Sciences and Technology., Harvard University--MIT Division of Health Sciences and Technology. |
| Publisher | Massachusetts Institute of Technology |
| Source Sets | M.I.T. Theses and Dissertation |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | 55 p., application/pdf |
| Rights | M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission., http://dspace.mit.edu/handle/1721.1/7582 |
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