Introduction: In patients who present with ST-elevation myocardial infarction (STEMI), primary percutaneous coronary intervention and the administration of dual antiplatelet therapy (aspirin plus a P2Y12 inhibitor) are recommended. This thesis aimed to determine the extent to which oral P2Y12 inhibitors (clopidogrel/prasugrel/ticagrelor) exert their antiplatelet effect during the acute phase of a STEMI compared to non-ST elevation myocardial infarction (NSTEMI). Methods: The degree and time-course of platelet inhibition following oral administration of P2Y12 inhibitors was determined in 87 patients from their pharmacokinetic (plasma concentration) and pharmacodynamic (degree of platelet inhibition) profiles at 20 minutes, balloon inflation, 60 and 240 minutes using liquid chromatography/mass spectrometry, VerifyNow and VASP-phosphorylation assays. Results: In STEMI patients, oral P2Y12 inhibitors do not provide adequate levels of platelet inhibition at the time of angioplasty and have a limited effect at 240 minutes. The NSTEMI group displayed a marked and rapid antiplatelet effect at all time points. A significant difference in the acute efficacy of oral P2Y12 inhibitors in STEMI vs NSTEMI patients (p < 0.001) was seen. Conclusion: Oral P2Y12 inhibitors display delayed and attenuated antiplatelet effects in STEMI patients in the immediate period following administration of a loading dose when compared with NSTEMI patients.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:707664 |
| Date | January 2017 |
| Creators | Khan, Nazish |
| Publisher | University of Birmingham |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://etheses.bham.ac.uk//id/eprint/7315/ |
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