title: Oral antiplatelet therapy and platelet inhibition: An experience from a tertiary care center.
abstract: OBJECTIVE
  Although clopidogrel combined with aspirin is the most commonly used dual drug combination to avert thrombotic events in patients with coronary artery disease, the poor responsiveness to clopidogrel remains a concern. The objective of the current study is to assess the extent of resistance to clopidogrel, prasugrel, and ticagrelor in a real life set of patients with coronary artery disease who underwent percutaneous coronary intervention (PCI).
  
  
  METHODS
  A total of 539 patients, who underwent PCI and were on aspirin and on any of the three drugs, namely, clopidogrel, prasugrel and ticagrelor, were followed up regularly in the outpatient department. After 24h of initiation of antiplatelet medication, response to the treatment in all the patients was assessed using thrombelastography. The average percentage platelet inhibition was assessed along with the resistance and sensitivity to the drug in each patient. Sensitivity and resistance to the specific drug was defined as >50% and <50% of mean platelet inhibition, respectively.
  
  
  RESULTS
  About 99.15% of the patients treated with ticagrelor were sensitive to the drug and the difference between ticagrelor, clopidogrel, and prasugrel groups for sensitivity was significant with a p value of 0.00001, in favor of ticagrelor. It was also found that ticagrelor was significantly (p value of 0.001) associated with least resistance as compared with the other drugs assessed in the study.
  
  
  CONCLUSIONS
  Use of ticagrelor as dual therapy along with aspirin in patients with coronary artery disease (CAD) and undergoing PCI was associated with a significantly higher mean percentage platelet inhibition, higher sensitivity, and lower resistance as compared with the usage of clopidogrel or prasugrel.
authors: Director - Centre for Cardiac Sciences, Kokilaben Hospital, Four Bungalows, Andheri, Mumbai 400053, India. Electronic address: jjdalal@hotmail.com.
authors: Jamshed J
authors: JJ
authors: Dalal
authors: Clinical Assistant, Department of Cardiology, Kokilaben Hospital, Mumbai, India.
authors: Aarti
authors: A
authors: Digrajkar
authors: Medical Affairs, AstraZeneca, Bangalore, India.
authors: Alap
authors: A
authors: Gandhi
mesh_terms: D000241:Adenosine / Q000008:administration & dosage / Q000031:analogs & derivatives*; D000284:Administration, Oral; D000077144:Clopidogrel; D003324:Coronary Artery Disease / Q000097:blood / Q000628:therapy*; D004305:Dose-Response Relationship, Drug; D004351:Drug Resistance; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D062645:Percutaneous Coronary Intervention; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage; D010976:Platelet Count; D000068799:Prasugrel Hydrochloride / Q000008:administration & dosage*; D011446:Prospective Studies; D058921:Purinergic P2Y Receptor Antagonists / Q000008:administration & dosage; D062606:Tertiary Care Centers; D013916:Thrombelastography; D000077486:Ticagrelor; D013988:Ticlopidine / Q000008:administration & dosage / Q000031:analogs & derivatives*; D016896:Treatment Outcome
chemical_list: D010975:Platelet Aggregation Inhibitors; D058921:Purinergic P2Y Receptor Antagonists; D000077144:Clopidogrel; D000068799:Prasugrel Hydrochloride; D000077486:Ticagrelor; D000241:Adenosine; D013988:Ticlopidine
keywords: Clopidogrel; Drug resistance; Percutaneous coronary intervention; Prasugrel; Ticagrelor