Background:

Patients undergoing percutaneous transluminal coronary angioplasty (PTCA) with drug eluting stent (DES) for acute coronary syndrome (ACS) are recommended dual antiplatelet drugs (APs) for a minimum of 12 months after the procedure to prevent stent thrombosis. However antiplatelet effect may not be identical. Some patients show non-responsiveness to APs and therefore may be at risk of catastrophic events. Lab assessment of platelet response may identify patients at higher risk.

OBJECTIVES

: Assessment of antiplatelet drug resistance using thromboelastography and its correlation with major adverse cardiac events (MACE) up to 90 days.

METHODS

: We conducted a prospective observational cohort study in a tertiary care center in South India including adult patients with acute coronary syndrome (ACS) who underwent primary PTCA with DES and were not on any antiplatelet drugs previously. Whole blood thromboelastography (TEG) with platelet mapping using arachidonic acid (AA) and adenosine diphosphate (ADP) as reagents was performed to assess the platelet response to aspirin and ticagrelor respectively within 24 hours after PTCA. MACE were observed for up to 90 days.

RESULTS

: Fifty six patients with mean age of 58.8±10.9 years were included of whom 72.4% were male. Nine (16.1%) patients showed a low response or no-response to ADP and 4 (7.1%) patients showed a low response or no-response to AA. Clinical MACE was seen in 6 (10.7%) of the patients, out of which 4 (66.7%) events occurred in those with abnormal platelet response to ticagrelor. Only one patient was not compliant to medications but no MACE occurred in that patient. Association between occurrence of MACE and abnormal platelet response to ticagrelor was significant (P= 0.002). However, association between MACE and platelet response to aspirin was not significant.

CONCLUSIONS

: TEG is relatively new investigational approach to assess the ticagrelor non-responsiveness. Abnormal platelet response detected by TEG-platelet mapping was associated with major adverse cardiac events.