Introduction : The number of Koreans with cardiovascular disease is increasing due to rapid sociocultural changes. The clopidogrel, one of the most commonly used anti-platelet agent in cardiovascular disease, shows medicinal effects by inhibiting platelet receptor P2Y12ADP irreversibly. In this study, I analyzed relationship between the PFA-200 P2Y test results and major adverse cardiac events (MACEs) including cardiac death, myocardial infarction, restenosis and ischemic stroke in cardiovascular disease patients taking clopidogrel.
Materials and Methods : Between August 2013 and June 2016, I enrolled 106 cardiovascular disease patients who have been treated with clopidogrel. Blood samples were collected from the patients and the closure time (CT) was measured using platelet function analyzer (PFA)-200 (INNOVANCE PFA-200 System; Siemens Healthcare, Germany) P2Y test. Based on a cut-off value (106 seconds) of the CT, the patients were divided into two groups. I investigated their age, sex, body mass index, clinical diagnosis, underlying diseases, other administered drugs and a variety of MACEs occurred during follow-up period.
Results : In the PFA-200 P2Y test, the CTs of 78 samples exceeded the cut-off value. 68 samples of the group over the cut-off value exceeded measurable upper limit, 300 seconds. The rest 10 samples of the group was within the measurable range. Those of 24 samples of the other group did not exceed the cut-off value. At the time of these analyses, 11 patients had been diagnosed with MACEs. In time-to-event analysis, there is a statistically significant difference between the two groups (P<0.001) and the estimated relative risk for the group under the cut-off value was 6.65. With adjustments for the presented variables, the CT value was the strongest factor of the occurrence of MACEs (P=0.002). The patients in the group under the cut-off value had a 7.30-fold adjusted occurrence risk of MACEs in the Cox proportional hazards regression analysis.
Conclusions : Patients showing clopidogrel resistance could be identified by the PFA-200 P2Y test results. Through the comparison between the two groups divided by the cut-off value of the CT, I found close correlation between the CTs and MACEs of Korean cardiovascular disease patients taking the clopidogrel. Based on this study, PFA-200 P2Y test results could be used as a predictive marker for MACEs risk in patients taking the clopidogrel.