The efficacy of ticagrelor in acute coronary syndrome has been fully demonstrated in PLATO, a prospective randomized study comparing ticagrelor and clopidogrel. Based on this study, the European and American Heart Association guidelines recommended the use of roticagrelor prior to initial and coronary reperfusion procedures in patients with acute coronary syndrome.
However, this study is mainly conducted for Westerners, and there is a problem that Asians have participated in small scale. Indeed, as known from studies conducted in Asian countries, there have been many studies that ticagrelor's inhibition of platelet function is different from that of Westerners, and even if the degree of platelet inhibition is smaller than that of Westerners, it is not a clinical problem. Rather, the drug called prasugrel, similar to tachygrelor, was more likely to cause bleeding problems than the clinical benefit when the current dose was used. In the case of prasugrel, bleeding frequency was reduced when the dose was lower than the approved dose, but the degree of platelet inhibition was similar. Ticagrelor is also a common side effect, and symptoms of breathing occur mainly at the beginning of drug administration, and the cause is known to be caused by increasing the concentration of adenosine in the blood. The frequency of these breathing symptoms increases in proportion to the dose, which can also be expected to decrease when a dose less than the approved dose is used. These low-dose drug therapies are likely to reduce the frequency of side effects and eventually increase drug compliance. In particular, after cardiovascular reperfusion, drug compliance and the incidence of clinical events are inversely related. Increasing drug compliance eventually plays a major role in reducing the recurrence of cardiac events. When using low dose ticagrelor therapy can be said to be an advantage. The purpose of this study is to evaluate the efficacy and safety of low-dose ticagrelor therapy in patients with acute bleeding.

Treatment

This study is to compare the bleeding frequency of the 90 mg ticagrelor bid group and the 45 mg ticagrelor bid group after evaluating the degree of platelet inhibition in patients with acute coronary artery.

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Target Number of Participant

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This study is to compare the bleeding frequency of the 90 mg ticagrelor bid group and the 45 mg ticagrelor bid group after evaluating the degree of platelet inhibition in patients with acute coronary artery.

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Description

Acute Coronary Syndrome
Patients who have completed a successful cardiovascular perfusion procedure
PRU <90 patients
Patients who voluntarily signed a research agreement

1. Patients unable to take ticagrelor (severe chronic obstructive pulmonary disease, history of cerebral hemorrhage)
2. Patients with multi-vascular disease and coronary artery bypass surgery
3. Moderate-Those with severe liver disease
4. Those who have bradycardia symptoms such as same-sex bradycardia and atrioventricular conduction block
5. Those with respiratory distress, such as those with chronic obstructive pulmonary disease.
6. Pregnant or lactating women
7. Those who have undergone hemodialysis or peritoneal dialysis due to end stage renal failure and have undergone kidney transplantation
8. A person who, due to other reasons, judges that participation in a clinical trial is inappropriate.

BARC bleeding

administration, 1month, 6 month

platelet reactivity unit by VerifyNow

administration, 1month

Borg Dyspnea scale

administration, 1month, 6 month

MACCE(CV death, MI, stroke), major bleeding

administration, 1month, 6 month

Bleeding episodes were most commonly observed at 1month and then decreased over time.
Compared with standard-dose ticagrelor, half-dose ticagrelor did not reduce total bleeding (BARC type 1-5) during 6month (odds ratio(OR) 0.900, 95% confidence interval [CI] 0.563-1.440, p=0.661). 
However, serious bleeding events (BARC type ≥2) occurred less often in half-dose ticagrelor (OR 0.284, 95% CI 0.088-0.921, p=0.036).
Likewise, the overall rate of moderate-to-severe dyspnoea was highest at 1 month, then decreased over time.
Half-dose ticagrelor did not decrease the rate of any dyspnoeaor moderate-to-severe dyspnoea during 6month.
The risk of ischemic events was also similar between the groups.