High-Dose Clopidogrel Loading in Percutaneous Coronary Intervention

2005 ◽  
Vol 39 (5) ◽  
pp. 918-922 ◽  
Author(s):  
Kristen L Longstreth ◽  
James R Wertz

OBJECTIVE: To review the use of a 600-mg clopidogrel loading dose in patients undergoing percutaneous coronary intervention (PCI). DATA SOURCES: Human clinical trials and platelet studies available through PubMed (1966–March 2005), bibliographies of pertinent articles, and citations supplied by the drug manufacturer were accessed. DATA SYNTHESIS: The administration of a 600-mg loading dose of clopidogrel can decrease the time required for maximum platelet inhibition to 2 hours compared with ⩾6 hours achieved with 300 mg. This higher loading dose has been investigated in multiple platelet studies and one observational report. Several randomized controlled trials have used a 600-mg loading dose; however, these studies were not designed to evaluate the efficacy and safety of this loading regimen. To date, only one randomized trial has compared the 600-mg loading dose with a 300-mg loading dose. CONCLUSIONS: When compared with a conventional loading regimen of 300 mg in lower-risk patients, pretreatment with clopidogrel 600 mg was shown to be more effective in reducing periprocedural events and demonstrated similar safety. Studies are needed to clarify the use of a 600-mg loading dose in higher-risk patients, with concomitant glycoprotein IIb/IIIa receptor antagonism, or when administration is delayed until immediately before or after PCI.

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Jorge Saucedo ◽  
Anand Singla ◽  
Karin Mauer ◽  
Kevin P Bliden ◽  
Mark J Antonino ◽  
...  

Despite dual antiplatelet therapy with aspirin and clopidogrel, patients with diabetes mellitus (DM) suffer from frequent recurrent ischemic events. Previous studies have shown that DM patients have a higher prevalence of aspirin resistance than non-DM patients. The aim of this analysis was to determine if DM patients have a decreased antiplatelet response to either maintenance or high loading clopidogrel administration when compared to non-DM patients. One hundred and thirty eight patients that underwent percutaneous coronary intervention (PCI) in the Clear Platelets-2 Study were included in this analysis. Patients were grouped according to clopidogrel dose use and presence of DM. Subjects were either on maintenance therapy with 75mg of clopidogrel (C75 group; n=72) or received a loading dose of 600mg of clopidogrel immediately after PCI (C600 group; n=66). All patients received 325-mg aspirin. Platelet function was measured by Light Transmission Aggregometry using ADP (5 and 20μM), TRAP (15 μM), and collagen (2μg/ml). Overall, DM patients in the C75 group had higher platelet aggregation using 5 and 20μM ADP and 2μg/ml collagen. DM patients had lower relative platelet inhibition at 24hrs with 5 μM ADP and 2μg/ml collagen in the C600 group when compared to non-DM patients (Table ). DM patients undergoing PCI exhibit higher platelet aggregation when receiving standard clopidogrel maintenance dose and lower relative platelet inhibition with high clopidogrel loading dose. Higher doses of clopidogrel or more potent P2Y12 receptor antagonists may be needed in DM patients to obtain comparable platelet inhibition to non-DM patients.


2017 ◽  
Vol 43 (04) ◽  
pp. 439-446 ◽  
Author(s):  
Thomas Bergmeijer ◽  
Thea Godschalk ◽  
Paul Janssen ◽  
Kim Berge ◽  
Nicoline Breet ◽  
...  

AbstractAntiplatelet therapy plays a pivotal role in patients with an ST-segment elevation myocardial infarction (STEMI) to prevent further atherothrombotic events, such as stent thrombosis. Although the risk of stent thrombosis is highest in the first hours after primary percutaneous coronary intervention (pPCI), little is known about when an adequate level of platelet inhibition is achieved following a clopidogrel or ticagrelor loading dose in STEMI patients. Patients presenting with STEMI in whom pPCI was performed and who were loaded with 600 mg clopidogrel or 180 mg ticagrelor were eligible for enrolment in this nonrandomized, open label, single-center study. Platelet reactivity was measured before PCI, 6 and 24 hours after loading dose and after 2, 7, and 14 days, using the VerifyNow P2Y12 assay as well as 20 µmol/L adenosine diphosphate stimulated light transmittance aggregometry (LTA). We analyzed the time until a VerifyNow result of < 236 P2Y12 reaction units or LTA maximum platelet aggregation of < 64.5% was reached. A total of 28 patients were participated in this study. Platelet reactivity dropped below the high platelet reactivity cutoff level after 11.4 (VerifyNow) and 5.7 (LTA) hours in patients who were loaded with clopidogrel, and after 2.4 (VerifyNow) and 3.9 (LTA) hours in patients who were loaded with ticagrelor. Despite the administration of a clopidogrel or ticagrelor loading dose, it still takes multiple hours (2–11) to reach adequate platelet inhibition in STEMI patients. This might indicate the need for additional antiplatelet therapy in the first hours after loading in patients undergoing pPCI with stenting.


2020 ◽  
Vol 14 ◽  
Author(s):  
Johny Nicolas ◽  
Usman Baber ◽  
Roxana Mehran

A P2Y12 inhibitor-based monotherapy after a short period of dual antiplatelet therapy is emerging as a plausible strategy to decrease bleeding events in high-risk patients receiving dual antiplatelet therapy after percutaneous coronary intervention. Ticagrelor With Aspirin or Alone in High-Risk Patients After Coronary Intervention (TWILIGHT), a randomized double-blind trial, tested this approach by dropping aspirin at 3 months and continuing with ticagrelor monotherapy for an additional 12 months. The study enrolled 9,006 patients, of whom 7,119 who tolerated 3 months of dual antiplatelet therapy were randomized after 3 months into two arms: ticagrelor plus placebo and ticagrelor plus aspirin. The primary endpoint of interest, Bleeding Academic Research Consortium type 2, 3, or 5 bleeding, occurred less frequently in the experimental arm (HR 0.56; 95% CI [0.45–0.68]; p<0.001), whereas the secondary endpoint of ischemic events was similar between the two arms (HR 0.99; 95% CI [0.78–1.25]). Transition from dual antiplatelet therapy consisting of ticagrelor plus aspirin to ticagrelor-based monotherapy in high-risk patients at 3 months after percutaneous coronary intervention resulted in a lower risk of bleeding events without an increase in risk of death, MI, or stroke.


Sign in / Sign up

Export Citation Format

Share Document