tailieunhanh - Textbook of Interventional Cardiovascular Pharmacology - part 3

thay thế thuốc chống đông máu trong can thiệp mạch vành qua da trong giảm tiểu cầu do heparin Nguy cơ chảy máu thấp nguy cơ chảy máu Không có kháng nguyên cao kháng thể hình thành (40%) kháng thể hình thành nguy cơ chảy máu thấp () | 104 Clinical application of direct antithrombin inhibitors Table 6 Alternative anticoagulants in percutaneous coronary intervention in heparin-induced thrombocytopenia Drug Dose regimen Monitoring Characteristics Approved countries Trial reference Argatroban 350 g kg bolus 25 g kg min during procedure Target ACT 300-450 sec Low bleeding risk No antigenicity US ARG 216 310 311 n 91 76 Hirudin kg bolus mg kg hr for 24 hr or mg kg hr for 24 hr Target aPTT 60-100 sec High bleeding risk Antibody formation 40 n 25 77 Bivalirudin kg bolus mg kg hr for 4 hr during procedure Target ACT 350 sec Low bleeding risk Antibody formation US ATBAT n 52 78 Abbreviations ACT activated clotting time aPTT activated partial thromboplastin time. of 25 g kg min adjusted to achieve an ACT of 300 to 450 seconds. Argatroban was found to be a safe and effective anticoagulant in HIT patients undergoing PCI without a significant increase in bleeding. On this basis argatroban was approved by the FDA as an anticoagulant for patients with or at risk for HIT undergoing PCI. When used in combination with GPIIb IIIa inhibitors the dose of argatroban was reduced to a bolus of 250 or 300 g kg followed by a 15 g kg min infusion to target lower ACT of about 300 seconds in non-HIT patients 34 . Strict monitoring by ACT is required to avoid unexpected overdose of argatroban in intensive-care patients with hepatorenal failure especially after cardiac surgery. Hirudin has been used for anticoagulation in non-HIT patients undergoing PCI treatment 50 . The molecular structure of drug is completely different from UFH and the drug does not stimulate generation of HIT antibodies. Although theoretically hirudin might be employed as an alternative to UFH it has not been studied in HIT patients undergoing PCI because of its higher incidence of bleeding. In a trial with 25 HIT patients who underwent PCI and were enrolled after platelet recovery to greater than 50 000 L the drug was