Oral Anticoagulation for Acute Coronary Syndromes

Abstract

The following 2 case presentations illustrate the range of considerations when formulating plans for oral anticoagulation in patients with acute coronary syndromes. A 59-year-old patient presented within 5-hours of the onset of an electrocardiographic wave segment (ST) elevation anterior myocardial infarction and was treated with the accelerated dose regimen of alteplase, adjunctive unfractionated heparin, aspirin, and a β-blocker. The maximum isoenzyme of creatine kinase with muscle and brain subunits was >10 times the upper limit of normal. At day 4, echocardiography revealed a mass suggestive of a mural left ventricular thrombus and important apical wall motion abnormalities. ACE inhibition therapy was initiated. To reduce the risk of systemic embolization, heparinization with a target activated partial thromboplastin time of 1.5 to 2.0 times control was started, followed by 6 months of dose-adjusted warfarin, target international normalized ratio (INR) 2.5 to 3.5 (Table 1). View this table: Table 1105594. Established Indications for Oral Anticoagulant Therapy and Recommended Therapeutic Range A 66-year-old diabetic patient, taking aspirin daily because of a prior transient ischemic attack, presented with chest pain at rest and dynamic ST depression >1 mm. He recovered from the acute phase after treatment with low-molecular-weight heparin, nitroglycerine, aspirin, and β-blocker therapy. Cardiac markers remained negative. During the convalescence period, no recurrent chest pain occurred, and exercise testing was negative with respect to symptoms and electrocardiographic signs of ischemia. Before discharge, dose-adjusted medium-intensity oral anticoagulation therapy (target INR, 2 to 3) was started in addition to aspirin (80 mg daily) as a strategy for secondary prevention of death, (re)infarction, and stroke. Notwithstanding the improvements in the secondary prevention of acute coronary syndromes, death and (re)infarction occur in ≈10% to 15% of patients in the 4 to 6 weeks after presentation despite the use of aspirin. Interestingly, increased activity of the coagulation cascade has been reported up to 6 …