Is heparin of value in the management of acute myocardial infarction?
The role of heparin in conjunction with thrombolytic therapy for the management of patients with acute myocardial infarction continues to be controversial. Many issues, including the possible benefits and risks of this therapy, are unresolved. Administration of high-dose subcutaneous heparin in the presence of thrombolytic therapy results in a significant mortality reduction during the treatment period of 55 lives saved per 10,000 patients treated (p < 0.01). At 35 days mortality is not significantly decreased by 22 lives and 18 nonfatal infarctions, at a cost of 32 transfusions and 6 strokes (half of which result in full recovery) per 10,000 patients treated. There have been fewer than 1250 patients randomized in trials comparing intravenous heparin with no heparin in patients receiving thrombolytic therapy and aspirin. These trials are too small to draw reliable conclusions, although several trials have suggested that intravenous heparin is beneficial for maintaining patency after t-PA therapy. In the the Global Use of Streptokinase and t-PA for Occluded Coronary Arteries (GUSTO) trial, patients receiving streptokinase were randomized to receive either delayed subcutaneous heparin or intravenous heparin. There were no differences in clinical endpoints. However, despite 36% crossover to intravenous heparin among patients randomized to receive subcutaneous heparin with streptokinase, patency of the infarct-related artery was 17% higher (84% vs. 72%, p < 0.05) at 5-7 days in patients randomized to receive intravenous heparin and streptokinase. This significant difference could potentially translate into an important effect on long-term prognosis. Therapy for acute myocardial infarction should include aspirin and a thrombolytic agent for patients without contraindications. Based on the current evidence, it is reasonable to also administer intravenous heparin with either streptokinase or TPA.
White
H D
HD
Coronary Care and Cardiovascular Research, Green Lane Hospital, Auckland, New Zealand.
D000208:Acute Disease; D000925:Anticoagulants / Q000627:therapeutic use*; D004347:Drug Interactions; D005343:Fibrinolytic Agents / Q000627:therapeutic use*; D006493:Heparin / Q000627:therapeutic use*; D006801:Humans; D009203:Myocardial Infarction / Q000188:drug therapy*
D000925:Anticoagulants; D005343:Fibrinolytic Agents; D006493:Heparin