The use of systemic thrombolytic agents is widely accepted as standard therapy for acute myocardial infarction. A history of active bleeding is appropriately considered a contraindication, and many clinicians equate menstrual bleeding with "active bleeding". However, because most clinical trials have excluded women of childbearing age, the use of thrombolytic agents during menstruation has not been clearly defined. We report the successful use of systemic thrombolytic therapy in an actively menstruating woman with acute myocardial infarction.

A 43-year-old woman came to the emergency room with a 4-hour history of chest pain, and an electrocardiogram showed evidence of an acute inferior myocardial infarction. Direct coronary angioplasty was not an immediate treatment option because the only available weekend catheterization laboratory was busy with another acute interventional case. To avoid a further delay in possible reperfusion, intravenous recombinant tissue-type plasminogen activator (rt-PA) was administered, along with intravenous heparin and oral aspirin. No contraindications to thrombolytic therapy were initially identified. However, shortly after beginning therapy with rt-PA, the patient reported that she had been menstruating more heavily than usual for the past 3 days. The emergency room physician immediately stopped the rt-PA and notified the cardiologist. Given the continuing unavailability of the interventional laboratory, completion of the rt-PA regimen was recommended. The patient became pain-free within 30 minutes of restarting rt-PA therapy, with resolution of her acute electrocardiographic changes. Her creatine kinase peaked at 603 IU/L (normal, 37 to 289 IU) with a positive CK-MB isoenzyme fraction (9.2%). Her hemoglobin fell slightly on hospital day 2 from 14.8 g/dL to 13.0 g/dL, and she reported less menstrual bleeding than normal. Her menstrual bleeding stopped by day 3 without problems, and she had a stable hemoglobin of 12.8 g/dL. Cardiac catheterization before discharge showed mild inferolateral hypokinesis and two-vessel coronary disease for which successful multivessel angioplasty was done.

Our report suggests that actively menstruating women with acute myocardial infarctions can be successfully treated with rt-PA without significant bleeding complications. Previous limited use of thrombolytic agents in menstruating women also tends to support their safety [1-5]. This may be explained physiologically by the fact that menstrual bleeding is more of a "sloughing" process induced by a prostaglandin-mediated vasospastic response than a true form of thrombus-dependent active bleeding. However, before widespread recommendations regarding thrombolytic therapy in this subgroup of patients can be made, more data from future clinical trials are warranted.