Comparison of "Accelerated" Tissue Plasminogen Activator with Streptokinase for Treatment of Suspected Myocardial Infarction

Abstract

Purpose. A computerized decision analysis, based on the results of published clinical trials, assessed the risks, benefits, and costs of different thrombolytic regimens for suspected myocardial infarction (MI) throughout the likely range of clinical circumstances. Data source. Medline search and articles' bibliographies. Study selection. All studies reporting efficacy and side effects of thrombolysis. Data analysis. Life-expectancy outcomes of thrombolytic therapies for possible MI modeled by decision analysis. Results. The analysis allows a clinician to estimate the benefits, risks, and relative costs of thrombolytic therapies throughout the likely range of individual clinical circumstances. When applied, for example, to the average patient in ISIS-2, estimated gains are 150 quality-adjusted days of life (QALDs) from treatment with streptokinase (SK) and 255 QALDs with "accelerated" tPA (tPA). tPA costs $1,686 more than SK, taking into account the cost of lifelong care of the extra strokes incurred. Nevertheless, the chances of stroke above which thrombolysis is not preferred are 5.0% for SK and 8.0% for tPA, with tPA remaining the preferred treatment for six hours after symptom onset; thereafter, SK is marginally preferred, but at much lower cost. Both regimens are beneficial in older patients provided the chances of MI and death are "average" or greater. Conclusion. Where the chances of MI and death are known, decision analysis can be a useful bedside tool to guide thrombolytic therapy and subsequently, if needed, to review and defend the treatment decisions made. Key words: decision analysis; thrombolytic therapy; myocardial infarction; streptokinase; tissue plasminogen activator. (Med Decis Making 1995;15:297-310)