INADVERTENT THROMBOLYTIC ADMINISTRATION IN PATIENTS WITHOUT MYOCARDIAL-INFARCTION - CLINICAL-FEATURES AND OUTCOME

Study objectives: Increasing pressure to deliver thrombolytic agents q uickly to patients with suspected myocardial infarction (MI), along wi th expanded indications, may contribute to inappropriate administratio n of these agents, with potentially catastrophic results. We sought to identify the extent to which MI is ruled out in patients given thromb olytic therapy for acute MI and to characterize the clinical course an d outcome in such patents. Methods: We studied 609 consecutive patient s admitted to the CCU of an urban teaching hospital who were treated w ith thrombolytic agents for suspected acute MI between January 1986 an d December 1993. In 35 (5.7%), MI was ruled out on the basis of persis tently normal serum creatine kinase-MB isoenzyme levels. Hospital cour se and alternative diagnoses were established by means of chart review and database inquiry. Results: Patients in whom MI was ruled out were similar to those with MI with regard to baseline demographic and clin ical features. Presenting ECGs in patients without MI were less likely to show Q waves (43 versus 64%, P<.02) but more likely to show left v entricular hypertrophy (26 versus 7%, P=.001) and nonspecific ST-segme nt and T-wave changes (54 versus 32%, P<.01) compared the ECGs of Mi p atients. Transient ST-segment elevation was detected in 51%. Hospital complications of patients without MI were similar to those of MI patie nts. No patient in whom MI was ruled out sustained a major hemorrhage. Final diagnoses of patients without Mi included unstable angina (n=20 , 57%) undefined chest pain (n=8, 17%) pericarditis (n=3), pancreatiti s (n=2), esophagitis (n=1), and aortic dissection (n=1). Two patients died, one of aortic dissection and another of pericarditis. Conclusion : In a consecutive series of CCU patients in whom MI was ruled after t hrombolysis, we found no demographic or presenting clinical features t o distinguish them from patients in whom MI was diagnosed. Transient S T-segment elevation potentially justifying thrombolytic therapy was pr esent in more than half of the patients in whom MI was ruled out but m ay have represented transient coronary occlusion, coronary spasm, or o ther manifestations of unstable angina, In this study, patients in who m Mi was ruled out had a high incidence of coronary disease and risk o f in-hospital complications similar to that of patients with acute MI, Our findings support the rationale and safety of policies to rapidly and aggressively administer thrombolytic agents in the emergency depar tment.