Accuracy of hospital diagnosis of myocardial infarction

The accuracy of diagnosis of myocardial infarction (MI) was investigated in 380 consecutive patients admitted to hospital with suspected MI. Patients were classified according to World Health Organization criteria as having either definite MI, possible MI, no MI or unclassified through insufficient information. Of 214 patients with definite MI, 202 were diagnosed as MI in the case records (false negative rate 6%). Of 32 patients with possible MI, one was diagnosed as MI in the case records (false negative rate 97%). All 129 patients with MI were correctly diagnosed in the case records. Five patients were unclassified. MI was therefore diagnosed with high specificity. A correct diagnosis in the group with possible MI may not be essential for optimal hospital management, since no deaths occurred in these patients and most were not monitored in hospital.