UTILITY AND SAFETY OF IMMEDIATE EXERCISE TESTING OF LOW-RISK PATIENTSADMITTED TO THE HOSPITAL FOR SUSPECTED ACUTE MYOCARDIAL-INFARCTION

More then 2 million patients are admitted to U.S. hospitals annually f or clinical suspicion of acute myocardial infarction (AMI), and >70% a re found not to have had a cardiac event. This study evaluates the saf ety and efficacy of immediate exercise testing for patients admitted t o the hospital for suspected AMI. Ninety-three nonconsecutive low-risk patients admitted to the hospital from the emergency department to ru le out AMI underwent exercise treadmill testing using a modified Bruce protocol immediately on admission to the hospital (median time <1 hou r). Twelve patients had positive exercise electrocardiograms , 6 of wh om had significant coronary narrowing by angiography. An uncomplicated non-Q-wave AMI was diagnosed in 1 patient. Fifty-nine patients had ne gative and 22 patients had nondiagnostic exercise electrocardiograms. Of these 81 patients, 44 were discharged immediately after exercise te sting 17 were discharged within 24 hours, and 20 were discharged after 24 hours of observation. There were no complications from exercise te sting. There were 2 late noncardiac deaths and a late AMI. Thus, immed iate exercise testing of low-risk patients with chest pain who are at sufficient risk to be designated for hospital admission is effective i n further stratifying this group into those who can be safely discharg ed immediately and those who require hospitalization.