The effects of a transtelephonic surveillance and prehospital emergency intervention system on the 1-year course following acute myocardial infarction.

We evaluated the effect on morbidity and mortality of a post-myocardial infarction management and intervention system. One thousand four patients were prospectively randomized to an intervention group that included routine and emergency transtelephonic follow-up and ECG monitoring or to control; all subjects were followed for 1 year. For symptoms suggestive of myocardial ischemia, intervention patients telephoned the project emergency office, were instructed by a project nurse to self-administer intramuscular lidocaine with an auto-injector, and were then transported to the nearest emergency facility. Cardiac death or arrest was decreased 29% in intervention patients (p = 0.066), while all-cause mortality was decreased by 24% (p less than 0.11). Routine transtelephonic ECG monitoring detected ventricular ectopy in 48% of intervention patients, with almost 50% of these findings classified as complex forms. Ventricular ectopy detected during routine calls within 60 days of the acute myocardial infarction conferred a threefold increase in mortality (p = 0.001). In addition, control patients were 2.4 times more likely to be clinically depressed (p less than 0.03) and returned to work less quickly (p less than 0.03) when compared to intervention patients. Lidocaine injections were associated with an absence of ventricular ectopy on arrival at the Emergency Room in 64% and with a low incidence of lidocaine-associated side effects. There was only one case of unauthorized use of the self-injector. These findings demonstrate that an outpatient post-myocardial infarction transtelephonic surveillance program can be safely and effectively conducted, can detect complex ventricular arrhythmias of prognostic significance, can improve the quality of life, and may reduce 1-year cardiac mortality.

RCT Entities:   Population Interventions Outcomes