Serial Holter ST-segment monitoring after first acute myocardial infarction. Prevalence, variability, and long-term prognostic importance of transient myocardial ischemia

Fifteen-year risk of major coronary events predicted by Holter ST-monitoring in asymptomatic middle-aged men

BACKGROUND

Ambulatory electrocardiogram monitoring (Holter) with ST-analysis as a measure of myocardial ischemia has in populations with coronary heart disease been shown to predict major coronary events: death, myocardial infarction or coronary revascularization. There has, however, been conflicting evidence regarding the usefulness of this technique in identification of healthy subjects with increased risk for coronary heart disease. The aim of this study was to assess if Holter monitoring with ST-analysis could be used to predict future major coronary events in asymptomatic middle-aged men with a defined aggregation of traditional risk factors for coronary heart disease.

METHODS

One hundred and fifty-five asymptomatic participants from the city of Malmö, Sweden, with known levels of conventional cardiovascular risk factors underwent Holter monitoring for analysis of transient ST-segment depression at the age of 55 years. Fifteen years after the Holter monitoring, hospital records, diagnosis and death registries were revisited for major coronary events.

RESULTS

An ST-segment depression of 1 mm or greater (0.1 mV) was considered significant for myocardial ischemia and was found in 54 of the 155 men. There were no significant differences in risk factors in the two groups at baseline. The 15-year incidence of a first major coronary event was significantly higher in men with ST-segment depression (39%) than in men without ST-segment depression (20%) (P<0.015). A Holter electrocardiogram could predict future major coronary events with a positive and negative predictive value of 35 and 80%, respectively.

CONCLUSIONS

Holter monitoring can be used as a complement to conventional risk factor evaluation in deciding whether or not to treat risk factors for CHD in asymptomatic subjects.