Identification of Patients at Increased Risk of First Unheralded Acute Myocardial Infarction by Electron-Beam Computed Tomography

Abstract

Background-There is a clear relationship between absolute calcium scores (CS) and severity of coronary artery disease.However, hard coronary events have been shown to occur across all ranges of CS. Methods and Results-We conducted 2 analyses: in group A, 172 patients underwent electron-beam CT (EBCT) imaging within 60 days of suffering an unheralded myocardial infarction. In group B, 632 patients screened by EBCT were followed up for a mean of 32Ϯ7 months for the development of acute myocardial infarction or cardiac death. The mean patient age and prevalence of coronary calcification were similar in the 2 groups (53Ϯ8 versus 52Ϯ9 years and 96% each). In group B, the annualized event rate was 0.11% for subjects with CS of 0, 2.1% for CS 1 to 99, 4.1% for CS 100 to 400, and 4.8% for CS Ͼ400, and only 7% of the patients had CS Ͼ400. However, mild, moderate, and extensive absolute CSs were distributed similarly between patients with events in both groups (34%, 35%, and 27%, respectively, in group A and 44%, 30%, and 22% in group B). In contrast, the majority of events in both groups occurred in patients with CS Ͼ75th percentile (70% in each group). Conclusions-Coronary calcium is present in most patients who suffer acute coronary events. Although the event rate is greater for patients with high absolute CSs, few patients have this degree of calcification on a screening EBCT. Conversely, the majority of events occur in individuals with high CS percentiles. Hence, CS percentiles constitute a more effective screening method to stratify individuals at risk. (Circulation. 2000;101:850-855.)

Distribuição dos escores de cálcio coronariano determinados pela tomografia ultra-rápida em 2.253 homens brancos assintomáticos

“…As in other populations, coronary artery calcium scores increased with age 13,16,17 ; however, the non-Gaussian distribution and the small number of individuals in the age groups > 60 years in our sample jeopardized the better comparison of coronary artery calcification between that age group and those immediately below and above it. Although the medians are greater, no statistical difference was observed in these values.…”

“…Therefore, it is necessary that other tests be used for a better stratification of the risks for coronary events. Data from the literature have shown that the presence of coronary artery calcification is associated with a greater risk for coronary events [11][12][13][14] , and its absence is associated with an almost-zero risk for coronary events in studies of 3-to-5 year follow-up 25 . Coronary artery calcium scores have their major usefulness in stratifying the risk for clinical events.…”

“…Ultrafast computed tomography is a noninvasive and very sensitive method to detect calcification in coronary arteries 7 . Evidence exists that the presence of coronary artery calcification on ultrafast computed tomography may be a risk marker of clinical events in coronary artery disease, independent of the risk factors for atherosclerosis [11][12][13][14] . Up to now, coronary artery calcium scores in the Brazilian population have not been reported.…”

Percutaneous coronary intervention in the elderly: current updates and trends

“…While the SYNTAX score did not predict long-term clinical outcomes, the CSS was useful in predicting the 1-year major adverse cardiac and cerebrovascular events, reflecting the potentially significant impact of the patient's clinical and demographic factors such as their ages on their clinical outcomes [34] . Previous studies have also shown that age is significantly associated with increased coronary artery calcium score [35,36] . Calcification of the coronary system is associated with coronary artery disease (CAD) and coronary artery calcium content is highly associated with increased cardiovascular events [36] .…”

“…Previous studies have also shown that age is significantly associated with increased coronary artery calcium score [35,36] . Calcification of the coronary system is associated with coronary artery disease (CAD) and coronary artery calcium content is highly associated with increased cardiovascular events [36] .…”