What is the clinical evidence from this study?

Study design: Cohort. Population: Acute Myocardial Infarction (n=830). Intervention: Infarct related artery (IRA) assessment vs. STEMI vs NSTEMI. Primary outcome: Distribution of infarct related artery (IRA) and its association with clinical characteristics and ST deviation pattern.

October 8, 2009Open Access

ST Deviation Pattern and Infarct Related Artery in Acute Myocardial Infarction

Key Result

In STEMI, the infarct-related artery was most frequently the LAD, with significant differences in age and TIMI flow depending on the IRA, whereas no such differences were observed in NSTEMI.

Study Design

Type

Cohort (n=830)

Multicenter

Structured PICO

Population

830 patients presenting with an acute myocardial infarction (MI) who underwent coronary angiography within 7 days of admission (563 with STEMI and 267 with NSTEMI).

Outcome

Distribution of infarct related artery (IRA), age, and TIMI flow rate

The distribution of the infarct-related artery and its association with patient age and TIMI flow differ significantly between STEMI and NSTEMI presentations.

Abstract

BACKGROUND: Myocardial infarction (MI) may be classified as ST-elevation MI (STEMI) or non-ST-elevation MI (NSTEMI). There is little data regarding the relationship between the infarct related artery (IRA), clinical characteristics of the patients, and the ST deviation pattern (ie, STEMI or NSTEMI). HYPOTHESIS: There is a predilection of any coronary artery to a particular ST deviation pattern of acute MI. METHODS: We reviewed our institutional database and selected patients who presented with an acute MI and underwent coronary angiography within 7 days of admission. The analysis included 830 patients of whom 563 had STEMI and 267 had NSTEMI. The culprit lesion was defined by reviewing each patient's angiographic report, electrocardiogram, and echocardiogram. TIMI flow rate was determined. RESULTS: The IRA in STEMI was most frequently the left anterior descending coronary artery (LAD) followed by the right coronary artery (RCA) and then the left circumflex coronary artery (LCX), a statistically significant difference. In patients with NSTEMI there were no significant differences in IRA. Patients with STEMI and LCX as the IRA were significantly younger and had a higher percentage of TIMI grade 3 flow then patients with STEMI and LAD or RCA as IRAs. These differences were not noted in patients with NSTEMI regardless of IRA. CONCLUSIONS: In STEMI there were significant differences in age and TIMI flow depending on the IRA. These findings were not demonstrated in patients with NSTEMI.