Yale: Acute Coronary Syndrome: Prognostic Value of ST-Segment Depression

CONTENTS

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Prognostic value of ST-Segment Depression in Acute Coronary Syndrome

A simple baseline ECG provides an immediate assessment of prognosis of patients presenting with an acute coronary syndrome. The most important adverse ECG marker of prognosis is the presence of ST-segment depression.

The relationship between various ECG presentations and clinical outcome was assessed in the GUSTO-IIb trial (Global Use of Strategies To Open Occluded Arteries in Acute Coronary Syndrome). The investigators retrospectively examined the ability of the presenting ECG to predict death or MI in 12,142 patients who reported symptoms of cardiac ischemia at rest within 12 hours of admission and had signs of myocardial ischemia confirmed by ECG. The 30-day incidence of death or MI was 5.5% in patients with T-wave inversion, 9.4% in those with ST-segment elevation, 10.5% in those with ST-segment depression, and 12.4% in those with ST-segment elevation and depression (P < 0.001) [1]. The presenting ECG therefore allowed immediate risk stratification in patients presenting with acute coronary syndromes.

Fig. 1.

Fig. 1

Savonitto et al. JAMA 1999: 281: 707-713.

A prospective analysis of the value of ischemic ECG changes among 1899 patients presenting with unstable angina or NQWMI has recently been reported. Mortality at 90 days was greatest in patients presenting with ST-segment depression (> 0.1mV) and lowest when the ECG was normal [2]. The specificity of the ST segment depression for acute MI is relatively high. In one recent study, the presence of any ST depression on the presenting ECG had a sensitivity of 42% and specificity of 80% for the diagnosis of acute MI. Maximal ST depression > 0.3 mV was highly specific (97%) for acute MI [3].

Fig. 2. Prognostic value of ST-segment depression during chest pain in patients with suspected UA or NQWMI.

Fig. 2

Lopez de Sa'E, et al. J Am Coll Cardiol. 1998; 31 (Suppl A): 79A.

In summary, ST-segment deviation greater than or equal to 1mm is a specific high-risk marker for adverse outcome, and warrants consideration of aggressive therapy, including the use of GP IIb/IIIa antagonists.

1. Savonitto S, Ardissino D, Granger CB, et al., Prognostic Value of the Admission Electrocardiogram in Acute Coronary Syndrome. JAMA 1999; 281:707-713.

2. Lopez de Sa'E, Lopez-Senon J, Bethencourt A, et al. Prognostic Value of ECG Changes During Chest Pain in Patients With Unstable Angina: Results of the Proyecto de Estudo del Progostico de la Angina (PEPA). J Am Coll Cardiol. 1998; 31 (Suppl A): 79A.

3. Lloyd-Jones DM, Camargo CA, Lapuerta P, et al. Electrographic and Clinical Predictors of Acute Myocardial Infarction in Patients With Unstable Angina Pectoris. Am J Cardiol. 1998; 81:1182-1186.