A Importância de um ECG Normal em Síndromes Coronarianas Agudas sem Supradesnivelamento do Segmento

BACKGROUND: Admission ECG has a major impact on the diagnosis and management of non-ST elevation acute coronary syndromes (ACS). OBJECTIVE: To assess the impact of the admission ECG on prognosis over non-ST ACS. Population: prospective, continuous, observational study of 802 non-ST ACS patients from a single center. METHODS: Patients were divided in 2 groups: A (n=538) - Abnormal ECG and B (n=264) - Normal ECG. Normal ECG was synonymous of sinus rhythm and no acute ischemic changes. A one-year clinical follow up was performed targeting all causes of mortality and the MACE rate. RESULTS: Group A patients were older (68.7+/-11.7 vs. 63.4+/-12.7Y, p<0.001), had higher Killip classes and peak myocardial necrosis biomarkers. Furthermore, they had lower left ventricular ejection fraction (LVEF) (52.01+/-10.55 vs. 55.34+/- 9.51%, p<0.001), glomerular filtration rate, initial hemoglobin, and total cholesterol levels. Group B patients were more frequently submitted to invasive strategy (63.6 vs. 46.5%, p<0.001) and treated with aspirin, clopidogrel, beta blockers and statins. They also more often presented normal coronary anatomy (26.2 vs. 18.0%, p=0.45). There was a trend to higher in-hospital mortality in group A (4.6 vs. 1.9%, p=0.054). Kaplan-Meyer analysis showed that at one month and one year (95.1 vs. 89.5%, p=0.012) survival was higher in group B and the result remained significant on a Cox regression model (normal ECG HR 0.45 (0.21 - 0.97). There were no differences regarding the MACE rate. CONCLUSION: In our non-ST elevation ACS population, a normal ECG was an early marker for good prognosis.