Abstract 2254: Can Left Atrium Predict Survival After an Acute Coronary Syndrome?
Echocardiography is a crucial tool for the management of the acute coronary syndrome (ACS) patients. To evaluate if left atrium (LA) diameter as a prognostic index in ACS patients. 886 consecutive patients admitted for ACS in a single coronary care unit, between May 2004 and December 2006, and who had echocardiography assessment during admission. Left atrium (LA) diameter was defined by M-Mode paraesternal long axis view. A one-year clinical follow up targeting all-cause mortality was performed. Median age of the population was 66.6±12.2 years, 71.0% were male, and 57.4% were admitted for a non-ST elevation ACS. The area under the operating curve for the LA as a predictor of one year all cause mortality was 0.65 and a cut off of 46 mm had a sensitivity of 67.5% and a specificity of 70.9% for this endpoint. After stratifying the population for this cutoff value of LA diameter, we concluded that patients with a LA diameter ≥ 44mm were older (69.6±11.2 vs 65.3±13.0 years), had a more frequent previous history of, diabetes, dyslipidemia, atrial fibrillation, and a higher body mass index. These patients were more often admitted for an invasive strategy (41.8 vs 32.3% p=0.005), but had a similar coronary anatomy and a similar chance for a complete percutaneous revascularization (49.0 vs 53.0, p=0.37). They had a lower left ventricular ejection fraction (49.6±11.8 vs 52.6±9.6%, p<0.001) higher ventricular dimensions, and presented more often on higher Killip-Kendal classes. There were no associations between LA diameter and LDL cholesterol, admission glycaemia or renal function. In-hospital mortality was similar for both groups (0.3 vs 0.0%, p=0.15), but patients with a LA diameter ≥ 46mm had a one-year survival significantly lower (86.6% vs 94.0%, log rank p < 0.001). This result persisted after an adjusted analysis on a Cox regression model (HR 1.69, 95%CI 1.02 – 2.80 for LA diameter ≥ 44) that included age, gender, diabetes, body mass index and treatment strategy during admission. In our population this simple echocardiographyc parameter was associated with a higher risk profile and worse prognosis on the medium term, and therefore LA diameter should also be included in the global risk assessment of ACS patients.