['In acute heart failure syndromes (AHFS), the prognostic value of left ventricular ejection fraction (LVEF), although widely accepted, has been recently challenged. In contrast, blood pressure is increasingly gaining ground over LVEF as predictor of mortality. Therefore, it is not clear whether both LVEF and mean arterial pressure (MAP) are independent risk factors in patients with AHFS.', 'The EFICA study enrolled 581 AHFS patients admitted to 60 CCU/ICUs. Survival at 4 weeks was analyzed for all cases with echocardiographic LVEF available on admission (n=355). Four-week mortality was 23%. Multivariable analysis identified lower LVEF, lower MAP and serum creatinine >1.5 mg/dl as independent correlates of mortality (respectively, OR: 1.27 per 10% decrease, CI: 1.05-1.53, p=0.012; OR: 1.30 per 10 mmHg decrease, CI: 1.15-1.48, p<0.0001; OR: 2.84, CI: 1.64-4.93, p=0.0002). LVEF interacted significantly with MAP (p<0.0001) and the subgroup analysis showed that reduced LVEF was a strong risk factor in patients with MAP <or=90 mmHg (OR: 2.73, CI: 1.23-5.98, p=0.01) but did not reach statistical significance in patients with MAP >90 mmHg.'] Are ejection fraction and blood pressure important and interactive predictors of 4-week mortality in severe acute heart failure?