Early prediction of 30-day mortality after Q-wave myocardial infarction byechocardiographic assessment of left ventricular function - A pilot investigation

Background: The GUSTO angiographic substudy demonstrated that left ventricu lar function measured 90 min after thrombolytic therapy was given had impor tant prognostic implications at 30 days in patients with an acute myocardia l infarction (MI). Hypothesis: Thirty-day prognosis after Q-wave MI can be determined by early echocardiographic assessment of left ventricular function. Methods: Using transthoracic echocardiography, semi quantitative ejection f raction and wall motion score index was assessed prospectively in 201 conse cutive patients within 24 h following Q-wave MI. Independent experts blinde d to the patient's status performed the echocardiographic assessment. All p atients received standard medical care as dictated by the attending cardiol ogist. Results: Of the 201 patients, 24 (11.9%) died within 30 days, with 70% of t he deaths occurring within 10 days after the infarction. Three deaths occur red in the 120 patients with an ejection fraction greater than or equal to 45% (2.5% mortality rate). In contrast, 21 deaths occurred among the 81 pat ients with an ejection fraction <45% (25.9% mortality rate) p = 0.0003. Two of the three patients who died in the high ejection fraction group died as a result of intracerebral hemorrhage from thrombolytic therapy. Ejection f raction was lower in nonsurvivors (32.3 +/- 10.3 vs. 46.3 +/- 13%) than in survivors, p < 0.0002. Wall motion score index (WMSI) of < 1.4 was associat ed with a 2.9% 30-day mortality (two deaths in 76 patients); WMSI off 1.4 w as associated with a 17.6% 30-day mortality (22 deaths in 125 patients), p = 0.0007. Average WMSI was higher in the nonsurvivors (1.95 +/- 0.5) than i n survivors (1.52 +/- 0.45), p = 0.00001. Conclusions: Echocardiographic assessment of left ventricular function duri ng the first 24 h after an acute Q-wave MI can be performed in all patients regardless of stability. High-risk patients are identified early in the ho spital course, with relative ease, at no risk and at an acceptable cost. An ejection fraction < 45% or WMSI greater than or equal to 1.4 identifies pa tients who are at a high risk of dying within 30 days. These are the patien ts who may benefit most from aggressive medical therapy and early angiograp hy to assess coronary pathology.