Early prediction of 30-day mortality after Q-wave myocardial infarction by echocardiographic assessment of left ventricular function--a pilot investigation.
BACKGROUND
The GUSTO angiographic substudy demonstrated that left ventricular function measured 90 min after thrombolytic therapy was given had important prognostic implications at 30 days in patients with an acute myocardial infarction (MI).


OBJECTIVE
Thirty-day prognosis after Q-wave MI can be determined by early echocardiographic assessment of left ventricular function.


METHODS
Using transthoracic echocardiography, semiquantitative ejection fraction and wall motion score index was assessed prospectively in 201 consecutive patients within 24 h following Q-wave MI. Independent experts blinded to the patient's status performed the echocardiographic assessment. All patients received standard medical care as dictated by the attending cardiologist.


RESULTS
Of the 201 patients, 24 (11.9%) died within 30 days, with 70% of the deaths occurring within 10 days after the infarction. Three deaths occurred in the 120 patients with an ejection fraction > or = 45% (2.5% mortality rate). In contrast, 21 deaths occurred among the 81 patients 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 fraction 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 associated with a 2.9% 30-day mortality (two deaths in 76 patients); WMSI of > or = 1.4 was 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 in survivors (1.52+/-0.45), p = 0.00001.


CONCLUSIONS
Echocardiographic assessment of left ventricular function during 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 hospital course, with relative ease, at no risk and at an acceptable cost. An ejection fraction < 45% or WMSI > or = 1.4 identifies patients who are at a high risk of dying within 30 days. These are the patients who may benefit most from aggressive medical therapy and early angiography to assess coronary pathology.
Smock
A L
AL
Cardiovascular Division, University of Florida, Gainesville, USA.
Larson
B
B
Brown
C
C
Conti
C
C
D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000401:mortality* / Q000503:physiopathology*; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D018570:Risk Assessment; D015912:Thrombolytic Therapy; D014463:Ultrasonography; D016277:Ventricular Function, Left