Mitral regurgitation in early myocardial infarction. Incidence, clinical detection, and prognostic implications. TIMI Study Group.
OBJECTIVE
To investigate mitral regurgitation occurring early in the course of acute myocardial infarction with respect to its incidence, the impact of infarct size and location, the accuracy of clinical detection, the contribution of global and regional left ventricular performance, and its influence on prognosis.


METHODS
Prospective observational study derived from patients entering Phase I of the Thrombolysis in Myocardial Infarction (TIMI) trial.


METHODS
Multicenter trial involving 13 university-affiliated medical centers.


METHODS
A total of 206 patients studied within 7 hours of symptom onset during their first myocardial infarction.


METHODS
Contrast left ventriculography was used to document mitral regurgitation.


RESULTS
Mitral regurgitation was present in 27 patients (13%). Although the presence of regurgitation correlated with the site of infarction (20 of 27 had anterior infarctions) and the number of akinetic chords, it was not statistically related to the peak creatine kinase value or to left ventricular chamber size or filling pressure. A murmur of mitral regurgitation was heard in only 2 patients (1 incorrectly). The presence of early mitral regurgitation predicted cardiovascular mortality at 1 year by univariate (relative risk, 12.2; 95% Cl, 3.5 to 42; P less than 0.0001) and multivariate (relative risk, 7.5; Cl, 2.0 to 28.6; P = 0.0008) analyses.


CONCLUSIONS
Mitral regurgitation in early myocardial infarction is generally clinically "silent," is more common in anterior infarction, is associated with regional dysfunction but not early ventricular dilation or peak enzyme release, and is an important predictor of cardiovascular mortality.
Lehmann
K G
KG
DVA Medical Center (111C), Seattle, WA 98108.
Francis
C K
CK
Dodge
H T
HT
D000328:Adult; D000368:Aged; D002933:Cineradiography; D005260:Female; D005500:Follow-Up Studies; D006326:Heart Auscultation; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology* / Q000401:mortality; D009203:Myocardial Infarction / Q000150:complications* / Q000401:mortality; D011379:Prognosis; D012044:Regression Analysis; D015996:Survival Rate; D013997:Time Factors