Natural history of left ventricular thrombi: Their appearance and resolution in the posthospitalization period of acute myocardial infarction

Abstract

A series of 198 consecutive patients with acute myocardial infarction were prospectively studied before hospital discharge and during 24.0 +/- 8.6 months of follow-up. A predischarge thrombus was found in 38 (31%) of 124 patients with anterior infarction but in none of 74 patients with inferior infarction (p less than 0.001). Early thrombolytic therapy in 34 patients did not decrease the rate of thrombus occurrence. Acute anterior infarction, ejection fraction less than or equal to 35% and apical dyskinesia or aneurysm (but not akinesia) were significantly related to the appearance of thrombus during hospitalization by stepwise logistic regression analysis. Echocardiographic follow-up of 159 patients for at least 6 months (mean 26.6 +/- 8.4) revealed that thrombus disappeared in 14 (48%) of 29. Disappearance of thrombus was related to predischarge apical akinesia (but not dyskinesia) and to warfarin therapy during the follow-up period. A new thrombus first appeared after hospital discharge in 13 of 130 patients, and in 7 of the 13 it resolved during further follow-up. Thus, 30% (13 of 42) of thrombi in these patients appeared after discharge from the hospital. Three factors were related to occurrence of new thrombi during the follow-up period: deterioration in left ventricular ejection fraction, predischarge ejection fraction less than or equal to 35% and ventricular aneurysm or dyskinesia. Systemic embolism occurred in six patients, all with a predischarge thrombus (p less than 0.001). Mobility of the thrombus was the only variable significantly related to subsequent embolic events (p = 0.001) by logistic regression analysis. Thus, the predischarge echocardiogram identifies patients with thrombus and those at highest risk of embolic events. It can indicate patients who are likely to have thrombus resolution and those at risk of developing a new thrombus after hospital discharge. Follow-up echocardiograms may help in guiding the length of long-term anticoagulant therapy. Four additional patients with a predischarge apical mobile thrombus (not part of the consecutive series) received thrombolytic therapy. In two of the four, lysis of thrombus was achieved without complications, but systemic embolism occurred in the other two, and proved fatal in one.

Dual Antiplatelet Compared to Triple Antithrombotic Therapy in Anterior Wall Acute Myocardial Infarction Complicated by Depressed Left Ventricular Ejection Fraction

“…In a natural history study of 198 patients admitted for acute MI in the 1980s, LVT developed only in patients with anterior wall MI (1). Stepwise logistic regression analysis identifi ed anterior location of the infarct, decreased left ventricular EF (<35%), and apical dyskinesia or aneurysm as having the highest association with LVT formation during hospitalization (1). Consistent with this, we included only patients with EF ≤35% in our study, which resulted in patients in the study having had an estimated median EF of 31%, with anterior akinesis described in 79% of patients.…”

“…Th e reported incidence of LVT formation and subsequent embolization varies based on the timing of the echocardiographic examination and the diagnostic, anticoagulation, and reperfusion strategies utilized in managing the initial presentation but is noted to range from 0 to as high as 86% (1)(2)(3)(4)(5)(6)(7)(8)(9). Warfarin as a prophylactic strategy is therefore utilized and suggested in guidelines based on data derived from pooled results of studies done before catheter-based treatment of STEMI was prominent (10,11).…”

“…A cute thromboembolic events due to left ventricular thrombus (LVT) formation, particularly in patients with reduced ejection fraction (EF), remain a risk for patients surviving an anterior ST elevation myocardial infarction (STEMI) (1). Th e reported incidence of LVT formation and subsequent embolization varies based on the timing of the echocardiographic examination and the diagnostic, anticoagulation, and reperfusion strategies utilized in managing the initial presentation but is noted to range from 0 to as high as 86% (1)(2)(3)(4)(5)(6)(7)(8)(9).…”

Comment on Guidelines on oral anticoagulation with warfarin – 4th edition

“…Regression in size of the thrombus was seen in those treated with anticoagulation. Low levels of symptomatic systemic embolization were seen in this and other studies that demonstrated similar incidence (Visser et al, 1985;Johannessen et al, 1987;Keren et al, 1990). In a review, Cregler (1992) advocated 3 months of warfarin therapy for those with large anterior myocardial infarction or post-infarct heart failure.…”

Rupture and Bleeding Secondary to Renal Infarction in a Patient with an Abdominal Aortic Aneurysm

“…6,7) Systemic embolism occurred in 4%-63% of patients with a ventricular thrombus documented by echocardiography. 8) We detected a left ventricular thrombus in the apical region on preoperative echocardiography. However, the left ventricular thrombus had disappeared on postoperative echocardiography.…”