Thrombolytic therapy reduces the incidence of left ventricular thrombus after anterior myocardial infarction. Relationship to vessel patency and infarct size.
BACKGROUND
Controversial evidence exists as to whether thrombolytic therapy reduces the incidence of left ventricular thrombus in acute myocardial infarction and, if so, how this relates to successful reperfusion.


METHODS
Four hundred and eighteen consecutive patients underwent echocardiography and coronary angiography within 3 weeks of an acute myocardial infarction. A dyssynergic score was calculated by analysing regional wall motion in 18 left ventricular segments. The infarct-related artery was considered patent if TIMI grade 2 or 3 flow and less than 90% stenosis were present. Retrograde perfusion by Rentrop's grade 2 or 3 collaterals was considered significant.


RESULTS
Large anterior myocardial infarctions were associated with the highest prevalence (39%) of left ventricular thrombosis. Thrombus was also very frequent if the left anterior descending coronary artery was occluded and no collaterals to the infarct area were seen (75%). Anticoagulant therapy reduced the prevalence of left ventricular thrombus, regardless of whether the infarct-related vessel was patent or not. Conversely, in patients undergoing thrombolysis the incidence of left ventricular thrombosis was lower when the left anterior descending coronary artery was patent, and especially when an early creatine kinase peak, suggestive of reperfusion, was recorded (7%). Finally, the presence of left ventricular thrombosis was inversely related to the asynergy score.


CONCLUSIONS
These observations suggest that the presence of left ventricular thrombus is related to the extent of myocardial damage. Thrombolytic therapy reduces thrombus probably by salvaging myocardium at risk.
Pizzetti
G
G
Department of Cardiology, Istituto Scientifico H S Raffaele, Milano, Italy.
Belotti
G
G
Margonato
A
A
Carlino
M
M
Gerosa
S
S
Carandente
O
O
Chierchia
S L
SL
D000328:Adult; D000368:Aged; D003328:Coronary Thrombosis / Q000209:etiology* / Q000517:prevention & control; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications* / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology; D010960:Plasminogen Activators / Q000627:therapeutic use*; D011446:Prospective Studies; D011994:Recombinant Proteins; D013300:Streptokinase / Q000627:therapeutic use*; D015912:Thrombolytic Therapy; D010959:Tissue Plasminogen Activator / Q000627:therapeutic use*; D016896:Treatment Outcome; D014654:Vascular Patency; D016277:Ventricular Function, Left
D005343:Fibrinolytic Agents; D011994:Recombinant Proteins; D013300:Streptokinase; D010960:Plasminogen Activators; D010959:Tissue Plasminogen Activator