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 th erapy reduces the incidence of left ventricular thrombus in acute myoc ardial infarction and, if so, how this relates to successful reperfusi on. Methods Four hundred and eighteen consecutive patients underwent e chocardiography and coronary angiography within 3 weeks of an acute my ocardial infarction. A dyssynergic score was calculated by analysing r egional wall motion in 18 left ventricular segments. The infarct-relat ed artery was considered patent if TIMI grade 2 or 3 flow and less tha n 90% stenosis were present. Retrograde perfusion by Rentrop's grade 2 or 3 collaterals was considered significant. Results Large anterior m yocardial infarctions were associated with the highest prevalence (39% ) of left ventricular thrombosis. Thrombus was also very frequent if t he left anterior descending coronary artery was occluded and no collat erals to the infarct area were seen (75%). Anticoagulant therapy reduc ed 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 w as lower when the left anterior descending coronary artery was patent, and especially when an early creatine kinase peak, suggestive of repe rfusion, was recorded (7%). Finally, the presence of left ventricular thrombosis was inversely related to the asynergy score. Conclusion The se observations suggest that the presence of left ventricular thrombus is related to the extent of myocardial damage. Thrombolytic therapy r educes thrombus probably by salvaging myocardium at risk.