[Left ventricle mural thrombus early after acute myocardial infarction]

Abstract

Before the widespread use of primary percutaneous coronary intervention (PCI) and glycoprotein llb/Illa inhibitors (GP lIb/Illa) the left ventricular thrombus (LVT) was reported to complicate up to 20% of acute myocardial infarctions (AMI). It still remains unknown how these modern therapies impact on LVT occurrence.

The aim of the study: We tried to define the frequency of LVT among the patients (pts) who underwent successful primary PCI and received aggressive antiplatelet therapy at the same time. We also wanted to assess the clinical and echocardiographic predictors of LVT formation.

Material and methods: 3158 pts who had underwent successful primary PCI within 12 hours from onset of AMI were retrospectively analyzed. Two-dimensional and Doppler echocardiographic examinations were performed in all these pts within three to four days after the PCI. LVT was defined as an echodense mass with definite margins, distinct from the endocardium and adjacent to an area of hypo- or akinetic myocardium. Baseline demographic characteristics, angiographic findings, type of intervention and medical treatment were analyzed.

Results: LVT was detected in 79 pts (2.5%). Pts with LVT and ones without it (n=3079, control group) were the same age (61.2+/-11.4 vs. 61.8 +/- 12.8 years, ns) and suffered from diabetes mellitus (29.1% vs. 22.4%, ns), lipid disorders (46.8% vs. 42.7%, ns) at the same frequency. Percentage of smokers was also similar in both groups (51.9% vs. 56%, ns). LVT pts had a history of hypertension more frequently (62.01% vs. 49.4%, p < 0.05). There were more men in LVT group (82.3% vs. 70.8%, p < 0.05). It included also more pts with anterior AMI (93.7% vs. 41.8%, p < 0.001). LVT pts had also a lower ejection fraction (43.4+/-12.4% vs. 55.7+/-12.7%, p < 0.001) and a higher wall motion score index (2.08+/-0.44 vs. 1.56+/-0.62, p < 0.001) than pts without LVT Percentage of stent implantations was similar in both groups (92.4% vs. 92.2%, ns), which also did not differ in treatment of glycoprotein llb/llla inhibitors (63.3% vs. 54.2%, ns) as well as administration of thienopyridines (92.4% vs. 92,2%). According to results of multiple log regression analysis, the presence of LVT was strongly associated with anterior AMI (adds ratio OR =25), male gender (OR = 2.21), EF < 40% (OR = 2.19) and previous hypertension (OR = 2.2).

Conclusions: The prevalence of LV thrombus early after AMI is very low in the era of primary PCI and aggressive antiplatelet treatment. The highest rate of LVT occurrence was found among male patients with anterior AMI, reduced left ventricular function and previous arterial hypertension.