Coronary thrombi neovascularization in patients with ST-elevation myocardial infarction - clinical and angiographic implications.
INTRODUCTION
Coronary artery thrombosis in ST-elevation myocardial infarction (STEMI) is a dynamic process often preceded by episodes of silent plaque rupture and subocclusive thrombosis. Thrombus organization is achieved by ingrowth of endothelial and smooth muscle cells. Clinical significance and impact of thrombus neovascularization on primary percutaneous coronary intervention (pPCI) outcome remain unclear. Therefore we investigated composition and neovascularization of thrombi aspirated during pPCI and their association with clinical and angiographic parameters of STEMI patients.


METHODS
Aspirated thrombi retrieved from 84 STEMI patients were classified as fresh (<1 day), lytic (1-5 days) or organized (>5 days). Thrombus neovascularization was evaluated immunohistochemically using CD34, CD31 and VEGF antibodies. CD34 and CD31 immunopositive (CD34/CD31+) cells were organized as single, clusters and microvessels. VEGF positivity was graded as low or high, based on thrombus surface immunopositive area.


RESULTS
CD34/CD31+ cells were present in 67% of all aspirated thrombi. Thrombus CD34/CD31 positivity was associated with previous history of angina pectoris (χ(2)=6.142, p=0.013) and lower myocardial blush grade (MBG<3, χ(2)=12.602, p<0.001). Organization of CD34/CD31+ cells showed inverse association with the extent of VEGF positivity (χ(2)=10.607, p=0.005). Fresh thrombi were associated with shorter ischemic time (U=237.5, p=0.002) and MBG 3 (χ(2)=6.379, p=0.012).


CONCLUSIONS
Older thrombus age and neovascularization are associated with suboptimal myocardial perfusion in STEMI patients. Thrombus VEGF expression is inversely associated with degree of CD34+ cell organization. Therefore, neovascularization of aspirated thrombi may indicate the duration of thrombosis, coronary microcirculation status and outcome in STEMI patients.
['Kostić|Jelena|J|', 'Orlić|Dejan|D|', 'Borović|Milica Labudović|ML|', 'Beleslin|Branko|B|', 'Milašinović|Dejan|D|', 'Dobrić|Milan|M|', 'Tešić|Milorad|M|', 'Ostojić|Miodrag|M|']
D000368:Aged D018952:Antigens, CD34 D003326:Coronary Circulation D003328:Coronary Thrombosis D042783:Endothelial Cells D006801:Humans D008297:Male D008875:Middle Aged D009203:Myocardial Infarction D009389:Neovascularization, Pathologic D019408:Platelet Endothelial Cell Adhesion Molecule-1 D017131:Thrombectomy D042461:Vascular Endothelial Growth Factor A
Neovascularization STEMI Thrombus Aspiration Acute myocardial infarction Thrombectomy