Rongkun Liu

Impact of the Metalloproteinase-9/Tissue Inhibitor of Metalloproteinase-1 System on Large Arterial Stiffness in Patients with Essential Hypertension

The extracellular matrix is vital for maintaining tissue integrity, and the matrix metalloproteinases/tissue inhibitors of metalloproteinases (MMPs/TIMPs) system is involved in the regulation of extracellular matrix metabolism. Extracellular matrix turnover plays an important role in the change of large arterial mechanical properties in hypertension. However, the association of the metalloproteinase-9/tissue inhibitor of metalloproteinase-1 (MMP-9/TIMP-1) system and arterial stiffness is not straightforward and existing data are rather limited. Our objective is to explore the impact of the MMP-9/TIMP-1 system on large arterial stiffness in patients with essential hypertension. An automatic pulse wave velocity (PWV) measuring system was used to examine carotid-femoral PWV (CFPWV) and carotid-radial PWV (CRPWV) as the parameters reflecting central elastic large arterial and peripheral muscular medium-sized arterial elasticity, respectively; and serum MMP-9 and TIMP-1 levels, along with a number of other established biomarkers, were measured by enzyme-linked immunosorbent assay (ELISA) in 202 essential hypertensive patients and 54 age and gender-matched control subjects. Compared with the control subjects, hypertensive patients exhibited higher levels of MMP-9 (p=0.001) and TIMP-1 (p=0.002). Spearmans correlation analysis showed that serum levels of MMP-9 (p=0.014) and TIMP-1 (p=0.005) were significantly and positively correlated with CFPWV in hypertensive patients. A stepwise multiple regressive analysis demonstrated that age, systolic blood pressure, heart rate and TIMP-1 were independent predictors of CFPWV in patients with essential hypertension (adjusted r2=0.458). In conclusion, our results imply that the MMP-9/TIMP-1 system may play an important role in the determination of arterial function, and these findings may have implications for the involvement of MMP-9/TIMP-1 system in the pathophysiology of cardiovascular disease.

Association between circulating levels of P-selectins and burden of thrombus formation in patients with ST- elevation acute myocardial infarction

We tested the hypothesis that, in the acute phase of ST-segment elevation myocardial infarction (STEMI), the circulating level of P-selectin (PS) is predictive of angiographic morphologic features that indicate burden of thrombus formation in the infarct-related artery (IRA). One hundred and ninety-five consecutive patients with acute myocardial infarction (AMI) who underwent primary percutaneous coronary intervention (PCI) within 12 h of symptom onset were divided into the high-burden thrombus formation (HBTF) (N = 84) group and low-burden thrombus formation (LBTF) group (N = 111) based on cineangiography carried out during PCI. Blood samples for measurement of the circulating levels of high-sensitive C-reactive protein (hs-CRP), interleukin-6 (IL-6), soluble intercellular cell adhesion molecule-1 (sICAM-1), PS and white blood cell (WBC) count were collected before PCI. The WBC count, neutrophil granulocyte count and PS level were significantly higher in the HBTF group than in the LBTF group (11.24 ± 3.62 vs 10.00 ± 3.35, p = 0.014; 8.84 ± 3.42 vs 7.66 ± 3.23, p = 0.015; 13.62 ± 8.13 vs 7.80 ± 4.17, p = 0.000, respectively). Patients in the HBTF group had a significantly lower prevalence of post-PCI thrombolysis in myocardial infarction (TIMI) grade-3 flow than that of the LBTF group (84.52% vs 93.69%, p = 0.037). Compared with the LBTF group, the HBTF group had higher peak values of the myocardial band (MB) fraction of creatine kinase (CK-MB). (308.52 ± 215.26 vs 213.79 ± 185.27, p = 0.005). By logistic regression analysis, PS (OR 1.259, 95%CI 1.125 - 1.408, p = 0.000) were independent predictors of thrombus formation. PS level was the strongest independent predictor of angiographic morphologic features that indicate HBTF in AMI.