Abstract: To evaluate the clinical value of quantitative myocardial acoustic densitometry in myocardial fibrosis in relative to an alteration in serum metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) concentrations in essential hypertensive patients. Methods72 essential hypertensive patients were divided into two groups based on the left ventricular mass index: 40 patients with left ventricular hypertrophy(the LVH group) and 32 patients without left ventricular hypertrophy(the NLVH group), and 30 normal persons served as healthy controls. Calibrated acoustic intensity in the septal(CAl1)　and posterior wall(CAI2) and cyclic variation of integrated backscatter in the septal(CVIB1)and posterior wall(CVIB2) were determined by the AD technique． Concentrations of MMP-9 and TIMP-1 were determined by enzyme-linked immunosorbent assays (ELISA). ResultsCAI1 and CAI2 in the LVH group(46.12±4.52 and 45.84±5.71, respectively) were significantly higher than those in the NLVH group (41.61±5.98 and 41.42±5.62, respectively) and the control group (38.30±3.87 and 37.18±3.88, respectively)(P＜0.01). However, CVIB1 and CVIB2 in the LVH group(7.19±1.27 and 8.99±1.35, respectively) were significantly lower than those in the NLVH group (8.59±1.89 and 10.23±1.80, respectively) and the control group (9.29±2.11 and 10.92±2.10, respectively)(P＜0.01). MMP-9 and TIMP-1 concentrations in the LVH group (32.75±4.95 and 83.21±32.65, respectively) were significantly higher than those in the NLVH group(28.20±5.70 and 60.09±28.51,respectively) and the control group (25.26±5.97 and 38.18±10.61, respectively)(P＜0.01)， while the MMP-9/TIMP-1 ratio in the LVH group (0.46±0.24) was significantly lower than that in the NLVH group (0.57±0.21) and the control group (0.69±0.19) (P＜0.05). MMP-9 level in the LVH group was positively related to CAI1 and CAI2(0.71 and 0.78, respectively)(P＜0.01), which was inversely related to CVIB1 and CVIB2(-0.80 and -0.70, respectively)(P＜0.01). Also the TIMP-1 level in the LVH group was positively related to CAI1 and CAI2(0.79 and 0.80, respectively)(P＜0.01). ConclusionMyocardial acoustic densitometry parameters are significantly related to MMP-9 and TIMP-1, which may be potentially used for evaluation of severity of myocardial fibrosis.

Key words: Myocardial acoustic densitometry, Hypertension, Gelatinase B