Abstract 3353: Impact of Metalloproteinases on LV Remodeling and Prognosis in Hypertrophic Cardiomyopathy
Background: The impact of extracellular collagen matrix regulation on left ventricular (LV) remodeling and the prognosis of patients with hypertrophic cardiomyopathy (HCM) is unresolved.
Methods and Results: Plasma levels of matrix metalloproteinase (MMP)-2, MMP-9, tissue inhibitor of metalloproteinase (TIMP)-1 and clinical findings were evaluated in 41 HCM patients, including eight with LV systolic impairment. Plasma B-type natriuretic peptide (BNP) levels were also measured. MMP-2 levels in patients with severe symptoms were higher than those in no or mild symptoms. The levels of MMP-2 and TIMP-1 were positively related to LV end-systolic and left atrial dimensions, and inversely related to %fractional shortening. MMP-2 levels were positively related to BNP levels (r=0.52, p=0.0009). However, MMP-9 levels were not related to echocardiographic parameters and plasma BNP levels. Patients with high plasma MMP-2 level (>1170 ng/ml) revealed poorer prognosis than those with low MMP-2 levels. Similarly, the prognosis in patients with high TIMP-1 levels was worse than that in patients with low TIMP-1 levels.
Conclusions: Elevated levels of MMP-2 and TIMP-1 were related to LV remodeling and poor prognosis in patients with HCM. These results suggest that regulation of the extracellular collagen matrix may be one of therapeutic targets in patients with HCM.