In 54 HCM patients (age 55.9 ± 14.3 y, 50% female) fibrosis was quantified by LGE-CMR. Serum concentrations of MMP-1, -2, -3, -9, and tissue inhibitor of MMP (TIMP) 1 were analyzed by means of enzyme-linked immunosorbent assay and PINP, PIIINP, and type I collagen C-terminal telopeptide (ICTP) concentrations by radioimmunoassay. MMP-9 was associated with fibrosis in LGE-CMR (mean increase 0.66 g/unit MMP9 [95% confidence interval [CI] 0.50–0.82]; P < .001) and with cardiac events in women (odds ratio [OR] 1.07 [1.01–1.12], P = .01) but not in men. Increased MMP-2 levels in women were associated with lower fibrosis (0.05 [−0.09 to −0.01]; P = .015). MMP-3 levels were positively associated with cardiac events (OR 1.13 [1.05–1.22]; P = .001) independently from fibrosis and sex. No association was detected for MMP-1, TIMP-1, PNPs, and ICTP.
These data suggest that MMP-9 is a useful biomarker for fibrosis and cardiac events in female HCM patients, whereas MMP-3 is associated with a higher event rate independent from fibrosis and sex.