Dynamic assessment of myocardial involvement in patients with end-stage renal disease by ultrasonic tissue characterization and serum markers of collagen metabolism.

BACKGROUND

Congestive heart failure is the most common cause of mortality in patients with end-stage renal disease (ESRD). However, noninvasive assessment for cardiac involvement in ESRD has not been established.

HYPOTHESIS: Assessment of ultrasonic tissue characterization and serum markers of collagen degradation is useful for defining myocardial involvement in ESRD.

METHODS

Cyclic variation of ultrasonic integrated backscatter of the ventricular septum (CV-IBS) and the serum levels of free matrix metalloproteinase-I (MMP-I) and tissue inhibitor of metalloproteinase-I (TIMP-I) were measured in 30 patients with ESRD undergoing routine hemodialysis (HD) and in 40 patients with essential hypertension (HTN).

RESULTS

Compared with the group with HTN, ESRD (before HD) showed larger left ventricular (LV) mass index (217 +/- 56 vs. 146 +/- 45 g/m2, p < 0.01), worse LV diastolic function (E/A, 0.6 +/- 0.2 vs. 0.9 +/- 0.3, p < 0.05), smaller CV-IBS (9.0 +/- 1.3 vs. 12.4 +/- 0.9 dB, p < 0.01), and larger TIMP-I/MMP-I (46 +/- 10 vs. 34 +/- 10, p < 0.05), in spite of the comparable ventricular wall thickness. Thus, these indices may possibly reflect myocardial interstitial fibrosis. After HD (after the improvement of myocardial interstitial edema), a negative linear relationship between CV-IBS and TIMP-I/MMP-I was observed (r= -0.52, p < 0.05).

CONCLUSIONS

Noninvasive assessment of ultrasonic tissue characterization and serum markers of collagen type I degradation may be a new diagnostic tool for defining myocardial interstitial fibrosis in patients with ESRD and LV hypertrophy.