Relationship of sustained brain natriuretic peptide release after reperfused acute myocardial infarction with gated SPECT infarct measurements and its connection with collagen turnover and left ventricular remodeling.

BACKGROUND: The relationship among plasma brain natriuretic peptide (BNP), markers of extracellular matrix (ECM) remodeling, and left ventricular (LV) dilation after reperfused acute myocardial infarction is poorly known. METHODS AND RESULTS: Echocardiogram, plasma BNP, and ECM degradation markers (serum amino-terminal telopeptide of type I procollagen and type III procollagen and carboxy-terminal telopeptide of type I procollagen [ICTP]) were evaluated in 34 patients at days 1, 3, and 30 after first reperfused acute myocardial infarction. At 1 month, infarct size and severity and LV volume were measured by sestamibi gated single photon emission computed tomography. Patients were stratified according to day 3 BNP levels into 2 groups: group 1 (n = 17) had BNP values over the median value, and group 2 (n = 17) had BNP values under the median value. Infarct size and severity were similar in the 2 groups. LV volumes increased in group 1 but decreased in group 2 (P < .01). BNP values, LV volume/mass index, and infarct size were independent predictors of 1-month LV dilation (beta = .58 [P = .001], beta = .41 [P = .01], and beta = .32 [P = .03], respectively). Levels of serum amino-terminal propeptide of type I procollagen and type III procollagen were similar in both groups. The level of ICTP increased significantly in group 1 only, and after 3 days, it was higher (P < .01) than in group 2. In group 1 ICTP significantly interacted with the relationship between BNP release and serial changes in LV volumes (F = 4.87, P = .03). CONCLUSIONS: ICTP is related to elevated BNP level independently of infarct size and severity and interacts with the relationship between BNP and LV dilation. BNP levels could play a role in LV remodeling by favoring ECM degradation.

Relation between plasma brain natriuretic peptide, serum indexes of collagen type I turnover, and left ventricular remodeling after reperfused acute myocardial infarction.

The aim of the study is to investigate the relation between plasma brain natriuretic peptide (BNP), collagen type I turnover, and left ventricular (LV) remodeling after primary angioplasty. Echo-Doppler, BNP, carboxy-terminal telopeptide of procollagen type I (ICTP), C-terminal propeptide of procollagen type I (PICP), and their ratio PICP/ICTP (as an index of coupling between the synthesis and degradation of collagen type I) were evaluated at days 1 and 3 and months 1 and 6 after primary angioplasty in 56 consecutive patients with a first large acute myocardial infarction (AMI). During the 6 months after AMI, a direct relation was shown between BNP and ICTP (day 1, r = 0.54, p = 0.000; day 3, r = 0.64, p = 0.000; month 1, r = 0.64, p = 0.000; month 6, r = 0.41, p = 0.005) and BNP and PICP/ICTP (day 1, r = -0.54, p = 0.003; day 3, r = -0.58, p = 0.000; month 1, r = -0.50, p = 0.000; month 6, r = -0.30, p = 0.043), but not between BNP and PICP. Using analysis of covariance, relations between BNP and ICTP and PICP/ICTP were independent from infarct size. Patients with LV remodeling had significantly higher plasma ICTP and BNP levels and lower PICP/ICTP than patients without LV remodeling. Day-1 ICTP independently predicted 6-month remodeling (exp beta = 2.14, 95% confidence interval 1,120 to 3,550, p = 0.01). In conclusion, a relation exists between plasma BNP collagen type I turnover and LV remodeling after reperfused AMI.

Urinary endothelin-1 excretion according to morpho-functional damage lateralization in reflux nephropathy.

BACKGROUND: Reflux nephropathy (RN) is a pathophysiological human model of reduced nephron reserve, due to loss of renal mass, but little information exists about the role of urinary endothelin-1 (uET-1) in this disease. The aim of this study was to assess the presence of uET-1-like-immunoreactivity (uET-1L) in RN patients, particularly if lateralized renal damage existed. METHODS: Thirty patients with vescico-ureteral reflux (VUR) and consequent RN, were studied. The presence of VUR was established by voiding cysto-urethrography. RN was assessed and graded by 99mTc-dimercapto-succinic acid scan (DMSA). Renal plasma flow (ERPF) was evaluated by (123)I-Hippuran renal sequential scintigraphy, and glomerular filtration rate (GFR) by creatinine clearance. Forty-five healthy subjects were selected as a control group. uET-1L excretion, in both affected and control groups, was assayed. RESULTS: Mann-Whitney U test showed a significant difference between control and patient groups in both GFR and uET-1L. A good correlation between DMSA grading, single kidney clearance and VUR grade was shown. A significant relationship was also shown between uET-1L and both ERPF and GFR. Patients with RN were divided into two subgroups according to functional damage lateralization. Between the two groups, a significant difference was found only for uET-1L when GFR was applied as a covariate in ANCOVA analysis. CONCLUSION: Our preliminary results confirmed the increase of urinary ET-1L excretion in RN, especially when renal functional injury was lateralized.