Plasma adrenomedullin relation with Doppler-derived dP/dt in patients with congestive heart failure

Left ventricular functional parameters by gated SPECT myocardial perfusion imaging in a Latin American country

BACKGROUND

There is paucity of data on left ventricular (LV) functional parameters using gated SPECT myocardial perfusion imaging (MPI) from the Latin American region. This study provides detailed information in low-risk patients both at rest and during exercise.

METHODS AND RESULTS

We studied 90 patients (50 men) with a very low likelihood of coronary artery disease. Gated-SPECT MPI was performed with Tc-99m MIBI using a 2-day protocol, with 16 frames/R-R cycle. The LV ejection fraction and volumes were not different between the rest and post-stress images. LVEF was 68 ± 7% post-stress and 70 ± 7% at rest in women, and 62 ± 7% and 63 ± 7%, respectively, in men (P = .19, .26). LV volumes were larger in men than women (P < .01). There were no differences in most variables obtained at rest or post-stress. Transient ischemic dilatation was similar, with upper limits of 1.20 and 1.19 in women and men, respectively (P = NS).

CONCLUSIONS

These data could prove helpful for the interpretation of gated SPECT MPI data in Latin America using identical protocol as used in this study.

Mid-regional-pro-adrenomedullin plasma levels are increased in obese adolescents

PURPOSE

Recently, adrenomedullin (ADM) was defined as a new member of the adipokine family. ADM secreted by adipocytes, through its vasodilator and antioxidant actions, might be protective against metabolic syndrome-associated cardiovascular complications. The aim of the study was to assess plasma mid-regional (MR)-proADM levels in obese adolescents compared to normal-weight subjects and its relation with BMI, body composition and metabolic indices.

METHODS

Plasma MR-proADM was measured in 32 healthy adolescents [BMI z-score (mean ± SEM) = 0.6 ± 0.09 and 0.8 ± 0.07 in females and males, respectively] and in 51 age-matched obese adolescents [BMI z-score (mean ± SEM) = 2.8 ± 0.12 and 2.9 ± 0.08 in female and males, respectively] by a time-resolved amplified cryptate emission technology assay.

RESULTS

Plasma MR-proADM levels resulted significantly higher in obese than in normal-weight adolescents (MR-proADM: 0.33 ± 0.1 vs 0.40 ± 0.1 nmol/L, p < 0.0001). Using univariate analysis, we observed that MR-proADM correlated significantly with BMI z-score (p < 0.0001), fat mass (p < 0.0001), circulating insulin (p < 0.004), HOMA-IR (p < 0.005), total cholesterol (p < 0.03) and LDL-cholesterol (p < 0.05). Including MR-proADM as response variable and its significant correlates into a multiple regression analysis, we observed that fat mass (p = 0.014) and BMI z-score (p = 0.036) were independent determinants of circulating MR-proADM.

CONCLUSIONS

Our study shows for the first time that obese adolescents have higher circulating levels of MR-proADM compared with normal-weight, appropriate controls suggesting its important involvement in obese patients.

Adrenomedullin and intermedin gene transcription is increased in leukocytes of patients with chronic heart failure at different stages of the disease

Adrenomedullin (ADM) is a vasodilatory peptide expressed in many tissues. Its levels are elevated in various diseases including chronic heart failure (CHF) and it has been suggested that the up-regulation of ADM in cardiac disease represents a protective mechanism. Similarly, intermedin (IMD), a novel member of the calcitonin/calcitonin gene-related peptide family, is considered a potential endogenous protector of the heart. Previous studies demonstrated that in CHF patients, elevated plasma concentrations of ADM and IMD reflect the patient's disease severity and prognosis, while the behavior of mRNA expression is not known. The aim of this study was to evaluate ADM/IDM transcriptomic profiling in human leukocytes of CHF patients as a function of clinical severity, assessing possible changes with respect to healthy subjects (C). mRNA expression was evaluated by Real-Time PCR and total RNA was extracted from leukocytes of C (n=8) and from CHF patients (NYHA I-II n=10; NYHA III-IV n=14) with PAXgene Blood RNA Kit. Significantly higher levels of ADM and IMD mRNA were found in CHF as a function of clinical severity (ADM: C=0.03 ± 0.013, NYHA I-II=0.11 ± 0.084, NYHA III-IV=11.46 ± 4.72, p=0.037 C vs NYHA III-IV, p=0.028 NYHA I-II vs NYHA III-IV; IMD: C=0.158 ± 0.041, NYHA I-II=0.93 ± 0.40, NYHA III-IV=2.6 ± 0.67, p=0.014 C vs NYHA III-IV, p=0.014 NYHA I-II vs NYHA III-IV). This study highlights, for the first time, the possibility of evaluating ADM and IMD mRNA expression in human whole blood samples by Real-Time PCR study providing further relevant information and providing a more complete interpretation of the pathophysiology of the disease.

Relationships between plasma adrenomedullin concentration and systolic time intervals during static handgrip in patients with heart failure

Our previous study showed elevation of plasma adrenomedullin (ADM) during static handgrip in patients with heart failure (HF). It is hypothesized that ADM increases with left ventricle dysfunction during handgrip and thus plays a compensatory role. In the present study pre-ejection period (PEP) and left ventricular ejection time (LVET) were used to assess cardiac performance in 24 male HF patients (II/III class NYHA) during two 3-min bouts of handgrip at 30% of maximal voluntary contraction (MVC) performed alternately with each hand without any break between the bouts. Plasma ADM, noradrenaline (NA), adrenaline (A), heart rate (HR), blood pressure (BP) and stroke volume (SV) were determined. During handgrip plasma ADM, NA, A, HR, BP, PEP/LVET increased, PEP was prolonged and LVET shortened. The increases in plasma ADM correlated with changes in: PEP (r = -0.881), LVET (r = 0.713), PEP/LVET (r = -0.769), SV (r = 0.836), diastolic BP (r = 0.700), total peripheral resistance (TPR) (r = 0.718) and noradrenaline (r = 0.756). The study demonstrated that in HF patients changes in plasma ADM during handgrip are related to cardiac performance.

C-type natriuretic peptide and its relation to non-invasive indices of left ventricular function in patients with chronic heart failure

C-type natriuretic peptide (CNP) significantly increases in chronic heart failure (CHF) patients as a function of clinical severity. Aim of this study was to evaluate in CHF patients the relationship between circulating CNP concentrations and echo-Doppler conventional indices of left ventricular (LV) function as well as less load independent parameters as dP/dt. LV ejection fraction (EF), left ventricular end-diastolic dimension (LVEDD) and LV dP/dt were evaluated together with plasma CNP levels in 38 patients with CHF and in 63 controls. CNP levels resulted significantly higher in CHF patients than in controls (7.19+/-0.59 pg/ml vs. 2.52+/-0.12 pg/ml, p<0.0001). A significant correlation between dP/dt and CNP levels (r=-0.61, p<0.0001) was observed. A good correlation with EF (r=-0.55, p<0.001) and a less significant relation with LVEDD (r=0.316, p<0.05) were also reported. When patients were divided according to dP/dt values a very significant difference in CNP levels was observed: Group I (<600, n=25) vs. Group II (>600, n=13): 8.46+/-0.69 and 4.75+/-0.75 pg/ml, respectively, p<0.001. This is the first study that reports a correlation between CNP and dP/dt in CHF patients, thus suggesting a possible role on cardiac contractility.