Insufficient secretion of atrial natriuretic peptide at acute phase of myocardial infarction

Atrial Natriuretic Peptides, Right Atrial Infarction and Prognosis of Patients with Myocardial Infarction-A Single-Center Study

Atrial natriuretic peptide (ANP) is secreted in response to the stretching of the atrial wall. Atrial ischemia most likely impairs the ability of atrial myocytes to produce ANP. Atrial infarction (AI) is rarely diagnosed but not infrequently associated with myocardial infarction (MI). The aim of the study was to assess the association between AI and the prognostic value of N-terminal proANP (NT-proANP) in patients with MI treated with primary percutaneous coronary intervention (PCI). We evaluated data of 100 consecutive patients. Plasma levels of NT-proANP were measured by the ELISA method. ECG recordings were interpreted to diagnose AI according to Liu's criteria. All patients were followed-up prospectively for 12 months for the manifestation of major adverse cardiovascular events (MACE), defined as unplanned coronary revascularization, stroke, reinfarction or all-cause death. AI was diagnosed in 36 patients. 14% of patients developed MACE. AI did not affect the incidence of MACE or any of its components, nor the patients' prognosis. NT-proANP revealed to be a strong predictor of death but was not associated with other adverse events. Conclusions: AI in patients with MI treated with primary PCI is not connected with their prognosis nor affects the usefulness of NT-proANP in predicting death during the 12-month follow-up.

Comparison of N-terminal pro-atrial natriuretic peptide and three cardiac biomarkers for discriminatory ability of clinical stage in dogs with myxomatous mitral valve disease

Plasma N-terminal pro-atrial natriuretic peptide (NT-proANP) concentration increases with progression of myxomatous mitral valve disease (MMVD) in dogs. This multicentre, prospective study compared plasma NT-proANP, N-terminal pro-brain natriuretic peptide (NT-proBNP), ANP, and cardiac troponin I (cTnI) concentrations in dogs with MMVD for their characteristics and discriminatory ability to detect cardiac dilatation and congestive heart failure (CHF). Thirty-six healthy dogs and 69 dogs with MMVD were included. Clinical variables were obtained via physical examination, thoracic radiography, and echocardiography. The discriminatory ability of each cardiac biomarker (CB) to determine the presence or absence of cardiac dilatation (event 1) and CHF (event 2) was evaluated using the receiver operating characteristic curves. Plasma NT-proANP, NT-proBNP, and ANP concentrations showed a significant association with the left atrium/aorta ratio (P<0.01). The area under the curve of plasma NT-proANP and NT-proBNP concentrations were 0.72 and 0.75, respectively in event1 and 0.72 and 0.76, respectively in event2. Plasma NT-proANP and NT-proBNP concentrations showed sensitivity 80.0 and 80.0%; specificity 67.6 and 64.7% in event1 (cutoff value; 8,497.81 pg/ml and 1,453.00 pmol/l, respectively) and sensitivity 85.7 and 81.0%; specificity 60.4 and 64.6% in event2 (cutoff value; 8,684.33 pg/ml and 1,772.00 pmol/l, respectively). In dogs with MMVD, plasma NT-proANP, NT-proBNP, and ANP concentrations increase with left atrial enlargement. Particularly, plasma NT-proANP and NT-proBNP concentrations appeared to be equally useful in the discriminatory ability to detect cardiac dilatation and CHF.

NT-proBNP, NT-proANP and cTnI concentrations in dogs with pre-capillary pulmonary hypertension

OBJECTIVES

To compare [NT-proBNP], [NT-proANP] and [cTnI] between control dogs with respiratory disease without pulmonary hypertension (PH) and dogs with pre-capillary PH, and to assess the accuracy of [NT-proBNP], [NT-proANP], [cTnI] to predict Doppler-derived peak tricuspid regurgitation (TR) gradient.

ANIMALS

20 dogs. 8 control dogs with respiratory disease with no PH and 12 with pre-capillary PH.

METHODS

[NT-proBNP], [NT-proANP] and [cTnI] were compared between the 2 groups and simple linear regression analysis was used to predict peak TR gradients from various blood biomarkers.

RESULTS

Median [NT-proBNP] was higher in the dogs with PH (2011 pmol/L, 274-7713 pmol/L) compared to control dogs (744 pmol/L; 531-2710 pmol/L) (p = 0.0339). [NT-proBNP] was associated with peak TR gradient (R(2) = 0.7851, p = 0.0001). Median [NT-proANP] did not differ between dogs with PH (1747 fmol/L; 894-2884 fmol/L) and control dogs (1209 fmol/L; 976-1389 fmol/L (p = 0.058). [NT-proANP] was not associated with peak TR gradient (R(2) = 0.2780, p = 0.0781). Median [cTnI] did not differ between dogs with PH (0.2850 ng/mL; 0.19-1.13 ng/mL) and control dogs (0.2 ng/mL; 0.19-0.82 ng/mL, p = 0.3051). Median [TnI] was not associated with peak TR gradient (R(2) = 0.024, p = 0.6307).

CONCLUSIONS

[NT-proBNP] concentration is significantly higher in dogs with pre-capillary PH when compared to dogs with respiratory disease without PH, and [NT-proBNP] may be useful to predict the severity of estimated PH. Elevations in [NT-proBNP] due to pre-capillary PH may complicate the interpretation of [NT-proBNP] elevations in patients presenting with cardiorespiratory abnormalities. [NT-proANP] and [cTnI] were not elevated in dogs with pre-capillary PH.

Risk assessment in patients with unstable angina/non-ST-elevation myocardial infarction and normal N-terminal pro-brain natriuretic peptide levels by N-terminal pro-atrial natriuretic peptide

AIMS

To compare the accuracy of the N-terminal fragment of its pro-hormone (Nt-proBNP) and N-terminal pro-atrial natriuretic peptide (Nt-proANP) in the prediction of the 2 year mortality and to investigate whether additional measurement of Nt-proANP to troponin I (TnI) could improve risk assessment in the subgroups of patients with unstable coronary artery disease (UCAD) and normal Nt-proBNP.

METHODS AND RESULTS

Plasma levels of the TnI, Nt-proANP, and Nt-proBNP were determined in 120 consecutive patients with UCAD without ST-segment elevations and normal left ventricular function. In multivariable logistic regression analysis, TnI and Nt-proBNP were independent predictors of mortality (P=0.01 and P=0.02, respectively). However, in the group of patients with normal Nt-proBNP levels, only Nt-proANP and TnI were independently associated with mortality (P=0.007 and P=0.03, respectively). Accordingly, patients with elevated Nt-proANP levels in this group of patients had significantly higher mortality rate than patients with normal Nt-proANP levels (P=0.003).

CONCLUSION

Our results suggest that determination of Nt-proANP might improve risk assessment in patients with UCAD, especially when Nt-proBNP is in the normal range.

Intravenous atrial natriuretic peptide prevents left ventricular remodeling in patients with first anterior acute myocardial infarction

OBJECTIVES

The study evaluates the effect of atrial natriuretic peptide (ANP) compared with nitroglycerin (GTN) on left ventricular (LV) remodeling after first anterior acute myocardial infarction (AMI).

BACKGROUND

Compared with GTN, ANP suppresses the renin-angiotensin-aldosterone system and endothelin-1 (ET-1), which stimulate LV remodeling.

METHODS

Sixty patients with a first anterior AMI were randomly divided into the ANP (n = 30) or GTN (n = 30) groups after direct percutaneous transluminal coronary angioplasty. We evaluated LV ejection fraction (LVEF), end-diastolic volume index (LVEDVI) and end-systolic volume index (LVESVI) at the acute phase and after one month. We also measured neurohumoral factors during study drug infusion.

RESULTS

There was no difference in the baseline characteristics or LVEF (46.9+/-1.0 vs. 46.8+/-1.3%) between the two groups. Although there was no difference in hemodynamics during the infusion periods, the LVEF was significantly improved after one month compared with the baseline value in both groups, but it was improved more in the ANP group than in the GTN group (54.6+/-1.1%, 50.8+/-1.3%, p < 0.05). Left ventricular enlargement was prevented in the ANP group (LVEDVI, 85.8+/-3.1 ml/m2 to 87.3+/-2.7 ml/m2; p = ns, LVESVI, 45.6+/-1.8 ml/m2 to 41.0+/-2.1 ml/m2, p < 0.05) but not in the GTN group (LVEDVI, 86.2+/-4.1 to 100.2+/-3.7, p < 0.01; LVESVI, 46.3+/-2.8 ml/m2 to 51.1+/-3.0 ml/m2, p = ns). During the infusion, ANP suppressed plasma levels of aldosterone, angiotensin II and ET-1 compared with GTN.

CONCLUSIONS

These findings indicate that in patients with a first anterior AMI, an ANP infusion can prevent LV remodeling better than can GTN, and effectively suppresses aldosterone, angiotensin II and ET-1.