Utility of B-type natriuretic peptide (BNP) as a screen for left ventricular dysfunction in patients with diabetes

OBJECTIVE: Routine screening of diabetic patients with echocardiography is not feasible due to its limited availability and high cost. B-type natriuretic peptide (BNP) is secreted from the left ventricle in response to pressure overload and is elevated in both systolic and diastolic dysfunction. RESEARCH DESIGN AND METHODS: BNP levels were compared to echocardiographic findings in 263 patients. Patients were divided into two groups: clinical indication for echocardiography (CIE) (n = 172) and those without clinical indication for echocardiography (no-CIE) (n = 91). Cardiologists making the assessment of left ventricular function were blinded when measuring plasma levels of BNP. RESULTS: The 91 patients with no-CIE with echoes had similar BNP levels (83 +/- 16 pg/ml) to the 215 patients with no-CIE without echoes (63 +/- 10, P = 0.10). Patients with CIE and subsequent abnormal left ventricular function (n = 112) had a mean BNP concentration of 435 +/- 41 pg/ml, compared with those with no-CIE, but had abnormal left ventricular function on echo (n = 32) (161 +/- 40 pg/ml). Twenty-one of 32 patients with no-CIE but with abnormal left ventricular function had diastolic dysfunction (BNP 190 +/- 60 pg/ml). A receiver-operating characteristic (ROC) curve revealed that the area under the curve was 0.91 for CIE patients and 0.81 for no-CIE patients (P < 0.001). For those with no congestive heart failure (CHF) symptoms, BNP levels showed a high negative predictive value (91% for BNP values <39 pg/ml), while in those patients who had a CIE, BNP levels showed a high positive predictive value for the detection of left ventricular dysfunction (96% with BNP levels >90 pg/ml). CONCLUSIONS: BNP can reliably screen diabetic patients for the presence or absence of left ventricular dysfunction.     

Systolic and diastolic heart failure are associated with different plasma levels of B-type natriuretic peptide

Previous studies have found that plasma B-type natriuretic peptide (BNP) is elevated during left ventricular systolic or diastolic dysfunction. It is unclear whether the ventricular systolic and diastolic function is associated with different levels of plasma BNP. Plasma BNP was measured in 149 heart failure patients by a rapid point-of-care assay. The patients were divided into left ventricular diastolic dysfunction (n = 48), left ventricular systolic dysfunction (n = 62) and right ventricular systolic dysfunction group (n = 39). The mean BNP level in the left ventricular diastolic dysfunction, left ventricular systolic dysfunction and right ventricular systolic dysfunction was 115 +/- 80 pg/ml, 516 +/- 445 pg/ml and 345 +/- 184 pg/ml, respectively (p < 0.05). We concluded that ventricular systolic and diastolic dysfunction increases plasma BNP levels to a different extent. Left and right ventricular systolic dysfunction is associated with a higher level of plasma BNP than left ventricular diastolic dysfunction.     

Increased secretion of atrial natriuretic polypeptide from the left ventricle in patients with dilated cardiomyopathy.

To examine whether atrial natriuretic polypeptide (ANP) is released from the left ventricle in patients with dilated cardiomyopathy (DCM) we measured plasma ANP level in the aortic root (Ao), the anterior interventricular vein (AIV), the great cardiac vein (GCV), and the coronary sinus (CS) in 11 patients with DCM and 18 control subjects. Plasma ANP levels in Ao, AIV, GCV, and CS were 454 +/- 360, 915 +/- 584, 1,308 +/- 926, and 1,884 +/- 1,194 pg/ml, respectively, in the patients with DCM and 108 +/- 42, 127 +/- 55, 461 +/- 224, and 682 +/- 341 pg/ml, respectively, in the control subjects. There was no significant difference in the plasma ANP levels between Ao and AIV in the control subjects. On the contrary, there was a significant (P less than 0.001) step-up in plasma ANP levels between Ao and AIV in patients with DCM. Thus, the difference in ANP levels between Ao and AIV was significantly increased in patients with DCM as compared with the control subjects (461 +/- 248 vs. 19 +/- 59 pg/ml, P less than 0.001). The difference in ANP levels between Ao and CS was also significantly increased in patients with DCM as compared with the control subjects (1,429 +/- 890 vs. 577 +/- 318 pg/ml, P less than 0.001). We conclude that ANP is released in increased amounts into the circulation from the left ventricle as well as from the heart as a whole in patients with DCM.     

Prognostic values of B-type natriuretic peptide in severe sepsis and septic shock

OBJECTIVE: To investigate the changes in B-type natriuretic peptide concentrations in patients with severe sepsis and septic shock and to investigate the value of B-type natriuretic peptide in predicting intensive care unit outcomes. DESIGN: Prospective observational study. SETTING: General intensive care unit. PATIENTS: Forty patients with severe sepsis or septic shock. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: B-type natriuretic peptide measurements and echocardiography were carried out daily for 10 consecutive days. In-hospital mortality and length of stay were recorded. The admission B-type natriuretic peptide concentrations were generally increased (747 +/- 860 pg/mL). B-type natriuretic peptide levels were elevated in patients with normal left ventricular systolic function (568 +/- 811 pg/mL), with sepsis-related reversible cardiac dysfunction (630 +/- 726 pg/mL), and with chronic cardiac dysfunction (1311 +/- 1097 pg/mL). There were no significance changes in B-type natriuretic peptide levels over the 10-day period. The daily B-type natriuretic peptide concentrations for the first 3 days neither predicted in-hospital mortality nor correlated with length of intensive care unit or hospital stay. CONCLUSION: B-type natriuretic peptide concentrations were increased in patients with severe sepsis or septic shock regardless of the presence or absence of cardiac dysfunction. Neither the B-type natriuretic peptide levels for the first 3 days nor the daily changes in B-type natriuretic peptide provided prognostic value for in-hospital mortality and length of stay in this mixed group of patients, which included patients with chronic cardiac dysfunction.     

Atrial natriuretic peptide in human essential hypertension

We measured the circulating levels of atrial natriuretic peptide (ANP) in 62 patients with untreated uncomplicated essential hypertension and in 30 normotensive subjects. In the hypertensive patients, mean systolic and diastolic blood pressures were 148 and 101 mm Hg, respectively, and the mean heart rate was 73 beats/min. ANP concentrations were not elevated in the hypertensive group but were actually decreased slightly over those of the control group (27.4 +/- 1.8 pg/ml versus 35.3 +/- 2.4 pg/ml [P less than 0.02]). No relationship was found between ANP levels and diastolic blood pressure, plasma renin activity, urinary sodium excretion, or serum creatinine level. In 8 of the 62 patients with essential hypertension, 6 weeks of treatment with a dihydropyridine calcium channel blocker, nitrendipine, significantly reduced plasma ANP levels from 28.6 +/- 4.3 pg/ml to 18.7 +/- 1.8 pg/ml (P less than 0.05). In 17 additional patients treated with the hypotensive agent ketanserin, ANP levels were not significantly reduced after treatment. Thus, this study demonstrates that circulating plasma ANP levels are not increased but are slightly decreased in patients with uncomplicated essential hypertension in comparison with normotensive subjects. Furthermore, antihypertensive treatment with a calcium channel antagonist reduced plasma levels of ANP.     

Myocardial velocity gradient reflects the severity of myocardial damage regardless of the presence or absence of mitral regurgitation.

Complicating mitral regurgitation (MR) apparently enhances left ventricular ejection fraction, thereby leading to the underestimation of myocardial damage by routine echocardiography. We sought to assess the significance of myocardial velocity gradient (MVG) derived from Doppler tissue imaging as an indicator of the severity of myocardial damage in the presence or absence of MR. Peak systolic and diastolic MVG was obtained from 39 participants: 12 healthy participants, 10 patients with dilated cardiomyopathy complicating moderate to severe MR [MR (+) group], and 17 patients with dilated cardiomyopathy without significant MR [MR (-) group]. MVG was compared with standard echocardiographic and Doppler transmitral flow velocity indices. Plasma brain natriuretic peptide levels were measured in all patients. Left ventricular dimension and fractional shortening was similar between MR (+) and MR (-) groups. Plasma brain natriuretic peptide levels were significantly increased in MR (+) group (440 +/- 417 pg/mL) as compared with MR (-) group (122 +/- 107 pg/mL, P <.05). Peak systolic MVG was significantly attenuated in dilated cardiomyopathy group with or without MR [MR (+) group = 1.3 +/- 0.5 seconds(-1), MR (-) group = 2.1 +/- 0.5 seconds(-1), where normal = 4.0 +/- 0.9 seconds(-1), P <.01, respectively]. Peak systolic MVG was further attenuated in MR (+) group than in MR (-) group (P <.01). Plasma brain natriuretic peptide levels were negatively correlated with peak systolic MVG (r = -0.66, P <.0005). Peak diastolic MVG was attenuated in MR (+) and also in MR (-) groups [MR (+) group = -4.5 +/- 2.0 seconds(-1), MR (-) group = -4.4 +/- 1.1 seconds(-1), where normal = -8.7 +/- 2.4 seconds(-1), P <.01, respectively], whereas transmitral flow indices failed to distinguish MR (+) group from normal as a result of pseudonormalization. MVG may reflect the severity of myocardial damage regardless of the presence or absence of complicating MR.     

Immunoreactive N-terminal pro-atrial natriuretic peptide in human plasma: plasma levels and comparisons with alpha-human atrial natriuretic peptide in normal subjects, patients with essential hypertension, cardiac transplant and chronic renal failure

1. Plasma levels of immunoreactive N-terminal pro-atrial natriuretic peptide (N-terminal ANP) have been measured in 25 normal subjects, 29 patients with essential hypertension, six cardiac transplant recipients, seven patients with dialysis-independent chronic renal failure and 11 patients with haemodialysis-dependent chronic renal failure. Plasma was extracted on Sep-Pak cartridges and N-terminal ANP immunoreactivity was measured using an antibody directed against pro-ANP (1-30). 2. Plasma levels of N-terminal ANP (means +/- SEM) were 235.3 +/- 19.2 pg/ml in normal subjects and were significantly raised in patients with essential hypertension (363.6 +/- 36.3 pg/ml), in cardiac transplant recipients (1240.0 +/- 196.2 pg/ml), in patients with chronic renal failure not requiring dialysis (1636.6 +/- 488.4 pg/ml) and patients with chronic renal failure on maintenance haemodialysis (10336.1 +/- 2043.7 pg/ml). 3. There were positive and significant correlations between the plasma levels of N-terminal ANP and alpha-human ANP (alpha-hANP) with individual correlation coefficients of 0.68 within the normal subjects, 0.47 in patients with essential hypertension, 0.78 in patients with dialysis-independent chronic renal failure and 0.68 in patients with haemodialysis-dependent chronic renal failure (P less than 0.05 in every case).(ABSTRACT TRUNCATED AT 250 WORDS)     

左旋氨氯地平联合缬沙坦治疗老年高血压并左心室肥厚

目的探讨苯磺酸左旋氨氯地平联合缬沙坦治疗老年高血压患者左心室肥厚的临床效果。方法将58例老年高血压伴左心室肥厚患者随机分为两组,治疗组30例,对照组28例。两组均给予苯磺酸左旋氨氯地平治疗,治疗组联合缬沙坦治疗,疗程6mo。治疗前及治疗6mo末采用超声心动图超声仪检测左室舒张末期内径,室间隔与左心室后壁舒张末期厚度等各项指标并进行对比分析。结果治疗6mo末两组左室后壁舒张末期厚度、室间隔厚度、左室舒张末期内径、左室收缩末期内经、左室心肌重量指数及等容舒张时间均较治疗前明显下降,左室射血分数及E/A均较治疗前显著提高(P<0.05或0.01);两组间比较,治疗组左室后壁舒张末期厚度、心室间隔舒张末期厚度、左室舒张末期内径、左室收缩末期内经、左室心肌重量指数、左室射血分数及E/A均较对照组改善显著,差异均有显著或极显著性(P<0.05或0.01)。结论缬沙坦和苯磺酸左旋氨氯地平均能改善左室舒张功能,逆转扩大的左心室;苯磺酸左旋氨氯地平联合缬沙坦治疗的临床效果显著优于单用左旋氨氯地平治疗,可作为治疗高血压伴左心室肥厚患者的一线用药。     

Effects of dobutamine on left ventricular shape and geometry: an easy way to detect the functional status of chronic heart failure in patients with dilated cardiomyopathy.

OBJECTIVE: Changes in left ventricular geometry and shape are prominent characteristics of cardiomyopathy. The aim of this study was to investigate left ventricular geometry and shape changes after inotropic stimulation in patients with chronic nonischemic dilated cardiomyopathy. METHODS: A low infusion rate echocardiography-dobutamine study was performed in 35 consecutive patients (age: 50 +/- 8 years) with known dilated cardiomyopathy. Peak exercise oxygen consumption was measured the day before. Overall left ventricular chamber shape was assessed by using the long-/minor-axis dimension ratio obtained at end-diastole and end-systole. RESULTS: After dobutamine infusion, in the entire study group an increase in systolic long-/minor-axis dimension ratio (0.11 +/- 0.13 mm, P <.001) was observed. The study population was further divided according to whether peak exercise oxygen consumption was less (group I) or more (group II) than 14 mL/kg/min. Although at baseline systolic long-/minor-axis dimension ratio was similar between groups, after dobutamine infusion it was higher in group II (1.51 +/- 0.19) than in group I (1.31 +/- 0.2, P <.01) indicating the abnormal response of systolic sphericity index to inotropic stimulation in patients with advanced functional class heart failure. CONCLUSION: The response of systolic sphericity index to dobutamine infusion might be an alternative index of the functional status of the failing heart in patients with nonischemic dilated cardiomyopathy.     

Prohormone brain natriuretic peptide (proBNP), BNP and N-terminal-proBNP circulating levels in chronic hemodialysis patients. Correlation with ventricular function, fluid removal and effect of hemodiafiltration

BACKGROUND: Brain natriuretic peptide (BNP), N-terminal proBNP (NT-proBNP) and to a lesser extent prohormone proBNP are recognized as biochemical markers of left ventricular dysfunction. In renal failure, interpretation of natriuretic peptide remains unclear, as natriuretic peptide levels may be not only be dependent on cardiac function and dimensions but also on renal function, fluid volume and removal by dialysis procedure including hemodiafiltration (HDF). The purpose of this study was (i) to assess BNP, NT-proBNP and proBNP levels and their correlation with clinical and echocardiographic data in chronic hemodialysis patients, and (ii) to investigate basal level alteration following HDF. METHODS: Baseline clinical and echocardiographic parameters were collected in 31 dialysis patients without evidence of cardiac failure. Pre- and post-HDF BNP, NT-proBNP and proBNP concentrations were measured. Correlations between echocardiographic measurements and basal circulating peptides, between changes in peptide values and changes in fluid volume after HDF were investigated. RESULTS: Baseline plasmatic levels were elevated (BNP=517+/-840 pg/mL, NT-proBNP=5340+/-6132 pg/mL and proBNP=3569+/-4683 pg/mL) and correlated with left auricular diameter and left ventricular mass index. HDF session induced a significant decrease of 39%, 59% and 36% for BNP, NT-proBNP and proBNP levels, respectively. This decrease was not correlated to post-HDF fluid removal or weight decrease. Correlation between BNP and proBNP was stronger (r(2)=0.88) than between NT-proBNP and proBNP (r(2)=0.54). CONCLUSIONS: Despite their elimination, BNP, NT-proBNP and proBNP could be potential markers of left ventricular remodeling in chronic renal failure patients on hemodialysis. According to these results, their cut-off values, however, need to be re-evaluated.     

Circulating natriuretic peptide concentrations in patients with end-stage renal disease: role of brain natriuretic peptide as a biomarker for ventricular remodeling.

OBJECTIVES: To determine levels of natriuretic peptides (NPs) in patients with end-stage renal disease (ESRD) and to examine the relationship of these cardiovascular peptides to left ventricular hypertrophy (LVH) and to cardiac mortality. PATIENTS AND METHODS: One hundred twelve dialysis patients without clinical evidence of congestive heart failure underwent plasma measurement of NP concentrations and echocardiographic investigation for left ventricular mass index (LVMI). RESULTS: Plasma atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) concentrations correlated positively with LVMI and inversely with left ventricular ejection fraction, whereas C-type NP and Dendroaspis NP levels did not correlate with LVMI. In dialysis patients with LVH (LVMI >125 g/m2), plasma ANP and BNP concentrations were increased compared with those in dialysis patients without LVH (both P<001). In a subset of 15 dialysis patients without LVH or other concomitant diseases, plasma BNP concentrations were not significantly increased compared with those in 35 controls (mean +/- SD, 20.1+/-13.4 vs 13.5+/-9.6 pg/mL; P=.06), demonstrating that the BNP concentration was not increased by renal dysfunction alone. Furthermore, the BNP level was significantly higher in the 16 patients who died from cardiovascular causes compared with survivors (mean +/- SD, 129+/-13 vs 57+/-7 pg/mL; P<.003) and was significantly associated with greater risk of cardiovascular death in Cox regression analysis (P<.001), as was the ANP level (P=.002). CONCLUSIONS: Elevation of the plasma BNP concentration is more specifically related to LVH compared with the other NP levels in patients with ESRD independent of congestive heart failure. Thus, BNP serves as an important plasma biomarker for ventricular hypertrophy in dialysis patients with ESRD.     

Left ventricular performance in subclinical hypothyroidism

Normal plasma thyroid hormones with elevation of thyrotrophin levels in asymptomatic patients is known as subclinical hypothyroidism. Radionuclide angiography was used to study left ventricular function in 10 such patients before and after establishment of normal thyrotrophin levels with thyroxine. Resting left ventricular ejection fraction was similar in both states but exercise left ventricular ejection fraction was less in the subclinical hypothyroid (61 +/- 3 per cent) compared with the euthyroid (68 +/- 3 per cent; p less than 0.025) state. Sodium nitroprusside caused similar increases in resting cardiac output but in subclinical hypothyroidism this resulted from a large increase in heart rate (26 +/- 4 beats/min) and reduction in stroke volume (11 +/- 4 per cent) whereas in the euthyroid state, the heart rate increment was less (14 +/- beats/min) and stroke volume was unchanged. Analysis of left ventricular pressure-volume relationships at end-systole during exercise showed a steeper pressure-volume slope in the euthyroid compared with the subclinical hypothyroid state (p less than 0.05). Subtle impairment of left ventricular function is detectable in subclinical hypothyroidism and may justify use of hormone replacement.     

Ultrasonic tissue characterization can predict beta-blocker efficacy in dilated cardiomyopathy

The aim was to determine if the combination of cyclic variation of myocardial integrated backscatter (variation IB) and left ventricular mass measurements can predict the efficacy of beta-blocker treatment in dilated cardiomyopathy. In 32 patients, left ventricular mass and variation IB were measured at baseline and during 6 microg/kg/min dobutamine infusion before the initiation of beta-blocker therapy. Variation IB was measured at left and right ventricular halves in the ventricular septum. The baseline left ventricular mass index and transseptal variation IB gradient during dobutamine were significantly greater in the effective group (1.16 +/- 0.18 g/mL and 1.8 +/- 0.6 dB) than in the ineffective group (0.94 +/- 0.28 g/mL, p = 0.032 and 0.4 +/- 0.6 dB, p < 0.005). When both baseline left ventricular mass index > or = 1.05 g/mL and transseptal variation IB gradient during dobutamine > or = 1.5 dB were defined as predictive criteria for the effective group, the sensitivity was 78% and the specificity was 86%. Analysis of transseptal variation IB during dobutamine may provide useful information predicting the efficacy of beta-blocker therapy in dilated cardiomyopathy.     

B-type natriuretic peptide levels in patients with COPD and normal right ventricular function

INTRODUCTION: Evidence suggests that elevated plasma levels of B-type natriuretic peptide (BNP) are found in patients with chronic obstructive pulmonary disease (COPD) and right ventricular dysfunction. We examined the effects of exercise on plasma BNP levels in patients with COPD who have normal right ventricular function METHODS: Seventeen patients with a diagnosis of COPD and normal right ventricular function demonstrated by radionuclide ventriculography, and 17 age-and sex-matched healthy subjects underwent a treadmill exercise test. Plasma BNP levels were measured sequentially before, immediately after, and 1 hour after the exercise test RESULTS: The mean plasma BNP+/-standard deviation levels of the COPD and control groups before exercise were 21.3+/-16 pg/ml and 13.4+/-11 pg/ml, respectively (P>0.05). Mean plasma BNP level measured immediately after exercise was 37.9+/-31 pg/ml in the COPD group, reflecting a statistically significant increase when compared with the initial value (P<0.05). The control group did not show any significant change in plasma BNP levels after the exercise test CONCLUSIONS: Exercise induces an increase in plasma BNP levels in patients with COPD who do not have right ventricular dysfunction at rest. Measurement of exercise-induced BNP levels may be a useful alternative to pulmonary artery catheterisation in identifying the patients who are likely to benefit from long-term oxygen therapy.     

Does acute-phase beta blockade reduce left atrial appendage function in patients with chronic nonvalvular atrial fibrillation?

To investigate whether acute-phase beta-blocker therapy has a harmful effect on left atrial appendage (LAA) function in patients with chronic nonvalvular atrial fibrillation by transesophageal echocardiography (TEE), we evaluated 21 patients with normal left ventricular systolic function and a poorly controlled ventricular rate, despite the use of digoxin. Baseline parameters that were obtained included heart rate, blood pressure, LAA emptying velocities, and left atrial spontaneous echo contrast intensity. Then, each patient was given a bolus dose of 5 mg metoprolol. Ten minutes later, a second set of assessments was performed. After the first TEE studies, each patient began treatment with metoprolol (50 mg orally twice daily for 1 week). A second TEE study was performed after 1 week of continuous oral metoprolol therapy at maintenance dose, and values were again determined. The average resting apical heart rate was 91 +/- 7 bpm. As expected, beta-blocker therapy showed a marked decrease in heart rate at 10 minutes (79 +/- 6 bpm, P <.001) and at 1 week (71 +/- 4 bpm, P <.001). Beta-blocker therapy caused a significant reduction in systolic and diastolic blood pressures (144 +/- 16 / 93 +/- 6 mm Hg at baseline, 137 +/- 16 / 87 +/- 9 mm Hg at 10 minutes, and 135 +/- 12 / 86 +/- 8 mm Hg at 1 week, P <.001). With the beta-blocker therapy, the baseline transesophageal Doppler parameter of LAA emptying velocities (at baseline 24 +/- 7 cm/s) fell significantly at 10 minutes (19 +/- 7 cm/s, P <.001) and at 1 week (17 +/- 6 cm/s, P <.001) after initiation of beta-blocker therapy. After a bolus of metoprolol, spontaneous echo contrast intensity did not change in any patients, but 1 week later, it increased in 1 patient. In 2 patients who had not been found to have an LAA thrombus at baseline TEE study, the second TEE examination demonstrated new thrombi in the LAA. In conclusion, our findings suggest that in patients with chronic nonvalvular atrial fibrillation who have normal left ventricular systolic function and a poorly controlled ventricular rate despite the use of digoxin, acute-phase beta blockade may have a harmful effect on LAA function.     

Assessment of left ventricular volume and mass by cine magnetic resonance imaging in patients with anterior myocardial infarction intra-observer and inter-observer variability on contour detection

Remodeling of the left ventricle after myocardial infarction can be documented by calculation of left ventricular volume and mass, using endocardial and epicardial tracings of multilevel multiphase short-axis cine magnetic resonance (MR) imaging series. We assessed left ventricular volume and mass from 8 slices and during 12 phases of the cardiac cycle in seven patients with an anterior wall myocardial infarction; one patient was studied twice, leaving eight MR examinations to be evaluated. Purpose of this study was to assess the intra-observer and interobserver variability of epicardial volume, endocardial volume, and left ventricular mass from contours manually traced by two independent observers. For the eight MR examinations, epicardial volume was found to be 292 ± 51 ml (mean ± SD) at end-diastole, which decreased to 237 ± 55 ml at end-systole. Endocardial volume was 141 ± 31 ml at end-diastole, which decreased to 79 ± 27 ml at end-systole. Left ventricular ejection fraction was 45 ± 8%. Mean left ventricular mass, when averaged over all patient studies and all phases, was 159 ± 30 g. Intra-observer and inter-observer variability were found to be 3.5% and 5.2% for endocardial volume, 2.0% and 2.5% for epicardial volume, and 3.6% and 3.6% for left ventricular mass, respectively. The contour analysis showed a statistically significant phase effect in the endocardial contour in the midventricular slices, which was resolved after establishing a more precise definition for the tracing of the endocardial border. In conclusion, left ventricular volume and mass in patients with an anterior wall myocardial infarction can be assessed with high reproducibility and relibility from manual contour tracings. A precise protocol for the definition of endocardial and epicardial contours is required to obtain reproducible and reliable results.     

B-type natriuretic peptide: a diagnostic, prognostic, and therapeutic tool in heart failure.

B-type natriuretic peptide is a neurohormone secreted from the cardiac ventricles in response to ventricular stretch and pressure overload. It counteracts the vasoconstriction that occurs as a compensatory mechanism in heart failure. A new test for measuring plasma levels of B-type natriuretic peptide can help in the diagnosis and treatment of patients with congestive heart failure. Dyspnea associated with cardiac dysfunction is highly unlikely in patients with levels of the peptide less than 100 pg/mL. Whereas most patients with significant congestive heart failure have levels of the peptide greater than 400 pg/mL, in patients with levels of 100 to 400 pg/mL, left ventricular dysfunction without volume overload, pulmonary embolism, and cor pulmonale must be ruled out. Thus, incorporating measurement of B-type natriuretic peptide into clinical evaluation helps physicians and nurses diagnose heart failure more quickly, especially in patients who have multiple comorbid conditions. Elevated levels of B-type natriuretic peptide indicate a poor prognosis in terms of a higher mortality and more hospital readmissions. Levels of B-type natriuretic peptide could be used to guide therapy and discharge planning for patients admitted with decompensated heart failure.     

Failure of atrial natriuretic factor to increase with saline load in patients with dilated cardiomyopathy and mild heart failure.

To investigate whether the response of atrial natriuretic factor (ANF) to volume expansion is impaired in the early stages of dilated cardiomyopathy, the effects of saline load (SL; 0.25 ml/kg.min for 120 min) were assessed in 12 patients with dilated cardiomyopathy and asymptomatic to mildly symptomatic heart failure (HF) and in nine normal subjects (N). SL increased plasma ANF levels in N (from 14.3 +/- 2 to 19.5 +/- 3 and 26 +/- 4 pg/ml, at 60 and 120 min, respectively, P less than 0.001), but not in HF (from 42.9 +/- 9 to 45.9 +/- 9 and 43.9 +/- 8 pg/ml). Left ventricular end-diastolic volume (LVEDV) and stroke volume were increased (P less than 0.001) by SL in N but not in HF. Urinary sodium excretion (UNaV) increased in N more than in HF during SL, whereas forearm vascular resistance (FVR) did not change in N and increased in HF (P less than 0.001). In five HF patients SL was performed during ANF infusion (50 ng/kg, 5 ng/kg.min) that increased ANF levels from 37.1 +/- 10 to 146 +/- 22 pg/ml. In this group, SL raised both LVEDV (P less than 0.01) and ANF (P less than 0.05), whereas FVR did not rise. In addition, the UNaV increase and renin and aldosterone suppressions by SL were more marked than those observed in HF under control conditions. Thus, in patients with dilated cardiomyopathy and mild cardiac dysfunction, plasma ANF levels are not increased by volume expansion as observed in N. The lack of ANF response is related to the impaired cardiac adaptations. The absence of an adequate increase of ANF levels may contribute to the abnormal responses of HF patients to saline load.     

Brain natriuretic peptide levels during cardiac reperfusion: comparison between percutaneous coronary angioplasty and aorto-coronaric bypass

BACKGROUND: Several studies have documented brain natriuretic peptide (BNP) behavior during cardiac ischemia and after myocardial necrosis. Peptide levels have been shown to be increased during acute phase of cardiac ischemia and during late ventricular remodelling; however, there are fewer data about hormone levels during percutaneous transluminal coronary angioplasty (PTCA) and aorto-coronaric by pass (CABG). METHODS: Aim of this study was to investigate plasma BNP during acute or sub-acute myocardial ischemia in patients undergoing to PTCA or CABG, taking blood samples before and after both procedures. We studied 59 consecutive subjects, 25 submitted to coronary by-pass and 34 submitted to coronary angioplasty. Blood BNP levels were measured the day before intervention and after 3, 7 and 90 days from the procedures. RESULTS: Peptide levels were significantly different just before intervention (GABG group 118.7+/-81 pg/ml vs. PTCA group 34.8+/-15 pg/ml, p<0.01). This difference was increased after 3 days (CABG group 403.2+/-185 pg/ml vs. PTCA group 105.3+/-56 pg/ml, p<0.0001) and after 7 days (CABG group 252.2+/-93 pg/ml vs. PTCA group 69.8+/-36 pg/ml, p<0.00001). These results trend to converge after 90 days (CABG group +/-93 pg/ml vs. PTCA group +/-36 pg/ml, p<0.05). CONCLUSIONS: Plasma BNP shows a different behavior during and after different myocardial reperfusion procedures. PTCA causes only mild and temporary elevation of peptide levels, otherwise CABG demonstrates a more enhancing of BNP release not only in early phase but also after one week; increased levels tend to return towards the reference range after few weeks from cardiac surgery.     

The circulating levels of cardiac natriuretic hormones in healthy adults: effects of age and sex.

In order to study the relationships between sex hormones, aging, and circulating levels of cardiac natriuretic peptides and to define reference values for atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) assays, we measured the plasma levels of cardiac natriuretic peptides in a large group of healthy adults divided according to age and sex. We studied 216 healthy subjects of both sexes (109 men and 107 women) with age ranging from 20 to 77 years (mean 43.2+/-14.8 years). All subjects were non-obese and had normal arterial blood pressure; they were free from acute diseases, including asymptomatic heart disease. Highly sensitive and specific IRMA methods were used to measure plasma ANP and BNP. The mean ANP value in healthy adult subjects of both sexes was 17.8+/-10.9 pg/ml with no significant difference between men (16.7+/-10.0 pg/ml) and women (18.8+/-11.7 pg/ml). The mean BNP value in healthy adult subjects of both sexes was 9.9+/-9.0 pg/ml with a significant difference (p<0.0001) between men (7.7+/-7.1 pg/ml) and women (12.2+/-10.2 pg/ml). There was a weak linear relationship between age and either ANP (r=0.350, p<0.0001) or BNP (r=0.254, p=0.0002) values. When the circulating levels of cardiac natriuretic hormones, and age and sex were analyzed by multiple stepwise regression analysis, both age and sex significantly and independently contributed to the regression. Our study indicates independent positive effects of aging and female sex hormones on ANP and BNP levels in healthy adult subjects. These effects should be taken into account in the calculation of appropriate reference values for cardiac natriuretic hormones.