Increased B-type Natriuretic Peptide Levels Research Articles

Is conventional cardiac pacing harmful in patients with normal ventricular function?

BackgroundRight ventricular pacing may be deleterious in patients with left ventricular dysfunction, but in patients with normal function the impact of this stimulation triggering clinically relevant ventricular dysfunction is not fully established.ObjectivesTo evaluate the clinical, echocardiographic findings of patients with previously normal left ventricular function underwent implantation of a pacemaker.MethodsObservational, cross-sectional study with 20 patients, who underwent implantation of pacemaker, prospectively followed-up, with the following inclusion criteria: normal left ventricular function defined by echocardiography and ventricular pacing higher than 90%. Were evaluated functional class (FC) (New York Heart Association), 6-minute walk test (6MWT), B-type natriuretic peptide (BNP), echocardiographic assessment (conventional and dyssynchrony parameters), and quality of life questionnaire (QLQ) (SF-36). The assessment was performed at ten days (t1), four months (t2), eight months (t3), 12 months (t4) and 24 months (t5).ResultsConventional echocardiographic parameters and dyssynchrony parameters showed statistically significant variation over time. The 6MWT, FC, and BNP showed worsening at the end of two years. QLQ showed initial improvement and worsening at the end of two years.ConclusionThe implantation of conventional pacemaker was associated with worsening in functional class, worsening in walk test, increased BNP levels, increased duration of QRS, and worsening in some domains of the QLQ at the end of two years. There were no changes in echocardiography measurements (conventional and asynchrony measures).

B-type natriuretic peptide level and postdischarge thrombotic events in older patients hospitalized with heart failure: Insights from the Acute Decompensated Heart Failure National Registry

Patients hospitalized with heart failure (HF) have elevated B-type natriuretic peptide (BNP) levels and increased risk for thromboembolic events. Associations between BNP level and thromboembolic events in patients with HF without atrial fibrillation (AF) are not well studied. We linked data from the ADHERE registry for 2003 through 2006 with Medicare claims to identify patients ≥65 years who were hospitalized with HF, did not have AF, and did not receive warfarin at discharge. We estimated rates of all-cause mortality, thromboembolic events, myocardial infarction (MI), and stroke using Kaplan-Meier methods and the cumulative incidence function. We used Cox models to assess associations between log BNP level and each outcome after adjustment for potential confounders. The study population included 11,679 patients from 146 sites. Patients in the highest quartile of BNP level were older and more often male and African American. They had higher rates of coronary artery disease, renal insufficiency, and peripheral vascular disease and lower rates of diabetes mellitus and chronic obstructive pulmonary disease. After multivariable adjustment, each 30% increase in BNP level was associated with increased risks of death (hazard ratio 1.07, 95% CI 1.05-1.08) and MI (1.07, 1.04-1.10) but not thromboembolism or stroke. Higher BNP level upon admission with HF among older patients without AF was associated with increased risks of MI and mortality; however, higher BNP level was not associated with subsequent thromboembolism or stroke.

Updating the Role of Natriuretic Peptide Levels in Cardiovascular Disease

Heart disease affects 1 in 3 individuals in the United States, and the prevalence of heart failure (HF) is increasing exponentially. Although our understanding of the disease progression of congestive HF (CHF) has advanced, refining the areas of diagnosis, risk stratification, prognosis, and treatment is still needed. The natriuretic peptides, specifically B-type natriuretic peptide (BNP) and N-terminal pro-B–type natriuretic peptide (NT-proBNP), have shown promise in clinical practice. Brain natriuretic peptide is released from cardiac ventricular myocytes in response to volume or pressure overload. Rapid measurement of plasma BNP or NT-proBNP has been shown to increase the diagnostic accuracy of HF exacerbations. A cutoff value of 100 pg/mL has a sensitivity and specificity of 90% and 73%, respectively, according to the Breathing Not Properly Study. In addition, BNP and NT-proBNP have been considered independent predictors of adverse outcome. One study calculated a 35% increase in risk of death due to HF for every 100-pg/mL increase in BNP level. Lastly, natriuretic peptides have been known to decrease following medical therapy of HF, suggesting the role of their measurement in monitoring inpatient disease progression and outpatient medical programs. The future of natriuretic peptides lies in risk stratification in other cardiac diseases, such as acute coronary syndrome, and possibly determining severity of valvular disease. Although there is substantial work done in elucidating the power of natriuretic peptides in clinical practice, more research is necessary to reach a consensus regarding how to appropriately utilize them in treatment regimens.

Increasing B‐type natriuretic peptide levels predict mortality in unselected haemodialysis patients

Cardiac disease is the major cause of death in patients undergoing chronic haemodialysis. Recent studies have found that B-type natriuretic peptide (BNP) levels accurately reflect the cardiovascular burden of dialysis patients. However, the prognostic potential of BNP measurements in dialysis patients remains unknown. The study included 113 chronic dialysis patients who were prospectively followed up. Levels of BNP were measured at baseline and every 6 months thereafter. The potential of baseline BNP and annual BNP changes to predict all-cause and cardiac mortality were assessed as endpoints. Median follow-up was 735 (354-1459) days; 35 (31%) patients died, 17 (15%) of them from cardiac causes. Baseline BNP levels were similar among survivors and non-survivors, and failed to predict all-cause and cardiac death. Cardiac death was preceded by a marked increase in BNP levels. In survivors BNP levels remained stable [median change: +175% (+20-+384%) vs. -14% (-35-+35%) over the 18 months preceding either death or the end of follow-up, P< 0.001]. Hence, annual BNP changes adequately predicted all-cause and cardiac death in the subsequent year {AUC(all-cause) = 0.70 [SD 0.05, 95% CI (0.60-0.81)]; AUC(cardiac) = 0.82 [SD 0.04, 95%CI (0.73-0.90)]}. A BNP increase of 40% provided the best cut-off level. Cox regression analysis confirmed that annual increases over 40% were associated with a seven-fold increased risk for all-cause and cardiac death. Annual BNP increases above 40% predicted all-cause and cardiac death in the subsequent year. Hence, serially measuring BNP levels may present a novel tool for risk stratification and treatment guidance of end-stage renal disease patients on chronic dialysis.

Alterations in cyclic GMP levels in preeclampsia may reflect increased B-type natriuretic peptide levels and not impaired nitric oxide activity

Objectives We compared nitrite, B-type natriuretic peptide (BNP), and cGMP levels in preeclamptic with those found in healthy pregnant. Methods We studied 21 healthy pregnant and 27 preeclamptic. Plasma cGMP and BNP levels were determined by ELISA. Nitrite levels were determined by chemiluminescence. Results Higher cGMP and BNP, and lower nitrite levels were found in preeclamptic versus healthy pregnant. Conclusions Altered cGMP levels reflect increased BNP levels and not impaired nitric oxide activity in preeclampsia.

Effects of right ventricular septal versus apical pacing on plasma natriuretic peptide levels

Background:To investigate the contribution of right ventricular (RV) pacing sites to the cardiac function, this study compares plasma B-type natriuretic peptide (BNP) levels during RV septal and apical pacing in patients implanted with a pacemaker.Materials and Methods and Results:Seventy-four consecutive patients with indication for permanent pacing were included. To provide for the possibility of appropriate subgroup analyses, patients were stratified according to their pacing mode into two groups: Those with dual chamber DDD(R)/VDD pacemakers (41 patients, mean age 54.1±18.4 years), and those with single chamber VVI pacemakers (33 patients, mean age 60.6±18.4 years). A prospective single-blinded randomized design was used. Randomization (1:1 way) was between lead placement on the RV septum or RV apex and occurred during the implant in both groups. Compared to baseline, a significant decrease in BNP (429.8±103 pg/ml and 291.7±138 pg/ml, respectively) levels was observed during DDD(R) /VDD pacing after two months. In contrast, during VVI (R) pacing, a significant increase in BNP levels was observed (657.5±104 pg/ml and 889.5±139 pg/ml, respectively). To determine the impact of pacing sites on cardiac function, we assessed the changes in BNP levels in each group separately. Despite the significant difference in the pattern of changes between the two groups (P < 0.02), no significant changes were observed within groups regarding the acute effect of the pacing site (RV apex vs. RV septal) on BNP levels (P=NS).Conclusions:Our main result showed no significant differences between pacing sites and concluded that hemodynamic improvement could be substantially influenced by pacing mode, more than by pacing site.

B-type natriuretic peptide levels predict functional capacity in postcardiac surgery patients

Plasma levels of B-type natriuretic peptide (BNP) are often increased in postcardiac surgery patients. The six-minute walking test (6MWT) is useful to assess functional capacity in postcardiac surgery patients. The aim of this study was to determine whether BNP levels are associated with exercise capacity evaluated by 6MWT in patients after cardiac surgery. Plasma BNP was measured in 101 consecutive patients referred to our center 8 ± 5 days after cardiac surgery who underwent echocardiography and 6MWT. We considered age, sex, diabetes, renal insufficiency, anemia, chronic obstructive pulmonary disease, hypertension, atrial fibrillation, beta-blocker therapy, left ventricular ejection fraction (LVEF), E/E', indexed left atrial volume (iLAV), type of surgery, and plasma BNP levels as potential predictors of reduced performance at 6MWT evaluated as percentages of the predicted values calculated according to the regression equation obtained in healthy individuals. The mean distance walked at 6MWT was 325 ± 100 m corresponding to 65 ± 20% of the predicted values. This was independent of the LVEF, E/E' or iLAV. Female patients or patients with atrial fibrillation had a reduced performance compared with male patients or patients with sinus rhythm (52 ± 19 vs. 70 ± 19%, P < 0.001; 50 ± 19 vs. 66 ± 19%, P = 0.017, respectively). BNP levels were inversely related to the performance at 6MWT (Pearson's correlation coefficient = -0.25, P = 0.010). At multivariate analysis, female sex (P < 0.001), atrial fibrillation (P = 0.031), and BNP levels (P = 0.040) remained the only independent predictive factors for reduced exercise capacity. The increase in BNP levels in postcardiac surgery patients is associated with reduced exercise capacity.

Meta-Analysis of B-Type Natriuretic Peptide's Ability to Identify Stress Induced Myocardial Ischemia

Studies in victims of sudden cardiac death and those surviving a cardiac arrest have confirmed that extent of coronary artery disease is similar in those with and without angina, suggesting that it is the presence of myocardial ischemia rather than associated symptoms that determine the prognosis. Experimental models show that hypoxic myocardial tissue results in production of extra B-type natriuretic peptide (BNP), suggesting that BNP could potentially serve as a biomarker of myocardial ischemia. We performed a meta-analysis of the studies that link BNP to inducible myocardial ischemia as indicated by noninvasive stress tests. Values of true positive, false positive, true negative, and false negative were calculated from the reported sensitivity, specificity, disease prevalence, and total number of patients studied. Sixteen studies reporting data on 2,784 patients across 14 study populations were included in the final analysis. Mean age of participants was 55 to 69 years and 55% to 90% were men. Pooled sensitivity and specificity of BNP for detection of stress-induced myocardial ischemia were 71% (95% confidence interval [CI] 68 to 74) and 52% (95% CI 52 to 54), respectively. Pooled diagnostic odds ratio was 3.5 (95% CI 2.46 to 5.04) and summary receiver operating characteristic curve revealed an area under the curve of 0.71 ± 0.02 (mean ± SE). In conclusion, this meta-analysis suggests that an increased BNP level can identify inducible ischemia as detected by standard noninvasive stress tests. This raises the possibility of a whole new role for BNP in the diagnosis and management of myocardial ischemia.

B-Type Natriuretic Peptide in Pregnant Women With Heart Disease

The objectives of this study were to examine: 1) B-type natriuretic peptide (BNP) response to pregnancy in women with heart disease; and 2) the relationship between BNP levels and adverse maternal cardiac events during pregnancy. Pregnancy imposes a hemodynamic stress on the heart. BNP might be a useful biomarker to assess the ability of the heart to adapt to the hemodynamic load of pregnancy. This was a prospective study of women with structural heart disease seen at our center. Serial clinical data and plasma BNP measurements were obtained during the first trimester, third trimester, and after delivery (>6 weeks). Seventy-eight pregnant women were studied; 66 women with heart disease (age 31 ± 5 years), and 12 healthy women (age 33 ± 5 years). During pregnancy, the median peak BNP level was higher in women with heart disease compared with control subjects (median 79, interquartile range 51 to 152 pg/ml vs. median 35, interquartile range 21 to 43 pg/ml, p < 0.001). In women with heart disease, those with subaortic ventricular dysfunction had higher BNP levels (p = 0.03). A BNP >100 pg/ml was measured in all women with events during pregnancy (n = 8). Sixteen women had increased BNP levels during pregnancy but did not have clinical events. None of the women with BNP ≤100 pg/ml had events. BNP ≤100 pg/ml had a negative predictive value of 100% for identifying events during pregnancy. Many pregnant women with heart disease have increased BNP levels during pregnancy. Incorporating serial BNP levels in into clinical practice can be helpful, specifically in adjudicating suspected adverse cardiac events during pregnancy.

Postoperative Increase in B-Type Natriuretic Peptide Levels Predicts Adverse Outcome After Cardiac Surgery

To evaluate the prognostic implication of changes in postoperative B-type natriuretic peptide (BNP) concentrations in patients undergoing cardiopulmonary bypass for cardiac surgery. A retrospective analysis of prospectively collected clinical data. Cardiothoracic surgery and an intensive care unit (ICU) in a university hospital. The present study included a total of 407 consecutive patients undergoing cardiac surgery. None. BNP concentrations were measured on admittance to the ICU (D0) and at day 1 after surgery. Patients were divided into quintiles according to their BNP level on admittance to the ICU. The predictive value of absolute changes in BNP levels during the first 24 hours postoperatively was analyzed with Kaplan-Meier estimates of survival and Cox multivariate proportional analysis. Prognostic factors for impaired midterm survival included elevation of the BNP level (HR, 7.3/ log10(x); 95% confidence interval, 1.8-29, p = 0.005). The BNP levels of patients undergoing isolated valve surgery or valve and concomitant CABG surgery were significantly higher (p = 0.012 and p = 0.032, respectively) than those undergoing isolated coronary artery bypass graft surgery. Patients in higher quintiles required ventilation for a longer time (p < 0.001), and prolonged inotropic support (p < 0.001). The mean plasma BNP concentration of 172 pg/mL (median, 64; interquartile range, 172) on arrival at the ICU had a sensitivity of 75% and a specificity of 74% for predicting 1-year mortality. Elevated BNP levels on admittance to the ICU and postoperatively increasing BNP levels are associated with adverse postoperative outcome and are predictive of impaired late survival. Sequential postoperative BNP monitoring facilitates the early identification of patients at an increased risk of heart failure and may be used as an adjunct for clinical decision making and optimized patient management.

B-type natriuretic peptide levels and cardiovascular risk in patients with diastolic dysfunction on chronic haemodialysis: cross-sectional and observational studies

Elevated B-type natriuretic peptide (BNP) levels are predictive of cardiovascular events in patients on chronic maintenance haemodialysis, even in those without apparent cardiovascular disorders when they start dialysis. In the present study, we tested the hypothesis that left ventricular diastolic dysfunction increases BNP levels and can predict cardiovascular events in patients on chronic haemodialysis without apparent cardiac disease. Patients on chronic maintenance haemodialysis in a stable condition and with normal systolic function were enrolled (n=98). BNP concentrations were measured, and left ventricular diastolic function was assessed using echocardiography after the first dialysis session of the week. Then, they were followed up for 2 years with the end point being the incidence of cardiovascular events. At baseline, left ventricular diastolic dysfunction was detected in 39 of 98 patients. After adjustment for known risk factors, multivariable regression analysis demonstrated that diastolic dysfunction was a significant predictor of increased BNP levels (P<0.05). During the follow-up period, 17 patients experienced cardiovascular events. Kaplan-Meier analysis demonstrated that the incidence of cardiovascular events was higher in patients with (28.2%) than without (10.2%) left ventricular diastolic dysfunction (log-rank, P<0.01). Univariate Cox proportional hazards regression analysis indicated that diastolic dysfunction and BNP were significant predictors of cardiovascular events (hazard ratio 3.63 and 4.87, respectively; P<0.05). Left ventricular diastolic dysfunction is associated with increased BNP levels and an increased risk of cardiovascular events in patients on haemodialysis.

Determinants of markedly increased B-type natriuretic peptide in patients with ST-segment elevation myocardial infarction

Background A modestly increased plasma B-type natriuretic peptide (BNP) level of greater than 80 pg/mL has been associated with increased mortality in patients with ST-segment elevation myocardial infarction (STEMI). However, the prognostic significance of larger increases in BNP during STEMI has not been reported. Methods A total of 420 patients with STEMI were identified from an administrative database, and 91 were found to have a BNP level measured within 24 hours of hospitalization. All patients underwent detailed angiographic and echocardiographic evaluation. Charts were abstracted in a blinded fashion to the BNP results. Results The mean ± SD age of the participants was 64 ± 13 years, and 53 (58%) of the participants were men. The median, 25th percentile, and 75th percentile of the BNP value were 366, 142, and 1011 pg/mL, respectively. The BNP level increased progressively in 1-, 2-, and 3-vessel coronary disease with medians of 253, 351, and 818 pg/mL, respectively ( P = .009). Patients with grade 3/4 diastolic dysfunction had significantly increased median BNP values vs all others, 786 vs 306 pg/mL ( P = .03). Eight (9%) patients died during their hospitalization. The median BNP values for 83 (91%) survivors and 8 (9%) nonsurvivors were 344 and 1420 pg/mL, respectively ( P = .007). By multiple logistic regression, BNP level more than 500 pg/mL was independently associated with female sex, increased number of vessels diseased (>75% stenosis), lower ejection fraction, higher creatine kinase level, and lower body mass index. Conclusion In patients with STEMI, markedly increased BNP level seems to reflect the extent of coronary disease, the degree of associated systolic and diastolic dysfunction, and a higher risk of in-hospital mortality.

Relationship between B-type natriuretic peptide levels and echocardiographic indices of left ventricular filling pressures in post-cardiac surgery patients

BackgroundB-type natriuretic peptide (BNP) is increased in post-cardiac surgery patients, however the mechanisms underlying BNP release are still unclear. In the current study, we aimed to assess the relationship between postoperative BNP levels and left ventricular filling pressures in post-cardiac surgery patients.MethodsWe prospectively enrolled 134 consecutive patients referred to our Center 8 ± 5 days after cardiac surgery. BNP was sampled at hospital admission and related to the following echocardiographic parameters: left ventricular (LV) diastolic volume (DV), LV systolic volume (SV), LV ejection fraction (EF), LV mass, relative wall thickness (RWT), indexed left atrial volume (iLAV), mitral inflow E/A ratio, mitral E wave deceleration time (DT), ratio of the transmitral E wave to the Doppler tissue early mitral annulus velocity (E/E').ResultsA total of 124 patients had both BNP and echocardiographic data. The BNP values were significantly elevated (mean 353 ± 356 pg/ml), with normal value in only 17 patients (13.7%). Mean LVEF was 59 ± 10% (LVEF ≥50% in 108 pts). There was no relationship between BNP and LVEF (p = 0.11), LVDV (p = 0.88), LVSV (p = 0.50), E/A (p = 0.77), DT (p = 0.33) or RWT (p = 0.50). In contrast, BNP was directly related to E/E' (p < 0.001), LV mass (p = 0.006) and iLAV (p = 0.026). At multivariable regression analysis, age and E/E' were the only independent predictors of BNP levels.ConclusionIn post-cardiac surgery patients with overall preserved LV systolic function, the significant increase in BNP levels is related to E/E', an echocardiographic parameter of elevated LV filling pressures which indicates left atrial pressure as a major determinant in BNP release in this clinical setting.

Tei Index Correlates with Tissue Doppler Parameters and Reflects Neurohormonal Activation in Patients with an Abnormal Transmitral Flow Pattern

Tei index (TI) is a Doppler parameter which reflects combined systolic and diastolic function. We aimed to study the relationship between TI, both traditional and tissue Doppler imaging (TDI) echocardiographic parameters and neurohormonal profile in outpatients with diastolic dysfunction expressed by an abnormal transmitral flow pattern. A total of 67 consecutive outpatients with diastolic dysfunction (abnormal transmitral flow pattern) were studied; all patients underwent clinical evaluation, blood sampling for B-type natriuretic peptide (BNP) plasma assaying, echocardiography for the determination of left ventricular ejection fraction (LVEF), dP/dt, left atrium (LA) dimensions, longitudinal systolic (S) and diastolic wall velocities (E'and A'), TI measured with Doppler echocardiography, and mitral regurgitation (MR) quantified on a semicontinuous scale. TI values were significantly correlated with BNP levels (r = 0.33; P < 0.01), LVEF (r =-0.56; P < 0.001), dP/dt (r =-0.52; P < 0.01), S (r =-0.45; P < 0.001), E'(r =-0.36; P < 0.01), A'(r =-0.27; P < 0.05), LA volume (r = 0.35; P < 0.01), and MR (P for trend < 0.05). In a multivariate regression analysis, TI was an independent predictor of increased BNP levels (beta= 0.32; P < 0.05), even after correction for potential confounders. ROC analysis showed as values of TI >0.59 identified subjects with combined systolic and diastolic dysfunction with a sensitivity of 73.8% and a specificity of 71.4%. In outpatients with diastolic dysfunction, TI, an easy to perform parameter for global ventricular performance assessment, might be useful in identifying subjects with concomitant systolic impairment and neurohormonal activation.

Baseline and 6-month B-type natriuretic peptide changes are independent predictors of events in patients with advanced heart failure awaiting cardiac transplantation

To assess the prognostic role of B-type natriuretic peptide (BNP) measured at baseline and after 6 months in advanced heart failure patients, candidates for heart transplantation. Ninety-nine patients with BNP evaluation (mean age 50.8 years, 85% men) were admitted in the heart transplantation waiting list; 39% were in New York Heart Association functional class IV; with hemodynamic patterns of severe heart failure, the cause was ischemic in 45% and idiopathic in 44%. In order to identify more severe patients, BNP values and changes at 6 months were dichotomized according to their upper tertile (>1100 and >or=70 pg/ml, respectively). Median baseline BNP was 719 pg/ml. After a median of 45 months, 40 events were observed (three cardiac assist device implants, 16 urgent heart transplantations, 13 sudden deaths and eight deaths from heart failure). The event rate was 10.0 and 32.3 per 100 person-years in patients with low and high BNP, respectively. In a bivariable Cox regression, BNP at entry in the list and change in BNP at 6 months were independent predictors of events, with hazard ratios of 4.10 (95% confidence interval 2.14-7.88, P<0.001) and 4.55 (95% confidence interval 2.36-8.80, P<0.001), respectively. Furthermore, the risk increased from neither BNP/BNP change, to one of them and to both of them present. Both high baseline and further increase in BNP levels during midterm follow-up are strong predictors of events in patients with advanced heart failure awaiting heart transplantation.

Correlation between Elevated D-Dimer and BNP Levels in Various Clinical Diagnoses

Background: D-Dimer level is most useful clinically in excluding the diagnosis of acute thromboembolism. The role of B-type natriuretic peptide (BNP) is well established in the diagnosis of heart failure. Heart failure state in itself predisposes one to thrombosis and may cause elevation in D-Dimer level. Pulmonary thromboembolism, on the other hand, may lead to elevated right sided heart pressure and cause an increase in BNP level. Despite this known potential interplay between BNP and D-Dimer levels, there is a paucity of data regarding their correlation in clinical setting. Methods: This is a single center retrospective study analyzing the correlation between elevated D-Dimer and BNP levels in patients who presented with admitting diagnosis of congestive heart failure, pulmonary embolism, sepsis syndrome and acute coronary syndromes. Spearman correlation coefficient was utilized to assess the correlation between the D-Dimer and BNP levels. All statistical analysis was done using SAS software. Results: A total of 145 consecutive patients with both elevated D-Dimer and BNP levels were included in this study. The most common admitting diagnosis was decompensated heart failure, followed by pulmonary embolism and sepsis syndrome. Among the reported co-morbidities, diabetes mellitus was present in 44%, hypertension in 77%, and coronary artery disease in 51%. Based on our analysis, there is a moderate correlation between the level of D-Dimer and BNP (Spearman correlation coefficient of 0.46) in all-various clinical diagnosis. The strongest correlation between these 2 biomarkers were found in decompensated heart failure patients, followed by pulmonary/deep venous thromboembolism, and sepsis syndrome patients. Conclusions: Based on this study, elevated levels of D-Dimer and BNP are commonly found in various clinical diagnosis, such as in decompensated heart failure, pulmonary embolism, and sepsis syndrome. This moderately strong correlation between the 2 biomarkers may mislead clinicians in achieving the correct diagnosis for their patients. Our finding should stress the importance of sound clinical judgment and the peril of over reliance in biomarkers to attain the correct diagnosis.

B-Type Natriuretic Peptide as a Predictor of Postoperative Heart Failure After Aortic Valve Replacement

B-type natriuretic peptide (BNP) has been established as a biomarker for heart failure. The objective was to evaluate BNP measured on arrival in the intensive care unit (ICU) as a predictor for heart failure defined as need for inotropic support or IABP beyond 24 hours postoperatively after aortic valve replacement. A prospective, observational study. A cardiothoracic surgery unit at a tertiary level hospital. One hundred sixty-one patients undergoing aortic valve replacement. Two levels of BNP were evaluated: the median (BNP >133 pg/mL) and a cutoff (BNP >82 pg/mL) based on receiver-operating characteristic (ROC) analysis. Uni- and multivariate analysis were performed to identify predictors of postoperative heart failure. Patients with postoperative heart failure (n = 37) showed a more than 10-fold increase in 30-day mortality (8.1%, 3/37) compared with patients without postoperative heart failure (0.8%, 1/124) (p = 0.038). Elevated postoperative BNP levels were identified as an independent predictor of postoperative heart failure: BNP >82 pg/mL (p = 0.004) and BNP >133 pg/mL (p = 0.013). The area under the ROC curve for BNP as a predictor of postoperative heart failure was 0.69. Postoperative heart failure after aortic valve replacement is still a very serious condition with increased early mortality. The results of the present study suggest that an elevated BNP level on arrival in the ICU is an independent predictor of postoperative heart failure after aortic valve replacement. In the authors' opinion, an increased BNP level on arrival in the ICU may support early diagnosis and allow optimal management of heart failure after aortic valve replacement.

B‐Type Natriuretic Peptide (BNP) in Patients Undergoing Mitral Valve Surgery

Plasma B-type natriuretic peptide (BNP) level may be increased in patients with valvular disease. Recent studies have suggested that in patients undergoing aortic valve replacement, an increased preoperative BNP is associated with a worse operative outcome. Little is known about the perioperative value of BNP in patients undergoing mitral valve (MV) surgery. We measured the preoperative and postoperative BNP levels in this population and analyzed the impact of the increased BNP level on surgical outcome. From March 2004 to February 2005, 42 patients (mean age 64 +/- 12 years, 18 [42%] male) were enrolled in a prospective study. All patients underwent surgery for severe mitral regurgitation. The mean ejection fraction was 49 +/- 13%, and 26 (62%) patients presented with atrial fibrillation (AF). The median preoperative and postoperative BNP levels were 108 (9.7 to 995) and 357 (143 to 904) pg/mL, respectively (p = 0.002). Heart failure (p = 0.03), atrial fibrillation (AF) (p = 0.01), and ejection fraction (p = 0.01) were associated with an increased preoperative BNP level. In a multivariate analysis, the only independent predictor of the increased BNP level was AF (p = 0.01). In a univariate analysis, the preoperative BNP level was a significant predictor for inotropic support (p < 0.001), ventilation time (p = 0.003), intensive care unit (ICU; p = 0.01), and hospital length of stay (p = 0.02). In the multivariate analysis, BNP was not a predictor of these variables. Preoperative plasma BNP level presents with a high individual variability in patients with MV regurgitation. AF was the only independent predictor of an increased preoperative BNP level. The preoperative BNP level was not a predictor of surgical outcome. Further studies are required to confirm these findings and evaluate the potential role of this marker for patient selection.

B‐type natriuretic peptide levels in patients with functionally univentricular hearts after total cavopulmonary connection

To assess plasma B-type natriuretic peptide (BNP) levels in patients with univentricular hearts late after volume unloading by total cavopulmonary connection (TCPC). Plasma BNP was measured by sandwich immunoassay in 67 patients after a modified Fontan procedure. BNP levels were compared with age and sex-specific normal values, clinical and echocardiographic data, and results of exercise testing. BNP had a wide range of 5-290 pg/ml, but was normal in 81% of patients, and median BNP was only 13 pg/ml. There was no difference between males and females, between patients with left or right ventricular morphology, and no correlation was found between BNP and age, post-operative follow-up period, maximum exercise capability, peak oxygen uptake, or blood oxygen saturation. New York Heart Association class I patients had lower BNP than class II patients (p=0.04). Plasma BNP concentration was positively correlated to the number of specific sequelae (r=0.59, p<0.001), and to severity of atrioventricular regurgitation (r=0.38, p=0.002). 5/13 patients with elevated BNP died during follow-up. BNP plasma concentration was normal in the majority of patients up to 15 years after TCPC. Elevated and increasing BNP levels were associated with increased morbidity and late mortality.

Alterations in cGMP, soluble guanylate cyclase, phosphodiesterase 5, and B‐type natriuretic peptide induced by chronic increased pulmonary blood flow in lambs

The objective of the study was to determine alterations in cGMP, soluble guanylate cyclase (sGC), phosphodiesterase type 5 (PDE5), and B-type natriuretic peptide (BNP), in an animal model of a congenital cardiac defect with increased pulmonary blood flow. Prospective, comparative, experimental study. Lambs, from birth until 8 weeks of age. Late gestation fetal lambs underwent in utero placement of an 8 mm aortopulmonary vascular graft (shunt). In shunted and normal age-matched control lambs, at 2, 4, and 8 weeks of age, cGMP and BNP levels were measured, and sGC subunit and PDE5 protein expression were determined by Western blot analysis and immunohistochemistry. In shunted lambs, tissue and plasma cGMP levels were greater than normal throughout the 8-week study period (P < 0.05). sGCalpha protein was greater at 2 and 4 weeks (P < 0.05), and sGCbeta and PDE5 protein were greater at 4 weeks in shunted lambs (P < 0.05). Plasma BNP levels did not change in normal lambs but increased in shunted lambs by 8 weeks of age (P < 0.05). BNP levels were greater in shunted lambs than normal at 4 and 8 weeks (P < 0.05). Alterations in sGC subunit protein expression during the first post-natal month, and increased BNP levels during the second post-natal month contribute to elevations in plasma and lung tissue cGMP in lambs with increased pulmonary blood flow.