Meta-analysis of B-type natriuretic peptide's ability to identify stress induced myocardial ischemia

Role of modified hydration for preventing contrast-associated acute kidney injury in patients with ST-segment elevation myocardial infarction after primary percutaneous coronary intervention

To assess the efficacy of modified hydration on contrast-associated acute kidney injury (CA-AKI) in ST-segment elevation myocardial infarction (STEMI) after primary percutaneous coronary intervention (pPCI). A total of 438 patients were randomly assigned to 2 groups. The traditional hydration group (group I) was given at a rate of 1 ml/kg/h for 24 h, and the modified hydration group (group II) was given at a rate of 3 ml/kg/h in the first 4 h, and then reduced to 1 ml/kg/h for 12 h. 0.3 mg/kg of furosemide was given 1-h after hydration. The primary endpoint was the incidence of CA-AKI, and the secondary endpoint was the incidence of major adverse cardiovascular events (MACEs) during a median of 22.4 months (IQR 9.6, 32.6 months) follow-up. The incidence of CA-AKI was 8.7%. Among these, Group I was 9.1% and group II was 8.2%, respectively. There was no significant difference in CA-AKI and creatinine levels between the two hydration groups. Multivariable logistics regression analysis revealed that creatinine, white blood cells, and N-terminal pro-B-type natriuretic peptide were associated with CA-AKI. Moreover, CA-AKI was an independent predictor for all-cause death and cardiac death during the follow-up period. The modified hydration may reduce the incidence of CA-AKI, although this difference was not statistically significant. The relationship between CA-AKI and mortality strengthened as creatinine times above baseline increased. Mitigating the occurrence of CA-AKI may reduce all-cause death and cardiac death.

Stress-Delta B-Type Natriuretic Peptide Does Not Exclude ACS in the ED

BACKGROUND

There are many detectable changes in circulating biomarkers in the setting of myocardial ischemia. We hypothesize that there are associated changes in circulating B-type natriuretic peptide (BNP) level after stress-induced myocardial ischemia, which can be used for emergency department (ED) acute coronary syndrome (ACS) risk stratification.

METHODS

In a prospective study, we enrolled 340 patients over the age of 30 receiving an exercise echocardiography stress test in an ED observational unit for suspected ACS. We collected blood samples at baseline and at 2 and 4 h post-stress test, measuring the relative and absolute changes (stress-delta) in plasma BNP concentrations. In addition, patients were contacted at 90 days and at 1 year posttest for a follow-up. We calculated the diagnostic test characteristics of stress-delta BNP for a composite outcome of ischemic imaging on stress echocardiogram, nonelective percutaneous coronary intervention, coronary artery bypass graft surgery, subsequent acute myocardial infarction, or cardiac death at 1 year via a logistic regression. We analyzed the 2-h BNP concentrations using an ANOVA model to adjust for the baseline BNP level.

RESULTS

Baseline and 2-h post-stress BNP were both higher in the positive outcome group, but the stress-delta BNP was not. Stress-delta BNP had a sensitivity and specificity, respectively, of 53% and 76% at 2 h and 67% and 68% at 4 h. It was noted that patients with the composite outcome had a higher baseline BNP level.

CONCLUSIONS

BNP stress-deltas are poor diagnostic means for ACS risk stratification, but resting BNP remains a promising prognostic tool for ED patients with suspected ACS.

Extracellular Vesicles in Diagnosing Chronic Coronary Syndromes the Bumpy Road to Clinical Implementation

Coronary artery disease (CAD), comprising both acute coronary syndromes (ACS) and chronic coronary syndromes (CCS), remains one of the most important killers throughout the entire world. ACS is often quickly diagnosed by either deviation on an electrocardiogram or elevated levels of troponin, but CCS appears to be more complicated. The most used noninvasive strategies to diagnose CCS are coronary computed tomography and perfusion imaging. Although both show reasonable accuracy (80–90%), these modalities are becoming more and more subject of debate due to costs, radiation and increasing inappropriate use in low-risk patients. A reliable, blood-based biomarker is not available for CCS but would be of great clinical importance. Extracellular vesicles (EVs) are lipid-bilayer membrane vesicles containing bioactive contents e.g., proteins, lipids and nucleic acids. EVs are often referred to as the “liquid biopsy” since their contents reflect changes in the condition of the cell they originate from. Although EVs are studied extensively for their role as biomarkers in the cardiovascular field during the last decade, they are still not incorporated into clinical practice in this field. This review provides an overview on EV biomarkers in CCS and discusses the clinical and technological aspects important for successful clinical application of EVs.

Stress-delta B-type Natriuretic Peptide Levels as a Test for Inducible Myocardial Ischemia: A Systematic Review and Meta-Analysis

Background Cardiac ischemia induces myocardial dysfunction and ventricular wall stretch, which causes the release of B-type natriuretic peptide (BNP) into the bloodstream. However, it is unclear whether inducible ischemia produces a significant change in BNP levels ("stress delta-BNP"). The objective of this study was to determine the utility of stress-delta BNP levels and its precursor NT-proBNP for detecting inducible myocardial ischemia during cardiac stress testing. Methods We conducted a systematic review and meta-analysis. We searched PubMed, EMBASE, Web of Science, Cumulative Index of Nursing and Allied Health Literature (CINAHL), and Ovid. Studies examining the changes in levels of BNP and its precursor, N-terminal pro-B-type natriuretic peptide (NT-proBNP), after an exercise cardiac stress test were included. Two reviewers independently analyzed titles and abstracts. Abstracts that did not provide enough information regarding eligibility criteria were kept for full-text evaluation. The same two reviewers also performed data extraction for analyses. Any disagreement was resolved by a consensus and, if it persisted, by a third reviewer adjudication. We report the median and mean values in studies in the order of sample size. Results A total of 15 studies met the inclusion criteria. Nine studies reported results in medians and six studies reported results in means. Of the nine studies, five assessed BNP alone, three assessed NT-proBNP, and one assessed both. Due to the non-normal distribution of results in these studies, they could not be meta-analyzed. Of the six studies that reported results in means, three assessed BNP and three assessed NT-proBNP. The standardized difference between normal and ischemic patients' stress-delta BNP values was -0.39 (95% confidence interval (CI): -0.61; -0.17) in a fixed-effects model and -0.73 (95% CI: -1.72; 0.28) in the random-effects model with high heterogeneity (I^2 = 94%, Q test P = 0.001). For NT-proBNP, the meta-analysis model showed no significant difference between the stress-delta test for ischemic and normal patients (standardized mean difference (SMD): -0.02, 95% CI: -0.31; 0.28). Patients without inducible ischemia appeared to have a lower baseline BNP and NT-proBNP compared to patients with inducible ischemia by stress testing. Although some studies report higher stress-delta BNP in the ischemic group, this pattern was not seen consistently across studies. There was high heterogeneity across studies which was not robust to sensitivity analysis. A random-effects model failed to find statistically significant differences in stress-delta BNP or NT-proBNP. Conclusions We failed to find a relationship between stress-delta BNP or NT-proBNP and the presence or absence of ischemia. This may be due to high heterogeneity in the underlying studies.

Adjuvant radiotherapy-induced cardiac changes among patients with early breast cancer: a three-year follow-up study. Acta Oncol 2019;58:1250-1258. [PMID: 31219359 DOI: 10.1080/0284186x.2019.1630751]

Background: In this study, we evaluate the evolution of cardiac changes during a three-year follow-up after adjuvant breast radiotherapy (RT). Methods: Sixty patients with left-sided and 20 patients with right-sided early stage breast cancer without chemotherapy were included in this prospective study. Echocardiography and cardiac biomarkers were evaluated before, immediately after and 3 years after RT. Radiation doses to cardiac structures were calculated. Results: In echocardiography, left ventricle (LV) systolic measurements had impaired at 3 years compared to baseline: the mean global longitudinal strain (GLS) worsened from -18 ± 3 to -17 ± 3 (p = .015), LV ejection fraction from 62 ± 5% to 60 ± 4% (p = .003) and the stroke volume from 73 ± 16 mL to 69 ± 15 mL (p = .015). LV diastolic function was also negatively affected: the isovolumetric relaxation time was prolonged (p = .006) and the first peak of diastole decreased (p = .022). Likewise, left atrial (LA) measurements impaired. These changes in echocardiography were more prominent in left-sided than in right-sided patients. The concurrent aromatase inhibitor (AI) use was associated with GLS impairment. In all patients, the N-terminal pro-brain natriuretic peptide (proBNP) values were median (interquartile range) 74 (41-125) ng/L at baseline, 75 (41-125) ng/L at the end of RT and 96 (56-162) ng/L at 3 years (p < .001 from baseline to 3 years). However, proBNP did not increase in right-sided patients. Conclusion: During the 3-year follow-up after RT, negative subclinical changes in cardiac biomarkers and in LV systolic and diastolic function were observed. The measured changes were more pronounced in left-sided patients. In addition, AI use was associated with impaired cardiac systolic function.

High-Sensitivity Troponin T and Incident Heart Failure in Older Men: British Regional Heart Study

OBJECTIVE

The aim of this work was to study the association of high-sensitivity troponin T (hsTnT) with incident heart failure (HF), and implications for its use in prediction models.

METHODS AND RESULTS

In the British Regional Heart Study, 3852 men aged 60-79years without baseline HF (3165 without baseline chronic heart disease) were followed for a median of 12.6years, during which 295 incident cases of HF occurred (7.7%). A 1-SD increase in log-transformed hsTnT was associated with a higher risk of incident HF after adjusting for classic risk factors (hazard ratio [HR] 1.58, 95% confidence interval [CI] 1.42-1.77) and after additional adjustment for N-terminal pro-B-type natriuretic peptide (NT-proBNP; HR 1.34, 95% CI 1.19-1.52). The strength of the association between hsTnT and incident HF did not differ by strata of other risk factors. An hsTnT concentration of <5ng/L had a sensitivity of 99.7% (95% CI 98.1%-99.9%) and a specificity of 3.4% (95% CI 2.8%-4.0%). A risk-prediction model including classic risk factors and NT-proBNP yielded a C-index of 0.791, but addition of hsTnT did not further improve prediction (P = .28).

CONCLUSIONS

Elevated hsTnT is consistently associated with risk of HF in older men. HF occurred rarely over 12years when baseline hsTnT was below the limit of detection. hsTnT measurement, however, does not improve HF prediction in a model already containing NT-proBNP.

Prognostic value of plasma NT-proBNP levels in very old patients with moderate renal insufficiency in China

BACKGROUND

The N‑terminal pro-brain natriuretic peptide (NT-proBNP) has an important prognostic value in chronic renal insufficiency; however, most studies have been conducted in patients with end-stage renal disease (ESRD). In this study we evaluated the prognostic significance of NT-proBNP in very old patients with stage 3 chronic kidney disease (CKD) and compared its prognostic value in CKD3a versus CKD3b patients.

METHODS

Patients (age ≥80 years old) hospitalized with stage 3 CKD from 2007 to 2010 who were eligible for this prospective study underwent follow-up examinations in 2015. The examinations included measurements of anthropometric characteristics, blood pressure, plasma NT-proBNP, creatinine, and lipids. End-point events were all-cause death and major adverse cardiac events (MACEs).

RESULTS

A total of 168 patients (mean age 87.4 ± 2.9 years, range 80-99 years) were included in the analysis (CKD3a, n = 117; CKD3b, n = 51). The results showed that CKD3b was associated with lower hemoglobin levels, higher NT-proBNP levels and a higher rate of hypertension compared with CKD3a. After a median follow-up of 3.8 years (interquartile range 1.5-6.1 years), a higher NT-proBNP level was associated with a higher risk of all-cause death (hazard ratio HR 1.986, 95% confidence interval CI 1.276-2.819, p = 0.028) and MACEs (HR 2.872, 95% CI 1.241-6.644, p = 0.014) after adjusting for age, sex, and traditional risk factors; however, a subgroup comparison showed that elevated NT-proBNP levels were associated with a higher risk of all-cause death (HR 2.350, 95% CI 1.906-6.091, p = 0.039) and MACEs (HR 3.025, 95% CI 1.024-8.940, p = 0.045) in CKD3a but not CKD3b.

CONCLUSION

Levels of NT-proBNP increased with decreased renal function in very old patients with stage 3 CKD; therefore, NT-proBNP is an independent predictor for all-cause death and MACEs in these patients but has a greater prognostic value in CKD3a than in CKD3b.

Combining high-sensitivity cardiac troponin and B-type natriuretic peptide in the detection of inducible myocardial ischemia

BACKGROUND

Single biomarker approaches provide only moderate accuracy in the non-invasive detection of exercise-induced myocardial ischemia. We therefore assessed the combination of the two most promising single biomarkers: high-sensitivity cardiac troponin I (hs-cTnI) and B-type natriuretic peptide (BNP).

METHODS

Consecutive patients with suspected myocardial ischemia referred to stress myocardial perfusion single-photon emission tomography imaging (MPI) were enrolled. Clinical judgment (CJ) of the treating cardiologist regarding myocardial ischemia, quantified using a visual analogue scale, and blood concentrations of hs-cTnI and BNP were determined before and after stress. The presence of myocardial ischemia was adjudicated by independent cardiologists using MPI, blinded to biomarker measurements. Death and acute myocardial infarction (AMI) during follow-up were the prognostic endpoints.

RESULTS

Among 1142 consecutive patients inducible myocardial ischemia was found in 456 (40%) of all patients. For the detection of inducible myocardial ischemia, CJ before exercise stress testing (CJb) showed an area under the receiver-operating-characteristics curve (AUC) of 0.66 (95%CI 0.63-0.69), hs-cTnI 0.70 (95%CI 0.67-0.73, p=0.07 vs CJb), and BNP 0.66 (95%CI 0.62-0.69, p=0.98). The use of a dual-biomarker strategy combining hs-cTnI and BNP with CJb did not provide a significant advantage over the combination of hs-cTnI alone and CJb (AUC 0.74, 95%CI 0.72-0.77 vs AUC 0.74, 95%CI 0.71-0.77, p=0.16). Hs-cTnI showed good prognostic value for AMI (HR 1.6, 95%CI 1.3-1.9), and BNP for death (HR 1.6, 95%CI 1.3-2.1).

CONCLUSION

A dual-biomarker strategy combing BNP and hs-cTnI does not further increase diagnostic accuracy on top of clinical judgment and hs-cTnI alone.

SUMMARY AND HIGHLIGHTS

We included 1142 consecutive patients with suspected inducible ischemia, and evaluated the added value of the biomarkers high-sensitivity cardiac troponin (hs-cTn) and B-type natriuretic peptide (BNP), alone and in combination, on top of clinical judgment.

CLINICAL TRIAL REGISTRATION

Biochemical and Electrocardiographic Signatures in the Detection of Exercise-induced Myocardial Ischemia (BASEL VIII), NCT01838148, https://clinicaltrials.gov/ct2/show/NCT01838148.

Prognostic impact of intensive statin therapy on N-terminal pro-BNP level in non-ST-segment elevation acute myocardial infarction patients

OBJECTIVE

This study explored the impact of intensive daily dosing of atorvastatin on in-hospital N-terminal pro-B-type natriuretic peptide level, left ventricular systolic function and incidence of major adverse cardiac events in non-ST-segment elevation myocardial infarction patients.

BACKGROUND

Several studies showed that early initiation of statin therapy in acute coronary syndrome patients has a favorable prognostic impact.

METHODS

Hundred statin naive patients were prospectively enrolled. Once eligible, patients were randomly assigned to receive either a moderate daily dose that is, 20 mg (Group A) or an intensified daily dose that is, 80 mg (Group B) of atorvastatin, in addition to an equally divided loading dose given 24 and 12 h before coronary angiography (80 mg each). N-terminal pro-B-type natriuretic peptide levels were recorded before and after coronary intervention. Collected data after 3 months included; N-terminal pro-B-type natriuretic peptide levels, left ventricle systolic function and major adverse cardiac events.

RESULTS

Mean age of the study cohort was 55 ± 10 years, 68% being males. There was no significant difference between both groups concerning procedural data. Group B patients showed a significantly lower N-terminal pro-B-type natriuretic peptide levels at both sampling occasions, i.e., after coronary intervention and 3 months later (P < 0.001). After 3 months, the same group showed higher left ventricle ejection fraction (P < 0.05), with no significant difference between both groups regarding incidence of major adverse cardiac events.

CONCLUSION

Intensive atorvastatin therapy in non-ST-segment elevation myocardial infarction patients undergoing percutaneous coronary intervention is associated with; lower in-hospital N-terminal pro BNP level and higher LVEF after 3 months.

N-terminal pro-brain natriuretic peptide improves the C-ACS risk score prediction of clinical outcomes in patients with ST-elevation myocardial infarction

Background

It remained unclear whether the combination of the Canada Acute Coronary Syndrome Risk Score (CACS-RS) and N-terminal pro-brain natriuretic peptide (NT-pro-BNP) could have a better performance in predicting clinical outcomes in acute ST-elevation myocardial infarction (STEMI) patients with primary percutaneous coronary intervention.

Methods

A total of 589 consecutive STEMI patients were enrolled. The potential additional predictive value of NT-pro-BNP with the CACS-RS was estimated. Primary endpoint was in-hospital mortality and long-term poor outcomes.

Results

The incidence of in-hospital death was 3.1%. Patients with higher NT-pro-BNP and CACS-RS had a greater incidence of in hospital death. After adjustment for the CACS-RS, elevated NT-pro-BNP (defined as the best cutoff point based on the Youden’s index) was significantly associated with in hospital death (odd ratio = 4.55, 95%CI = 1.52–13.65, p = 0.007). Elevated NT-pro-BNP added to CACS-RS significantly improved the C-statistics for in-hospital death, as compared with the original score (0.762 vs. 0.683, p = 0.032). Furthermore, the addition of NT-pro-BNP to CACS-RS enhanced net reclassification improvement (0.901, p < 0.001) and integrated discrimination improvement (0.021, p = 0.033), suggesting effective discrimination and reclassification. In addition, the similar result was also demonstrated for in-hospital major adverse clinical events (C-statistics: 0.736 vs. 0.695, p = 0.017) or 3-year mortality (0.699 vs. 0.604, p = 0.004).

Conclusions

Both NT-pro-BNP and CACS-RS are risk predictors for in hospital poor outcomes in patients with STEMI. A combination of them could derive a more accurate prediction for clinical outcome s in these patients.

Incremental value of B-type natriuretic peptide for detection and risk reclassification of obstructive coronary artery disease on computed tomography angiography

BACKGROUND

B-type natriuretic peptide (BNP) is well known to increase as a result of left ventricular systolic dysfunction and is a useful diagnostic marker for heart failure. The purpose of this study was to assess the incremental value of BNP for predicting obstructive coronary artery disease (CAD) on computed tomography angiography (CTA) in patients with suspected CAD.

METHODS

This was an observational analysis of patients with stable CAD undergoing CTA in our institution between April 2008 and June 2014. Consecutive 947 patients with suspected CAD who underwent 64-slice CTA were enrolled. Obstructive CAD was defined as more than 50% luminal narrowing. We divided the patients into 2 groups according to median BNP value (20.3pg/ml). Duke clinical score for obstructive CAD was calculated for each patient.

RESULTS

Obstructive CAD was found in 273 (28.0%) patients. Median follow-up period was 37 months (interquartile range 21-55 months). Kaplan-Meier curves showed that BNP above median was significantly associated with major adverse cardiac events (p=0.001). In multivariable logistic analysis, patients with BNP above median were associated with the presence of obstructive CAD, as compared with BNP below median [odds ratio, 2.55; 95% confidence interval (CI), 1.79-3.63; p<0.001]. Analyzing the incremental value of the Duke clinical score and BNP, the predictive value of the Duke clinical score [area under the curve (AUC), 0.714] could be increased by BNP (AUC 0.745 for the combined model; p<0.001). Addition of BNP to a model containing the Duke clinical score resulted in net reclassification improvement index of 0.14 (95% CI: 0.053-0.205, p<0.001).

CONCLUSIONS

BNP might provide an incremental improvement in the detection of obstructive CAD on CTA when combined with a conventional cardiovascular risk score.

Association of N-terminal pro-B-type natriuretic peptide with contrast-induced nephropathy and long-term outcomes in patients with chronic kidney disease and relative preserved left ventricular function

The aim of the present article was to evaluate the association of N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) with contrast-induced nephropathy (CIN) and long-term outcomes in patients with chronic kidney disease (CKD) and relative preserved left ventricular function (LVF) undergoing percutaneous coronary intervention (PCI). We prospectively enrolled 1203 consecutive patients with CKD and preserved LVF undergoing elective PCI. The primary end point was the development of CIN, defined as an absolute increase in serum creatinine (SCr) ≥0.5 mg/dL, from baseline within 48 to 72 hours after contrast medium exposure. CIN incidence varied from 2.2% to 5.2%. Univariate logistic analysis showed that lg-NT-pro-BNP was significantly associated with CIN (odds ratio [OR] = 3.93, 95% confidence interval [CI], 2.22-6.97, P < 0.001). Furthermore, lg-NT-pro-BNP remained a significant predictor of CIN (OR = 3.30, 95% CI, 1.57-6.93, P = 0.002), even after adjusting for potential confounding risk factors. These results were confirmed by using other CIN criteria, which were defined as elevations of the SCr by 25% or 0.5 and 0.3 mg/dL from the baseline. The best cutoff value of lg-NT-pro-BNP for detecting CIN was 2.73 pg/mL (537 pg/mL) with 73.1% sensitivity and 70.0% specificity according to the receiver operating characteristic (ROC) analysis (C statistic = 0.754, 95% CI, 0.67-0.84, P < 0.001). In addition, NT-pro-BNP ≥537 pg/mL (2.73 pg/mL, lg-NT-pro-BNP) was associated with an increased risk of all-cause mortality and composite end points during 2.5 years of follow-up. NT-pro-BNP ≥537 pg/mL is independently associated with an increased risk of CIN with different definitions and poor clinical outcomes in patients with CKD and relative preserved LVF undergoing PCI.

BNP was associated with ischemic myocardial scintigraphy and death in patients at chest pain unit

BACKGROUND

Recent studies have suggested that B-type Natriuretic Peptide (BNP) is an important predictor of ischemia and death in patients with suspected acute coronary syndrome. Increased levels of BNP are seen after episodes of myocardial ischemia and may be related to future adverse events.

OBJECTIVES

To determine the prognostic value of BNP for major cardiac events and to evaluate its association with ischemic myocardial perfusion scintigraphy (MPS).

METHODS

This study included retrospectively 125 patients admitted to the chest pain unit between 2002 and 2006, who had their BNP levels measured on admission and underwent CPM for risk stratification. BNP values were compared with the results of the MPS. The chi-square test was used for qualitative variables and the Student t test, for quantitative variables. Survival curves were adjusted using the Kaplan-Meier method and analyzed by using Cox regression. The significance level was 5%.

RESULTS

The mean age was 63.9 ± 13.8 years, and the male sex represented 51.2% of the sample. Ischemia was found in 44% of the MPS. The mean BNP level was higher in patients with ischemia compared to patients with non-ischemic MPS (188.3 ± 208.7 versus 131.8 ± 88.6; p = 0.003). A BNP level greater than 80 pg/mL was the strongest predictor of ischemia on MPS (sensitivity = 60%, specificity = 70%, accuracy = 66%, PPV = 61%, NPV = 70%), and could predict medium-term mortality (RR = 7.29, 95% CI: 0.90-58.6; p = 0.045) independently of the presence of ischemia.

CONCLUSIONS

BNP levels are associated with ischemic MPS findings and adverse prognosis in patients presenting with acute chest pain to the emergency room, thus, providing important prognostic information for an unfavorable clinical outcome.

An increased B-type natriuretic peptide in the absence of a cardiac abnormality identifies those whose left ventricular mass will increase over time

OBJECTIVES

The purpose of this study was to identify the relationship of B-type natriuretic peptide (BNP) with evolution of left ventricular mass (LVM) in optimally treated primary prevention patients.

BACKGROUND

Patients who have an elevated BNP no cardiac abnormality on echocardiography are common and at increased risk of adverse events. One hypothesis is that an elevated BNP is an early sensitive indicator of who will develop future structural abnormalities such as left ventricular (LV) hypertrophy.

METHODS

We identified optimally treated primary prevention patients with no cardiac abnormality at baseline. In particular, they had no myocardial ischemia, LV hypertrophy, LV dysfunction, or left atrial enlargement. They had a diverse range of plasma BNP levels and underwent cardiac magnetic resonance at baseline and 3 years later on a 3-T scanner.

RESULTS

Fifty patients with a diverse range of BNP were studied (with BNP ≤ 10 pg/ml in 25 patients and >10 pg/ml in 25 patients). LVM increased (+4.7 ± 3.5 g) in 24 patients and decreased (-4.9 ± 2.8 g) in 26 patients (p < 0.01). Blood pressure by 24-h monitoring was virtually identical between those whose LVM increased (systolic blood pressure 122 ± 14 mm Hg) and those whose LVM decreased (systolic blood pressure 121 ± 11 mm Hg, p = 0.77). Plasma BNP was nearly 3 times higher in those whose LVM increased versus those in whom LVM decreased (21 ± 9.6 pg/ml vs. 7.9 ± 3.9 pg/ml, p < 0.01). The c-statistic for BNP was 0.88.

CONCLUSIONS

In optimally treated primary prevention patients, plasma BNP levels are able to distinguish between those whose LVM will increase during the next 3 years versus those whose LVM will decrease during the next 3 years. This may explain why individuals with high BNP are at increased risk even if no cardiac abnormality can be detected initially.

B-type natriuretic peptide and clinical judgment in the detection of exercise-induced myocardial ischemia

BACKGROUND

Myocardial ischemia has been shown to be associated with increased levels of B-type natriuretic peptide (BNP). However, it remains unclear whether and how BNP levels could be used clinically in patients with suspected exercise-induced myocardial ischemia.

METHODS

We enrolled 274 consecutive patients with suspected exercise-induced myocardial ischemia referred for evaluation by rest/bicycle myocardial perfusion single-photon emission computed tomography (SPECT). All clinical information available to the treating cardiologist was used to quantify the clinical judgment regarding the presence of myocardial ischemia using a visual analogue scale twice: once before and once after bicycle exercise stress testing. BNP measurements were obtained before, immediately after, and 2 hours after stress testing in a blinded manner. The presence of myocardial ischemia was adjudicated on the basis of perfusion SPECT combined with coronary angiography findings.

RESULTS

Exercise-induced myocardial ischemia was adjudicated to be present in 103 patients (38%). BNP levels were significantly higher at all time points in patients with myocardial ischemia compared with those without (P < .01 for all). The accuracy of BNP levels as quantified by the area under the receiver operating characteristic curve (AUC) was similar among the time points evaluated (AUC, 0.677-0.697). Combining clinical judgment before exercise testing with BNP levels at rest increased diagnostic accuracy from AUC 0.708 to 0.754 (P = .018). When combining clinical judgment after exercise testing with BNP levels, AUC increased from 0.741 to 0.771 (P = .055).

CONCLUSIONS

Combining clinical judgment with BNP levels increased the diagnostic accuracy regarding the presence of myocardial ischemia.

The Value of N-Terminal Pro–B-Type Natriuretic Peptide in Determining Antihypertensive Benefit

We investigated 3 hypotheses: (1) N-terminal pro–B-type natriuretic peptide (NT-proBNP) predicts cardiovascular disease events in patients with hypertension, (2) NT-proBNP is associated with blood pressure variability, and (3) NT-proBNP predicts benefit from antihypertensive regimens. The Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT) randomized a subset of 6549 patients at risk with no history of coronary heart disease to either atenolol-based or amlodipine-based blood pressure–lowering treatment. During 5.5 years of follow-up, 485 cardiovascular disease cases accrued and were matched with 1367 controls. Baseline and 6-month in-trial NT-proBNP were measured. The results show that NT-proBNP improves cardiovascular disease risk prediction beyond established predictors, continuous net reclassification improvement of 22.3% ( P <0.0001). Furthermore, a 1-mm Hg increase in the SD of systolic blood pressure was associated with 2% higher baseline NT-proBNP in a multivariable regression analysis ( P <0.0001). However, NT-proBNP predicted cardiovascular disease risk independently of blood pressure variation (odds ratio per SD increase in log NT-proBNP 1.24; 95% confidence interval, 1.06–1.45; P =0.007). Atenolol-based treatment led to a 69.6% increase in NT-proBNP at 6 months ( P <0.0001). In contrast, amlodipine-based treatment reduced NT-proBNP by 36.5% ( P <0.0001). Amlodipine recipients who achieved a 6-month NT-proBNP below the median (61 pg/mL) were at lower risk of cardiovascular disease when compared with those who did not (odds ratio, 0.58; 95% confidence interval, 0.37–0.91) after adjustment for confounders inclusive of baseline NT-proBNP and achieved blood pressure. If confirmed, these novel results suggest that NT-proBNP, as well as aiding cardiovascular disease risk assessment, may also help assess the efficacy of specific antihypertensive regimens. Further relevant studies seem warranted.

Physiology of natriuretic peptides: The volume overload hypothesis revisited

The discovery of the natriuretic peptide system in the early 1980s aroused great interest among clinical cardiologists. The heart was not a mechanical pump alone, but also an endocrine organ that had powerful effects on blood circulation. Natriuretic peptides caused both natriuresis and diuresis, and they responded to a volume overload which caused either stretch or pressure on the heart. As a result, the findings led to the conclusion that the human body had a hormone with effects similar to those of a drug which treats high blood pressure. Later, it became evident that the volume contraction was fortified by extrarenal plasma shift. Here, a hypothesis is presented in which the role of natriuretic peptides is to regulate oxygen transport as the volume contraction leads to hemoconcentration with an increased oxygen-carrying capacity. Wall stress, either chemical or mechanical, changes the oxygen gradient of the myocardium and affects the diffusion of oxygen within a myocyte. In support of this hypothesis, hypoxia-response elements have been found in both the atrial natriuretic peptide and the brain natriuretic peptide genes.

Clinical use of ultrasensitive cardiac troponin I assay in intermediate- and high-risk surgery patients

Background. Cardiac troponin levels have been reported to add value in the detection of cardiovascular complications in noncardiac surgery. A sensitive cardiac troponin I (cTnI) assay could provide more accurate prognostic information. Methods. This study prospectively enrolled 142 patients with at least one Revised Cardiac Risk Index risk factor who underwent noncardiac surgery. cTnI levels were measured postoperatively. Short-term cardiac outcome predictors were evaluated. Results. cTnI elevation was observed in 47 patients, among whom 14 were diagnosed as having myocardial infarction (MI). After 30 days, 16 patients had major adverse cardiac events (MACE). Excluding patients with a final diagnosis of MI, predictors of cTnI elevation included dialysis, history of heart failure, transoperative major bleeding, and elevated levels of pre- and postoperative N-terminal pro-B-type natriuretic peptide (NT-proBNP). Maximal cTnI values showed the highest sensitivity (94%), specificity (75%), and overall accuracy (AUC 0.89; 95% CI 0.80–0.98) for postoperative MACE. Postoperative cTnI peak level (OR 9.4; 95% CI 2.3–39.2) and a preoperative NT-proBNP level ≥917 pg/mL (OR 3.47; 95% CI 1.05–11.6) were independent risk factors for MACE. Conclusions. cTnI was shown to be an independent prognostic factor for cardiac outcomes and should be considered as a component of perioperative risk assessment.

High-sensitive troponin T and N-terminal pro-B type natriuretic peptide are associated with cardiovascular events despite the cross-sectional association with albuminuria and glomerular filtration rate

AIMS

It has been suggested that troponins and natriuretic peptides can be falsely elevated in subjects with impaired kidney function because of decreased renal clearance. The value of these biomarkers in subjects with impaired kidney function has therefore been debated. We tested in a population-based cohort study, first, whether high-sensitive troponin T (hsTnT) and N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) levels are cross-sectionally associated with the estimated glomerular filtration rate (eGFR) and albuminuria, and secondly, whether these markers are associated with cardiovascular outcome, independent of eGFR, albuminuria and conventional cardiovascular risk factors.

METHODS AND RESULTS

We included 8121 subjects from the PREVEND study with both values of hsTnT and NT-pro-BNP available. High-sensitive troponin T >0.01 µg/L and NT-pro-BNP >125 ng/L were defined as elevated. We first performed linear regression analyses with hsTnT and NT-pro-BNP as dependent variables. Next, we performed Cox-regression analyses, studying the associations of hsTnT and NT-pro-BNP with incident cardiovascular events. Of our cohort, 6.7% had an elevated hsTnT and 12.2% an elevated NT-pro-BNP. Also, the estimated glomerular filtration rate, albuminuria, and ECG-assessed ischaemia and left ventricular hypertrophy were all significantly associated with hsTnT and NT-pro-BNP in the linear regression analyses. Both hsTnT and NT-pro-BNP appeared associated with cardiovascular events, and these associations remained significant after adjustment for eGFR, albuminuria, age, gender and conventional cardiovascular risk factors (P= 0.03 and P< 0.001, respectively). Only a few subjects with markedly reduced renal function were included. The results presented are therefore mainly valid for a population with mildly impaired renal function.

CONCLUSION

These data indicate that a finding of an increased hsTnT or NT-pro-BNP in subjects with chronic kidney disease stages 1/3 should be taken seriously as a prognostic marker for a worse cardiovascular outcome and not be discarded as merely a reflection of decreased renal clearance.

Clinical Use of Natriuretic Peptides

Either B-type natriuretic peptide (BNP) or NT-proBNP may be used as a diagnostic, screening, prognostic and therapeutic tool for CHF. The Food and Drug Administration (FDA) cleared the cut-off point for BNP at 100 pg/mL, and that of NT-proBNP at 125 pg/mL for patients <75 years and 450 pg/mL for those >75. A steadily rising titre even below the cut-off value should be raised as a concern as heart failure is progressive if left untreated and may result in cardiac death. Both biomarkers are also featured in lab investigations for patients with acute coronary syndrome (ACS).

Diabetic neuropathy and heart failure: role of neuropeptides

Cardiovascular autonomic neuropathy (CAN), in which patients present with damage of autonomic nerve fibres, is one of the most common complications of diabetes. CAN leads to abnormalities in heart rate and vascular dynamics, which are features of diabetic heart failure. Dysregulated neurohormonal activation, an outcome of diabetic neuropathy, has a significant pathophysiological role in diabetes-associated cardiovascular disease. Key players in neurohormonal activation include cardioprotective neuropeptides and their receptors, such as substance P (SP), neuropeptide Y (NPY), calcitonin-gene-related peptide (CGRP), atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and C-type natriuretic peptide (CNP). These neuropeptides are released from the peripheral or autonomic nervous system and have vasoactive properties. They are further implicated in cardiomyocyte hypertrophy, calcium homeostasis, ischaemia-induced angiogenesis, protein kinase C signalling and the renin-angiotensin-aldosterone system. Therefore, dysregulation of the expression of neuropeptides or activation of the neuropeptide signalling pathways can negatively affect cardiac homeostasis. Targeting neuropeptides and their signalling pathways might thus serve as new therapeutic interventions in the treatment of heart failure associated with diabetes. This review discusses how neuropeptide dysregulation in diabetes might affect cardiac functions that contribute to the development of heart failure.