B-type natriuretic peptide predicts sudden death in patients with chronic heart failure

End-of-life care in the treatment of advanced heart failure in the elderly

Heart failure presents its own unique challenges to the clinician who desires to make excellent and humane care near the end of life a tangible reality. Accurate prediction of mortality in the individual patient is complicated by both the frequent occurrence of sudden death, both with and without devices, and the frequently chronic course that is punctuated by recurrent and more prominent acute episodes. A significant literature demonstrates that healthcare providers continue to have difficulty communicating effectively with terminally ill patients and their caregivers regarding end-of-life care preferences, and it is clear from the prognostic uncertainty of advanced heart failure that this kind of communication, and discussions regarding palliative care, need to occur earlier rather than later. This article discusses various means of providing palliative care, and specific issues regarding device therapy, cardiopulmonary resuscitation, and palliative sedation, with concurrent discussion of the ethical ramifications and pitfalls of each. A recent scientific statement from the American Heart Association begins to address some of the methodological issues involved in the care of patients with advanced heart failure. Above all, clinicians who wish to provide the highest quality of care to the dying patient need to confront the existential reality of death in themselves, their loved ones, and their patients so as to best serve those remanded to their care.

B-type natriuretic peptide as a biochemical marker of left ventricular diastolic function: assessment in asymptomatic patients 1 year after valve replacement for aortic stenosis

OBJECTIVES Left ventricular (LV) diastolic dysfunction after aortic valve replacement (AVR) carries a substantial risk of development of heart failure and reduced survival. In addition to echocardiography, B-type natriuretic peptide (BNP) provides a powerful incremental assessment of diastolic function. This study evaluates BNP as a marker of LV diastolic dysfunction in a cohort of patients with preserved LV ejection fraction who underwent AVR for pure aortic stenosis and the relationship between BNP values and the grade of LV diastolic dysfunction. METHODS A total of 113 patients were included in the study. Echocardiographic evaluation was performed preoperatively, 5 days postoperatively and at 12-month follow-up, to assess LV dimensional and functional parameters. Diastolic function was labelled as normal, mild, moderate or severe dysfunction. Concomitantly, BNP levels were evaluated. RESULTS Mild to severe diastolic dysfunction occurred preoperatively in all patients. At 12-month follow-up, 65 (62.5%) patients had mild and 25 (24.1%) moderate to severe diastolic dysfunction. BNP values, categorized for quartile distribution, correlated with diastolic dysfunction grade (P<0.001 for each comparison). At receiver operating characteristic analysis, the BNP level of 120 pg/ml was 91% sensitive and 85% specific for diastolic disease, while 300 pg/ml was 80% sensitive and 91% specific for moderate or severe diastolic dysfunction. Twelve months after AVR, BNP values were strongly correlated with the significant echocardiographic parameters suggestive of diastolic dysfunction (P≤0.006 in all cases). CONCLUSIONS The BNP level following AVR is related to diastolic disease severity and may complement echocardiographic evaluation when symptoms are unclear and LV function is difficult to interpret.

Sensitive troponin assays and N-terminal pro-B-type natriuretic peptide in acute coronary syndrome: prediction of significant coronary lesions and long-term prognosis

BACKGROUND

Sensitive troponin assays have substantially improved early diagnosis of myocardial infarction. However, the role of sensitive cardiac troponin (cTn) assays in prediction of significant coronary lesions and long-term prognosis in non-ST-elevation acute coronary syndrome (NSTE-ACS) remains unresolved.

METHODS

This prospective study includes 458 consecutive patients with NSTE-ACS admitted for coronary angiography. Serum levels of 4 commercial available sensitive troponin assays were analyzed (Roche high-sensitive cTnT [hs-cTnT; Roche Diagnostics, Basel, Switzerland], Siemens cTnI Ultra [Siemens, Munich, Germany], Abbott-Architect cTnI [Abbott, Abbott Park, IL], Access Accu-cTnI [Beckman Coulter, Nyon, Switzerland]), as well as a standard assay (Roche cTnT) and N-terminal pro-B-type natriuretic peptide (NT-proBNP), before coronary angiography.

RESULTS

The relationship between the analyzed biomarkers and significant coronary lesions on coronary angiography, as quantified by area under the receiver operating characteristic curve, was significantly higher with Roche hs-cTnT, Siemens cTnI Ultra, and Access Accu-cTnI as compared with standard troponin T assay (P < .001 for all comparisons). This difference was mainly caused by increased sensitivity below the 99th percentile. Also, NT-proBNP was associated with the presence of significant coronary lesions. Cardiac troponin values were correlated with cardiac death (primary end point) during 1373 (1257-1478) days of follow-up. In both univariate and multivariate Cox regression analyses, NT-proBNP was superior to both hs-cTnT and cTnI in prediction of cardiovascular mortality. Troponin values with all assays were correlated with the need for repeated revascularization (secondary end point) during follow-up.

CONCLUSIONS

Sensitive cTn assays are superior to standard cTnT assay in prediction of significant coronary lesions in patients with NSTE-ACS. However, this improvement is primary caused by increased sensitivity below the 99th percentile. N-terminal pro-B-type natriuretic peptide is superior to cTns in prediction of long-term mortality.

Changes in BNP and QTc for prediction of sudden death in heart failure

Evaluation of: Vrtovec B, Knezevic I, Poglajen G, Sebesjen M, Okrajsek R, Haddad F. Relation of B-type natriuretic peptide level in heart failure to sudden cardiac death in patients with and without QT interval prolongation. Am. J. Cardiol. 111(6), 886–890 (2013). Guidelines recommend an implantable cardioverter defibrillator (ICD) for patients with chronic heart failure (HF) and left ventricular ejection fraction (LVEF) <35%, and New York Heart Association (NYHA) class II/III, despite optimal medical treatment. However, by this mode of patient selection, many patients receive an ICD but never use it. Therefore, additional clinical and laboratory parameters, including estimated glomerular filtration rate and B-type natriuretic petide (BNP), and ECG parameters such as the corrected QT-interval (QTc), have been suggested for a more refined assessment of the risk of sudden cardiac death (SCD). However, changes in these parameters over time may be even more informative for SCD prediction than single measures, but this had not been investigated so far. In the present paper, the authors assessed the association between changes in BNP and QTc during a 3-month period in 398 patients with advanced chronic HF (NYHA III/IV) and LVEF <40%. After a follow-up of 1 year, 20 patients had suffered SCD. Patients with a significant (≥10%) increase in BNP were more likely to have a significant (≥10%) increase in QTc and had a longer QTc at 3 months than those without. The risk of SCD did not differ between patients with and without a significant increase in BNP, but was higher in patients with a significant increase in QTc compared with those without. Among patients with an increase in BNP of ≥10%, those with an increase in QTc of ≥10% were several-fold more likely to experience SCD compared with those without, whereas there was no such association between the change in QTc and SCD among patients without an increase in BNP of ≥10%. Thus, this study showed that changes in QTc better predicted SCD than changes in BNP, and that a strategy using both a marker of heart failure severity and a marker of the propensity of the left ventricle for arrhythmia better predicted SCD than a single-marker strategy. Further studies are required to evaluate whether novel markers besides LVEF and NYHA class alone (e.g., biomarkers and cardiac MRI) will allow a more accurate selection of patients with chronic HF who need an ICD.

Heart failure biomarkers

Biomarker testing in patients with heart failure (HF) is rapidly expanding. With high-quality research indicating its diagnostic and prognostic capabilities, biomarkers are excellent adjuncts to manage patients with HF. Their superiority lies mainly in their reflection of ongoing pathophysiological events at a cellular level. Monitoring biomarker levels has been shown to provide incremental information on the progression of disease, thus allowing to better tailor treatment and management. Several biomarkers have gained attention in the past decade and continuing research demonstrates the specificity of each biomarker to be used on its own or in combination to improve diagnostic accuracy. This review will provide an insight into the role of such biomarkers, which are widely studied in the setting of HF so as to delineate their role in diagnosing, prognosticating, and titrating HF therapy.

Prediction of Atrial Fibrillation by B-type Natriuretic Peptide

Background: Although several conditions have been proposed as risk factors contributing to the incidence of atrial fibrillation, many individuals without such 'risk factors' also suffer from atrial fibrillation. The present study tested the hypothesis that the risk of new-onset atrial fibrillation increases with increasing circulating levels of B-type natriuretic peptide in the general population. Methods: Participants in our health checkup program without atrial fibrillation or a history of atrial fibrillation were enrolled (n=10,058, 54.3±11.3 years old). After baseline evaluation, subjects were followed up for the median of 1,791 days with the endpoint being the new onset of atrial fibrillation. Results: Atrial fibrillation occurred in 53 subjects during the follow-up period (1.16 per 1,000 person-year). The risk of new-onset atrial fibrillation increased across the gender-specific quartiles of B-type natriuretic peptide levels at baseline. In multivariate Cox proportional hazard regression analysis where B-type natriuretic peptide concentrations were taken as a continuous variable, B-type natriuretic peptide was a significant predictor of new onset of atrial fibrillation after adjustment for possible factors (hazard ratio 5.65 [95% CI 2.63-12.41]). Conclusions: The risk of new onset of atrial fibrillation increases with increasing B-type natriuretic peptide levels in the general population. Measurement of B-type natriuretic peptide may improve the prediction of incident atrial fibrillation.

Efficacy and safety of bisoprolol fumarate compared with carvedilol in Japanese patients with chronic heart failure: results of the randomized, controlled, double-blind, Multistep Administration of bisoprolol IN Chronic Heart Failure II (MAIN-CHF II) study

Bisoprolol fumarate (bisoprolol) is a β-blocker widely used to treat chronic heart failure (CHF). However, few studies have compared its efficacy and safety with those of the widely used β-blocker carvedilol in Japanese patients with CHF. We designed a confirmatory trial of bisoprolol using carvedilol as a control drug; however, the trial was discontinued after an off-label use of bisoprolol was approved during the study. Bisoprolol and carvedilol were administered for 32 weeks in 31 and 28 patients, respectively. The mean maintenance doses of bisoprolol and carvedilol were 3.3 and 13.6 mg/day, respectively, and the mean durations of treatment were 188.2 and 172.9 days, respectively. Heart-rate changes were similar in both groups. The mean changes from baseline to Week 32 in left ventricular (LV) ejection fraction (EF) (bisoprolol vs carvedilol groups; 11.7 % ± 8.6 % vs 10.1 % ± 10.5 %), LV end-diastolic volume (-37.5 ± 48.7 vs -24.7 ± 29.4 ml), and LV end-systolic volume (-41.9 ± 43.0 vs -29.3 ± 25.9 ml) revealed a decrease in LV volume and an increase in LVEF in both groups. The cumulative event-free rate for a composite of cardiovascular death or admissions to hospital for worsening of CHF was 92.4 % and 94.7 % in the bisoprolol and carvedilol groups, respectively. Overall, 90.3 % and 85.7 % of patients were titrated up to the maintenance doses of bisoprolol and carvedilol, respectively. Bisoprolol, at half the dose used in other countries, is well tolerated and is as effective as carvedilol for treating Japanese patients with mild to moderate CHF.

Review on natriuretic peptides: where we are, where we are going

BACKGROUND

Tremendous advances have been made in our understanding of the pathophysiology and treatment of congestive heart failure. However, diagnosis of the disease still remains difficult, even with a comprehensive physical examination. Symptoms such as dyspnea are nonspecific and insensitive indicators for heart failure, which can go largely undetected. Several studies have suggested the need for new diagnostic capabilities, especially with the increasing prevalence of heart failure in the US. The discovery of natriuretic peptides as diagnostic biomarkers has been one of the most critical advances for the management of heart failure. Both B-type natriuretic peptide and N-terminal pro-B-type natriuretic peptide have the potential to diagnose heart failure, assess prognostic risk of rehospitalization and mortality, and even help guide treatment. Their relative cost-effectiveness and availability have also facilitated their acceptance into many emergency departments, clinics and in-patient units as standard care when evaluating patients with suspected heart failure. Our understanding of the natriuretic peptide system is still in its infancy, but natriuretic peptides have emerged as important diagnostic and prognostic tools that have generated interest in finding broader applications for their use.

OBJECTIVE

The purpose of this review is to discuss the clinical approaches and future applications of natriuretic peptides in diagnosing and managing treatment of congestive heart failure.

METHOD

A comprehensive review of studies to assess the utility of natriuretic peptides for diagnosis and prognosis of heart failure and other conditions.

CONCLUSION

Natriuretic peptides are powerful tools to aid the physician in the diagnosis, prognosis and management of heart failure in both in-patient and out-patient settings. However, natriuretic peptides should be used as an adjunct test as many circumstances can also influence changes in natriuretic peptide levels.

Relation of B-type natriuretic peptide level in heart failure to sudden cardiac death in patients with and without QT interval prolongation

Increased levels of B-type natriuretic peptide (BNP) are associated with prolongation of the action potential in ventricular myocardium. We investigated the relation of a BNP increase, QT interval, and sudden cardiac death (SCD) in the presence of heart failure (HF). We enrolled 398 patients with HF, New York Heart Association class III or IV, and left ventricular ejection fraction <40%. At baseline and after 3 months, we measured BNP and the QT interval. A BNP increase was defined as a change in BNP of ≥+10%. The QTc interval was calculated using the Bazett formula. QTc interval prolongation was defined as a change in QTc of ≥+10%. The patients were followed up for 1 year. During a 3-month period, BNP increased significantly in 53% of the patients (group 1) and did not in 47% (group 2). During the same period, the QTc interval was more prolonged in group 1 (+44 ± 12 ms) than in group 2 (+7 ± 6 ms; p = 0.01). During 1 year of follow-up, 20 patients died suddenly (SCD), 16 from pump failure. Although the SCD rates did not differ between the 2 groups (5.7% in group 1 vs 4.2% in group 2, p = 0.53), they were significantly greater in the patients in group 1 with QTc interval prolongation ≥+10% (13.8%, p <0.001). The Kaplan-Meier-derived SCD-free survival rates were 2.9 times greater in patients without QTc interval prolongation than in those with prolonged QTc (p <0.001). QTc interval prolongation was an independent correlate of SCD (p = 0.006), but BNP increase was not (p = 0.32). In conclusion, a BNP increase in patients with HF was associated with an increased risk of SCD only in patients with QTc interval prolongation.

Effects of caesarean section on serum levels of NT-proBNP

OBJECTIVE

To determine the effects of delivery by caesarean on serum levels of N-terminal fragment of precursor protein brain-type natriuretic peptide (NT-proBNP).

METHODS

Serum NT-proBNP levels were determined longitudinally at 24 and 36 weeks of gestation (GW) and on post-partum day 3 and month 1 (PPD3 and PPM1, respectively) in 78 women with normotensive singleton pregnancies. Thirty-nine women underwent caesarean delivery. Plasma renin activity (PRA) and plasma aldosterone concentration (PAC) were determined on PPD3. Effects of maternal demographic characteristics on NT-proBNP levels were also analysed.

RESULTS

NT-proBNP levels (pg/ml) either in pregnancy or on PPM1 did not differ between women with vaginal and caesarean deliveries (44 ± 24 vs 41 ± 30, 24 GW; 37 ± 22 vs 29 ± 22, 36 GW; 43 ± 28 vs 39 ± 24, PPM1, respectively). Levels on PPD3 were significantly higher (94 ± 105 vs 247 ± 186, P < 0.0001) in women with caesarean delivery. Among women with caesarean delivery, a larger rise of NT-proBNP on PPD3 occurred in nulliparous than in multiparous women (319 ± 232 vs 185 ± 107, P = 0.023), while no rise occurred among multiparous women with vaginal delivery (108 ± 115 vs 47 ± 27). NT-proBNP levels on PPD3 were significantly and negatively correlated with PRA, PAC and maternal weight loss after childbirth on PPD3. These 3 variables on PPD3 were significantly lower in women undergoing caesarean than vaginal delivery (0.8 ± 0.4 vs 1.9 ± 1.4 ng/ml/h for PRA; 70 ± 38 vs 136 ± 88 pg/ml for PAC; 2.7 ± 1.2 vs 4.3 ± 1.1 kg for weight loss, each P < 0.0001).

CONCLUSIONS

The transient post-partum rise in serum NT-proBNP may reflect transient volume overload after parturition and is remarkable in nulliparous women, especially after caesarean section.

Effect of omega-3 on brain natriuretic peptide and echocardiographic findings in heart failure: Double-blind placebo-controlled randomized trial

BACKGROUND

Possible beneficial effects of dietary omega-3 supplementation on patients with congestive heart failure (CHF) were investigated.

METHODS AND RESULTS

100 patients with CHF who had a tri-chamber pacemaker and automated defibrillator were initially recruited, and 70 agreed to participate.38 patients received 2 g/day of omega-3 and 32 received placebo capsules. BNP level, 6-min walk test and echocardiographic parameters were recorded at baseline and after 6 months of treatment. BNP levels decreased significantly after 6 months in the omega-3 group, from 1766.2 ± 1978.1 pg/mL to 1159.4 ± 1430.9 pg/dL (P < 0.005). Tei index and late diastolic velocity index were significantly improved in treated group. Mortality and hospitalization rates did not differ.

CONCLUSION

The beneficial effects of omega-3 supplementation in patients with CHF were not as clear as hypothesized; however, omega-3 fatty acids can result in small changes in plasma BNP levels and modest improvements in echocardiographically assessed diastolic function (Clinical trial.gov registration: NCT01227837).

Role of serum N-terminal pro-brain natriuretic peptide measurement in diagnosis of cardiac involvement in patients with anderson-fabry disease

Enzyme replacement therapy has the potential to delay or reverse adverse cardiac remodeling in Anderson-Fabry disease (AFD); however, the current indications for enzyme replacement therapy rely on detecting relatively advanced features of the disease. We aimed to determine the relation between the serum N-terminal pro-brain natriuretic peptide (NT-proBNP) concentration and cardiac abnormalities in patients with AFD. We hypothesized that it might help to detect early disease. NT-proBNP was measured under at rest conditions in 117 patients with AFD (age 48 ± 15 years, 46.2% men). All patients underwent clinical evaluation with electrocardiography and echocardiography. The median NT-proBNP concentration was 24 pmol/L (range <5 to 6,059). Of the 117 patients, 67 (57%) had elevated, age-corrected, NT-proBNP levels. In the 56 patients (48%) with normal echocardiographic findings, the NT-proBNP levels were greater than the age-predicted cutoffs in 10 of 25 patients with abnormal electrocardiographic findings and 3 of 31 patients with normal electrocardiographic findings (p <0.05). On multiple regression analysis, age, creatinine, left atrial volume index, E/Ea, and the presence of abnormal electrocardiographic findings were independently associated with log NT-proBNP (R(2) = 0.67, p <0.05). In conclusion, NT-proBNP concentrations were elevated in patients with AFD and early cardiac involvement, suggesting its measurement could assist in decisions regarding the timing of enzyme replacement therapy.

Ambient temperature and biomarkers of heart failure: a repeated measures analysis

BACKGROUND

Extreme temperatures have been associated with hospitalization and death among individuals with heart failure, but few studies have explored the underlying mechanisms.

OBJECTIVES

We hypothesized that outdoor temperature in the Boston, Massachusetts, area (1- to 4-day moving averages) would be associated with higher levels of biomarkers of inflammation and myocyte injury in a repeated-measures study of individuals with stable heart failure.

METHODS

We analyzed data from a completed clinical trial that randomized 100 patients to 12 weeks of tai chi classes or to time-matched education control. B-type natriuretic peptide (BNP), C-reactive protein (CRP), and tumor necrosis factor (TNF) were measured at baseline, 6 weeks, and 12 weeks. Endothelin-1 was measured at baseline and 12 weeks. We used fixed effects models to evaluate associations with measures of temperature that were adjusted for time-varying covariates.

RESULTS

Higher apparent temperature was associated with higher levels of BNP beginning with 2-day moving averages and reached statistical significance for 3- and 4-day moving averages. CRP results followed a similar pattern but were delayed by 1 day. A 5°C change in 3- and 4-day moving averages of apparent temperature was associated with 11.3% [95% confidence interval (CI): 1.1, 22.5; p = 0.03) and 11.4% (95% CI: 1.2, 22.5; p = 0.03) higher BNP. A 5°C change in the 4-day moving average of apparent temperature was associated with 21.6% (95% CI: 2.5, 44.2; p = 0.03) higher CRP. No clear associations with TNF or endothelin-1 were observed.

CONCLUSIONS

Among patients undergoing treatment for heart failure, we observed positive associations between temperature and both BNP and CRP-predictors of heart failure prognosis and severity.

Prognostic factors of mid-term clinical outcome in congestive heart failure patients discharged after acute decompensation

INTRODUCTION

Risk stratification in congestive heart failure (CHF) patients is based on a variety of clinical and laboratory variables. We analysed renal function, BNP, water composition, echocardiographic and functional determinations in predicting mid-term outcome in CHF patients discharged after decompensation.

MATERIAL AND METHODS

All subjects with NYHA class II-IV were enrolled at hospital discharge. NYHA class, BNP, water body composition, non-invasive cardiac output and echocardiogram were analysed. Death, cardiac transplantation and hospital readmission for CHF were scheduled.

RESULTS

Two-hundred and thirty-seven (64.5% males, age 71.1±10.1) patients were discharged after obtaining normal hydration; left ventricular ejection fraction (LVEF) was 43.2±16.2%, cardiac output was 3.8±1.1 l/min and BNP at discharge resulted 401.3±501.7 pg/ml. During the 14-month follow-up 15 patients (6.3%) died, 1 (0.4%) underwent cardiac transplantation and 18 (7.6%) were readmitted for CHF (event group); in 203 (85.6%) no events were observed (no-event group). Higher NYHA class (2.1±0.7 vs. 1.9±0.4, p=0.01), BNP at discharge (750.2±527.3 pg/ml vs. 340.7±474.3 pg/ml, p=0.002) and impaired LVEF (33.7±15.7% vs. 44.5±15.8%, p=0.0001) and creatinine (1.7±0.6 vs. 1.2±0.8 mg/dl, p=0.004) were noticed in the event group. At multivariate Cox analysis LVEF (p=0.0009), plasma creatinine (p=0.006) and BNP at discharge (p=0.001) were associated with adverse mid-term outcome. Kaplan-Meier survival curves demonstrated that adding cut-off points for creatinine 1.5 mg/dl and discharged BNP of 250 pg/ml discriminated significantly prognosis (p=0.0001; log rank 21.09).

CONCLUSIONS

In predicting mid-term clinical prognosis in CHF patients discharged after acute decompensation, BNP at discharge ≥ 250 pg/ml added with plasma creatinine > 1.5 mg/dl are strong adverse predictors.

Study designs and statistical analyses for biomarker research

Biomarkers are becoming increasingly important for streamlining drug discovery and development. In addition, biomarkers are widely expected to be used as a tool for disease diagnosis, personalized medication, and surrogate endpoints in clinical research. In this paper, we highlight several important aspects related to study design and statistical analysis for clinical research incorporating biomarkers. We describe the typical and current study designs for exploring, detecting, and utilizing biomarkers. Furthermore, we introduce statistical issues such as confounding and multiplicity for statistical tests in biomarker research.

Prognostic power of pre- and postoperative B-type natriuretic peptide levels in patients undergoing abdominal aortic surgery

OBJECTIVES

The first aim of the present study was to evaluate the pre- and postoperative B-type natriuretic peptide (BNP) levels in patients undergoing surgery for repair of an infrarenal abdominal aortic aneurysm (AAA) and analyze their power as a predictor of in-hospital cardiac events. The second aim was to evaluate the association among pre- and postoperative BNP levels, postoperative patient complications, and length of hospital stay.

DESIGN

Prospective observational study.

SETTING

A university hospital.

PARTICIPANTS

Forty-five patients undergoing elective surgery for an abdominal aortic aneurysm.

INTERVENTIONS

The plasma BNP level was assessed just before surgery and then on postoperative day 1. Cardiac troponin I levels were measured postoperatively on arrival to the intensive care unit (time 0) and then 12, 48, and 72 hours later.

MEASUREMENTS AND MAIN RESULTS

The preoperative BNP concentration in patients who developed an acute myocardial infarction was 209 (IQR 84-346) pg/mL compared with 74 (IQR 28-142) pg/mL in those who did not. The difference between groups was statistically significant (p = 0.04). The Spearman correlation showed that postoperative BNP levels correlated significantly with preoperative BNP levels (r = 0.73, p = 0.0001), length of hospital stay (r = 0.35, p = 0.04), and troponin I concentration at 0 hour (r = 0.42, p = 0.02), 12 hours (r = 0.51, p = 0.0052), and 48 hours (r = 0.40, p = 0.033). In contrast, preoperative BNP levels correlated with troponin I at only 12 hours (r = 0.34, p = 0.02). Postoperative BNP levels were influenced significantly by transfusions (p = 0.035) and cross-clamping times (p = 0.038).

CONCLUSIONS

The present results confirm the high negative predictive value of preoperative BNP levels; and postoperative BNP levels showed a better correlation with postoperative troponin levels, blood transfusion, and postoperative cardiac events.

Multiple biomarkers for risk prediction in chronic heart failure

BACKGROUND

Prior studies have suggested using a panel of biomarkers that measure diverse biological processes as a prognostic tool in chronic heart failure. Whether this approach improves risk prediction beyond clinical evaluation is unknown.

METHODS AND RESULTS

In a multicenter cohort of 1513 chronic systolic heart failure patients, we measured a contemporary biomarker panel consisting of high-sensitivity C-reactive protein, myeloperoxidase, B-type natriuretic peptide, soluble fms-like tyrosine kinase receptor-1, troponin I, soluble toll-like receptor-2, creatinine, and uric acid. From this panel, we calculated a parsimonious multimarker score and assessed its performance in predicting risk of death, cardiac transplantation, or ventricular assist device placement in comparison to an established clinical risk score, the Seattle Heart Failure Model (SHFM). During a median follow-up of 2.5 years, there were 317 outcomes: 187 patients died; 99 were transplanted; and 31 had a ventricular assist device placed. In unadjusted Cox models, patients in the highest tertile of the multimarker score had a 13.7-fold increased risk of adverse outcomes compared with the lowest tertile (95% confidence interval, 8.75-21.5). These effects were independent of the SHFM (adjusted hazard ratio, 6.80; 95% confidence interval, 4.18-11.1). Addition of the multimarker score to the SHFM led to a significantly improved area under the receiver operating characteristic curve of 0.803 versus 0.756 (P=0.003) and appropriately reclassified a significant number of patients who had the outcome into a higher risk category (net reclassification improvement, 25.2%; 95% confidence interval, 14.2-36.2%; P<0.001).

CONCLUSIONS

In ambulatory chronic heart failure patients, a score derived from multiple biomarkers integrating diverse biological pathways substantially improves prediction of adverse events beyond current metrics.

Profile of microvolt T-wave alternans testing in 1003 patients hospitalized with heart failure

AIMS

Observational studies in selected populations have suggested that microvolt T-wave alternans (MTWA) testing may identify patients with heart failure (HF) at risk of sudden cardiac death. The aims of this study were to investigate the utility of MTWA testing in an unselected population of patients with HF and to evaluate the clinical characteristics associated with the MTWA results.

METHODS AND RESULTS

A total of 1003 patients hospitalized with decompensated HF were enrolled. MTWA testing was planned 1 month post-discharge; 648 patients returned for MTWA testing. Mean age was 70.8 ± 10.6 years and 58% were male. Of these patients who returned, 318 (49%) were ineligible for MTWA testing due to atrial fibrillation (AF), pacemaker dependency, or physical inability to undertake the test. Of the MTWA tests, 100 (30%) were positive, 78 (24%) were negative, and 152 (46%) were indeterminate; 112/152 indeterminate tests (74%) occurred because of failure to achieve target heart rate (HR) due to chronotropic incompetence or physical limitations. There were differences in patient characteristics according to MTWA result. Independent predictors of a negative result included younger age and higher left ventricular ejection fraction (LVEF). Independent predictors of a positive result included higher HR during MTWA testing and lower LVEF. Independent predictors of an indeterminate result included older age and history of previous/paroxysmal AF.

CONCLUSIONS

Only half of patients with HF are eligible for MTWA testing and the most common result is an indeterminate test. Patients with positive and indeterminate tests have different clinical characteristics. MTWA treadmill testing is not widely applicable in typical HF patients and is unlikely to refine risk stratification for sudden death on a population level.

Body mass index and rest myocardial perfusion defect predicts cardiac death in patients with chronic heart failure

Gated single photon emission computed tomography (SPECT) myocardial perfusion imaging has proven to be invaluable not only in assessing myocardial perfusion, but also in providing functional and volumetric information. The aim of this study was to investigate the value of clinical variables and rest gated SPECT myocardial perfusion imaging for predicting cardiac death in patients with chronic heart failure (CHF). Seventy-three consecutive hospitalized patients with CHF (aged 50.7 ± 16.5 years, 60 men and 13 women; 25 ischemic CHF and 48 non-ischemic CHF) and left ventricular ejection fraction on echocardiography <40%, who underwent rest gated SPECT myocardial perfusion imaging, were followed up for this study. Univariate and multivariate analysis of clinical characteristics and gated SPECT parameters for prediction of cardiac death were performed. During the follow-up period (18.6 ± 8.5 months), 14 (19.2%) cardiac deaths occurred. Multivariate Cox analysis showed that body mass index (BMI, 23.3 ± 4.1 kg/m(2), hazard ratio = 0.85, P = 0.025) and summed rest score (SRS, 11.8 ± 11.5, hazard ratio = 1.05, P = 0.021) were predictive for cardiac death. The optimal threshold of BMI was 25 kg/m(2) and patients with BMI < 25 kg/m(2) had lower survival rate (P = 0.013). The optimal threshold of SRS was set as 11 and patients with SRS > 11 had lower survival rate (P = 0.009). Rest gated SPECT myocardial perfusion imaging provides prognostic information in patients with CHF. BMI and SRS are both predictors of cardiac death in patients with CHF.

Correlation between T-Wave Alternans and Cardiac Volume Status via Intrathoracic Impedance Measurements

Introduction. The presence of T-wave alternans (TWA) has been shown to correlate with a higher risk for sudden cardiac death. The mechanism of TWA may be related to abnormalities in intracellular calcium handling, which is a mechanism in heart failure and associated arrhythmias as well. However, an association between TWA and cardiac volume status has not been demonstrated. Methods Used. We report the case of a 54-year-old man with a dilated cardiomyopathy who had a biventricular defibrillator system implanted with intrathoracic impedance measurement capability. We performed baseline TWA testing, which was normal and was associated with normal clinical status and normal intrathoracic impedance. We followed intrathoracic impedance measurements, and when the measurement suggested volume overload eight months later, we repeated the TWA test. TWA was grossly positive, and volume overload was corroborated with clinical heart failure. The patient was diuresed, and when clinical status and intrathoracic impedance returned to normal a month later, we repeated TWA, which was again negative. Conclusion. This case demonstrates a correlation between cardiac volume status, as measured by intrathoracic impedance measurements, and TWA status. This data suggests that conditions of volume overload such as heart failure could be causally related to increased TWA, perhaps by the common mechanism of altered intracellular calcium handling.

Prognostic role of high-sensitivity C-reactive protein and B-type natriuretic peptide in implantable cardioverter-defibrillator patients

BACKGROUND

High-sensitivity C-reactive protein (hs-CRP) and B-type natriuretic peptide (BNP) are useful biomarkers for cardiovascular risk stratification. Little data are available regarding the prognostic value of hs-CRP and BNP serum levels and future ventricular arrhythmic events triggering implantable cardioverter defibrillator (ICD) therapy.

METHODS

A total of 100 patients eligible for ICD implantation were enrolled in a prospective cohort study. Serum levels of hs-CRP and BNP were obtained the day before ICD implantation and at scheduled follow-up visits. For risk analysis, the study cohort was dichotomized based on serum level of hs-CRP using a cut-off value of 3 mg/L. The endpoint was appropriate ICD therapy triggered by ventricular arrhythmias during a follow-up of 24 months.

RESULTS

Appropriate ICD therapy was delivered in 20% of patients. Median baseline serum level of hs-CRP was significantly higher in patients with appropriate ICD therapy than in those without appropriate ICD therapy (5.33 mg/L vs 2.19 mg/L; P = 0.002). The same was true for median serum levels of hs-CRP and BNP during follow-up (5.43 mg/L vs 2.61 mg/L, P = 0.001 and 261.0 pg/mL vs 80.1 pg/mL, P = 0.01, respectively). Multivariate analysis demonstrated that baseline hs-CRP level > 3 mg/L was independently associated with appropriate ICD therapy (odds ratio 4.0, 95% 1.1-14.2; P = 0.03).

CONCLUSION

Elevated preimplantation hs-CRP serum level is independently associated with increased risk for appropriate ICD therapy. Monitoring for elevated BNP levels during follow-up adds to the assessment of risk for future arrhythmias.

Neuro-endocrine regulation of blood pressure

As our understanding of the underlying aetiology of hypertension is far from adequate, over 90% of patients with hypertension receive a diagnosis of essential hypertension. This non-specific diagnosis leads to suboptimal therapeutics and a major problem with non-compliance. Understanding the normal control of blood pressure (BP) is, hence, important for a better understanding of the disease.This review attempts to unravel the present understanding of BP control. The local mechanisms of BP control, the neural mechanisms, renal-endocrine mechanisms, and a variety of other hormones that have a bearing in normal BP control are discussed and the possible role in the pathophysiology is alluded to.

Measurement of NT-proBNP with LOCI technology in heart failure patients

OBJECTIVES

The aim of our study was to determine NT-proBNP concentrations in heart failure (HF) patients with a luminescent oxygen channeling immunoassay (LOCI).

DESIGN AND METHODS

Seventy HF patients were enrolled. NT-proBNP levels were measured with LOCI method and compared to a reference NT-proBNP assay.

RESULTS

LOCI NT-proBNP levels were significantly correlated with the reference NT-proBNP assay and were related to HF severity.

CONCLUSIONS

LOCI assay demonstrates performances close to the comparative assay for NT-proBNP testing and allows a significant reduction of the time of analysis.

Multivariate risk scores and patient outcomes in advanced heart failure

Significant improvements in survival have occurred for patients with advanced heart failure, with an increasing array of therapeutic options sharing quite varied properties of cost, invasiveness, and impact on life expectancy. Risk models allow patients and providers to achieve a better understanding of prognosis than is possible through unstructured holistic assessment. This article reviews scoring systems for heart failure prognostication in the general sense and in the setting of providing answers to specific clinical queries. Topics addressed include outpatient survival, risk of inpatient and post-discharge mortality, potential changes to clinician decision-making through better understanding of prognosis, and mortality after having a left ventricular assist device placed or receiving an implantable cardiac-defibrillator.

The role of B-type and other natriuretic peptides in health and disease

Natriuretic peptide (NP) physiology is a complex field. NPs also are known to be highly phylogenetically preserved. NPs can be thought of as counterregulatory hormones antagonizing the effects of the renin-angiotensin-aldosterone and sympathetic systems. These peptides are primarily responsible for maintaining salt and water homeostasis, but they also have vasodilatory properties. It was originally thought that B-type NP (BNP) and N-terminal-pro-BNP are secreted in a 1:1 ratio. However, recent data has shed further light into this area. Commercial assays for NPs will need to keep up with these changes. Currently, BNP levels within Kaiser Permanente are obtained by multiple providers in a variety of clinical scenarios in order to help them manage their patients. Therefore, a basic understanding of the physiology of NPs and the methodology of assays are needed to appropriately interpret an NP test result within the corresponding clinical scenario.

Genetic Polymorphisms as Risk Stratification Tool in Primary Preventive ICD Therapy

More and more implantable cardioverter-defibrillators (ICDs) are implanted as primary prevention of sudden cardiac death (SCD). However, major problem in practice is to identify high-risk patients for SCD. Different methods for noninvasive risk stratification do not have a sufficient positive or negative predictive value. Since current approaches lead to implantation of ICDs in a large number of patients who will never suffer an arrhythmic event and simultaneously patients still die of SCD who currently did not seem eligible for primary preventive ICD implantation, there is a need for additional tools for risk stratification. Epidemiological studies point to a hereditary risk of SCD. Different susceptibility of each person concerning arrhythmogenic events might be explained by genetic polymorphisms. By obtaining an individual “pattern” of polymorphisms of genes encoding for proteins which are important in arrhythmogenesis in one patient, risk stratification in primary prevention of SCD might by improved.

Prognostic utility of NT-proBNP in acute exacerbations of chronic pulmonary diseases

BACKGROUND

The prognostic value of NT-proBNP levels in patients admitted to hospital due to acute exacerbations of chronic pulmonary diseases (CPDs) is unknown.

SETTING

Internal Medicine units at two general hospitals.

METHODS

NT-proBNP levels were obtained within 72 h after admission in 192 consecutive patients with acute exacerbations of CPDs and no history of heart failure or diuretic treatment. Clinical characteristics and main outcomes were assessed over a 12-month follow-up. NT-proBNP cut-points for outcomes were obtained by ROC (receiver operating characteristics) curve analysis.

RESULTS

Chronic obstructive lung disease (69.3%) and chronic asthma (22.4%) were the most prevalent CPDs, and non-pneumonic acute respiratory infection (72.4%) and pneumonia (22.9%) were the most frequent causes of exacerbation. Atrial flutter or fibrillation rate was 11%. During the one-year follow-up period, 22 patients died, 42 were re-admitted, 46 received new long-term oxygen therapy, and 39 received new diuretic treatment. NT-proBNP values correlated with hospitalisation days. NT-proBNP values over 587.9 pg/ml were associated with significantly raised one-year mortality (OR=3.90; 95% IC 1.46-10.47; p=0.006) and over 782.2 pg/ml with cardio-pulmonary deaths (OR=6.38; 95% IC 1.91-21.3; p=0.002). That association persisted after adjustment for age, gender, creatinine levels and cardiac rhythm. NT-proBNP values over 628.7 pg/ml were associated with significantly higher probability of new diuretic treatment (OR=4.38; IC 95% 2.07-9.25; p<0.001). The negative predictive values for these cut-points ranged from 89% to 97%.

CONCLUSION

NT-proBNP levels below 587.9 pg/ml in patients with acute exacerbations of CPD were associated with favourable one-year outcomes.

Prediction of long-term survival in chronic heart failure by multiple biomarker assessment: a 15-year prospective follow-up study

BACKGROUND

In chronic heart failure (CHF), several plasma biomarkers identify subjects at risk of death over the midterm. However, their long-term predictive value in the context of other candidate predictors has never been assessed. This information may prove valuable in the management of a chronic disease with a long natural history, as CHF is today.

HYPOTHESIS

We aimed to assess the very-long-term prognostic power of a set of biomarkers to identify CHF patients at highest risk for all-cause mortality.

METHODS

A group of 106 consecutive outpatients with CHF (85 male and 21 female, median age 56 y) was followed for 15 years. Echocardiographic tracings and blood samples were collected at study entry to evaluate cardiac function, plasma atrial natriuretic peptide (ANP), aldosterone, and erythropoietin, and plasma renin activity. The relationships between biomarkers, clinical and echocardiographic variables, and mortality were assessed.

RESULTS

After 15 years, 86 of the 106 patients (81%) had died. Multivariate analysis showed that ANP was the best independent predictor of survival over several clinical, echocardiographic, and humoral variables (hazard ratio: 5.62, 95% confidence interval: 3.37-9.39, P < 0.001 for plasma levels < median value of 71 pg/mL). Plasma renin activity and erythropoietin provided prognostic information in univariate analysis, but lost their predictive power when adjusted for covariates.

CONCLUSIONS

The present study represents the longest available follow-up of patients with CHF evaluating the prognostic power of multiple biomarkers. It shows that a simple assessment of plasma ANP levels is the strongest long-term predictor of death in all stages of heart failure.

Profiling B-type natriuretic peptide in a stable heart failure population: a valuable adjunct to care

AIM

To examine the prognostic importance of absolute values and change in values of BNP in patients with stable heart failure (HF).

METHODS

Five-hundred and fifty-nine patients attending a disease management programme were categorized into tertiles of BNP (group 1; ≤ 95 pg/ml, group 2; 96-249 pg/ml and group 3; ≥ 250 pg/ml). A change in BNP between two stable visits was recorded. Patients were followed up for 1 year for death and a composite morbidity measure of HF hospitalization, all-cause hospitalization, unscheduled visits for clinical deterioration(UC) of HF using survival analysis.

RESULTS

The risk of the combined morbidity outcome increased with increasing tertiles of BNP (Log rank = 17.8 (2), p < 0.001). Furthermore, a 50 and 25% increase in BNP predicted morbidity in stable HF patients with an initial BNP > 200 pg/ml (p = 0.02) and > 450 pg/ml (p = 0.03), respectively.

CONCLUSION

In a stable community HF population, an elevated BNP or an increase in BNP predicts an adverse prognosis thereby potentially identifying a population in need of closer clinical follow-up.