B-type natriuretic peptide: a strong predictor of early and late mortality in patients with acute chest pain without ST-segment elevation in the emergency department

Use of Preoperative Natriuretic Peptide in Predicting Mortality After Coronary Artery Bypass Grafting: A Systematic Review and Meta-analysis

The objective of this systematic review was to evaluate the current evidence on the utility of preoperative B-type natriuretic peptide (BNP) and N-terminal-pro B-type natriuretic peptide (NT-proBNP) in predicting short-term and long-term mortality after coronary artery bypass grafting (CABG). OVID MEDLINE, EMBASE, SCOPUS, and PUBMED were searched from 1946 to August 2022 using the following terms: "coronary artery bypass grafting" and "BNP" and "outcomes." Eligible studies included observational studies reporting the association between preoperative BNP and NT-proBNP levels and short- and long-term mortality after CABG. Articles were selected systematically, assessed for bias, and, when possible, meta-analyzed using a random effect model. After retrieving 53 articles, 11 were included for qualitative synthesis and 4 for quantitative meta-analysis. Studies included in this review showed that elevated preoperative natriuretic peptide levels, despite variable cut-offs, have been consistently shown to be associated with short- and long-term mortality after CABG. The median BNP cut-off value was 145.5 pg/mL (25th-75th percentile 95-324.25 pg/mL), and the mean NT-proBNP value was 765 ± 372 pg/mL. Compared to patients with normal natriuretic peptide levels, patients with elevated BNP and NT-proBNP presented higher mortality rates after CABG (odds ratio 3.96, 95% confidence interval 2.41-6.52; p < 0.00001). Preoperative BNP level is a powerful predictor of mortality in patients undergoing CABG. The measurement of BNP can add significant value to these patients' risk stratification and therapeutic decision-making.

NT-proBNP is associated with mortality and adverse cardiac events in patients with atrial fibrillation presenting to the emergency department

BACKGROUND

Atrial fibrillation (AF) is the most common cardiac arrhythmia in the emergency department. The CHA₂ DS₂ -VASc score helps to predict thromboembolic risk; however, the rate of other adverse cardiac events is more difficult to predict.

HYPOTHESIS

The biomarker N-terminal pro-brain natriuretic peptide (NT-proBNP) has prognostic value in patients presenting to the emergency department with AF.

METHODS

During a 1.5-year period, a prospective study was performed in consecutive patients presenting to the emergency department with AF on the presenting electrocardiogram. At baseline, NT-proBNP was measured. The primary endpoints were all-cause death and major adverse cardiac events (MACE: all-cause mortality, myocardial infarction, or revascularization).

RESULTS

A total of 355 patients were included (mean age, 71 years; 55% male). The median duration of follow-up was 2 years. After adjustment for baseline variables, the logNT-proBNP was independently correlated with death (hazard ratio [HR]: 1.54, 95% confidence interval [CI]: 1.18-1.99) and MACE (HR: 1.27, 95% CI: 1.03-1.58). After adjustment for baseline variables, a high NT-proBNP value (>500 pmol/L) was independently correlated with death (HR: 2.26, 95% CI: 1.19-4.28), and for MACE a trend was seen (HR: 1.67, 95% CI: 0.96-2.91) compared with a low value (<250 pmol/L).

CONCLUSIONS

In patients presenting to the emergency department with AF, higher NT-proBNP values are independently associated with an increased mortality and MACE. Therefore, this biomarker may be a useful prognostic marker in the management and treatment of these patients.

Novel Emergency Department Risk Score Discriminates Acute Coronary Syndrome Among Chest Pain Patients With Known Coronary Artery Disease

BACKGROUND

Patients with known coronary artery disease presenting to the emergency department (ED) with chest pain are often admitted, yet may not be having an acute coronary syndrome (ACS).

METHODS

We assessed whether the use of a novel risk score and a modified thrombolysis in myocardial infarction risk score obtained in the ED could discriminate which of these high-risk patients have ACS. Chart review was performed on a cohort of 285 patients with known coronary artery disease presenting to the ED with chest pain thought to be of ischemic origin and admitted to the hospital. The ED variables were assessed with logistic regression for their association with eventual ACS diagnosis at hospital discharge. ACS was diagnosed in 74 (26%) of the patients.

RESULTS

Non-ACS patients had a 2-day median length of stay and $6875 median inpatient (post ED) hospital charges (not including physician fees), totaling 566 hospital bed days and $1,871,250 for the 211 (74%) non-ACS patients. A novel risk score, including (1) history of prior revascularization, (2) comorbid chronic kidney disease, (3) onset of chest discomfort at rest, (4) dynamic electrocardiogram changes in the ED, (5) elevated troponin I (>0.05 ng/mL) in the ED, and (6) associated illness at presentation, discriminated ACS and non-ACS with a c statistic of 0.767; the c statistic for a modified thrombolysis in myocardial infarction risk score was 0.712.

CONCLUSIONS

Application of these risk scores may reduce the number of potentially avoidable admissions and their associated hazards and costs.

Very Long-Term Prognostic Role of Admission BNP in Non-ST Segment Elevation Acute Coronary Syndrome

Background

BNP has been extensively evaluated to determine short- and intermediate-term prognosis in patients with acute coronary syndrome, but its role in long-term mortality is not known.

Objective

To determine the very long-term prognostic role of B-type natriuretic peptide (BNP) for all-cause mortality in patients with non-ST segment elevation acute coronary syndrome (NSTEACS).

Methods

A cohort of 224 consecutive patients with NSTEACS, prospectively seen in the Emergency Department, had BNP measured on arrival to establish prognosis, and underwent a median 9.34-year follow-up for all-cause mortality.

Results

Unstable angina was diagnosed in 52.2%, and non-ST segment elevation myocardial infarction, in 47.8%. Median admission BNP was 81.9 pg/mL (IQ range = 22.2; 225) and mortality rate was correlated with increasing BNP quartiles: 14.3; 16.1; 48.2; and 73.2% (p < 0.0001). ROC curve disclosed 100 pg/mL as the best BNP cut-off value for mortality prediction (area under the curve = 0.789, 95% CI= 0.723-0.854), being a strong predictor of late mortality: BNP < 100 = 17.3% vs. BNP ≥ 100 = 65.0%, RR = 3.76 (95% CI = 2.49-5.63, p < 0.001). On logistic regression analysis, age >72 years (OR = 3.79, 95% CI = 1.62-8.86, p = 0.002), BNP ≥ 100 pg/mL (OR = 6.24, 95% CI = 2.95-13.23, p < 0.001) and estimated glomerular filtration rate (OR = 0.98, 95% CI = 0.97-0.99, p = 0.049) were independent late-mortality predictors.

Conclusions

BNP measured at hospital admission in patients with NSTEACS is a strong, independent predictor of very long-term all-cause mortality. This study allows raising the hypothesis that BNP should be measured in all patients with NSTEACS at the index event for long-term risk stratification.

INTERACTING DISCIPLINES: Cardiac natriuretic peptides and obesity: perspectives from an endocrinologist and a cardiologist

Since their discovery in 1981, the cardiac natriuretic peptides (cNP) atrial natriuretic peptide (also referred to as atrial natriuretic factor) and brain natriuretic peptide have been well characterised in terms of their renal and cardiovascular actions. In addition, it has been shown that cNP plasma levels are strong predictors of cardiovascular events and mortality in populations with no apparent heart disease as well as in patients with established cardiac pathology. cNP secretion from the heart is increased by humoral and mechanical stimuli. The clinical significance of cNP plasma levels has been shown to differ in obese and non-obese subjects. Recent lines of evidence suggest important metabolic effects of the cNP system, which has been shown to activate lipolysis, enhance lipid oxidation and mitochondrial respiration. Clinically, these properties lead to browning of white adipose tissue and to increased muscular oxidative capacity. In human association studies in patients without heart disease higher cNP concentrations were observed in lean, insulin-sensitive subjects. Highly elevated cNP levels are generally observed in patients with systolic heart failure or high blood pressure, while obese and type-2 diabetics display reduced cNP levels. Together, these observations suggest that the cNP system plays a role in the pathophysiology of metabolic vascular disease. Understanding this role should help define novel principles in the treatment of cardiometabolic disease.

Factors related to NT-proBNP levels in HIV patients aged over 40 years

Objective

To determine the levels of NT-pro BNP in HIV patients over 40 years who are receiving highly active antiretroviral therapy (HAART) and investigating potential independent clinical or laboratory factors.

Method

We determine levels of NT-pro BNP in peripheral blood of HIV patients from Costa del Sol Hospital, over 40 years.

We collected epidemiological, classical cardiovascular risk factors and variables associated with HIV infection status. The qualitative variables were compared using the χ2 test. NT-proBNP levels were taken as the dependent variable. The association between these levels and the quantitative variables were studied by analysis of variance (ANOVA), and the association with the qualitative variables, using Student’s t test.

Results

Nt-pro BNP levels were determined in 146 HIV patients. We assess the 10-year cardiovascular risk calculated by the Framingham equation, 59 (41.5%) were classified as low risk, 46 (32.4%) as a moderate risk and 37 (26.1%) as a high risk. The higher levels of NT-pro BNP were found in women, and in those patient with lower filtration rate and high levels of triglycerides. An association was also observed between higher levels of NT-proBNP and the recent use of lamivudine and fosamprenavir. After a multivariate analysis we found an association between higher levels of NT-proBNP and the current use of fosamprenavir and a lower glomerular filtration rate.

Conclusions

We found, with the limitations of a small serie, that higher levels of NTproBNP in HIV patients could be linked to the occurrence of cardiovascular events, this fact suggest that NTpro BNP could be used in patients at moderate or high vascular risk in order to optimise the primary prevention of vascular events.

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.

High BNP level as risk factor for acute kidney injury and predictor of all-cause mortality in STEMI patients

OBJECTIVES

The aim of this study was to evaluate the predictive value of brain natriuretic peptide (BNP) in the development of acute kidney injury (AKI) and 6-month all-cause mortality after primary percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction (STEMI) in a modest-risk population.

BACKGROUND

The prognostic value of BNP has been well documented in patients with acute coronary syndrome. However, its value in development of AKI and 6-month all-cause mortality in patients with STEMI undergoing primary PCI remains unclear.

METHODS

We prospectively enrolled 424 consecutive STEMI patients (mean age 53.6 ± 12.1 years) undergoing primary PCI. The population was divided into two groups: a high (n = 110) and a low (n = 314) admission BNP group according to the cut-off value (> 88.7 pg/ml) determined by ROC analysis to have the best predictive accuracy for 6-month all-cause mortality. The clinical characteristics as well as the in-hospital and 6-month outcomes of patients undergoing primary PCI were analyzed.

RESULTS

Cox multivariate analysis showed that a high-admission BNP value (> 88.7 pg/ml) was an independent predictor of AKI development (odds ratio, 1.002; 95 % confidence interval, 1.000–1.003; p = 0.02) and 6-month all-cause mortality (odds ratio, 1.003; 95 % confidence interval; 1.001–1.004; p = 0.004).

CONCLUSION

These results suggest that a high-admission BNP level is associated with an increased risk of AKI development and 6-month all-cause mortality in patients with STEMI undergoing primary PCI.

Brain natriuretic peptide predicts functional outcome in ischemic stroke

BACKGROUND AND PURPOSE

Elevated serum levels of brain natriuretic peptide (BNP) have been associated with cardioembolic stroke and increased poststroke mortality. We sought to determine whether BNP levels were associated with functional outcome after ischemic stroke.

METHODS

We measured BNP in consecutive patients aged ≥ 18 years admitted to our stroke unit between 2002 to 2005. BNP quintiles were used for analysis. Stroke subtypes were assigned using Trial of ORG 10172 in Acute Stroke Treatment criteria. Outcomes were measured as 6-month modified Rankin Scale score ("good outcome"=0-2 versus "poor") as well as mortality. Multivariate logistic regression was used to assess association between the quintiles of BNP and outcomes. Predictive performance of BNP as compared with clinical model alone was assessed by comparing receiver operating characteristic curves.

RESULTS

Of 569 patients with ischemic stroke, 46% were female; mean age was 67.9 ± 15 years. In age- and gender-adjusted analysis, elevated BNP was associated with lower ejection fraction (P<0.0001) and left atrial dilatation (P<0.001). In multivariate analysis, elevated BNP decreased the odds of good functional outcome (OR, 0.64; 95% CI, 0.41-0.98) and increased the odds of death (OR, 1.75; 95% CI, 1.36-2.24) in these patients. Addition of BNP to multivariate models increased their predictive performance for functional outcome (P=0.013) and mortality (P<0.03) after cardioembolic stroke.

CONCLUSIONS

Serum BNP levels are strongly associated with cardioembolic stroke and functional outcome at 6 months after ischemic stroke. Inclusion of BNP improved prediction of mortality in patients with cardioembolic stroke.

BNP and admission glucose as in-hospital mortality predictors in non-ST elevation myocardial infarction

OBJECTIVES

Admission hyperglycemia and B-type natriuretic peptide (BNP) are associated with mortality in acute coronary syndromes, but no study compares their prediction in-hospital death.

METHODS

Patients with non-ST-elevation myocardial infarction (NSTEMI), in-hospital mortality and two-year mortality or readmission were compared for area under the curve (AUC), sensitivity (SEN), specificity (SPE), positive predictive value (PPV), negative predictive value (NPV), and accuracy (ACC) of glycemia and BNP.

RESULTS

Respectively, AUC, SEN, SPE, PPV, NPV, and ACC for prediction of in-hospital mortality were 0.815, 71.4%, 84.3%, 26.3%, 97.4%, and 83.3% for glycemia = 200 mg/dL and 0.748, 71.4%, 68.5%, 15.2%, 96.8% and 68.7% for BNP = 300 pg/mL. AUC of glycemia was similar to BNP (P = 0.411). In multivariate analysis we found glycemia ≥200mg/dL related to in-hospital death (P = 0.004). No difference was found in two-year mortality or readmission in BNP or hyperglycemic subgroups.

CONCLUSION

Hyperglycemia was an independent risk factor for in-hospital mortality in NSTEMI and had a good ROC curve level. Hyperglycemia and BNP, although poor in-hospital predictors of unfavorable events, were independent risk factors for death or length of stay >10 days. No relation was found between hyperglycemia or BNP and long-term events.

Prognostic value of N-terminal pro-B-type natriuretic peptide in patients with acute coronary syndromes undergoing left main percutaneous coronary intervention

BACKGROUND

Patients undergoing acute left main (LM) coronary artery revascularization have a high mortality and natriuretic peptides such as N-terminal pro-B-type (NT-proBNP) have been shown to have prognostic value in patients with acute coronary syndromes. The present study looked at the prognostic value of NT-proBNP in these patients.

METHODS AND RESULTS

We studied all consecutive patients undergoing acute LM coronary artery percutaneous coronary intervention between January 2005 and December 2008 in whom NT-proBNP was measured (n=71). We analyzed the clinical characteristics and the short- and long-term outcomes in relation to NT-proBNP level at admission. Median NT-proBNP was 1,364 ng/L, ranging from 46 to 70,000 ng/L. NT-proBNP was elevated in 63 (89%) patients and was ≥1,000ng/L in 42 (59%). Log NT-proBNP (hazard ratio [HR] 3.51, 95% confidence interval [CI] 1.55-7.97, P=0.003) and left ventricular ejection fraction (HR 0.95, 95%CI 0.91-0.99, P=0.007) were predictors for all-cause mortality. Log NT-proBNP was the only independent significant predictor of cardiovascular mortality. In-hospital mortality was 0% for patients with NT-proBNP <1,000, but 17% for those with NT-proBNP ≥1,000 (P=0.036).

CONCLUSIONS

NT-proBNP is a strong predictor of outcome in patients undergoing acute LM coronary artery stenting. Mortality in such patients is high, but those with NT-proBNP < 1,000ng/L may have a favorable short- and long-term prognosis. Further research, including a larger patient population, is needed to determine the optimal cut-off value for NT-proBNP in patients undergoing acute LM coronary artery intervention.

Increased peak postoperative B-type natriuretic peptide predicts decreased longer-term physical function after primary coronary artery bypass graft surgery

BACKGROUND

Increased peak postoperative B-type natriuretic peptide (BNP) is associated with increased major adverse cardiovascular events and all-cause mortality after coronary artery bypass graft (CABG) surgery. Whether increased postoperative BNP predicts worse postdischarge physical function (PF) is unknown. We hypothesized that peak postoperative BNP associates with PF assessed up to 2 yr after CABG surgery, even after adjusting for clinical risk factors. including preoperative PF.

METHODS

This two-institution prospective cohort study included patients undergoing primary CABG surgery with cardiopulmonary bypass. Short Form-36 questionnaires were administered to subjects preoperatively and 6 months, 1 yr, and 2 yr postoperatively. Short Form-36 PF domain scores were calculated using the Short Form-36 norm-based scoring algorithm. Plasma BNP concentrations measured preoperatively and on postoperative days 1-5 were log(10) transformed before analysis. To determine whether peak postoperative BNP independently predicts PF scores 6 months through 2 yr after CABG surgery, multivariable longitudinal regression analysis of the postoperative PF scores was performed, adjusting for important clinical risk factors.

RESULTS

A total of 845 subjects (mean ± SD age, 65 ± 10 yr) were analyzed. Peak postoperative BNP was significantly associated with postoperative PF (effect estimate for log(10) peak BNP, -7.66 PF score points [95% CI, -9.68 to -5.64]; P = <0.0001). After multivariable adjustments, peak postoperative BNP remained independently associated with postoperative PF (effect estimate for log(10) peak BNP, -3.06 PF score points [95% CI, -5.15 to -0.97]; P = 0.004).

CONCLUSIONS

Increased peak postoperative BNP independently associates with worse longer-term PF after primary CABG surgery. Future studies are needed to determine whether medical management targeted toward reducing increased postoperative BNP can improve PF after CABG surgery.

B-type natriuretic peptide in the early diagnosis and risk stratification of acute chest pain

BACKGROUND

Myocardial ischemia is a strong trigger of B-type natriuretic peptide (BNP) release. As ischemia precedes necrosis in acute myocardial infarction, we hypothesized that BNP might be useful in the early diagnosis and risk stratification of patients with acute chest pain.

METHODS

In a prospective, international multicenter study, BNP was measured in 1075 unselected patients with acute chest pain. The final diagnosis was adjudicated by 2 independent cardiologists. Patients were followed long term regarding mortality.

RESULTS

Acute myocardial infarction was the adjudicated final diagnosis in 168 patients (16%). BNP levels at presentation were significantly higher in acute myocardial infarction as compared with patients with other diagnoses (median 224 pg/mL vs. 56 pg/mL, P <.001). The diagnostic accuracy of BNP for the diagnosis of acute myocardial infarction as quantified by the area under the receiver operating characteristic curve (AUC) (0.74; 95% confidence interval [CI], 0.70-0.78) was lower compared with cardiac troponin T at presentation (AUC 0.88; 95% CI, 0.84-0.92; P <.001). Cumulative 24-month mortality rates were 0.5% in the first, 2.1% in the second, 7.0% in the third, and 22.9% in the fourth quartile of BNP (P <.001). BNP predicted all-cause mortality independently of and more accurately than cardiac troponin T: AUC 0.81 (95% CI, 0.76-0.86) versus AUC 0.70 (95% CI, 0.62-0.77; P <.001). Net reclassification improvement for BNP was 0.10 (P=.04), and integrated discrimination improvement 0.068 (P=.01).

CONCLUSIONS

BNP accurately predicts mortality in unselected patients with acute chest pain independently of and more accurately than cardiac troponin T, but does not seem to help in the early diagnosis of acute myocardial infarction.

Biochemical markers in acute coronary syndrome

Owing to their higher risk for cardiac death or ischemic complications, patients with acute coronary syndrome (ACS) must be identified from other causes of chest pain. Patients with acute coronary syndrome are divided into categories based on their electrocardiogram; those with new ST-segment elevation and those who present with ST-segment depression. The subgroups of patients with ST-segment elevation are candidates for immediate reperfusion, while fibrinolysis appears harmful for those with non-ST elevation myocardial infarction. There is increasing evidence to encourage appropriate risk stratification before deciding on a management strategy (invasive or conservative) for each patient. The TIMI, GRACE or PURSUIT risk models are recommended as useful for decisions regarding therapeutic options. Cardiac biomarkers are useful additions to these clinical tools to correctly risk stratify ACS patients. Cardiac troponin is the biomarker of choice to detect myocardial necrosis and is central to the universal definition of myocardial infarction. The introduction of troponin assays with a lower limit of detection will allow for earlier diagnosis of patients who present with chest pain. Analytical and clinical validations of these new assays are currently in progress. The question is whether the lower detection limit of the troponin assays will be able to indicate myocardial ischemia in the absence of myocardial necrosis. Previous to the development of ultrasensitive cardiac troponin assays free fatty acids unbound to albumin and ischemia modified albumin were proposed as biochemical markers of ischemia. Advances in our knowledge of the pathogenesis of acute coronary thrombosis have stimulated the development of new biomarkers. Markers of left ventricular performance (N-terminal pro-brain natriuretic peptide) and inflammation (e.g. C-reactive protein) are generally recognized as risk indicators. Studies suggest that using a number of biomarkers clinicians can risk stratify patients over a broad range of short and long term cardiac events. Nevertheless, it is still under debate as to which biomarker combination is best preferred for risk prediction. This review will focus on recent practice guidelines for the management of patients with ACS as well as current advances in cardiac biomarkers, their integration into clinical care and their diagnostic, prognostic and therapeutic utility.

N-terminal-proB-type natriuretic peptide predicts cardiovascular disease events in HIV-infected patients

BACKGROUND

Cardiovascular disease (CVD) is increasing in HIV-infected patients. N-terminal pro-B-type natriuretic peptide (NT-proBNP) is a significant predictor of CVD in the general population. We aimed to quantify the risk of CVD events associated with NT-proBNP at baseline in the Strategies for Management of Anti-Retroviral Therapy study.

METHODS

In a nested case-control study, NT-proBNP was measured at baseline in 186 patients who experienced a CVD event over an average of 2.8 years of follow-up and in 329 matched controls. Odds ratios (ORs) associated with baseline levels of NT-proBNP for CVD were estimated using conditional logistic regression.

RESULTS

At baseline median NT-proBNP [interquartile range (IQR)] was 48.1 (18.5, 112.9) pg/ml in patients who developed a CVD event and 25.7 (12.4, 50.2) pg/ml in controls. The unadjusted OR for the highest versus the lowest quartile was 3.7 [95% confidence interval (CI) 2.1-6.5, P < 0.0001]. After adjustment for baseline covariates and CVD risk factors, OR was 2.8 (95% CI 1.4-5.6, P = 0.003); with additional adjustment for IL-6, high-sensitivity C-reactive protein and D-dimer, OR was 2.3 (95% CI 1.1-4.9, P = 0.02).

CONCLUSIONS

Higher levels of NT-proBNP are associated with increased risk of CVD in HIV patients after considering established CVD risk factors and markers for inflammation and thrombosis.

Comparison of the utility of preoperative versus postoperative B-type natriuretic peptide for predicting hospital length of stay and mortality after primary coronary artery bypass grafting

BACKGROUND

Preoperative B-type natriuretic peptide (BNP) is known to predict adverse outcomes after cardiac surgery. The value of postoperative BNP for predicting adverse outcomes is less well delineated. The authors hypothesized that peak postoperative plasma BNP (measured postoperative days 1-5) predicts hospital length of stay (HLOS) and mortality in patients undergoing primary coronary artery bypass grafting, even after adjusting for preoperative BNP and perioperative clinical risk factors.

METHODS

This study is a prospective longitudinal study of 1,183 patients undergoing primary coronary artery bypass grafting surgery. Mortality was defined as all-cause death within 5 yr after surgery. Cox proportional hazards analyses were conducted to separately evaluate the associations between peak postoperative BNP and HLOS and mortality. Multivariable adjustments were made for patient demographics, preoperative BNP concentration, and clinical risk factors. BNP measurements were log10 transformed before analysis.

RESULTS

One hundred fifteen deaths (9.7%) occurred in the cohort (mean follow-up = 4.3 yr, range = 2.38-5.0 yr). After multivariable adjustment for preoperative BNP and clinical covariates, peak postoperative BNP predicted HLOS (hazard ratio [HR] = 1.28, 95% CI = 1.002-1.64, P = 0.049) but not mortality (HR = 1.62, CI = 0.71-3.68, P = 0.25), whereas preoperative BNP independently predicted HLOS (HR = 1.09, CI = 1.01-1.18, P = 0.03) and approached being an independent predictor of mortality (HR = 1.36, CI = 0.96-1.94, P = 0.08). When preoperative and peak postoperative BNP were separately adjusted for within the clinical multivariable models, each independently predicted HLOS (preoperative BNP HR = 1.13, CI = 1.05-1.21, P = 0.0007; peak postoperative BNP HR = 1.44, CI = 1.15-1.81, P = 0.001) and mortality (preoperative BNP HR = 1.50, CI = 1.09-2.07, P = 0.01; peak postoperative BNP HR = 2.29, CI = 1.11-4.73, P = 0.02).

CONCLUSIONS

Preoperative BNP may be better than peak postoperative BNP for predicting HLOS and longer term mortality after primary coronary artery bypass grafting surgery.