Plasma Brain Natriuretic Peptide Levels Indicating Thromboembolism in Very Elderly Patients With Non-Valvular Atrial Fibrillation

Relationship between Brain Natriuretic Peptide and Thromboembolic Events in Elderly Patients with Nonvalvular Atrial Fibrillation

Objective

To investigate the relationship between brain natriuretic peptide (BNP) and thromboembolic events in elderly patients with nonvalvular atrial fibrillation (NVAF).

Methods

This is a prospective cohort study, and based on the inclusion and exclusion criteria, 180 elderly patients with NVAF were included. The patients received follow-up appointments in the clinic or by telephone every 6 months after the beginning of the study. The primary follow-up endpoints were thromboembolic and atherosclerotic events, including ischaemic stroke, myocardial infarction, and systemic embolism. The secondary endpoints were adverse events, including cardiovascular death, all-cause death, and hospitalisation for heart failure. Patients were divided into three groups according to their BNP level at admission: group A (BNP ≤334.5 pg/mL), group B (BNP = 334.5-1,288 pg/mL), and group C (BNP ≥1,288 pg/mL).

Results

A total of 180 patients were enrolled in this study, with 50 patients in group A, 68 in group B, and 62 in group C. Compared with groups A and B, group C had a higher CHA2DS2-VASc score (Z = 15.142; P=0.001) and a lower ejection fraction (EF) value (Z = 119.893; P=0.001). The left atrium (LA) and left ventricular end-diastolic diameter (LVEDD) were larger (Z = 105.031; P=0.001 and Z = 74.430; P=0.001), respectively, suggesting that patients with significantly increased BNP had a higher risk of thromboembolism and atherosclerosis, lower EF, larger LA and LVEDD, and worse cardiac function. After 1 year of follow-up, the incidence of primary endpoint events (χ2 = 9.556; P=0.008) and secondary endpoint events (χ2 = 59.485; P=0.001) in group C were higher than those in groups A and B.

Conclusion

Higher BNP levels may be an independent risk factor for thromboembolic and atherosclerotic events in elderly patients with NVAF. The higher the BNP level, the greater the risk of thromboembolic and atherosclerotic events.

Predictors for reduced flow velocity in left atrial appendage during sinus rhythm in patients with atrial fibrillation

Discontinuation of anticoagulation therapy after catheter ablation (CA) for atrial fibrillation (AF) remains controversial. While decreased left atrial appendage flow velocity (LAAFV) during AF leads to left atrial appendage thrombus and embolic events, some AF patients show decreased LAAFV even during sinus rhythm (SR). We studied 392 patients (256 males, 68 ± 10 years) who exhibited SR during transesophageal echocardiography (TEE) before CA for AF. Clinical factors, transthoracic echocardiography, and blood samples were obtained before TEE. Reduced LAAFV was defined as < 35 cm/s of LAAFV. Reduced LAAFV was observed in 72/392 patients (18%). Reduced LAAFV was significantly associated with high prevalence of non-paroxysmal AF, elevated brain natriuretic peptide (BNP), prior heart failure, high CHADS₂ score, high CHA₂DS₂-VASc score, no beta blocker administration, increased left atrial volume index (LAVI), elevated E/e' ratio, reduced left ventricular ejection fraction and high prevalence of left ventricular hypertrophy. On multivariate analysis, BNP (P = 0.0005, OR 1.045 for each 10 pg/ml increase in BNP, 95% CI 1.018-1.073) and LAVI (P = 0.0045, OR 1.044 for each 1 increase in LAVI, 95% CI 1.013-1.077) were associated with decreased LAAFV. The elevated BNP levels and large LAVI predict decreased LAAFV during SR in patients with AF.

Correlation between plasma brain natriuretic peptide levels and left atrial appendage flow velocity in patients with non-valvular atrial fibrillation and normal left ventricular systolic function

BACKGROUND

The left atrial appendage (LAA) flow velocity is an important factor for thrombus formation in patients with non-valvular atrial fibrillation (NV-AF). Recently, the relation of plasma brain natriuretic peptide (BNP) levels and thromboembolism has been reported in patients with NV-AF. The aim of this study was to determine whether the plasma BNP is predictive of lower LAA flow velocity in patients with NV-AF and normal left ventricular (LV) systolic function.

METHODS AND RESULTS

A total of 184 patients with NV-AF (132 men; 65 ± 12 years, LV ejection fraction; 65 ± 10%) underwent transthoracic echocardiography, transesophageal echocardiography (TEE), and measurement of plasma BNP. The LAA flow velocity was obtained by pulsed Doppler TEE. Multivariate logistic regression analysis demonstrated that plasma BNP levels, left atrial volume index (LAVI), LV mass index (LVMI), and the CHADS₂ score were independent predictors of lower LAA flow velocity (< 20 cm/s). Plasma BNP levels (r = - 0.58, p < 0.001) were correlated with LAA flow velocity. The area under the curve (AUC) for BNP (AUC 0.803) was larger than that for the CHADS₂ score (AUC 0.712), LAVI (AUC 0.664) and LVMI (AUC 0.608) with an optimal BNP cut-off value of 164 pg/ml (sensitivity 75.7%, specificity 71.1%).

CONCLUSIONS

This study showed that a higher plasma BNP was associated with a lower LAA flow velocity in patients with NV-AF and normal LV systolic function. The plasma BNP may complement the role of the CHADS₂ score in predicting lower LAA flow velocity.

Usefulness of brain natriuretic peptide for predicting left atrial appendage thrombus in patients with unanticoagulated nonvalvular persistent atrial fibrillation

BACKGROUND

The CHADS2 scoring system is simple and widely accepted for predicting thromboembolism in patients with nonvalvular atrial fibrillation (NVAF). Although congestive heart failure (CHF) is a component of the CHADS2 score, the definition of CHF remains unclear. We previously reported that the presence of CHF was a strong predictor of left atrial appendage (LAA) thrombus. Therefore, the present study aimed to elucidate the relationship between LAA thrombus and the brain natriuretic peptide (BNP) level in patients with unanticoagulated NVAF.

METHODS

The study included 524 consecutive patients with NVAF who had undergone transesophageal echocardiography to detect intracardiac thrombus before cardioversion between January 2006 and December 2008, at Hiroshima City Asa Hospital. The exclusion criteria were as follows: paroxysmal atrial fibrillation, unknown BNP levels, prothrombin time international normalized ratio ≥2.0, and hospitalization for systemic thromboembolism.

RESULTS

Receiver operating characteristic analysis yielded optimal plasma BNP cut-off levels of 157.1 pg/mL (area under the curve, 0.91; p<0.01) and 251.2 pg/mL (area under the curve, 0.70; p<0.01) for identifying CHF and detecting LAA thrombus, respectively. Multivariate analyses demonstrated that a BNP level >251.2 pg/mL was an independent predictor of LAA thrombus (odds ratio, 3.51; 95% confidence interval, 1.08-10.7; p=0.046).

CONCLUSIONS

In patients with unanticoagulated NVAF, a BNP level >251.2 pg/mL may be helpful for predicting the incidence of LAA thrombus and may be used as a surrogate marker of CHF. The BNP level is clinically useful for the risk stratification of systemic thromboembolism in patients with unanticoagulated NVAF.

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

BACKGROUND

Patients hospitalized with heart failure (HF) have elevated B-type natriuretic peptide (BNP) levels and increased risk for thromboembolic events. Associations between BNP level and thromboembolic events in patients with HF without atrial fibrillation (AF) are not well studied.

METHODS

We linked data from the ADHERE registry for 2003 through 2006 with Medicare claims to identify patients ≥65 years who were hospitalized with HF, did not have AF, and did not receive warfarin at discharge. We estimated rates of all-cause mortality, thromboembolic events, myocardial infarction (MI), and stroke using Kaplan-Meier methods and the cumulative incidence function. We used Cox models to assess associations between log BNP level and each outcome after adjustment for potential confounders.

RESULTS

The study population included 11,679 patients from 146 sites. Patients in the highest quartile of BNP level were older and more often male and African American. They had higher rates of coronary artery disease, renal insufficiency, and peripheral vascular disease and lower rates of diabetes mellitus and chronic obstructive pulmonary disease. After multivariable adjustment, each 30% increase in BNP level was associated with increased risks of death (hazard ratio 1.07, 95% CI 1.05-1.08) and MI (1.07, 1.04-1.10) but not thromboembolism or stroke.

CONCLUSION

Higher BNP level upon admission with HF among older patients without AF was associated with increased risks of MI and mortality; however, higher BNP level was not associated with subsequent thromboembolism or stroke.

Relation of hs-CRP and BNP levels with the atrial spontaneous echo contrast and thrombi in permanent atrial fibrillation patients with different etiologies

Background

Thromboembolic risk in permanent atrial fibrillation (AF) is strongly associated with the underlying etiology, and inflammatory parameters may contribute. The present study aimed to investigate the relationship of hs-CRP and BNP levels with left and right atrial appendage (LAA and RAA) function, presence of spontaneous echo contrast (SEC) and thrombus.

Material/Methods

Eighty-four permanent AF patients with different etiologies (20 mitral stenosis, 44 hypertension and 20 hyperthyroidism) and 23 patients with sinus rhythm were included. LAA and RAA flow velocities were measured by pulsed-wave Doppler and wall motion velocities with tissue Doppler imaging (TDI) in transesophageal echocardiography.

Results

Hs-CRP and BNP levels significantly differed among the 3 AF groups: levels were highest in mitral stenosis patients (8.6±5.3 mg/L and 98.0±125.7 pg/mL, respectively), the lowest hs-CRP was in hyperthyroidism patients (4.3±3.8 mg/L), and the lowest BNP was in hypertensive patients (64.8±44.3 pg/mL). There were also significant differences between the AF group and controls regarding hs-CRP and BNP levels. In the correlation analysis, BNP level was not significantly correlated with LAA and RAA functions, whereas hs-CRP level was significantly correlated with some LAA and RAA functions. On the other hand, hs-CRP level was significantly related to the presence of mild-moderate SEC and thrombi, mainly in mitral stenosis patients. Moreover, hs-CRP was the most important determinant of RAA thrombus formation, followed by RAA ejection fraction. In contrast, no positive or negative correlation was found between BNP levels and RAA and LAA thrombi.

Conclusions

Higher hs-CRP levels in AF patients may be a predictor for the presence of SEC and thrombi in the atria.

A clinical prediction model to estimate risk for 30-day adverse events in emergency department patients with symptomatic atrial fibrillation

STUDY OBJECTIVE

Atrial fibrillation affects more than 2 million people in the United States and accounts for nearly 1% of emergency department (ED) visits. Physicians have little information to guide risk stratification of patients with symptomatic atrial fibrillation and admit more than 65%. Our aim is to assess whether data available in the ED management of symptomatic atrial fibrillation can estimate a patient's risk of experiencing a 30-day adverse event.

METHODS

We systematically reviewed the electronic medical records of all ED patients presenting with symptomatic atrial fibrillation between August 2005 and July 2008. Predefined adverse outcomes included 30-day ED return visit, unscheduled hospitalization, cardiovascular complication, or death. We performed multivariable logistic regression to identify predictors of 30-day adverse events. The model was validated with 300 bootstrap replications.

RESULTS

During the 3-year study period, 914 patients accounted for 1,228 ED visits. Eighty patients were excluded for non-atrial-fibrillation-related complaints and 2 patients had no follow-up recorded. Of 832 eligible patients, 216 (25.9%) experienced at least 1 of the 30-day adverse events. Increasing age (odds ratio [OR] 1.20 per decade; 95% confidence interval [CI] 1.06 to 1.36 per decade), complaint of dyspnea (OR 1.57; 95% CI 1.12 to 2.20), smokers (OR 2.35; 95% CI 1.47 to 3.76), inadequate ventricular rate control (OR 1.58; 95% CI 1.13 to 2.21), and patients receiving β-blockers (OR 1.44; 95% CI 1.02 to 2.04) were independently associated with higher risk for adverse events. C-index was 0.67.

CONCLUSION

In ED patients with symptomatic atrial fibrillation, increased age, inadequate ED ventricular rate control, dyspnea, smoking, and β-blocker treatment were associated with an increased risk of a 30-day adverse event.

Impact of atrial fibrillation on NT-proBNP levels in a 75-year-old population

OBJECTIVE

The objective of this study was to investigate the impact of atrial fibrillation (AF) on serum levels of N-terminal fragment of pro-brain natriuretic peptide (NT-proBNP) in a 75-year-old population.

METHODS

All 75-year-old citizens in Asker and Baerum counties in Norway were invited to participate in a prevalence study of AF. Blood samples for measurement of NT-proBNP were collected at rest from 61 subjects with AF and a gender-matched control group of 126 subjects in sinus rhythm. NT-proBNP was measured in serum using the Elecsys proBNP sandwich immunoassay (Roche Diagnostics, Basel, Switzerland).

RESULTS

Subjects with permanent AF had higher levels of NT-proBNP (median 1119 pg/mL (interquartile range 701, 1643)) than subjects with paroxysmal AF (257 pg/mL (169, 382)) and controls (95 pg/mL (60, 171)), p<0.001 for both.The presence of AF was still significantly associated with higher log NT-proBNP (B=0.61, p<0.001) after adjusting for the presence of heart failure, coronary heart disease and hypertension.

CONCLUSION

In this stable, out-of-hospital population of 75-year-old subjects, AF was independently associated with increased levels of NT-proBNP. Permanent AF was associated with higher NT-proBNP levels than paroxysmal AF.