Natriuretic peptides for the detection of paroxysmal atrial fibrillation in patients with cerebral ischemia--the Find-AF study.

BACKGROUND AND PURPOSE: Diagnosis of paroxysmal atrial fibrillation (AF) can be challenging, but it is highly relevant in patients presenting with sinus rhythm and acute cerebral ischemia. We aimed to evaluate prospectively whether natriuretic peptide levels and kinetics identify patients with paroxysmal AF. METHODS: Patients with acute cerebral ischemia were included into the prospective observational Find-AF study. N-terminal pro brain-type natriuretic peptide (NT-proBNP), brain-type natriuretic peptide (BNP) and N-terminal pro atrial-type natriuretic peptide (NT-proANP) plasma levels were measured on admission, after 6 and 24 hours. Patients free from AF at presentation received 7 day Holter monitoring. We prospectively hypothesized that patients presenting in sinus rhythm with NT-proBNP>median were more likely to have paroxysmal AF than patients with NT-proBNP<median. RESULTS: 281 patients were included, of whom 237 (84.3%) presented in sinus rhythm. 220 patients naïve to AF with an evaluable prolonged Holter ECG were analysed. In patients with NT-proBNP>median (239 pg/ml), 17.9% had paroxysmal AF in contrast to 7.4% with NT-proBNP<239 pg/ml (p = 0.025). The ratio of early (0 h) to late (24 h) plasma levels of NT-proBNP showed no difference between both groups. For the detection of paroxysmal atrial fibrillation, BNP, NT-proBNP and NT-proANP at admission had an area under the curve in ROC analysis of 0.747 (0.663-0.831), 0.638 (0.531-0.744) and 0.663 (0.566-0.761), respectively. In multivariate analysis, BNP was the only biomarker to be independently predictive for paroxysmal atrial fibrillation. CONCLUSIONS: BNP is independently predictive of paroxysmal AF detected by prolonged ECG monitoring in patients with cerebral ischemia and may be used to effectively select patients for prolonged Holter monitoring

NT-proBNP and NT-proBNP ratio and paroxysmal atrial fibrillation.

<p>Left panel: Percentage of study participants with paroxysmal atrial fibrillation on Holter monitoring in the two sub-groups of patients with NT-proBNP plasma levels below and above the median NT-proBNP plasma level (239 pg/ml). Right panel: Percentage of study participants with paroxysmal atrial fibrillation below and above the median ratio of early (0 h) to late (24 h) NT-proBNP plasma level (0.78).</p

Natriuretic peptides plasma levels at three different timepoints and the ratio of early (0 h) to late (24 h) natriuretic peptide level.

<p>All data are displayed as median (25%–75% percentile). Data are compared by Mann-Whitney-U-Test.</p

Test characteristics for different BNP cut-offs and corresponding sensitivity, specificity, positive and negative predictive values and the number of patients needing Holter.

<p>PPV: Positive predictive value. NPV: Negative predictive value.</p>*<p>denotes the Youden point.</p

Study flow of the Find-AF trial. 281 patients were included, 237 had sinus rhythm on the admission ECG.

<p>1 patient withdrew consent, 16 patients were excluded from the analysis for different reasons, given a total of 220 study participants analysed.</p

Diagnostic properties of natriuretic peptide levels for detecting paroxysmal atrial fibrillation.

<p>Upper panel: Receiver operating characteristic curve for NT-proBNP plasma levels in the detection of paroxysmal atrial fibrillation. The arrow indicates the Youden-point, which was a NT-proBNP plasma level of 210 pg/ml. Middle panel: Receiver operating characteristic curve for BNP plasma levels in the detection of paroxysmal atrial fibrillation. The arrow indicates the Youden-point, which was a BNP plasma level of 118 pg/ml. Lower panel: Receiver operating characteristic curve for NT-proANP plasma levels in the detection of paroxysmal atrial fibrillation. The arrow indicates the Youden-point, which was a NT-proANP plasma level of 99,500 pg/ml.</p

Patient characteristics.

†<p>Minor stroke resolved completely within 30 days or change in NIH stroke scale by 3 points; major stroke neurologic deficit persisted after 30 days and increased NIH stroke scale by 3 points.</p><p>ARB: Angiotensin receptor blocker.</p