NT-proBNP in Cardioembolic Stroke
Prahlad K Sethi1, R Rajeswari1, Nitin K Sethi2
1 Department of Neurology, Sir Ganga Ram Hospital, Rajinder Nagar, New Delhi, India
2 Department of Neurology, New York-Presbyterian Hospital, Weill Cornell Medical Center, New York, NY, United States of America
Correspondence Address:
Prahlad K Sethi
Professor of Neurology, Department of Neurology, Sir Ganga Ram Hospital, Rajinder Nagar, New Delhi - 110 060
India
Source of Support: None, Conflict of Interest: None
DOI: 10.4103/0028-3886.383842
Clinically, the cause for stroke cannot be determined in around 30–45% of cases even after extensive investigations.[1] The most common causes for the embolic stroke of undetermined source (ESUS) and cryptogenic stroke have been found to be cardiac embolism followed by vasculopathy and coagulopathy.[2] After ruling out structural causes by echocardiography, ECG/24-hour Holter monitoring is commonly used to evaluate cardioembolic stroke. The EMBRACE trial showed that 30-day outpatient event-triggered external loop recorder was superior to 24-hour Holter monitoring in detecting episodes of atrial fibrillation (AF) lasting ≥30 s (16.1% versus 3.2%; P < 0.001).[3] However, an extended loop recorder is neither practical nor feasible in all patients with acute ischemic stroke whose cause cannot be elucidated after routine initial stroke evaluation. Hence, there is a need for a biomarker which can predict the possibility of cardioembolism as the cause of the stroke. A reliable biomarker shall also aid in identifying the target population in whom extended cardiac monitoring with a loop recorded shall have the highest yield. N-terminal pro b-type natriuretic peptide (NT-proBNP) also referred to as brain natriuretic peptide is a small peptide (protein) produced in the heart and serves as a biomarker for cardiac function. It increases during atrial fibrillation, heart failure, left ventricular dysfunction, and acute coronary syndrome and is valuable in the diagnoses and prognosis of these patients.[4],[5] Given the link between cardiac dysfunction and stroke, NT-proBNP has the potential to serve as a biomarker for stroke risk and etiology. In the ARIC study (atherosclerosis risk in communities study), NT-proBNP was found to be associated with total stroke, non-lacunar ischemic, and especially cardioembolic stroke but not with lacunar or hemorrhagic stroke.[6] In a case-cohort study derived from the REGARDS cohort (reasons for geographic and racial differences in stroke), the authors confirmed that the association of NT-proBNP with stroke was greatest for cardioembolic stroke.[7]
In the present study, the authors studied levels of NT-proBNP in acute ischemic stroke (AIS) and correlated it in patients who had no evidence of AF (sinus rhythm group), paroxysmal AF (pAF), and chronic AF (cAF). NT-proBNP levels were significantly higher in the cardioembolic group as compared to the large artery atherosclerosis group and small vessel disease group. In the cardioembolic group, a positive correlation was found between NT-proBNP level and 3-months modified Rankin score (mRS).
How useful NT-proBNP shall be as a biomarker for screening patients with suspected cardioembolic stroke is yet unclear until now. In patients with cryptogenic stroke, it may help in identifying patients in whom long-term ECG monitoring with a loop recorder may be well advised. Such patients would benefit from oral anticoagulation therapy for stroke prophylaxis as against the use of aspirin or clopidogrel. Furthermore, future well-designed studies should explore the sensitivity and specificity of this potential stroke biomarker.
Author contributions
PKS, RR, NKS conceived, drafted and revised the manuscript.
Data sharing statement
The authors have no additional data to share.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
References
Comments (0)