AHS Laboratory Services is pleased to announce that B-type natriuretic peptide (BNP) or N-terminal proBNP (NT-proBNP) testing will be implemented in hospital laboratories across the province in early 2012. Emergency Department Physicians and Cardiologists will be able to order BNP or NT-proBNP (depending on their local hospital lab) to assist with diagnosing and treating heart failure (HF).

What are BNP and NT-proBNP?

B-type natriuretic peptide (BNP) is a protein neurohormone that increases urinary excretion of water and sodium and relaxes blood vessels. The heart is the main source of BNP in humans.

Excessive stretching of the myocytes (heart muscle cells) in the ventricles, results in the release of pre-proBNP which is ultimately split into BNP (active neurohormone) and NT-proBNP (an inactive subunit.)

The levels of BNP and NT-proBNP are elevated in patients with left ventricular dysfunction. The levels correlate with both the severity of the symptoms and the patient’s prognosis in heart failure. Various studies have demonstrated that increased levels of these hormones are found in early stages of heart failure. The levels continue to increase as the disease progresses.

BNP and NT-proBNP levels are higher in patients with dyspnea (shortness of breath) due to heart failure than in patients with dyspnea from other causes. Therefore, blood testing in emergent situations supports the evaluation and treatment of patients with acute dyspnea, reducing time to treatment and discharge, and potentially reducing the overall cost of treatment.

Why Are Two Tests Being Introduced? Why Not Standardize?

Tests for both BNP and NT-proBNP are Health Canada approved, and are equally valuable and acceptable tests for diagnosing whether a patient’s dyspnea is caused by heart failure.

Laboratory Services considered standardizing to a single test, but also recognized the need to utilize existing resources most effectively. In many cases, labs are already equipped with the necessary analyzers to perform one of the two possible tests. We didn’t feel it would be a responsible use of scarce resources to purchase additional instruments unnecessarily. For this reason, each rural laboratory supporting an emergency department will be equipped to provide testing using one of the two approved methodologies.

BNP or NT-proBNP Implementation:

• B-type natriuretic peptide (BNP) or N-terminal proBNP (NT-proBNP) On-Site Availability and Test Utilization Criteria (February 29, 2012)
• Hospital Laboratories implementing BNP or NT-proBNP Testing
• Frequently Asked Questions

Implementation Schedule:

Education Resources:

• Lab Report: Biomarkers for Heart Failure, BNP and NT-proBNP, Coming to Town
• Use of BNP/NT-proBNP in the ER - Dr. Jonathan Howlett, University of Calgary (video presentation)
• Biomarkers for diagnosis and management of Heart Failure – Dr. Debra Isaac, University of Calgary - January 24, 2012 (powerpoint presentation)
• Canadian Cardiovascular Society
• Heart and Stroke Foundation of Alberta, NWT and Nunavut

Contact Information:

Questions and concerns regarding the BNP/NT-proBNP implementation may be directed to labclientservices@ahs.ca