Measuring NT

Two peptides produced in the heart, called B-type natriuretic peptide (BNP) and N-terminal-pro hormone BNP, are commonly used cardiac health indicators. Research published on Wednesday in JAMA Cardiology indicates that measuring changes in NT-proBNP over time may improve risk stratification -- the process of assigning a risk status to heart patients to direct their care and improve health outcomes.

BNP is a hormone produced by the heart. N-terminal-pro hormone BNP (NT-proBNP) is a non-active prohormone -- an inactivated hormone precursor -- released from the same molecule that produces BNP. Both BNP and NT-proBNP are released in response to pressure changes inside the heart, which can be related to cardiac problems, including heart failure. Levels go up when heart failure develops or gets worse, and down when conditions are stable. BNP and NT-proBNP levels are often higher in patients with heart failure than in those with normal heart function.

Previous studies have primarily evaluated the prohormone NT-proBNP at a single point in time. Researchers sought to find out whether long-term NT-proBNP changes were associated with heart failure and death risk among middle-aged adults without prevalent heart failure.

Participants were recruited from four U.S. communities enrolled in the Atherosclerosis Risk in Community (ARIC) study. Individuals who attended ARIC visits 2 and 4 (approximately six years apart) with NT-proBNP measurements and without prevalent heart failure were included. Assays of NT-proBNP were conducted between 2011 and 2013, and analyzed between July 2021 and October 2022.

The primary exposure variable was NT-proBNP change between visits 2 and 4, modeled as change categories (<125 pg/mL or 125 pg/mL) and as percent change. The primary outcome measures were incident heart failure hospitalization and death. The association between changes in cardiovascular risk factors with changes in NT-proBNP was further assessed.

A total of 9,776 individuals (mean age 57.1 years at visit 2; 5,523 [56.5%] women) were included in this cohort study. Compared with participants with NT-proBNP levels less than 125 pg/mL at both visits, participants with NT-proBNP level of 125 pg/mL or higher at both visits had an increase in incident heart failure and mortality risk. Participants with NT-proBNP levels of 125 pg/mL or higher at visit 2 and less than 125 pg/mL at visit 4 had heart failure and death risk similar to the group with NT-proBNP levels of less than 125 pg/mL at both visits. Changes in systolic blood pressure, low-density lipoprotein cholesterol, triglyceride level, body mass index, and estimated glomerular filtration rate were significantly associated with NT-proBNP changes.

The researchers concluded that the six-year change in NT-proBNP reflected a dynamic change in risk for heart failure events and death among adults without prevalent clinical heart failure. Persistently elevated and significantly increasing levels were associated with higher risk, while decreased levels over time were associated with lower risk.

The researchers believe the results support the value of taking serial NT-proBNP measurements to improve risk stratification, identifying pre-heart failure patients who may benefit most from heart failure prevention efforts.