NTproBNP levels can predict future events in non-severe AS, JAMA study.

Is non-severe aortic stenosis (AS) really as benign as we think? Recent studies have questioned the presumed low-risk status of patients with asymptomatic non-severe aortic stenosis (AS). This calls for a novel marker to risk stratify non-severe AS patients into those at high clinical risk and those at lower risk for disease progression.

In the recent issue of JAMA Cardiology, researchers Hadziselimovic et al have proposed a new risk marker for AS i.e. NT proBNP and have shown that NT-proBNP concentrations within the reference range at year 1 are associated with low clinical risk in patients with asymptomatic nonsevere AS. Conversely, an increased 1-year NT-proBNP level may be associated with high aortic valve events (AVE) rates.

Analysis of annual NT-proBNP concentrations in the multicenter, double-blind Simvastatin and Ezetimibe in Aortic Stenosis (SEAS) randomized clinical trial was performed. SEAS included 1873 patients with asymptomatic AS not requiring statin therapy with transaortic maximal flow velocity from 2.5 to 4.0 m/s and preserved ejection fraction.

Aortic valve events (AVEs), which are a composite of aortic valve replacement, cardiovascular death, or incident heart failure due to AS progression, were noted. Landmark analyses from year 1 examined the association of NT-proBNP concentrations with outcomes.

Adjusted NT-proBNP concentrations were normal in 77% patients with NT-proBNP values available at baseline and in 70.8% at year 1. During the next 2 years of follow-up, the AVE rates per 100 patient-years for normal vs increased adjusted NT-proBNP levels at year 1 were 1.39 vs 7.05 for patients with mild AS (P < .01), and 10.38 vs 26.20 for those with moderate AS (P < .01).

Corresponding all-cause mortality rates were 1.05 vs 4.17 for patients with mild AS (P < .01), and 1.60 vs 4.78 for those with moderate AS (P < .01).

The present study clarifies 2 fundamental notions regarding age- and sex-adjusted NT-proBNP level monitoring in patients with asymptomatic nonsevere AS. First, an increased NT-proBNP level at year 1, coupled with a 1.5-fold or greater increase from baseline, is associated with a substantial risk of subsequent AVEs. Second, a normal NT-proBNP level at year 1 is associated with a low incidence of AVEs and all-cause mortality over 2 subsequent years of follow-up.

Does this change our current practice?

"For patients with mild AS, a normal NT-proBNP level carries less than 5% AVE risk for at least 24 months, supporting the recommended 2- to 3-year interval for repeated echocardiography. The frequency of echocardiography may need to be individualized, however, for patients with mild AS with increased NT-proBNP levels, especially those with a 50% or greater increase during 1 year. Similar concerns relate to patients with moderate AS", note the authors.

Source: JAMA Cardiology: doi:10.1001/jamacardio.2021.5916