Role of BNP in patients with severe asymptomatic aortic stenosis

Abstract

This editorial refers to Predictors of outcome in patients with severe aortic stenosis and normal left ventricular function: role of B-type natriuretic † by P. Lim et al. on page 2048 Senile degenerative valvular aortic stenosis affects approximately 2% of the population over the age of 65. Aortic stenosis impedes left ventricular emptying and increases left ventricular wall stress, which leads to elevation of brain natriuretic peptide (BNP) levels. Aortic stenosis progresses slowly, allowing the left ventricle to develop concentric hypertrophy, which normalizes wall stress. These compensatory mechanisms maintain cardiac output for several years, during which time the patient remains asymptomatic. Development of haemodynamically significant aortic stenosis (aortic valve area <1.0 cm2) is associated with symptoms of exercise-induced angina, syncope and dyspnoea. Lim et al.,1 in this issue of the Journal , provide insight into the possible use of BNP as a screening tool to stratify symptomatic and asymptomatic patients with isolated aortic stenosis at risk for future events (death or aortic valve replacement). Natural history studies have demonstrated that the onset of symptoms is associated with limited survival (average of 2–3 years). However, surgical replacement of the aortic valve is also associated with significant morbidity and mortality. Randomized trials comparing surgery versus continuing medical therapy are lacking but observational studies have demonstrated that aortic valve replacement at the onset of symptoms is associated with improved symptoms and prolonged survival. A major problem with the reliance on symptoms alone is that it is based upon the patient's ability to exercise, or the physician's willingness to exercise a patient, who may have critical aortic … *Correspondence to: Dr. Steven R. Bailey, University of Texas Medical Center, Mail Code 7872, 7703 Floyd Curl Dr, San Antonio, TX 78229-3901, USA. Tel.: +1 210 5674601; fax: +1 210 5676960 (E-mail: baileys{at}uthscsa.edu).