Clinical Outcome in Asymptomatic Severe Aortic Stenosis

Posted On 2012-01-09 11:58:41
J Am Coll Cardiol . 2012; 59:235-243(doi:10.1016/j.jacc.2011.08.072):
Lancellotti P, Magne J, Donal E, Davin L, O'Connor K, Rosca M, MD*, Catherine Szymanski, Cosyns B, Piérard LA

In the aging populations of developed nations, aortic stenosis (AS) is one of the most common valvular pathologies, and its prevalence is increasing. Although current guidelines provide clear recommendations for diagnosis and treatment of symptomatic severe AS, inconsistent grading of disease severity remains a problem. Further management of patients with asymptomatic severe AS remains controversial.

In the current paper, Lancellotti et al. (http://www.ncbi.nlm.nih.gov/pubmed/22240128) examine the clinical course of patients with asymptomatic severe aortic stenosis. The authors hypothesize that in this patient population, several entities might be identified according to transvalvular flow rates and pressure gradients, resulting in 4 distinct flow-gradient patterns.

The authors performed transthoracic echocardiography and analyzed levels of B-type natriuretic peptide from venous blood samples in 150 consecutive patients with asymptomatic severe AS and normal exercise test. Patients were classified in 4 groups, depending on left ventricular flow state (normal flow [NF] vs. low flow [LF]: 35 ml/m2) and pressure gradient levels (low gradient [LG] vs. high gradient [HG]: 40 mm Hg).

The authors report that patients with NF/LG had significantly lower B-type natriuretic peptide than those with LF/HG and LF/LG. After 2 year follow-up, cardiac event-free survival was 83 ± 6%, 44 ± 6%, 30 ± 12%, and 27 ± 13% in NF/LG, NF/HG, LF/HG, and LF/LG groups, respectively (p < 0.0001). In multivariable analysis, LF/LG (hazard ratio [HR]: 5.26, 95% confidence interval [CI]: 2.04 to 14.3, p = 0.045) and LF/HG (HR: 2.38, 95% CI: 1.02 to 5.55, p = 0.001) were identified as strong independent determinants of poor prognosis as compared with NF/HG. By limiting the multivariable analysis to patients with LF, LF/LG was an independent predictor of markedly reduced cardiac event-free survival when compared with LF/HG (HR: 5.4, 95% CI: 1.03 to 28.6, p = 0.046).

The authors propose that use of a AS grading classification integrating valve area and flow-gradient patterns allows better prediction of the clinical outcome of patients with asymptomatic severe AS.

The editorial team would like to announce that in the upcoming issue of the journal Dr. Ozkan et al. will discuss a related topic in his review paper entitled:  “Low Gradient Severe Aortic Stenosis with Preserved Left Ventricular Ejection Fraction”