Critical Value of the Aortic Valve Area in Very Severe Aortic Stenosis

Introduction: Despite being asymptomatic, the patients with very severe aortic stenosis (AS) defined as aortic velocity >5.0 m/sec or mean pressure gradient >60 mm Hg, have a poor prognosis. In accordance with previous studies, aortic jet velocity, but not aortic valve area (AVA) affects the outcome of these patients. In this study we aimed to determine the value of critical valvular narrowing which corresponds with very severe AS.

Methods and Results: A total of 108 patients with isolated aortic stenosis, AVA 0.8 cm², demonstrating incremental decrease of cardiac output during progression of AS. Also, valvular resistance (R) showed escalating increase with slope -1023 of the relationship between R and AVA in patients with AVA0.8 cm². Similarly, accelerating growth of R was noted in patients with AVAi<0.4cm²/m². Furthermore, in patients with AVA0.6 cm². In patients with AVAi0.4 cm²/m².

Conclusion: AVA below 0.6 cm² or AVAi below 0.4 cm²/m² are accompanied by decrease of myocardial contractility, incremental growth of the valvular resistance and, therefore, accelerated decline of cardiac output. This study confirms significance of this critical value of AVA and AVAi.