Prognostic Value of Hemodynamic Parameters in Asymptomatic Aortic Valve Stenosis
– The COFRASA / GENERAC study
Background: Whether risk-stratification in aortic valve stenosis (AS) should rely on a single hemodynamic parameter or a combination of hemodynamic parameters is still debated. This is why, we aimed to evaluate the prognostic value of mean pressure gradient (MPG), aortic valve area (AVA) and dimensionless index (DI) in patients with AS and to test whether their combination provides additional prognostic information.
Methods: Between 2006 and 2014 we prospectively enrolled 319 asymptomatic patients with AS (90 mild, 173 moderate, and 56 severe AS) in two ongoing prospective studies . Clinical, biological, and echocardiographic evaluations were performed at study entry. All patients were followed on a yearly basis and the occurrence of AS related events (sudden death, congestive heart failure, or new onset of symptoms) was prospectively recorded.
Results: After a mean follow-up of 3.1±1.7 years, an AS-related event occurred in 84 patients (26%). When considered in isolation, after adjustment for age, sex, history of coronary artery disease, valve anatomy and left ventricular ejection fraction, MPG, AVA and DI predicted the occurrence of AS-related events (all p<0.0001). When considered in combination, MPG and AVA (p=0.0009 and p<0.0001 respectively) or MPG and DI (p=0.0001 and p<0.0001 respectively) remained independent predictors of outcome. In patients with severe AS (AVA<1.0cm2 or DI<0.25) event-free survival was significantly different between patients with a MPG ≤ or > to 50 mmHg in these 2 subsets (p=0.001 and p<0.0001 respectively). Results were sustained after exclusion of the 31 patients (10%) with discordant grading.
Conclusion: In a large prospective cohort of asymptomatic patients with a wide range of AS severity, AVA, MPG and DI were all important prognostic factors. More importantly, irrespective of the presence of patients with discordant grading, MPG and either the AVA or the DI provided complementary prognostic information. Our results show that these hemodynamic parameters should be considered in combination in the clinical management of AS patients.