Predictors of Major Adverse Cardiac Events in Asymptomatic Low Gradient Aortic Stenosis with Preserved Ejection
Al-Darzi W, Kupsky D, Entz A, Roumayah T, Seudeal C, Burmeister C, and Ananthasubramaniam K. Predictors of Major Adverse Cardiac Events in Asymptomatic Low Gradient Aortic Stenosis with Preserved Ejection. J Am Soc Echocardiogr 2019; 32(6):B47.
J Am Soc Echocardiogr
Background: Patients with low mean pressure gradient (<40mmHg) severe aortic stenosis (Aortic valve area <1.0 cm2) despite preserved ejection fraction (≥50%) have had varying outcomes in prior studies. We sought to evaluate what clinical and echocardiographic parameters would help predict major adverse cardiac events (MACE) in these patients. Methods: A retrospective data review of patients with asymptomatic low gradient aortic stenosis with preserved ejection fraction was performed. Patients with prior valvuloplasty, surgical aortic valve replacement (SAVR), or transcatheter aortic valve replacement (TAVR) were excluded. Comprehensive demographic, clinical, echocardiographic parameters of 287 patients from January 2014 till December 2015 were obtained. Left ventricular global longitudinal strain (GLS) was able to be measured in 94 patients by using speckle tracking imaging. Composite MACE included congestive heart failure, myocardial infarction, SAVR, TAVR, or death were obtained after the initial echocardiogram date. Results: The average age of our studied population is 79.4 years (SD: 13.6). Of them, 67% (n=63) are females. Nineteen patients (20%) have atrial fibrillation, 77 patients have hypertension (82%), and 40 patients (43%) have history of coronary artery disease. Baseline echocardiographic parameters include mean aortic valve area of 0.8 cm2 (SD: 0.2) with indexed aortic valve area of 0.5 cm2/m2 (SD: 0.1). The average of mean pressure gradient is 27.8 mmHg (SD: 12.6) and the average stroke volume index (SVi) is 38.6 mL/m2 (SD: 11.5). Sixty-three patients had normal-flow low-gradient severe aortic stenosis (SVi ≥34mL/m2), while 31 patients had paradoxical low-flow low-gradient aortic stenosis (SVi <34mL/m2). Composite outcomes of MACE developed in 58.5% (n=55) of the studied population (n=94). Independent univariate predictors of MACE were atrial fibrillation (OR, 4.9; 95% CI, 1.3-18.3; p=0.0174). Using a multivariate logistic regression, there were higher odds of having MACE among patients with higher mean gradient across aortic valve (OR, 1.1; 95% CI, 1.0-1.1; p=0.0025), with lower SVi (OR, 0.9; 95% CI, 0.9-1.0; p=0.0061), and with history of atrial fibrillation (OR, 5.3; 95% CI, 1.4-20.6; p=0.0163). Valvuloarterial impedance or GLS did not add any independent predictive value for MACE. Conclusion: Our single center study of low gradient aortic stenosis patients suggests that commonly used indices such as SVi, mean pressure gradient, and history of atrial fibrillation could best help predict MACE. Larger studies are necessary for further assessment.