Impact of Renal Function on Myocardial Remodeling and Outcomes in Patients With Moderate Aortic Stenosis

Abstract

Background: Patients with moderate aortic stenosis (AS) and cardiac damage have poor prognosis, and whether early aortic valve replacement benefits these patients is under investigation. However, besides valvular hemodynamics, comorbidities such as chronic kidney disease (CKD) can contribute to myocardial damage and affect prognosis. The aim of this study was to investigate the impact of renal function on myocardial remodeling and outcomes in patients with moderate AS. Methods: The study cohort included 865 consecutive patients diagnosed with moderate AS (aortic valve area > 1.0 and <= 1.5 cm(2), mean gradient > 20 mmHg) between 2008 and 2020. Patients were categorized into five stages of CKD according to estimated glomerular filtration rate. Echocardiographic measures of myocardial remodeling and the composite outcome of all-cause mortality and heart failure hospitalization were assessed. Results: Higher CKD stage was associated with greater valvuloarterial impedance, as well as greater left ventricular (LV) hypertrophy, worse LV diastolic function, and lower LV and left atrial strain, despite similar AS severity. These associations were independent of age, sex, comorbidities, and LV pressure overload. During a median follow-up period of 4.0 years, 310 composite outcome events (39.3%) occurred, including 258 deaths (32.7%). Severe CKD (stage 4 or 5) and myocardial dysfunction were independent predictors of the composite outcome, after adjustment for key clinical variables including aortic valve replacement. Mediation analysis showed that myocardial dysfunction partially mediated the impact of renal function on outcome. Conclusions:<bold> </bold>In patients with moderate AS, renal dysfunction was independently associated with adverse myocardial remodeling and dysfunction, irrespective of valvular hemodynamics. The role of earlier intervention in patients with moderate AS whose cardiac damage is driven by comorbidities, rather than AS itself, warrants further investigation.