New study findings provide critical insights into the natural history of mild to moderate aortic stenosis (AS) and identify potential risk factors for disease progression. Further findings by the study’s investigators revealed that moderate AS was associated with higher mortality rates compared to mild AS with the overall one-year all-cause mortality noted at 8.8%. During Sunday’s Late Breaking Clinical Science Structural I session at Cardiovascular Research Technologies (CRT) 2025, Baravan Al-Kassou, MD, Consultant Interventional Cardiologist at University Hospital Bonn, Germany, revealed that nearly half of the patients (47.2%) in the study experienced AS progression by at least one degree over a median interval of 511 days. Patients who experienced progression had significantly higher baseline phosphate levels (p=0.02) and elevated C-reactive protein levels (p=0.02), indicating increased inflammation, the study’s investigators noted.A ccording to Dr. Al-Kassou, this observation was significantly higher in patients with moderate AS compared to those with mild AS (13.6% vs 6.4%, p=0.05). Kaplan-Meier survival analysis confirmed that this difference persisted over a two-year follow-up period (p=0.04). Progression risk “The present study underscores the progression risk in patients with mild to moderate AS, with nearly half progressing within 17 months,” said Dr. Al-Kassou, who is also Project Leader of Genes Underlying Aortic Valve Disease (GUARD), a project funded by the German Research Foundation. “AS progression was linked to increased phosphate levels and inflammation, suggesting potential predictors for disease advancement,” he said. Dr. Al-Kassou added that moderate AS was significantly associated with higher mortality rates than mild AS. “These findings highlight the need for regular monitoring and suggest that early, targeted interventions based on identified risk factors could improve patient outcomes,” he said. Aortic stenosis is characterized by calcification of the aortic valve cusps, which can lead to significant morbidity and mortality if left untreated. While severe AS has been extensively studied, the clinical implications of mild to moderate AS are less well understood. Research approach The study enrolled 307 patients diagnosed with mild to moderate AS. The mean age of this study population was 74.1±10.7 years, with 37.8% being female. Transthoracic echocardiography was performed at baseline and at six-month intervals, using qualitative and quantitative assessments to evaluate aortic valve anatomy and function. Additionally, biochemical evaluations, including markers of inflammation and cardiovascular stress, were conducted at each visit. The study’s primary clinical endpoints were AS’ progression rate — defined by echocardiographic parameter changes indicative of AS severity over time — and all-cause mortality. Image Credit: Rahab Sheikh Image Caption: Baravan Al-Kassou, MD, presents during a Late-Breaking Clinical Science session Sunday at Cardiovascular Research Technologies (CRT) 2025.