Impact and prognostic implications of aortic stenosis across the heart failure spectrum: a cohort study

Background Aortic stenosis (AS) frequently coexists with heart failure (HF), but its prevalence, prognostic impact and management across the full HF spectrum remain incompletely characterised. Methods In this retrospective cohort study, we analysed 22 906 patients with HF undergoing echocardiography between 2010 and 2020. AS was classified as mild, moderate, low-gradient (LG) or severe according to guideline criteria. Outcomes were assessed using Cox regression, stratified by HF subtype and adjusted for clinical confounders. The primary endpoint was event-free survival, defined as all-cause mortality or aortic valve replacement (AVR). Results Moderate AS was present in 5.5%, LG AS in 2.5% and severe AS in 6.5% of HF patients, with HF with preserved ejection fraction (HFpEF) being the most common HF subtype across all AS grades. Increasing AS severity was associated with a stepwise increase in adverse outcomes compared with HF patients without AS (adjusted HR 2.20 (95% CI 2.00 to 2.41) for moderate AS; 3.32 (95% CI 2.97 to 3.72) for LG AS and 6.20 (95% CI 5.74 to 6.69) for severe AS). These associations were consistent across HFpEF, HF with mildly reduced EF and HF with reduced EF. Despite established guideline indications, only 59.5% (95% CI 57% to 62%) of HF patients with severe AS underwent AVR within 2 years. Conclusions AS is common in HF and is associated with substantially worse long-term outcomes across all HF subtypes, even at non-severe stages. The high mortality risk and frequent lack of intervention highlight major treatment gaps and underscore the need for prospective trials evaluating earlier intervention strategies.