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.