Association between demographic, organizational, clinical, and socio‐economic characteristics and underutilization of cardiac resynchronization therapy: results from the Swedish Heart Failure Registry

<jats:title>Abstract</jats:title><jats:sec><jats:title>Aims</jats:title><jats:p>Cardiac resynchronization therapy (CRT) improves outcomes in heart failure (<jats:styled-content style="fixed-case">HF</jats:styled-content>) but may be underutilized. The reasons are unknown.</jats:p></jats:sec><jats:sec><jats:title>Methods and results</jats:title><jats:p>We linked the Swedish Heart Failure Registry to national registries with <jats:styled-content style="fixed-case">ICD</jats:styled-content>‐10 (International Classification of Diseases‐10th Revision) co‐morbidity diagnoses and demographic and socio‐economic data. In patients with <jats:styled-content style="fixed-case">EF</jats:styled-content> ≤39% and <jats:styled-content style="fixed-case">NYHA II–IV</jats:styled-content>, we assessed prevalence of <jats:styled-content style="fixed-case">CRT</jats:styled-content> indication and <jats:styled-content style="fixed-case">CRT</jats:styled-content> use. In those with <jats:styled-content style="fixed-case">CRT</jats:styled-content> indication, we assessed the association between 37 potential baseline covariates and <jats:styled-content style="fixed-case">CRT</jats:styled-content> non‐use using multivariable generalized estimating equation (<jats:styled-content style="fixed-case">GEE</jats:styled-content>) models. Of 12 807 patients (mean age 71 ± 12 years, 28% female), 841 (7%) had <jats:styled-content style="fixed-case">CRT</jats:styled-content>, 3094 (24%) had an indication for but non‐use of <jats:styled-content style="fixed-case">CRT</jats:styled-content>, and 8872 (69%) had no indication. Important variables independently associated with <jats:styled-content style="fixed-case">CRT</jats:styled-content> non‐use were: <jats:styled-content style="fixed-case">HF</jats:styled-content> duration <6 months [risk ratio (<jats:styled-content style="fixed-case">RR</jats:styled-content>) 1.21, 95% confidence interval (<jats:styled-content style="fixed-case">CI</jats:styled-content>) 1.17–1.24]; non‐cardiology planned follow‐up (<jats:styled-content style="fixed-case">RR</jats:styled-content> 1.14, 95% <jats:styled-content style="fixed-case">CI</jats:styled-content> 1.09–1.18); age >75 years (<jats:styled-content style="fixed-case">RR</jats:styled-content> 1.13, 95% <jats:styled-content style="fixed-case">CI</jats:styled-content> 1.09–1.18); non‐cardiology care at baseline (<jats:styled-content style="fixed-case">RR</jats:styled-content> 1.10, 95% <jats:styled-content style="fixed-case">CI</jats:styled-content> 1.07–1.14); small‐town non‐university centre (<jats:styled-content style="fixed-case">RR</jats:styled-content> 1.08, 95% <jats:styled-content style="fixed-case">CI</jats:styled-content> 1.05–1.12); female sex (<jats:styled-content style="fixed-case">RR</jats:styled-content> 1.07 95% <jats:styled-content style="fixed-case">CI</jats:styled-content> 1.03–1.10) (all <jats:italic>P</jats:italic> < 0.05); as was absence of <jats:styled-content style="fixed-case">AF</jats:styled-content>, living alone; psychiatric diagnosis; smoking; and non‐use of <jats:styled-content style="fixed-case">HF</jats:styled-content> drugs. Education, income, cancer, or <jats:styled-content style="fixed-case">HF</jats:styled-content> characteristics were not independently associated with <jats:styled-content style="fixed-case">CRT</jats:styled-content> non‐use.</jats:p></jats:sec><jats:sec><jats:title>Conclusion</jats:title><jats:p>In this population‐wide <jats:styled-content style="fixed-case">HF</jats:styled-content> registry, <jats:styled-content style="fixed-case">CRT</jats:styled-content> was underutilized. Non‐use was associated mostly with demographic and organizational, but not clinical or socio‐economic factors. This calls for programmes to raise awareness of <jats:styled-content style="fixed-case">CRT</jats:styled-content> indications and improve access and referrals to cardiology specialists.</jats:p></jats:sec>