Defining patterns of comorbidity accrual before and after the diagnosis of heart failure

Abstract Introduction People with heart failure (HF) usually have multiple comorbidities and these confer adverse prognosis. The chronology of comorbidity development in relation to HF has not been investigated, which hinders development of preventative strategies. Purpose We aimed to define the chronology of comorbidity diagnoses in relation to HF diagnosis and hypothesised that HF is preceded by most of its comorbidities. Methods We used UK Biobank data to identify 21,127 people with HF diagnosis at any stage before or after recruitment. Comorbidities were defined using primary care records, and were not included if self-reported or their date of diagnosis unknown. Comorbidities were selected based on methods of Conrad et al. (Lancet 2018; 391(10120): 572-580), and defined using CALIBER or UK Biobank criteria. We investigated the time between first diagnosis of HF and first diagnosis of 15 common comorbidities, including after stratification by sex and age at HF diagnosis. Analysis was conducted using RStudio. Results For all studied comorbidities, except dementia, at least half of diagnoses predated or developed synchronously with HF. For myocardial infarction, obesity, cancer, atrial fibrillation, hypertension, diabetes and depression, at least three quarters of diagnoses predated or developed synchronously with HF. The median time between comorbidity and HF diagnoses varied substantially between comorbidities, ranging from depression preceding HF by 10.7 years to dementia proceeding HF by 0.7 years. The interquartile range of time between comorbidity and HF diagnoses varied substantially, ranging from 2.4 years for myocardial infarction to 15.2 years for depression, indicating most cases of the former develop in a narrow window (usually prior to HF diagnosis). All comorbidities presented earlier in women, with this being most marked for cancer (median time between cancer and HF -2.6 years for men and -7.1 years for women). As the age of HF diagnosis increased, the time spent with all studied comorbidities also increased. Indeed, in HF diagnosed before the age of 60, a majority of comorbidity diagnoses (except for depression) occurred after HF. Conclusion HF most often develops late in the process of comorbidity accrual, although this pattern is reversed in people developing HF at younger ages. Sex differences are also notable, with women developing comorbidities earlier in relation to their HF diagnosis. Understanding the chronology of comorbidity development may help to guide strategies to prevent multimorbidity, which are likely to require a personalised approach. For people with established HF, our data also emphasise the importance of holistic care that accounts for complex multimorbidity.Figure 1