Chronic kidney disease incidence following myocardial infarction: an investigation of the COVID-19 pandemic and health inequalities using nationally linked healthcare records in England, 2017-2024

Background Whilst cardiovascular disease remains the global leading cause of death, survival following myocardial infarction (MI) has improved dramatically in recent decades. However, increased survival is associated with adverse health outcomes including the development of chronic kidney disease (CKD). Whilst our previous hospital-only analyses demonstrated a substantial excess incidence of CKD following MI, they did not capture the post-COVID-19 pandemic period, incorporate primary care or clinical registry data, nor allow robust investigation of ethnicity-related health inequality. Purpose To investigate the totality of new onset CKD for survivors of MI, assess impact of the COVID-19 pandemic and differences by ethnicity. Methods This study includes all adults (≥18yrs) with index MI between 1st Jan 2017 to 31st Dec 2023 in England from the Myocardial Ischaemia National Audit Project. Incident cases of CKD following MI were identified from linked nationwide primary and secondary care records (the General Practice Extraction Service Data for Pandemic Planning and Research and Hospital Episode Statistics, respectively) with final follow-up to 31 Dec 2024. Age- and sex-adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for the development of incident CKD by ethnicity and pandemic period (Jan 2017–Feb 2020 [pre-]; Mar 2020–Mar 2022 [during-] and Apr 2022–Dec 2024 [post-pandemic]) were determined using flexible parametric survival models treating death without outcome as competing risk. The cumulative incidence over 8-years of follow-up was calculated from standardised survival curves obtained from the same set of adjusted models. Results There were 294,165 individuals with MI (median age 64 (IQR 55-74); 70.4% male) of whom 37,030 (12.6%) developed CKD (median age 73 (IQR 65-80); 62.6% male). The overall cumulative incidence of CKD increased over time, rising from 22.2% (95% CI 21.9-22.4) of individuals up to 8 years after MI in the pre-pandemic period to 27.5% (27.0-28.0) during and 31.0% (30.3-31.8) post the pandemic respectively. Compared with individuals of White ethnicity, those of Black ethnicity had a significantly increased risk of CKD following MI (aHR = 1.89; 95% CI 1.75–2.03), as did Asian ethnicity (1.36; 1.30–1.41), Mixed or Multiple ethnicities (1.26; 1.11–1.43), and Other ethnicity (1.17; 1.06–1.30). There was no ethnicity effect modification by pandemic period (Pinteraction = 0.411). Thus, whilst the overall incidence of CKD following MI increased - health inequalities by ethnicity remained consistent (Fig 1). Conclusions Our national linkage of clinical registry, primary and secondary care data shows a substantial burden of CKD after MI, with cumulative incidence reaching 31% post-COVID19. All non-white ethnic groups experienced persistently higher CKD incidence. Updated ethnicity-specific risk estimates are crucial to guide strategies to mitigate the rising CKD burden in MI survivors.