Acute kidney injury in patients presenting with acute coronary syndrome, with and without diabetes mellitus

Introduction Acute kidney injury (AKI) remains an important complication associated with acute cardiovascular insult. Assessing the prevalence of AKI in patients with acute coronary syndrome (ACS) as well as in the period following discharge, with and without DM, are important factors in early identification of high-risk individuals and timely initiation of appropriate therapies. Purpose To assess the (i) incidence of AKI in all patients presenting with an ACS, (ii) incidence of further AKI in the 12 months following successful discharge based on the presence or absence of DM. Methods A single centre retrospective analysis was performed on all patients presenting with an ACS, admitted between July 2020 and June 2021. Exclusion criteria comprised a diagnosis other than ACS. Baseline characteristics were obtained, and blood tests were reviewed using locally installed IT system including the occurrence of any events of AKI in the 12 months following successful discharge. Intergroup comparison and significance was assessed using Pearson's Chi Square, Wilcoxon ranked sum and Fishers exact test where applicable with p<0.05 as significant. Results Of 1,012 individuals registered in the database, 990 patients were deemed eligible for the study and included in the analysis. Overall, 14.2% (141/990) patients had an AKI during admission, with majority having stage 1 (12.2% [121/990] and less frequently, stages 2 (0.6% [6/990]) and 3 (1.4% [14/990]). These individuals had a longer length of in-hospital stay (7.5 days [3.2-14.3] vs 3.0 days [1.5-5.8], relative ratio (RR) 2.5, p<0.001) and had a higher in-hospital mortality (22.0% [31/141] vs 2.8% [24/849], RR 7.9, p<0.001). Based on severity of AKI at admission, in-hospital was mortality was 16.5% (20/121), 50.0% (3/6) and 57.1% (8/14) for stages 1, 2 and 3 respectively. Baseline characteristics shown in table 1. Three hundred and fifteen (31.8%) had DM. Intergroup comparison showed that those with DM were more likely to have an AKI at admission (20.0% [63/315] vs 11.6% [78/675], RR 1.7, p<0.001), and were also more likely to have the severe form i.e. stage 3, of the condition (2.9% [9/315] vs 0.7% [5/675], RR 4.1, p=0.017, with and without DM respectively). Further analysis among individuals who were successfully discharged (n=935) showed that 9.2% (86) individuals had at least one further episode of AKI, more common in those with DM (15.0% [44/294] vs 6.6% [42/641], RR 2.3, p<0.001). Specifically, of those successfully discharged having had an AKI during admission (n=110), 20.0% (22) developed at least one further episode of AKI. Conclusion Patients presenting with ACS continue to be complicated by events of AKI which are more common in those with DM. These individuals remain at higher risk of further events and therefore would benefit from closer continued monitoring in the primary care setting after discharge and may benefit from the early initiation of cardio-renal protective agents.