Impact of Acute Kidney Injury in Elderly (≥80 Years) Patients Undergoing Percutaneous Coronary Intervention

Background and Aim: Chronic renal disease is commonly found in individuals hospitalized for acute coronary syndrome, and its frequency rises drastically with advancement of age. The increasing rate of mortality in chronic kidney disease is primarily caused by cardiovascular disease. Acute kidney injury has been associated with adverse outcomes in patients undergoing percutaneous coronary intervention. There is a scarcity of data on AKI after PCI in older individuals. Therefore, the aim of the study was to determine the impact of AKI in elderly patients (≥80 years) undergoing PCI. Patients and Methods: This study retrospectively investigated 350 patients undergoing PCI at Cardiology Department of Lady Reading Hospital, MTI Peshawar from February 2022 to February 2023. All the ACS diagnosed patients aged ≥80 years undergoing PCI were enrolled. Patient’s clinical and procedural details were recorded comprised of different variables and outcomes. Non-fatal myocardial infarction, disabling stroke, cardiovascular mortality, re-hospitalization for cardiovascular causes, and bleeding types were recorded. For renal assessment, Serum creatinine levels were carefully evaluated during the index hospitalization. Patients were distributed into mild, moderate, and severe renal dysfunction based on estimated glomerular filtration rate (e-GFR). The increase of 0.3 mg/dl in serum creatinine from baseline was considered as AKI. Results: Out of 350 ACS patients, there were 156 (44.6%) female and 194 (55.4%) male. Based on estimated glomerular filtration rate (e-GFR), the incidence of mild, moderate, and severe renal dysfunction was 85 (24.3%), 54.3% (n=190), and 21.4% (n=75) respectively. The composite ischemia endpoint rate increased with reduction in e-GFR and renal dysfunction from 8.6% to 14.5% and 25.8% in mild, moderate, and severe AKI, respectively. Furthermore, individuals with renal impairment had a significantly higher risk of hospitalization owing to cardiovascular reasons (6.3%, 9.4%, and 15.9%, respectively). On the other hand, no substantial association and variation between groups in terms of recurrent non-fatal MI (5.8%, 6.2%, and 9.2), debilitating stroke (0.3%, 0.8%, and 1.6%), and hospital bleeding (1.2%, 0.9%, 2.1%) in mild, moderate, and severe renal impairment. Conclusion: The present study found that Elderly patients (≥80 years) undergoing percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS) exhibit a higher mortality rate, primarily attributable to baseline renal dysfunction. Renal impairment is a prevalent condition in older ACS patients who undergo PCI during their initial hospitalization, and it serves as a standalone predictor of both all-cause and cardiovascular mortality within one year.