Contrast Induced Nephropathy in Very Elderly Patients Undergoing Percutaneous Coronary Intervention for Acute Coronary Syndrome

Contrast-Induced Nephropathy (CIN) is associated with significant morbidity and mortality after Percutaneous Coronary Intervention (PCI). Very elderly patients undergoing PCI are at higher risk of CIN because of age and associated multiple comorbidities. The purpose of our study was to asses factors associated with CIN in very elderly patients. We retrospectively studied 128 very elderly patients who underwent PCI for ACS between January 2018 and December 2019 at our hospital. CIN was defined as 25% rise in the baseline creatinine level, within 48 to 72 hours of intravenous contrast administration. CIN occurred in 27 patients (26.7%). The mean age of patients with CIN was 80.63 ± 5.52 years and those without CIN, the mean age was 79.33± 4.1 years ( P -value 0.181). Of the 34 patients with baseline GFR < 60 mL/min/1.73 m 2 , 9 patients (26.5%) developed CIN and of the 94 patients with baseline GFR above 60 mL/min/1.73 m 2 , 18 patients (19.1%) developed CIN ( P -value 0.370). The factors associated with CIN were: STEMI compared to NSTEMI (30.4% vs. 15.9%, P -value 0.05), history of coronary events (35% vs. 14.8%, P -value 0.009), heart failure at admission (35.7% vs. 17% P -value 0.06), and no reflow post PCI (66.7% vs. 21.3%, P -value 0.013). At a median follow-up of 12 months, major cardiovascular events including cardiovascular death, reinfarction, and stroke were more frequents in patients with CIN (36% vs. 14%, P -value 0.011). CIN frequently complicate PCI in very elderly patients, especially those with STEMI and heart failure at admission. It is associated with prolongation of hospital stay and increased rate of cardio-vascular complications at medium and long term follow-up.