Ultra-low contrast PCI vs conventional PCI in patients of ACS with an increased pre-procedural risk of CI-AKI (CONSaVE-AKI study)

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Patients with acute coronary syndrome (ACS) and at an increased risk of developing CI-AKI can be identified prior to percutaneous coronary intervention (PCI) based on their pre-procedural risk scores. Ultra-low contrast PCI (ULC-PCI) is a novel contrast conservation strategy in such high risk patients for prevention of CI-AKI, however evidence of its feasibility and clinical utility is limited with no prospective randomized control trial available. Purpose This single center, prospective, randomized study assessed short-term outcomes and safety of ULC-PCI vs conventional PCI. It tested the hypothesis that in ACS patients undergoing PCI who are at an increased pre-procedural risk of developing CI-AKI, use of ULC-PCI strategy will cause less incidence of CI-AKI than in conventional PCI. Methods 82 patients [age 60.12 (±8.98) years] undergoing PCI for ACS were enrolled between December 2019 and August 2021 in a tertiary care center in India having creatinine clearance <60 ml/min/1.73 m2 by the MDRD equation and having a moderate to very high pre-procedural risk of developing CI-AKI as calculated by Maioli et al risk score(1). They were randomized into two groups of 41 patients each. In the ULC-PCI group, the total volume of contrast used was ≤ 1 x patient’s GFR and in the conventional PCI group, contrast volume was kept ≤ 3 x patient’s GFR. ULC-PCI protocol used aggressive intra-procedural contrast sparing strategies along with the use of IVUS guidance or staging of the multi-vessel PCI whenever feasible. Patients were followed up for primary end point of development of CI-AKI and secondary end point of any need for dialysis, re-hospitalization, death, repeat myocardial infarction or unplanned coronary re-interventions in a follow-up of 30 days. Primary PCI, chronic total occlusions and patients on maintenance hemodialysis were excluded from the study. Results Baseline clinical and angiographic characteristics were similar between groups. The primary outcome of CI-AKI occurred more in patients of the conventional PCI group [7 (17.1%)] than in the ULC PCI group [(0 patients), p = 0.012]. Contrast volume (41.02 (±9.8) mL vs 112.54 (±25.18) mL; P<.0001) was markedly lower in the ULC-PCI group. 6 patients had stage 1 AKI with recovery and 1 patient had stage 3 AKI requiring dialysis. ULC PCI was reasonably safe and effective with no significant difference in secondary safety outcomes between the two study arms. It was also applicable without lesion restriction. IVUS was used in 17% patients in the ULC PCI group. Conclusion An ULC-PCI in patients with increased risk of developing CI-AKI is feasible, appears to be safe, and has the potential to decrease the incidence of CI-AKI, compared with conventional PCI specially in resource limited setting such as ours where coronary imaging by IVUS is not possible in every patient. Also, in ACS patients with baseline renal dysfunction, revascularization is associated with improved GFR post PCI.