Remote ischaemic pre-conditioning, kidney injury, and outcomes after coronary angiography and intervention: a randomized trial

BACKGROUND AND AIMS: Remote ischaemic pre-conditioning (RIPC) delivered shortly prior to an angiographic procedure may reduce contrast-associated acute kidney injury (CA-AKI). Whether a longer interval between RIPC and contrast administration also reduces CA-AKI and post-procedural complications after coronary angiography (CAG) or percutaneous coronary intervention (PCI) is unknown. METHODS: This was a multicentre, randomized trial of patients at risk of CA-AKI undergoing elective CAG or PCI comparing delayed RIPC (four cycles of 5 min inflations on one upper arm 24 h before the procedure) with sham RIPC. The primary endpoint was the incidence of AKI, defined according to the Kidney Disease Improving Global Outcomes criteria. Secondary endpoints included renal replacement therapy during hospitalization, changes in urinary biomarkers of kidney injury, and occurrence of non-fatal myocardial infarction, stroke, re-hospitalization, and all-cause mortality by day 90. RESULTS: Altogether, 501 patients (age, 74 [66, 78] years) were randomly assigned to delayed (n = 250) or sham (n = 251) RIPC, of which 467 (93.2%) completed outcome assessments at day 90. The incidence of CA-AKI was 7.6% with sham and 3.2% with delayed RIPC (odds ratio 0.4, 95% confidence interval 0.17-0.94; P = .03). The trial was not adequately powered to show effects on secondary outcomes. CONCLUSIONS: Among at-risk patients undergoing CAG or PCI, the incidence of CA-AKI was lower in patients receiving delayed compared with sham RIPC. These results should be confirmed in larger trials to investigate whether reductions in CA-AKI with delayed RIPC lead to important clinical benefits.