Intravenous versus oral hydration to reduce the risk of postcontrast acute kidney injury after intravenous contrast-enhanced CT in patients with severe chronic kidney disease (ENRICH): a study protocol for a single-centre, parallel-group, open-labelled non-inferiority randomised controlled trial in Denmark.

INTRODUCTION: Contrast-enhanced CT (CECT) is widely used for diagnostic purposes. The use of contrast medium carries a risk for postcontrast acute kidney injury (PC-AKI), especially in patients with AKI or chronic kidney disease (CKD). Current guidelines recommend prophylactic intravenous hydration to prevent PC-AKI in high-risk patients. Oral hydration is non-inferior to intravenous hydration in patients with moderate CKD, but it has not been evaluated in high-risk patients. METHODS AND ANALYSIS: The ENRICH trial will enrol 254 patients with estimated glomerular filtration rate ≤30 mL/min/1.73 m2 undergoing intravenous CECT, who are block randomised (2-4-2) with stratification for CKD stage, diabetes status, and indication for referral to prophylactic treatment with oral or intravenous hydration. PC-AKI is defined as an absolute increase in SCr of >0.3 mg/dL or >1.5 from baseline at 2-5 days. Renal function will also be evaluated <90 days, <7 days and 1-3 days before intravenous CECT, and 25-40 days after intravenous CECT. Secondary outcomes include dialysis, renal adverse events, hospitalisation due to hydration-related or contrast-related sequelae, and all-cause mortality ≤30 days postcontrast. Pre- and postcontrast plasma and urinary biomarkers will be evaluated for diagnostic and prognostic accuracy of the primary and secondary outcomes. ETHICS AND DISSEMINATION: Oral hydration is patient-friendly and less costly compared with intravenous hydration. If oral hydration is non-inferior to intravenous hydration in high-risk patients, it could be implemented as new hydration strategy, which will facilitate the clinical diagnosing of elective patients with severe CKD without unnecessary resource utilisation. The protocol is approved by the Regional Scientific Ethical Committee for Southern Denmark (S-20210126), and the Data Protection Agency (21/66779). The study is conducted in accordance with the Declaration of Helsinki. Positive as well as negative findings will be reported in international peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT05283512.

Effects of vitamins K2 and D3 supplementation in patients with severe coronary artery calcification: a study protocol for a randomised controlled trial.

INTRODUCTION: Coronary artery calcification (CAC) and especially progression in CAC is a strong predictor of acute myocardial infarction and cardiovascular mortality. Supplementation with vitamin K2 and D3 has been suggested to have a protective role in the progression of CAC. In this study, we will examine the effect of vitamins K2 and D3 in men and women with severe CAC. We hypothesise that supplementation with vitamins K2 and D3 will slow down the calcification process. METHOD AND ANALYSIS: In this multicentre and double-blinded placebo-controlled study, 400 men and women with CAC score≥400 are randomised (1:1) to treatment with vitamin K2 (720 µg/day) and vitamin D3 (25 µg/day) or placebo treatment (no active treatment) for 2 years. Among exclusion criteria are treatment with vitamin K antagonist, coagulation disorders and prior coronary artery disease. To evaluate progression in coronary plaque, a cardiac CT-scan is performed at baseline and repeated after 12 and 24 months of follow-up. Primary outcome is progression in CAC score from baseline to follow-up at 2 years. Among secondary outcomes are coronary plaque composition and cardiac events. Intention-to-treat principle is used for all analyses. ETHICS AND DISSEMINATION: There are so far no reported adverse effects associated with the use of vitamin K2. The protocol was approved by the Regional Scientific Ethical Committee for Southern Denmark and the Data Protection Agency. It will be conducted in accordance with the Declaration of Helsinki. Positive as well as negative findings will be reported. TRIAL REGISTRATION NUMBER: NCT05500443.