French AKI Registry (FAKIR): A Multicenter Study on the In-Hospital Management and Outcomes of Severe Acute Kidney Injury in Nephrology Units

N/ANot Yet RecruitingNCT07123324

University Hospital, Strasbourg, France750 enrolled

Overview

Acute Kidney Injury (AKI) is a common and serious condition in hospitalized patients, especially when it reaches stages 2 or 3 according to the KDIGO classification. These severe forms are associated with high mortality, a risk of progression to chronic kidney disease (CKD), and frequent cardiovascular complications. However, current data on how nephrologists manage these patients during hospitalization-and how these practices influence long-term outcomes-are limited and heterogeneous. The FAKIR study (French AKI Registry) is a prospective, multicenter, non-interventional observational study designed to describe the clinical management of patients admitted to nephrology departments for AKI stage 2 or 3 and to assess their renal and cardiovascular outcomes up to one year. The study hypothesizes that better characterization of in-hospital practices and patient trajectories will help identify predictors of renal recovery, progression to end-stage renal disease, and major cardiovascular events. Patients will be followed during hospitalization and at 3, 6, and 12 months to assess renal function, mortality, cardiovascular events, and rehospitalizations. This registry aims to provide real-life, multicenter data to support future guidelines and the development of structured post-AKI care pathways.

Study Type

OBSERVATIONAL

Enrollment

750

Conditions

Acute Kidney Injury Kidney Failure Chronic Cardiorenal Syndrome Renal Replacement Therapies

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Age ≥ 18 years at admission * Hospitalized in a nephrology ward (standard or intensive nephrology care unit) * Diagnosis of acute kidney injury (AKI) stage 2 or 3 according to KDIGO criteria at the time of admission * Availability of follow-up data at 3 months (clinical or laboratory) Exclusion Criteria: * AKI stage 1 only * AKI acquired outside the nephrology department without subsequent transfer to nephrology * Hospitalized for another reason without documented AKI stage 2 or 3 * Refusal or opposition to data reuse for research purposes * Under legal protection (guardianship or trusteeship) without a representative to provide non-opposition * Incomplete medical records preventing collection of required baseline data

Outcomes

Primary Outcomes

Rate of Complete Renal Recovery at 3 Months After Hospitalization for AKI KDIGO Stage 2 or 3

Renal recovery is defined as a return of serum creatinine to ≤125% of the patient's baseline (pre-AKI) value, estimated using the CKD-EPI formula. Creatinine values are collected from medical records or follow-up labs performed at 3 months post-discharge. This outcome reflects the extent of renal function recovery following hospitalization for severe AKI and helps identify prognostic factors associated with favorable evolution.

Time frame: Assessed at 3 months (±30 days) after admission for AKI in nephrology ward

Secondary Outcomes

All-Cause Mortality at 12 Months After Hospitalization for AKI KDIGO Stage 2 or 3

All-cause mortality is defined as the proportion of patients who die from any cause within 12 months following their admission for AKI KDIGO stage 2 or 3. Vital status is obtained from hospital records, follow-up contact, or national registries. This outcome will allow assessment of medium-term prognosis and identification of clinical factors associated with mortality in patients with severe AKI managed in nephrology units.

Time frame: Assessed at 12 months post-admission (±30 days)

Incidence of Major Adverse Cardiovascular Events (MACE) at 12 Months

MACE includes non-fatal myocardial infarction, non-fatal stroke, hospitalization for acute heart failure, and cardiovascular death. Events will be identified from medical records, discharge summaries, and follow-up contacts. This outcome will assess the cardiovascular burden among patients with severe AKI managed in nephrology settings, and help determine the link between in-hospital management strategies and long-term cardiovascular risk.

Time frame: Assessed throughout the 12-month follow-up period

Progression to End-Stage Renal Disease (ESRD) at 12 Months

ESRD is defined as the initiation of chronic renal replacement therapy (dialysis or kidney transplantation) or a sustained eGFR \<15 mL/min/1.73m². Data are collected through follow-up visits, patient contact, or hospital records. This measure evaluates long-term renal outcomes and identifies risk factors for irreversible kidney failure following AKI KDIGO stage 2 or 3.

Time frame: Assessed at 12 months post-AKI hospitalization