Clinically significant high-grade AV block as a reversible cause for acute kidney injury in hospitalized patients – a propensity score matched cohort.

Introduction. High-grade AV block (HGAVB) has many known detrimental hemodynamic effects. Acute kidney injury (AKI) is a frequent clinical entity, usually caused by renal hypo-perfusion, and is associated with adverse clinical outcomes. Here we aimed to investigate the association between AKI and HGAVB.

Methods. This is a retrospective cohort study comparing the incidence of AKI among patients admitted with HGAVB requiring pacemaker implantation, and propensity score matched controls admitted to the cardiology department for any other diagnoses. The primary endpoint was the incidence of AKI at admission. Secondary outcomes were change in creatinine levels, AKI during stay, recovery from AKI, mortality and major adverse kidney events (MAKE).

Results. 80 HGAVB patients (50.0% female, aged 80.4±10.8) were compared to 400 (47.7% female, aged 79.3±10.2) controls. Patients with HGAVB had higher proportion of AKI on admission compared to controls (36.2% versus 21.1%, RR=1.71 [1.21 - 2.41], p=0.004). Change in creatinine level from baseline to admission and to maximal value during hospitalization, was also higher in HGAVB patients (p=0.042 and p=0.033, respectively). Recovery from AKI was more common among the HGAVB group (55.2% vs. 25.9%, RR=2.13 [1.31-3.47], p=0.004). Hospitalization time, future need for dialysis, MAKE and crude mortality were similar between groups (p>0.158).

Conclusions. AKI occurs in about one third of patients admitted with clinically significant HGAVB, more frequent compared to controls. Patients with AKI accompanying HGAVB presented higher recovery rates then controls. Further prospective studies are needed to confirm this relationship, and aid in clinical decision making for this patient population.