Association of bleeding events and acute kidney failure in patients with ST-Elevation myocardial infarcation undergoing emergency percutaenous coronary intervention
Authors: Schmucker J , Fach A , Osteresch R , Mata Marin L A , Retzlaff T , Ruehle S , Garstka D , Hambrecht R , Wienbergen H 
Published: October 2021

Abstract

Background
Acute kidney injury (AKI) is associated with a worse overall prognosis in patients with ST-elevation myocardial infarctions (STEMI). At the same time bleeding complications during emergency percutaneous interventions (PCI) in STEMI-patients are often associated with hemodynamic impairement, which might contribute to renal tissue damage. Aim of the present study was to investigate an association between bleeding complications and AKI and the interaction between bleedings events and other possible contributors to AKI.

Methods
All patients with STEMI admitted to a German heart center between 2006 and 2020 were analysed. AKI was defined as KDIGO stage ≥1. Bleedings were characterised by BARC criteria or by decrease in total hemoglobin (ΔHb = Hb(admission) − Hb(minimal).

Results
Of a total of 7381 patients, 6805 (92%) showed no or only minmal bleedings (BARC 0/1), in 300 (4%) a BARC 2 bleeding, in 200 (3%) a BARC 3a and in 76 (1%) a BARC 3b/c or 5-major-bleeding event was documented. In patients with bleeding events, higher age, female gender (BARC 0/1: 25%, BARC 3b/c+5: 41%) and cardiogenic shock (BARC 0/1: 11%, BARC 3b/c and 5: 38%) were more prevalent. Furthermore BARC was associated with higher rates of AKI (BARC 0/1: 13%, BARC 2: 24%, BARC 3a: 43%, BARC 3b/c+5: 57%, p (for trend) &lt;0.01). Of the significant bleedings (≥BARC 2) 51% were femoral/retroperitoneal, 21% gastrointestinal, 2% intracerebral and 26% various. When estimating AKI-rates by decrease in Hemoglobin (ΔHb = Hb(admission) − Hb(minimal during the hospital stay in the PCI-center)), an association between any decrease in hemoglobin and AKI-rate was evident: ΔHb &lt;1 g/dL: AKI-rate: 7%, ΔHb 3 to 3.9 g/dl: 29%, ΔHb ≥6 g/dl: 57%, p (for trend) &lt;0.01. For every 1 g/dl decrease in hemoglobin, AKI-rates increased by on average the factor 1.44. When comparing the impact of the amount of contrast media (CM) used during emergency-PCI and Hb-decrease on AKI-rates it became evident that while higher CM-doses were associated with a modest rise in AKI-rates, the effect of an Hb-decrease on AKI-rates was more pronounced. A major decrease in Hemoglobin (≥4 g/dl) was associated with an at least 3.5 fold higher risk for AKI irrespective of amount of contrast media applied (Figure).

Conlusions
This registry data shows that bleeding events in STEMI-patients, classified by BARC-criteria or alternatively stratified by decrease in hemoglobin-levels are closely associated with incidence-rates of AKI. This indicates the importance of bleeding complications and its hemodynamic alterations in STEMI, which most likely contribute to renal tissue damage. Less access site complications might therefore result in renal protection.

Funding Acknowledgement
Type of funding sources: Public hospital(s). Main funding source(s): State of BremenStiftung Bremer Herzen Predictors of AKI in STEMI