1Bremer Institut für Herz- und Kreislaufforschung (BIHKF) Bremen, Deutschland; 2Klinikum Bremen-Mitte Klinik für Innere Medizin III Bremen, Deutschland
Introduction: Recent studies have shown that in patients with ST-elevation myocardial infarctions (STEMI) the main contributor of acute kidney injury (AKI) maybe the STEMI itself with its hemodynamic sequelae and to a lesser extent contrast media induced nephropathy (CIN). However, the possible toxicity of very high doses of contrast media (CM) on kidney function in STEMI-patients remains unclear. Aim of the present study was therefore to investigate, how very high doses of CM influenced AKI-rates in patients admitted with STEMI.
Methods: Patients admitted with STEMI between 2006 and 2022 to a large heart center entered analysis. A very high dose of contrast media was defined as >250 ml. AKI was defined by KDIGO-criteria (2012). To properly assess AKI, patients with a hospital stay <48 hours were excluded. To adaquately adjust for confounders patients were first stratified by TIMI-risk-score and then the excess AKI-risk for very high CM-amounts was calculated for each subgroup in a multivariate model.
Results: Of a total of 8856 patients included, 699 patients (7.9%) received a CM-dose >250 ml with an average CM-amount of 303.4±63 ml vs. 133.8±46 ml in the control group. Patients receiving very high CM-doses were older (64.9±12 yrs. vs. 63.8±13 yrs., p<0.01), showed more extensive STEMIs (peak CK 2221±2348 U/ml vs. 1888±2164 U/ml, p<0.01), had a higher likelihood of unsuccessful PCI (TIMI 0/1: 6.6% vs. 3.8%, p<0.01) and higher AKI-rates: AKIN 1: 21.3% vs. 14.4%, p<0.01, AKIN 3: 5.6% vs. 3.1%, p<0.01. The association between very high-CM and likelihood of AKI remained after adjusting for confounders in a multivariate model: AKIN 1: OR 1.34, 95% CI 1.1-1.7, p=0.013. However, the effect was weaker than the effect of major bleeding events after intervention on AKI (OR 4.5, 95% CI 3.1-6.7, p<0.01) or a reduced LV-EF: LV-EF<40%: OR 4.469, 95% CI: 3.3-6.0, p<0.01. When stratifying the patients by initial TIMI-risk-score two observations could be made: First, there was a strong association between TIMI-risk-score and AKI-rates, and second, an excess risk for very high CM-doses on AKI could only be independently detected for patients with a high TIMI-risk-score (TIMI-risk-score≥7), while in all other groups (TIMI score 0-6) no independent effect of very high CM-amounts on AKI could be found (table).
Table : Excess risk for very high CM-amounts on AKI-rates* in patient cohorts stratified by TIMI-risk-score
| TIMI score | N(%) | Overall AKI-rates (%) | OR for excess risk for very high CM (>250 ml)* | ||
| OR | 95% CI | P | |||
| 0 to 1 | 1343 (15) | 5.2 | 0.89 | 0.4-1.3 | 0.24 |
| 2 to 3 | 2657 (30) | 8.3 | 1.10 | 0.6-1.9 | 0.73 |
| 3 to 4 | 2966 (34) | 16.3 | 1.28 | 0.9-1.9 | 0.22 |
| 5 to 6 | 1311 (15) | 26.0 | 1.31 | 0.8-2.1 | 0.27 |
| ≥7 | 579(7) | 36.4 | 2.73 | 1.4-5.3 | <0.01 |
Conclusions: STEMI-Patients receiving very high amounts of contrast media were on average older with larger infarctions and showed lower rates of successful percutaneous coronary interventions (PCI). While there was an association between very high CM-doses and AKI-rates, its impact was weaker than other STEMI-sequelae like bleeding events or heart failure. Furthermore, an independent effect of very high CM-amounts on AKI-rates could only be shown for patients with a high overall TIMI-risk-score while the detrimental effect of very high CM-amounts on renal function could not be proven for the majority of STEMI-patients.