Mortality and complications of Impella use in dialysis patients with acute myocardial infarction complicated by cardiogenic shock: insights from the J-PVAD Registry

Background Mechanical circulatory support (MCS) with Impella has demonstrated improved hemodynamics and survival benefits in acute myocardial infarction complicated by cardiogenic shock (AMI-CS), particularly in selected populations, as shown in the DanGer Shock trial [1-3]. However, outcomes of dialysis patients treated with Impella for AMI-CS remain poorly characterized. While dialysis patients with AMI experience higher rates of ischemic and bleeding complications compared with non-dialysis patients [4-6], the specific incidence of complications in dialysis patients treated with Impella for AMI-CS has never been investigated. Purpose To evaluate 30-day mortality and complication rates in dialysis patients with AMI-CS treated with Impella. Methods Data were extracted from the Japanese registry for Percutaneous Ventricular Assist Device (J-PVAD) in which all Japanese patients treated with Impella were registered. Among 4,032 patients registered in J-PVAD between February 1, 2020, and December 31, 2022, a total of 1,920 AMI-CS patients with available renal function data were included in the present study. Patients were stratified into three groups: dialysis (n=65, 3.4%), non-dialysis chronic kidney disease (CKD) (n=824, 42.9%), and non-CKD (n=1,031, 53.7%). The primary endpoint was all-cause mortality at 30 days after Impella implantation. Multivariable Cox-proportional hazards model was applied to compare all-cause mortality between the three groups. Secondary endpoints included cardiovascular mortality at 30 days analyzed using Fine-Gray subdistribution hazard models with non-cardiovascular death as a competing event, and complication rates including major bleeding, ischemic and hemorrhagic stroke, hemolysis, infection, and limb ischemia. Results Both the all-cause mortality (Figure 1) and the cardiovascular mortality (Figure 2) differed significantly among the three groups (P<0.01), with the highest mortality observed in the dialysis group; however, no significant difference was observed between the dialysis and the CKD groups. Limb ischemia occurred most frequently in the dialysis group (12.3%) and differed significantly between the three groups (P=0.02); however, no significant differences were observed in the incidence of other complications between the three groups. Conclusions Among patients with acute myocardial infarction complicated by cardiogenic shock treated with Impella, dialysis patients demonstrated comparable all-cause and cardiovascular mortality to non-dialysis CKD patients, but significantly higher mortality than patients without CKD. Notably, patients on dialysis had a significantly higher risk of limb ischemia than those not on dialysis.Figure 1Figure 2