Utility and safety of single access technique in ST-elevation myocardial infarction patients with cardiogenic shock

Background The Impella, a micro-axial pump, has been widely used for the treatment of cardiogenic shock (CS) as it provides both circulatory support and left ventricular unloading. Recently, the combination of veno-arterial extracorporeal membrane oxygenation (VA-ECMO) and Impella (ECPELLA) has seen expanded use. The Single Access Technique (SAT), which allows for simultaneous Impella support and percutaneous coronary intervention (PCI) through a single access site by inserting a 6Fr sheath within a 14Fr Impella-specific introducer sheath, has gained attention. Purpose This single-center retrospective cohort study aimed to evaluate the utility and safety of SAT in ST-segment elevation myocardial infarction (STEMI) patients with CS treated with Impella CP. Methods Between September 2018 and December 2024, a total of 213 patients underwent Impella insertion at our facility. Among them, 59 STEMI patients who underwent PCI with Impella support were analyzed and divided into two groups: the SAT group (n=28) and the non-SAT group (n=31). In the non-SAT group, a 16Fr another sheath was frequently used instead of the Impella introducer sheath due to its association with reduced bleeding. Baseline characteristics, procedural times, safety outcomes, and prognostic indicators were compared between the groups. Since SAT is an off-label procedure, we obtained approval from our institutional ethics committee in 2019 and subsequently included an additional description regarding SAT in the Impella informed consent form. Results Baseline characteristics, including age, sex, coronary risk factors, comorbidities, and culprit lesion, were similar between groups. The proportion of ECPELLA was significantly higher in the SAT group because one femoral artery was already in use for VA-ECMO insertion. Procedural times, including door-to-unload time (SAT: 56 min vs. non-SAT: 63 min, p=0.8) and door-to-balloon time (SAT: 71 min vs. non-SAT: 78 min, p=0.7), were comparable between groups. However, the interval from Impella activation to reperfusion was significantly shorter in the SAT group (SAT: 12 min vs. non-SAT: 16 min, p=0.02). SAT was successfully performed in all cases without technical difficulties; however, it was associated with significantly higher rates of access site bleeding (SAT: 71% vs. non-SAT: 42%, p=0.02) and increased transfusion requirements (SAT: 15U vs. non-SAT: 4U, p=0.02) due to bleeding caused by the Impella inner sheath. There were no significant differences between the two groups regarding peak CK-MB, left ventricular ejection fraction at discharge, or 30-day all-cause mortality. Conclusion SAT was more frequently selected for ECPELLA patients and proved effective for performing PCI during ECPELLA support. Although SAT could be performed safely, it did not shorten overall procedural times. Furthermore, SAT was associated with significantly higher bleeding complications compared to the 16Fr another sheath.