Protective effect of Impella on left ventricular function after acute broad anterior wall ST elevation myocardial infarction with cardiogenic shock: cardiaovascular magnetic resonance imaging strain analysis

Background The clinical efficacy of Impella for high-risk percutaneous coronary intervention and cardiogenic shock remains under debate. We thus sought to investigate the protective effects on the heart by the early use of Impella before percutaneous coronary intervention using cardiovascular magnetic resonance imaging (CMR). Methods We evaluated cardiac magnetic resonance imaging results in 22 broad anterior ST-elevation myocardial infarction cases between 2017 and 2019. A mechanical circulation system (Impella or intra-aortic balloon pump) was implanted before percutaneous coronary intervention if needed; all patients underwent cardiac magnetic resonance imaging 2 weeks later. Results There were 6 patients in the Impella group and 16 in the non-Impella group; no differences were found in the door-to-balloon time (60 ± 17 vs. 58 ± 25 min, P = 0.58), peak creatine kinase (7922 ± 4864 vs. 6950 ± 4801 IU/L, P = 0.74), and hospital admission days (28 ± 8 vs. 25 ± 7 days, P = 0.40) between the two groups; however, cardiac magnetic resonance imaging-derived left ventricular end-diastolic volume was significantly smaller in the Impella group (140.6 ± 28 vs. 182.5 ± 45 ml, P = 0.004). Overall diastolic strain rate (SR) at the non-infarcted area in the IMPELLA group was significantly higher as compared to non IMPELLA group (longitudinal diastolic SR: 1.1 ± 0.4 vs 0.7 ± 0.3 S− 1, P = 0.04, radial diastolic SR: -1.8 ± 0.4 vs -1.1 ± 0.4 S− 1, P = 0.004, circumferential diastolic SR: 1.0 ± 0.1vs 0.6 ± 0.2 S− 1, P = 0.001). Conclusions Early implantation of Impella before percutaneous coronary intervention for anterior ST-elevation myocardial infarction acutely prevented enlargement of left ventricular end-diastolic volume and worsening of diastolic SR in the remote myocardium. This study provides clinical insight into understanding the usefulness of Impella to prevent future heart failure.