Long-term 5-year outcome of the randomized IMPRESS in severe shock trial: percutaneous mechanical circulatory support versus intra-aortic balloon pump in severe cardiogenic shock

Abstract Funding Acknowledgements Type of funding sources: None. Background The role of percutaneous mechanical circulatory support (pMCS) in cardiogenic shock (CS) is still a subject of debate. The IMPRESS in Severe Shock trial is still the largest RCT on the effectiveness of pMCS in CS patients. We performed a follow-up at 5-years of the IMPRESS in Severe Shock trial to assess differences in long-term clinical outcome and functional status between pMCS and intra-aortic balloon pump (IABP) treated patients. Methods The IMPRESS in Severe Shock trial (NTR3450) is an investigator-initiated, multicentre, randomized, open-label trial. Between June 2012 and September 2015, a total of 48 patients with severe CS from AMI with ST-segment elevation undergoing immediate revascularisation were randomized to pMCS with the Impella CP (n = 24) or IABP (n = 24). The trial design and primary end-point results (30-day all-cause mortality) have been previously published. For the 5-year assessment, all-cause mortality and the occurrence of major adverse cardiovascular and cerebrovascular events (MACCE) were evaluated. MACCE consisted of death, myocardial re-infarction, repeat PCI, CABG and stroke. In survivors, a structured interview was conducted and follow-up echocardiography was obtained. Data were analysed according to the intention-to-treat principle. Results Long-term follow-up was performed 5.5 years (IQR 5.3-6.5) after initial randomization and completed for all patients regarding mortality status. Five-year mortality was 50% (n = 12/24) in the pMCS group and 63% (n = 15/24) in the IABP group (RR 0.87, 95% CI 0.47-1.59, p = 0.65). After 6 months, only 3 additional deaths occurred, all in the IABP group. MACCE occurred in 12/24 (50%) of the pMCS patients versus 19/24 (79%) of the IABP patients (p = 0.07) (Figure 1). Myocardial re-infarction occurred in 1 pMCS patient and in 2 IABP patients, repeat PCI in 3 IABP patients, CABG in 1 IABP patient and stroke in 2 pMCS patients and in 2 IABP patients. Among 5-year survivors, follow-up interview was successfully conducted in 11/12 (92%) pMCS and 7/9 (78%) IABP patients. All patients except for one were in NYHA class I or II (pMCS n = 10 [91%] and IABP n = 7 [100%], p = 1.00) and none of the patients had residual angina complaints. Echocardiography was obtained in 10/12 (83%) pMCS and 6/9 (67%) IABP patients. There were no differences in LVEF between the two groups (pMCS 52 ±11% vs. IABP 48 ±10%, p = 0.53). Conclusions In this randomized trial of patients with CS after AMI, there was no difference in long-term 5-year mortality between pMCS (by Impella CP) and IABP treated patients, supporting previously published 30-day and 6-month data. Interestingly, we did observe a not significantly different (p = 0.07) higher occurrence of MACCE in the IABP group. Abstract Figure. Kaplan Meier Impella vs. IABP: MACCE