Optimized patient selection in high-risk protected percutaneous coronary intervention

Mechanical Circulatory Support with Impella: Principles, Evidence, and Daily Practice

The Impella (Abiomed, Danvers, MA, USA) microaxial pump is a percutaneous mechanical circulatory support (MCS) that has been shown to increase coronary perfusion, reduce myocardial oxygen demand, and improve peripheral organ perfusion. Therefore, indications for the Impella device include emergency use for cardiogenic shock (CS) and pre-emptive implantation during high-risk percutaneous coronary intervention (HR-PCI). However, despite their exponential use in cardiovascular practice over the past decade, there is limited randomized evidence to support the benefits of this therapy and growing concern regarding complication rates. In this review, we summarize the principles, evidence, and practical considerations of the most widely used Impella CP percutaneous left ventricular support in both CS and HR-PCI settings, moving from the historical background to current issues and future expectations for this device.

Predictors of left ventricular ejection fraction in high-risk percutaneous coronary interventions

Revascularization completeness after percutaneous coronary intervention (PCI) is associated with improved long-term outcomes. Mechanical circulatory support [intra-aortic balloon pump (IABP) or Impella] is used during high-risk PCI (HR-PCI) to enhance peri-procedural safety and achieve more complete revascularization. The relationship between revascularization completeness [post-PCI residual SYNTAX Score (rSS)] and left ventricular ejection fraction (LVEF) in HR-PCI has not been established. We investigated LVEF predictors at 90 days post-PCI with Impella or IABP support. Individual patient data (IPD) were analyzed from PROTECT II (NCT00562016) in the base case. IPD from PROTECT II and RESTORE-EF (NCT04648306) were naïvely pooled in the sensitivity analysis. Using complete cases only, linear regression was used to explore the predictors of LVEF at 90 days post-PCI. Models were refined using stepwise selection based on Akaike Information Criterion and included: treatment group (Impella, IABP), baseline characteristics [age, gender, race, New York Heart Association Functional Classification, LVEF, SYNTAX Score (SS)], and rSS. Impella treatment and higher baseline LVEF were significant predictors of LVEF improvement at 90 days post-PCI (p ≤ 0.05), and a lower rSS contributed to the model (p = 0.082). In the sensitivity analysis, Impella treatment, higher baseline LVEF, and lower rSS were significant predictors of LVEF improvement at 90 days (p ≤ 0.05), and SS pre-PCI contributed to the model (p = 0.070). Higher baseline LVEF, higher SS pre-PCI, lower rSS (i.e. completeness of revascularization), and Impella treatment were predictors of post-PCI LVEF improvement. The findings suggest potential mechanisms of Impella include improving the extent and quality of revascularization, and intraprocedural ventricular unloading.

Comparison of mid-term mortality after surgical, supported or unsupported percutaneous revascularization in patients with severely reduced ejection fraction: A direct and network meta-analysis of adjusted observational studies and randomized-controlled

INTRODUCTION

The optimal revascularization strategy in patients with heart failure with reduced ejection fraction (HFrEF) remains to be elucidated. The aim of this paper is to compare the mid-term mortality rate among patients with severely reduced ejection fraction (EF) and complex coronary artery disease who underwent coronary artery bypass grafting (CABG), percutaneous coronary intervention (PCI) with Impella support, or without.

METHODS

Randomized control trials and propensity-adjusted observational studies including patients with ischemic cardiomyopathy (ICM) and severe EF reduction undergoing revascularization were selected. Different revascularization strategies (CABG, supported PCI, and PCI without Impella) were compared in pairwise and network meta-analysis. The primary endpoint was mid-term mortality (within the first year after revascularization).

RESULTS

Fifteen studies, mostly observational (17,841 patients; 6779 patients treated with CABG, 8478 treated with PCI without Impella, and 2584 treated with Impella-supported PCI) were included in this analysis. The median age was 67.8 years (IQR 65-70.1), 21.2% (IQR 16.4-26%) of patients were female sex, and a high prevalence of cardiovascular risk factors was noted across the entire population. At pairwise analysis, CABG and PCI without Impella showed similar one-year all-cause mortality (10.6% [IQR 7.5-12.6%] vs 12% [IQR 8.4-11.5%]) RR 0.85 CI 0.67-1.09, while supported PCI reduced one-year all-cause mortality compared to PCI without Impella (9.4% [IQR 5.7-12.5%] vs 10.6% [IQR 8.9-10.7%]) RR 0.77 CI 0.6-0.89. At network meta-analysis, supported PCI showed better results (RR 0.75, 95% CI 0.59-0.94) compared to CABG.

CONCLUSION

Our analysis found that supported PCI may have a benefit over standard PCI in patients in direct comparison, and over CABG from indirect comparison, and with HFrEF undergoing revascularization. Further RCTs are needed to confirm this result. (PROSPERO CRD42023425667).

Impella-Driven High-Risk Percutaneous Coronary Intervention: A Novel, Single Non-Surgical-Centre Case Report

Complex percutaneous coronary intervention (PCI) procedures have been routinely performed in non-surgical centres in the UK for more than two decades. These procedures follow strict guidelines and recommendations by the British Cardiovascular Intervention Society to ensure a more effective running of PCI programs. Even more so, expected guiding principles necessary for the safe optimisation of complex PCI procedures have also been created.  An 81-year-old male was admitted with non-ST-elevation myocardial infarction (NSTEMI) and severely impaired left ventricle ejection fraction (LVEF; 26% according to the cardiac MRI report). Angiogram findings revealed severe multiple-vessel coronary artery disease affecting the following arteries: right coronary artery (RCA), left anterior descending artery (LAD), left circumflex artery (LCx), and intermediate artery (IM). There was also severe disease in the distal left main stem (LMS) bifurcation extending to the ostia of the LAD, LCx, and IM branches. Following a multidisciplinary meeting, the patient underwent Impella-supported high-risk PCI (complex PCI) using the DK crush technique with no peri- and post-procedure complication and a significant LV function improvement (45-49%). This is the first known case of this procedure performed at the Royal Cornwall Hospital in Treliske (RCHT), Truro, Cornwall. This case report highlights that when the decision to choose between coronary artery bypass graft (CABG) and PCI is not straightforward following an individualised risk-stratification scoring system analysis and in the setting of patient comorbidities, a high-risk PCI supported with the Impella device is a suitable alternative with promising short-term and long-term outcomes.