Percutaneous Mechanical Ventricular Support in Acute Cardiac Care: A UK Quaternary Centre Experience Using 2.5L, 3.8L and 5.0L Impella Catheters

Optimized patient selection in high-risk protected percutaneous coronary intervention

Percutaneous mechanical circulatory support (pMCS) is increasingly used in patients with poor left-ventricular (LV) function undergoing elective high-risk percutaneous coronary interventions (HR-PCIs). These patients are often in critical condition and not suitable candidates for coronary artery bypass graft surgery. For the definition of HR-PCI, there is a growing consensus that multiple factors must be considered to define the complexity of PCI. These include haemodynamic status, left-ventricular ejection fraction, clinical characteristics, and concomitant diseases, as well as the complexity of the coronary anatomy/lesions. Although haemodynamic support by percutaneous LV assist devices is commonly adopted in HR-PCI (protected PCI), there are no clear guideline recommendations for indication due to limited published data. Therefore, decisions to use a nonsurgical, minimally invasive procedure in HR-PCI patients should be based on a risk-benefit assessment by a multidisciplinary team. Here, the current evidence and indications for protected PCI will be discussed.

A Review of Bleeding Risk with Impella-supported High-risk Percutaneous Coronary Intervention

Complex, high-risk percutaneous coronary intervention (HR-PCI) is increasingly being performed, often with mechanical circulatory support (MCS), though to date, there are limited randomised data on the efficacy of MCS for HR-PCI. The majority of MCS is provided by intra-aortic balloon pumps, but increasingly Impella® (Abiomed, Danvers, MA, USA) heart pumps are being used. While the Impella pumps provide greater increases in cardiac output, these devices require large bore access, which has been associated with an increased risk of bleeding and vascular complications. Decisions regarding the use of Impella are often based on risk-benefit considerations, with Impella-related bleeding risk being a major factor that can impact decisions for planned use. While bleeding risk related to large bore access is a concern, published data on the risk have been quite variable. Thus, the goal of this article is to provide a comprehensive review of reports describing bleeding and vascular complications for Impella-supported HR-PCI.

Balloon Aortic Valvuloplasty Followed by Impella®-Assisted Left Main Coronary Artery Percutaneous Coronary Intervention in Patients With Severe Aortic Stenosis as a Bridge to Transcatheter Aortic Valve Replacement

BACKGROUND

The use of Impella® to provide hemodynamic support during unprotected left main coronary artery (LMCA) percutaneous coronary intervention (PCI) has been shown to be feasible, but severe AS is a relative contraindication for its use. Balloon aortic valvuloplasty (BAV) may facilitate the use of Impella® in these patients.

OBJECTIVE

To assess the feasibility of BAV followed by Impella®-assisted LMCA PCI in patients with severe AS as bridge to TAVR.

METHODS

Patients with symptomatic severe AS with LMCA stenosis ≥70% requiring PCI prior to TAVR were included. Outcomes were retrospectively collected.

RESULTS

Seven patients underwent BAV followed by Impella®-assisted LMCA PCI. Five patients were male; mean age 86 (75-91; SD ± 5.5). Mean STS score was 6.5% (4.3-13.8; SD ± 3.4). Impella® 2.5 L was used in all cases. The procedure was successful in all patients without peri-procedure complications. At 30-day post-BAV/PCI follow up, all patients had experienced improvement in NYHA class (N = 2 NYHA IV to III, N = 5 NYHA III to II). At such interval, mean EF was 54% (30-77; SD ± 17.7). The post BAV change in AVA [0.8 cm² (0.4-1.5; SD ± 0.3; P = 0.07)], and AV mean gradient [30.8 mmHg (21-45; SD ± 8.9; P = 0.95)] after the procedure were not statistically significant. All patients underwent TAVR after a median PCI-to-TAVR interval of 62 days (33-339; SD ± 96.7).

CONCLUSIONS

BAV followed by Impella®-assisted LMCA PCI appears to be a feasible strategy for intermediate and high surgical risk patients with severe AS undergoing LMCA PCI as bridge to TAVR.

Indication and short-term clinical outcomes of high-risk percutaneous coronary intervention with microaxial Impella® pump: results from the German Impella® registry

BACKGROUND

Percutaneous coronary intervention (PCI) is an alternative strategy to coronary artery bypass grafting (CABG) in patients with high perioperative risk. The microaxial Impella^® pump (Abiomed, Danvers, MA, USA), used as prophylactic and temporary support, is currently the most common device for "protected high-risk PCI" to ensure hemodynamic stability during complex coronary intervention.

METHODS

The study is an observational, retrospective multi-center registry. Patients from nine tertiary hospitals in Germany, who have undergone protected high-risk PCI, are included in the present study.

RESULTS

A total of 154 patients (mean age 72.6-10.8 years, 75.3% male) were enrolled. The majority were at a high operative risk illustrated by a logistic EuroSCORE of 14.7-17.4. The initial SYNTAX score was 32.0-13.3, indicating very complex CAD and could be reduced to 14.1-14.3 (p < 0.0001) after PCI. The main reasons for protected PCI were complex coronary anatomy (70.8%), personal impression (56.5%), reduced ventricular ejection fraction (49.4%), comorbidities (47.4%), and surgical turndown (30.5%). Four patients (2.6%) experienced an intrahospital death.

CONCLUSIONS

Data from the study show that protected PCI is a safe and effective approach to revascularize high-risk patients with complex coronary anatomy and comorbidities.

The effectiveness and safety of the Impella ventricular assist device for high-risk percutaneous coronary interventions: A systematic review

BACKGROUND

Small randomized controlled trials (RCTs) and observational studies have examined the effectiveness and safety of the Impella device, a percutaneous left ventricular assist device, in the setting of high-risk percutaneous coronary intervention (PCI). However, data are sparse and results are conflicting. Our objective was to evaluate the effectiveness and safety of the Impella device in high-risk patients undergoing PCI via a systematic review of the literature.

METHODS

We searched Medline, EMBASE, and the Cochrane Library for RCTs and observational studies that evaluated the Impella device in high-risk patients undergoing PCI. Inclusion was restricted to studies in which ≥10 patients received the Impella device; both uncontrolled and controlled (versus intra-aortic-balloon pump [IABP]) studies were included.

RESULTS

A total of 20 studies (4 RCTs, 2 controlled observational studies, and 14 uncontrolled observational studies; 1,287 patients) were included, with follow-up ranging from 1 to 42 months. The use of Impella resulted in improved procedural and hemodynamic characteristics in controlled and uncontrolled studies. In controlled studies, the 30-day rates of all-cause mortality and MACE were similar across groups. In most uncontrolled studies, the 30-day rates of all-cause mortality were generally low (range: 3.7%-10%), though rates of MACE were slightly higher (range: 5%-20%).

CONCLUSION

The Impella device was found to improve procedural and hemodynamic parameters, but only limited randomized data are available regarding clinical outcomes associated with its use. Large, multicenter RCTs are needed to definitively establish the effectiveness of the Impella device among high-risk PCI patients.

Percutaneous Ventricular Assist Devices: A Health Technology Assessment

BACKGROUND

Percutaneous coronary intervention (PCI)-using a catheter to place a stent to keep blood vessels open-is increasingly used for high-risk patients who cannot undergo surgery. Cardiogenic shock (when the heart suddenly cannot pump enough blood) is associated with a high mortality rate. The percutaneous ventricular assist device can help control blood pressure and increase blood flow in these high-risk conditions. This health technology assessment examined the benefits, harms, and budget impact of the Impella percutaneous ventricular assist device in high-risk PCI and cardiogenic shock. We also analyzed cost-effectiveness of the Impella device in high-risk PCI.

METHODS

We performed a systematic search of the literature for studies examining the effects of the Impella percutaneous ventricular assist device in high-risk PCI and cardiogenic shock, and appraised the evidence according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group criteria, focusing on hemodynamic stability, mortality, major adverse cardiac events, bleeding, and vascular complications. We developed a Markov decision-analytical model to assess the cost- effectiveness of Impella devices versus intra-aortic balloon pumps (IABPs), calculated incremental cost-effectiveness ratios (ICERs) using a 10-year time horizon, and conducted sensitivity analyses to examine the robustness of the estimates. The economic model was conducted from the perspective of the Ontario Ministry of Health and Long-Term Care.

RESULTS

Eighteen studies (one randomized controlled trial and 10 observational studies for high-risk PCI, and one randomized controlled trial and six observational studies for cardiogenic shock) were included in the clinical review. Compared with IABPs, Impella 2.5, one model of the device, improved hemodynamic parameters (GRADE low-very low) but showed no significant difference in mortality (GRADE low), major adverse cardiac events (GRADE low), bleeding (GRADE low), or vascular complications (GRADE low) in high-risk PCI and cardiogenic shock. No randomized controlled trials or prospective observational studies with a control group have studied Impella CP and Impella 5.0 (other models of the device) in patients undergoing high-risk PCI or patients with cardiogenic shock. The economic model predicted that treatment with the Impella device would have fewer quality-adjusted life-years (QALYs) and higher costs than IABP in high-risk PCI patients. These observations were consistent even when uncertainty in model inputs and parameters was considered. We estimated that adopting Impella would increase costs by $2.9 to $11.5 million per year.

CONCLUSIONS

On the basis of evidence of low to very low quality, Impella 2.5 devices were associated with improved hemodynamic stability, but had mortality rates and safety profile similar to IABPs in high-risk PCI and cardiogenic shock. Our cost-effectiveness analysis indicated that Impella 2.5 is likely associated with greater costs and fewer quality-adjusted life years than IABP.

Meta-Analysis of Usefulness of Percutaneous Left Ventricular Assist Devices for High-Risk Percutaneous Coronary Interventions

High-risk percutaneous coronary intervention (PCI) is often offered to patients with extensive coronary artery disease, decreased left ventricular function, and co-morbid conditions that increase surgical risk. In these settings, percutaneous left ventricular assist devices (PVADs) can be used for hemodynamic support. To assess the effects of PVAD use on mortality, myocardial infarction, and complication rates in patients undergoing high-risk PCI, we systematically searched the electronic databases, MEDLINE, PUBMED, EMBASE, and Cochrane for prospective controlled trials and cohort studies of patients that received hemodynamic support with PVADs for high-risk PCI. The primary outcome measures were 30-day all-cause mortality, 30-day myocardial infarction rates, periprocedural major bleeding, and vascular complications. We included 12 studies with 1,346 participants who underwent Impella 2.5 L device placement and 8 cohort studies with 205 patients that received TandemHeart device for high-risk PCI. Short-term mortality rates were 3.5% and 8% and major bleeding rates were 7.1% and 3.6% with Impella and TandemHeart, respectively. Both devices are associated with comparable periprocedural outcomes in patients undergoing high-risk PCI.

Percutaneous Mechanical Support in Cardiogenic Shock: A Review

Cardiogenic shock (CS) is a life-threatening condition associated with significant morbidity and mortality. Pharmacological therapy is often the first line of treatment but mechanical support can provide substantial hemodynamic improvement in refractory CS. Percutaneous mechanical support devices are placed in a minimally invasive manner and provide life-saving assistance to the failing myocardium. We review the percutaneous devices currently available, the evidence behind their use, and the new advances in percutaneous technology being evaluated for the treatment of CS.