Early vs Late Impella® Device Support is Associated with a Better Survival Benefit in AMICS: A Meta-Analysis
- In patients with acute myocardial infarction complicated by cardiogenic shock (AMICS), early mechanical circulatory support with the Impella® device is associated with a greater survival advantage compared with post-revascularization support.
According to a meta-analysis by Flaherty et al, the initiation of early Impella® support before revascularization is associated with a survival benefit among patients with acute myocardial infarction complicated by cardiogenic shock (AMICS).1
Investigators pooled outcomes data from 3 studies which assessed early Impella support initiated prior to revascularization in AMICS: an exploratory analysis of a randomized-controlled trial (n = 24), findings derived from a retrospective, global catheter-based ventricular assist device registry (n = 287), and a single-center report (n = 68).2,3,4
Early Impella device support was defined as the placement of the Impella device prior to revascularization/early-on during angiography, whereas late support was defined as support initiated immediately following revascularization. The primary outcome was comprised of either 30-day or in-hospital mortality.
Prior to Impella device support, approximately 49% of patients in this pooled analysis had cardiac arrest at presentation. Additionally, 82% required inotropes and 81% were indicated for ventilator support.
Compared with late Impella support, the meta-analysis of these different forms of data suggests that early Impella initiation in AMICS patients reduced 30-day or in-hospital mortality by approximately 48%. Overall, patients receiving early Impella support in the 3 studies experienced a survival benefit that was considered statistically significant (risk ratio: 0.52; 95% confidence interval: 0.31 to 0.88, I2 = 0%; P=0.01).
“Our results are in agreement with the rationale from preclinical work performed in animal models demonstrating that early initiation of Impella provides effective left ventricular unloading, maintains adequate systemic and coronary perfusion, [and] decreases endothelin release and calcium overload,” concluded the investigators. “This [helps] prevent the downward spiral that may otherwise ensue with organ hypoperfusion, systemic inflammatory response, and multiorgan dysfunction leading to death.”
Clinical Relevance and Study Limitations
Although this study demonstrates a significant survival benefit of early vs late Impella support, it fails to establish causation. In addition, the lack of a comparison group as well as the potential for known and unknown confounders due to variability in the patient population slightly limits the findings of this meta-analysis.
Despite these limitations, the Flaherty meta-analysis validates previous research, which demonstrates associations between Impella support and hemodynamic improvement, infarct size reduction, and minimization of reperfusion injury.
In a small study by Kapur et al, the use of mechanical support for reducing left ventricular (LV) wall stress prior to reperfusion was associated with a greater percent reduction of infarcted LV myocardium vs no support (49±14% vs 28±7%, respectively; P=0.03).5 An animal study also confirmed the hypothesis that pre-reperfusion LV unloading with an LV assist device results in a greater reduction in myocardial infarct size vs post-reperfusion (P<0.05) and control (P=0.011).6
Further prospective randomized-controlled trials are necessary to further explore and validate the causative factors and survival advantage of early Impella support found in this meta-analysis.
- Flaherty MP, Khan AR, O'Neill WW. Early Initiation of Impella in Acute Myocardial Infarction Complicated by Cardiogenic Shock Improves Survival: A Meta-Analysis. JACC Cardiovasc Interv. 2017;10(17):1805-1806.
- Ouweneel DM, Eriksen E, Sjauw KD, et al. Percutaneous Mechanical Circulatory Support Versus Intra-Aortic Balloon Pump in Cardiogenic Shock After Acute Myocardial Infarction. J Am Coll Cardiol. 2017;69(3):278-287.
- Basir MB, Schreiber TL, Grines CL, et al. Effect of Early Initiation of Mechanical Circulatory Support on Survival in Cardiogenic Shock. Am J Cardiol. 2017 Mar 15;119(6):845-851.
- Schroeter MR, Köhler H, Wachter A, et al. Use of the Impella Device for Acute Coronary Syndrome Complicated by Cardiogenic Shock - Experience From a Single Heart Center With Analysis of Long-term Mortality. J Invasive Cardiol. 2016 Dec;28(12):467-472.
- Kapur NK, Paruchuri V, Urbano-Morales JA, et al. Mechanically unloading the left ventricle before coronary reperfusion reduces left ventricular wall stress and myocardial infarct size. Circulation. 2013;128(4):328-336.
- Achour H, Boccalandro F, Felli P, et al. Mechanical left ventricular unloading prior to reperfusion reduces infarct size in a canine infarction model. Catheter Cardiovasc Interv. 2005 Feb;64(2):182-192.
Impella® Device — Indication & Safety Information
INDICATIONS FOR USE
The Impella 2.5® and Impella CP® Systems are temporary (≤ 6 hours) ventricular support devices indicated for use during high-risk percutaneous coronary interventions (PCI) performed in elective or urgent, hemodynamically stable patients with severe coronary artery disease, when a heart team, including a cardiac surgeon, has determined high-risk PCI is the appropriate therapeutic option. Use of the Impella 2.5 and Impella CP Systems in these patients may prevent hemodynamic instability, which can result from repeat episodes of reversible myocardial ischemia that occur during planned temporary coronary occlusions and may reduce peri- and post-procedural adverse events.
The Impella 2.5®, Impella CP®, Impella 5.0®, and Impella LD® Catheters, in conjunction with the Automated Impella Controller (collectively, “Impella® System Therapy”), are temporary ventricular support devices intended for short term use (≤ 4 days for the Impella 2.5 and Impella CP, and ≤ 6 days for the Impella 5.0, and Impella LD) and indicated for the treatment of ongoing cardiogenic shock that occurs immediately (< 48 hours) following acute myocardial infarction or open heart surgery or in the setting of cardiomyopathy, including peripartum cardiomyopathy, or myocarditis as a result of isolated left ventricular failure that is not responsive to optimal medical management and conventional treatment measures (including volume loading and use of pressors and inotropes, with or without IABP). The intent of Impella System Therapy is to reduce ventricular work and to provide the circulatory support necessary to allow heart recovery and early assessment of residual myocardial function.
Important Risk Information for Impella devices
The Impella 2.5, Impella CP, Impella 5.0 and Impella LD are contraindicated for use with patients experiencing any of the following conditions: Mural thrombus in the left ventricle; Presence of a mechanical aortic valve or heart constrictive device; Aortic valve stenosis/calcification (equivalent to an orifice area of 0.6 cm2 or less); Moderate to severe aortic insufficiency (echocardiographic assessment graded as ≥ +2); Severe peripheral arterial disease precluding placement of the Impella System; Significant right heart failure*; Combined cardiorespiratory failure*; Presence of an Atrial or Ventricular Septal Defect (including post-infarct VSD)*; Left ventricular rupture*; Cardiac tamponade*
* This condition is a contraindication for the cardiogenic shock indication only.
POTENTIAL ADVERSE EVENTS
Acute renal dysfunction, Aortic valve injury, Bleeding, Cardiogenic shock, Cerebral vascular accident/Stroke, Death, Hemolysis, Limb ischemia, Myocardial infarction, Renal failure, Thrombocytopenia and Vascular injury
In addition to the risks above, there are other WARNINGS and PRECAUTIONS associated with Impella devices. Visit http://www.abiomed.com/important-safety-information to learn more.
Right-Side Support – Indication & Safety Info.
INDICATIONS FOR USE
The Impella RP® System is indicated for providing temporary right ventricular support for up to 14 days in patients with a body surface area ≥1.5 m2, who develop acute right heart failure or decompensation following left ventricular assist device implantation, myocardial infarction, heart transplant, or open-heart surgery.
Important Risk Information for Impella RP
The Impella RP System is contraindicated for patients with the following conditions: Disorders of the pulmonary artery wall that would preclude placement or correct positioning of the Impella RP device. Mechanical valves, severe valvular stenosis or valvular regurgitation of the tricuspid or pulmonary valve. Mural thrombus of the right atrium or vena cava. Anatomic conditions precluding insertion of the pump. Presence of a vena cava filter or caval interruption device, unless there is clear access from the femoral vein to the right atrium that is large enough to accommodate a 22 Fr catheter.
POTENTIAL ADVERSE EVENTS
The potential adverse effects (eg, complications) associated with the use of the Impella RP System: Arrhythmia, Atrial fibrillation, Bleeding, Cardiac tamponade, Cardiogenic shock, Death, Device malfunction, Hemolysis, Hepatic failure, Insertion site infection, Perforation, Phlegmasia cerulea dolens (a severe form of deep venous thrombosis), Pulmonary valve insufficiency, Respiratory dysfunction, Sepsis, Thrombocytopenia, Thrombotic vascular (non-central nervous system) complication, Tricuspid valve injury, Vascular injury, Venous thrombosis, Ventricular fibrillation and/or tachycardia.
In addition to the risks above, there are other WARNINGS and PRECAUTIONS associated with Impella RP®. Visit http://www.abiomed.com/impella/impella-rp to learn more.
General Indication and Safety Information
To learn more about the Impella platform of heart pumps, including important risk and safety information associated with the use of the devices, please visit: www.protectedpci.com/indications-use-safety-information/