What are the options for mechanical circulatory support in patients with impaired cardiac function?

Mechanical Circulatory Support Options in Impaired Cardiac Function

For patients with impaired cardiac function requiring mechanical circulatory support, select devices based on the clinical scenario: IABP for initial stabilization in suspected coronary hypoperfusion, ECMO for rapid biventricular support with respiratory failure, percutaneous devices (Impella, TandemHeart) for intermediate support, and durable LVADs for long-term support as bridge to transplant or destination therapy. 1

Short-Term Mechanical Circulatory Support

Intra-Aortic Balloon Pump (IABP)

IABP should be your first-line device for cardiac dysfunction with suspected coronary hypoperfusion, particularly in perioperative settings. 1 The device provides hemodynamic support through diastolic augmentation of aortic pressure and afterload reduction, increasing coronary perfusion while decreasing myocardial oxygen consumption. 1, 2

Key clinical points:

• Insert IABP as soon as evidence points to cardiac dysfunction, preferably intraoperatively, to avoid excessive inotropic requirements 1
• IABP is contraindicated in severe aortic insufficiency and advanced peripheral/aortic vascular disease 1
• Support duration is limited to days due to arterial complications and patient immobilization 1
• However, note that IABP is NOT routinely recommended in cardiogenic shock based on more recent evidence 1

Extracorporeal Membrane Oxygenation (ECMO)

Use ECMO for medically refractory cardiogenic shock with poor oxygenation requiring rapid emergency biventricular support. 1, 2 ECMO can be placed rapidly at bedside via peripheral femoral vessel cannulation. 1

Clinical outcomes and considerations:

• Adult survival: 58% to hospital discharge, with 76% at 3 days, 38% at 30 days, and 24% at 5 years 1
• Pediatric survival: 43-54% overall, but up to 83% in pediatric and 75% in adult acute myocarditis 1
• ECMO provides an elegant low-cost short-term solution as bridge to recovery or decision-making when hemodynamics are inadequate with unclear long-term indication 1
• Duration limited to weeks of support with necessary perfusion support and vascular access complications 1

Percutaneous Devices

Percutaneous MCS devices (TandemHeart, Impella) generate up to 5 L/min flow but cannot be recommended as proven efficacious treatment for acute cardiogenic shock. 1 A meta-analysis of three randomized trials (100 patients) showed these devices were safe with better hemodynamics than IABP but did not improve 30-day mortality and caused more bleeding complications. 1

These devices may serve as bridge to definitive therapy in selected patients. 1

Centrifugal Pumps

CentriMag and similar centrifugal pumps provide intermediate support with 30-day survival of 47%. 1 Several studies report support for 100 days without pump failure or thromboembolic events. 1 Some centers use CentriMag for ECMO support, allowing rapid biventricular support initiation. 1

Long-Term Mechanical Circulatory Support

Left Ventricular Assist Devices (LVADs)

For end-stage chronic heart failure, continuous-flow LVADs achieve excellent outcomes with 2-3 year survival rates of approximately 90% at 1 year and 80% at 2 years, comparable to early heart transplantation survival. 1

Device technology progression:

• Second-generation continuous-flow devices (axial/centrifugal) have miniaturized components, thin flexible drive-lines, and prospective lifetimes exceeding 10 years 1
• Third-generation devices use magnetic field or hydrodynamic levitation, eliminating mechanical wear 1
• Modern LVAD therapy goals include ventilator weaning, mobilization, ICU discharge, home discharge, and return to work—not just survival 1

Clinical Strategy Framework

Bridge to Recovery (BTR)

Use temporary MCS to sustain circulation after acute events (postcardiotomy shock, acute myocarditis) until cardiac recovery occurs. 1, 2 This was the earliest MCS application, established with postcardiotomy shock where failure to wean from bypass meant certain death without temporary support. 1

Bridge to Transplantation (BTT)

LVADs are indicated for bridging to transplantation in patients at high risk of death while awaiting donor hearts. 1, 2 Currently, more than 60% of patients are transplanted in high-urgency status, with median waiting times of 16 months in Eurotransplant regions. 1 Only 10% of BTT patients receive organs within 1 year of listing. 1

Destination Therapy (DT)

For patients ineligible for transplantation, permanent LVAD as destination therapy reduces mortality and is a Class IIa recommendation. 1, 2 This applies to patients with advanced heart failure, high 1-year mortality risk, and absence of other life-limiting organ dysfunction. 2

Bridge to Decision (BTD)

Use short-term MCS to stabilize hemodynamics and end-organ function while evaluating for definitive therapy. 2 This is particularly relevant when the patient's candidacy for transplant or long-term support is unclear.

Device Selection by Clinical Scenario

Precardiotomy Heart Failure

Available options: IABP, micro-axial flow pumps, percutaneous ECMO, or left atrial-femoral artery centrifugal pumps. 1

Failure to Wean from Cardiopulmonary Bypass

Options include: IABP, micro-axial flow pumps, ECMO, centrifugal pumps as LVAD/RVAD/BiVAD, percutaneous pulsatile devices, or long-term implantable devices. 1

Postcardiotomy Heart Failure

Full range of devices available: IABP, micro-axial flow pumps, ECMO, centrifugal pumps, percutaneous pulsatile devices, and first/second/third generation long-term implantable devices. 1

Cardiogenic Shock

All cardiogenic shock patients should be rapidly transferred to tertiary care centers with 24/7 cardiac catheterization and dedicated ICU with short-term MCS availability. 1 Short-term MCS may be considered in refractory shock depending on age, comorbidities, and neurological function. 1 Based on current evidence, no single mode of short-term circulatory support is recommended over another. 1

Critical Decision-Making Principles

Complex MCS candidacy decisions must be made by experienced multidisciplinary teams. 1, 2 While smaller programs may implant elective destination therapy devices in highly selected patients, acutely ill patients require referral to quaternary care hospitals experienced in managing such cases. 1

Consider MCS early rather than late, before end-organ dysfunction becomes evident. 1 Patients too profoundly ill with multisystem organ failure cannot benefit even from aggressive MCS and inotropic therapy. 1 MCS should be considered as a course of treatment, not as a last effort in failing hearts. 1

A difficult decision to withdraw MCS may be necessary when patients have no potential for cardiac recovery and are ineligible for longer-term support or transplantation. 1