What are the indications and management strategies for using a Left Ventricular Assist Device (LVAD) versus Extracorporeal Membrane Oxygenation (ECMO) in a patient with severe heart failure or cardiogenic shock?

LVAD and ECMO in Severe Heart Failure and Cardiogenic Shock

Use ECMO (or other short-term mechanical circulatory support) for patients in INTERMACS Level 1-2 cardiogenic shock to stabilize hemodynamics and end-organ perfusion as a bridge-to-decision, then transition to LVAD for longer-term support once contraindications are excluded and the patient is optimized. 1

Device Selection Algorithm Based on Clinical Severity

INTERMACS Level 1 (Cardiogenic Shock)

• Deploy ECMO or percutaneous support devices immediately in patients with hemodynamic instability despite escalating catecholamines and critical hypoperfusion of target organs 1
• ECMO serves as bridge-to-decision until hemodynamics stabilize, contraindications for long-term support are excluded (particularly brain damage after resuscitation), and candidacy for LVAD or transplant can be evaluated 1
• One-year survival with LVAD therapy at this level is only 52.6±5.6%, reflecting the severity of illness 1
• Critical pitfall: Waiting too long before initiating mechanical support leads to irreversible end-organ damage and worse outcomes 1

INTERMACS Level 2 (Progressive Decline)

• Either ECMO or LVAD can be used in patients on intravenous inotropic support with acceptable blood pressure but rapid deterioration of renal function, nutritional state, or congestion 1
• ECMO is preferred when there is uncertainty about candidacy for durable support or need for rapid stabilization 1
• One-year survival with LVAD therapy is 63.1±3.1% 1
• If ECMO is deployed first, plan transition to LVAD after 8±4 days once organ function improves 2

INTERMACS Level 3-7 (Stable but Inotrope Dependent to Ambulatory)

• LVAD is the device of choice for patients with hemodynamic stability on low-to-intermediate inotropes or those who are ambulatory but severely limited 1
• One-year survival improves dramatically: Level 3 (78.4±2.5%), Level 4 (78.7±3.0%), Level 5 (93.0±3.9%) 1
• Earlier implantation at Levels 4-5 shows superior outcomes compared to waiting until more severe deterioration 1, 3

ECMO-Specific Indications and Management

When to Choose ECMO

• Refractory cardiogenic shock with critical hypoperfusion despite maximal pharmacological therapy and IABP support 4
• Underlying cause is potentially reversible (acute myocarditis, peripartum cardiomyopathy, post-cardiotomy shock) 4
• Need for rapid stabilization while determining candidacy for definitive therapy 1
• Biventricular failure requiring both cardiac and respiratory support 4

ECMO Contraindications

• Irreversible brain damage (particularly after prolonged cardiac arrest) 1, 4
• Advanced age with multiple comorbidities indicating poor recovery potential 4
• Prolonged CPR without adequate perfusion 4

ECMO Management Strategy

• Use veno-arterial ECMO configuration for cardiogenic shock 4
• Critical limitation: ECMO increases left ventricular afterload and does not unload the LV, potentially causing ventricular distension and pulmonary edema 5, 6
• Solution: Consider adding transapical left ventricular vent or maintaining Impella device during ECMO support to prevent LV distension 5, 6
• Plan for transition within days to weeks: either to recovery, durable LVAD, or transplantation 4

ECMO-to-LVAD Bridge Strategy

• ECMO stabilizes circulation and improves organ perfusion before LVAD implantation 2
• Optimal timing for transition is when liver function (GOT decreased from 206.25±106.93 to 70.6±32.9 U/L, GPT from 333.5±207.3 to 77.8±39.7 U/L) and renal function (creatinine from 2.2±0.9 to 1.2±0.2 mg/dL) improve 2
• Keep ECMO running for 3 days after LVAD implantation to provide right ventricular support during the immediate postoperative period 2
• One-year survival from LVAD implant after initial ECMO stabilization is 75%, not significantly different from direct LVAD implantation 7

LVAD-Specific Indications and Management

Primary LVAD Indications

• End-stage heart failure with LVEF <25% and peak VO₂ <12 mL/kg/min on cardiopulmonary exercise testing after >2 months of optimal medical therapy 3
• ≥3 heart failure hospitalizations in the previous 12 months without obvious precipitating cause 3
• Dependence on continuous intravenous inotropic therapy 3
• Progressive end-organ dysfunction with worsening renal and/or hepatic function 3
• Severe hemodynamic compromise: pulmonary capillary wedge pressure ≥20 mmHg AND systolic blood pressure ≤80-90 mmHg OR cardiac index ≤2 L/min/m² 3

LVAD Strategy Selection

Bridge to Transplantation (BTT)

• Use LVAD in transplant-eligible patients with end-stage heart failure at high risk of death before donor organ availability 1
• Post-transplant survival is similar or better than patients not requiring bridging 1

Bridge to Candidacy (BTC)

• Deploy LVAD to improve end-organ function in initially ineligible patients to make them transplant candidates 1
• Allows recovery of end-organ dysfunction, improved RV function, and relief of pulmonary hypertension 1

Destination Therapy (DT)

• Long-term LVAD use in patients ineligible for transplantation (NYHA Class IIIB/IV, LVEF ≤25%, peak VO₂ <14 mL/kg/min) 1
• Two-year actuarial survival with continuous-flow devices is 58% overall, but 85% in patients up to 70 years without diabetes, renal impairment, or cardiogenic shock 1
• Patient selection is crucial: exclude patients with severe renal, pulmonary, or hepatic dysfunction, active infection, or cardiogenic shock 1

Bridge to Recovery (BTR)

• More likely in younger patients with acute fulminant but reversible causes (acute myocarditis, peripartum cardiomyopathy) 1, 3

Critical LVAD Contraindications

• Active infection 1, 3
• Severe right ventricular dysfunction with severe tricuspid regurgitation 3
• Irreversible severe renal or hepatic dysfunction 1, 3
• Uncertain neurological status after cardiac arrest 3
• Severe peripheral arterial or cerebrovascular disease 3

Right Ventricular Assessment

• Evaluation of RV function is crucial since postoperative RV failure greatly increases perioperative mortality 3
• If severe biventricular failure or high risk for persistent RV failure, consider BiVAD (only for transplant-eligible patients, not destination therapy) 3

Outcomes Comparison

LVAD Survival by INTERMACS Level

• Continuous-flow LVADs achieve 80% survival at 1 year and 70% at 2 years in predominantly non-transplant-eligible patients 1
• Survival is significantly better with earlier implantation (Level 5: 93.0% vs Level 1: 52.6% at 1 year) 1

ECMO as Bridge to Advanced Therapies

• ECMO use as bridge to LVAD or transplant has increased from 1.7% in 2010 to 22.2% in 2019 8
• Mortality is similar between ECMO-to-LVAD (28.7%) and ECMO-to-transplant (29.1%) 8
• Length of stay is longer for transplant (59.5 days) versus LVAD (49.6 days) 8

Key Management Principles

Timing Considerations

• Do not wait until INTERMACS Level 1-2 to refer for LVAD evaluation - earlier implantation shows better outcomes 1, 3
• ECMO should be initiated early, before irreversible end-organ damage occurs 4
• Decision to transition from ECMO to LVAD should occur within 8±4 days once organ function improves 2

Center Requirements

• LVADs should only be implanted and managed at specialized centers with trained heart failure physicians, cardiac surgeons, and outpatient LVAD clinics with trained nursing staff 1, 3
• ECMO requires specialized expertise and equipment, limiting availability to tertiary care centers 4

Common Complications

• LVAD complications include bleeding, thromboembolism (causing stroke), pump thrombosis, driveline infections, and device failure 1
• ECMO complications include bleeding at cannulation sites, limb ischemia, and LV distension with pulmonary edema 4, 6