Mechanical Support for Acute Cardiogenic Shock

Mark J. Russo, MD, MSAssistant Professor of Surgery

Section of Cardiac and Thoracic SurgeryUniversity of Chicago

Disclosures

No relevant disclosures

Severe Acute Cardiogenic Shock

• Associated w excessive mortality

• If untreated will lead to imminent death

• Etiology: Post-cardiotomy, AMI, Myocarditis, Acute on chronic cardiomyopathy, Malignant arrhythmia

• Goals: Must rapidly stabilize and “rest” heart

• Treatment: Mechanical support + OMM

• Endpoint: Recovery• Definitive surgical therapy should not be offered in the acute setting

When and How to Initiate MCS

Simple Rules for Initiating MCS

• Pt continues to deteriorate despite increasing drugs

• Initiate before the patient absolutely needs it

• If you put an unsalvageable patient on MCS, they remain unsalvageable

• Its not the devices that are bad, it’s the patients who are sick

Hard Parameters for Initiating MCS• Already on inotropes and IABP

Increasing support level required

• Hemodynamics – must maintain– CI >2.0 – BP mean >60mmHg – SBP> 85 mmg– CVP <15 – PCWP <20– End organ function : renal, hepatic, pulmonary, cerebral

• Balance– Hemodynamics not attainable– Increasing inotrope requirements especially vasoconstrictors

MCS Options

• Partial Circulatory Support

• Full Circulatory Support

• Full Cardiopulmonary Support

Partial Circulatory Support

• IABP

• Impella/Abiomed

• Subclavain-IABP

Impella Abiomed

• Micro rotary pump– 2.5

• Cath lab, percutaneous insertion

– 5.0 (larger, more flow)• Graft or cutdown

• Advantages– Easy to insert– Active de-compression of LV

– Less invasive• Less support than rotary pumps

Impella Abiomed

Subclavian Intra-Aortic Balloon• Intra-aortic balloon pumps

(IABPs) are traditionally inserted through the femoral artery, limiting the patient’s mobility.

• Advantages of SC: • PVD less of an issue, • minimally invasive support, • ambulatory

• Limitations: • Time (40-1 hr), peri-stable, • Connective tissue disease

Subclavian Intra-Aortic Balloon• The graft is then tunneled into the

pocket.

• The guidewire is though the skin and then into the graft and then through the subclavian artery into the aorta.

• Under fluoroscopic guidance, the balloon wire is positioned in the descending thoracic aorta.

• The balloon is inserted and screened into an appropriate position.

• The wound over the Gore-Tex graft is closed in layers.

Operative Approach

Ambulating with IABP

Introduction

Methods

Results

Conclusions

• Mean duration of support : 21 days (range: 3 – 90)

• 19 patients (95%) were successfully bridged to transplant or LVAD.

• 2 patients (10%) required an emergent LVAD for worsening heart failure.

• All patients were extubated and ambulatory within 24 hours following the procedure

• No device-related complications while on support• 1 device exchanged at bedside

Outcomes (n=20)

Full Circulatory Support

• Extracorporeal VADs– LVADs– RVADs– BIVADs

• Implantable VADs – are not for acutely decompensating patients– Surgical trauma– Bridge to ?

Management options – what to support?

• LVAD– ECHO (function and MR)– High filling pressures with hypotension and low CO– PCWP >18 with mean BP <70mmHg and CI<1.8

• RVAD– ECHO (function and TR)– CVP > 15mmHg with mPA < 1.5 x CVP– Underfilled LV– mPA > 2x CVP relative exclusion (may need LVAD or ECMO)

Centrimag• Indications:

• Short-term support (<15 days) • Bridge-to-decision (recovery vs definitive

therapy)

• Device:• a single-use centrifugal pump, a motor,

and a primary drive console. • the motor magnetically levitates the

impeller, • achieving rotation with no friction or wear• rotates at 1500-5500 rpm • Flows: up to 9.9L/min

LVAD cannulation

• Surgical– Outflow from device

• Aorta, femoral artery

– Inflow to device• LA/PV• LV

Centrimag

• Off Pump

• Sternotomy

• Left Thoractomy

RVAD cannulation

• Surgical– Outflow from device

• PA - Do not push in too far• RVOT across PV

– Inflow to device• RA – careful positioning• RV

• Percutaneous– Outflow from device

• Via long cannula to PA

– Inflow to device• Femoral vein, IJ, subclavian

Advantages of Centrimag

• Relatively inexpensive• Reliable• High level of support• Allows for further esculation of care

– Implantable device– RVAD– ECMO

Case

• 65 year old male• S/P traumatic right BKA after MVA• Fully functional, employed as businessman• Crescendo chest pain for 2 weeks, neglected• Unrelenting angina for 24 hours before presenting to ER• LHC performed

Coronary angiogram

Patient course

• Emergency IABP placed• Transferred to tertiary care center• Hemodynamic data

– BP 70/50 augmented– PA 45/27– CVP 16– CI 1.2

• Labs: Cr 2.5; TB 4.0; AST/ALT >1,000• Support: IABP, dopamine 20 mg/kg/min, dobutamine 20

mg/kg/min, ventilator with paO2 70 on FIO2 80%

Patient course

• Anuric• Peripherally cold• Obtunded• ECHO:

– No AI– Severe MR– Moderate TR– LVEF <10%, without thrombus

Hospital course

• Centri-Mag LVAD placed off pump.• Reversed acidosis• Recovered renal and hepatic function• Pulmonary edema resolved• Total CT output <300cc• Anticoagulation started POD#1• Extubated POD#3• HeartMate II placed POD#5 to allow for rehabilitation

Full Cardiopulmonary Support

• Heart and pulmonary failure

• ECMO– Standard (Thoratec Centri-mag/Maquet Quadrox)– Portable (Maquet Cardiohelp)

Criteria

• With optimized ventilator settings– pO2 < 65mmHg– Sa02 < 90%– PEEP > 10

Standard ECMO: Centrimag + Quadrox

Centrimag Quadrox

In Situ

Centrimag

Quadrox

Advantages of Centrimag/Quadrox

• High level of support• Reliable• Relatively Inexpensive• Peripheral/Percutaneous/Central Access• Oxygenator can be cut-in to BIVAD/RVAD circuit at

the bedside

Disadvantages of ECMO

• It does not decompress the heart– unless LV vent placed

• Contraindicated in moderate to severe AI

• Oxygenator induced inflammatory response

• Need for anticoagulation– ACT 150-200

MCV00006533

CARDIOHELP – INSPIRING INNOVATIONS

• Acute Respiratory Distress Syndrome (ARDS)

• Septic Shock Syndrome• Multiple Organ System

Failure• Pulmonary Embolism

CRITICAL CARE MEDICINEPOSSIBLE APPLICATIONS

CARDIOHELP

• All in one heart-lung support system• 10 kg (22lbs)• 14 x 10 x 17 inches• Optional Sprinter Cart for in hospital

mobility

General Surgery

Neurosurgery

Cardiac Surgery

Vascular Surgery

Operating Room:

Cardiac Care

Neonatal Intensive Care

Critical CareUnit:

Options

Patient Transport:

Interventional

Cardiology Procedures

Hybrid OR / Cath Lab:

TRANSFER OPTIONS

• Transfer pt and initiate at accepting center

• Transferring center initiates ECMO– Convert to Cardiohelp

• Accepting initiates ECMO on site using Cardiohelp

In cardiovascular disease, we have a just say “YES” policy

Case

• 54yo M p/w CP to outside ED

• Troponin 20

• Taken to cath lab– Found to have RCA occlusion– Intervention unsuccessful– Worsening stability c high dose pressors– Intubated/IABP placed

• Transferred to UofC

Case

• Airlifted to UofC

• Directly to the OR

• Peripherally cool, MAPs 55, anuric, SaO2 85%

• Lactate: 7, pH 7.21, pO2 57

• ECHO: severe RV failure, LVEF=35%

Case

• Peripheral cannulation via femoral cutdown– RFA – arterial inflow– RFV – venous drainage– Antegrade to RFA via 12Fr cannula

Case• OR

– Flow: 6.0L, FiO2=100%– MAPs 70s, SaO2=100%

• HD#1– Weaning pressors– CVVHD– pH normalized, PaO2=300s

• HD#4– Off pressors and inotropy

Case• HD#6

– Weaned from ECMO after 2 day wean• Wean flows

– IABP, inotropy

• HD#10– Extubated

• HD#12– Off inotropy

• HD#19– Discharged to rehab

Support initiated – then what?• Maintenance:

– Anticoagulation• Initial – ECMO ACT 150 – 180, VAD none• After bleeding stops – 150 – 180 sec

– Minimize inotropic support– Evaluate cerebral and other end organ function– IABP for some pulsatility

• End goals:– Recovery and wean– Bridge to longer term solution

• Definitive surgical treatment is not appropriate in acute setting

Weaning / recovery

• Native ejections with decreasing support• Allow time to re-equilibrate• Continuous SG useful for LVAD (even for RVAD as it

give MVO2 saturation)• ECHO• Minimize anesthesia• Bad sign if escalating inotropes or requiring IABP

Outcomes

• Difficult to characterize given heterogeneity of patients• Recovery depends on ability to repair myocardium• Bridge to device depends on:

– Earlier initiation of mechanical therapy– Single vs bi-VAD support– Liver function marker for survival– Respiratory status– Neuro

• Reports vary from 30 – 80% success rates

Summary

• Paradigm shift– Initiate earlier–Better less inflammatory technology–Easier to initiate–Better Outcomes

Take Home Points

• MCS should be initiated early

• Temporary support, not implantable device

• Definitive therapy should only be offered after patient demonstrates measurable recovery