Anaesthesia in ACHD Dr Amit Ranjan

Consultant Cardiac anaesthetist and cardiac intensive care

Bristol Heart Institute

Introduction

CHD is most common birth defects, 1% of newly born .

Improvement and new surgical technique- CHD pt live longer, and pose

significant challenge .

Perioperative care is challenging and need to be evidence based.

Thorough knowledge of pathology and physiological changes is key of

successful management of ACHD.

Physiologic Classification Congenital

Heart Disease

Acyanotic CHD

• With Left-to-Right Shunt

• Without Left-to-Right Shunt

Cyanotic CHD

• Ductal-dependent Pulmonary Blood Flow

• Ductal-dependent Systemic Blood Flow

• Mixing Lesions

Acyanotic CHD

1. With L-to-R shunt

• Physiology - Volume overload in at least 1 cardiac chamber • Increase

Pulmonary Blood Flow can lead to PHTN

exp..ASD, VSD, PDA, PAPVR

2. Without L-to-R shunt

• Physiology- Increase pressure load • Limited CO/blood flow • Can lead to

significant cardiac hypertrophy

Exp.. Valve disease , Coarctation of Aorta

Cyanotic CHD

Right-to-Left shunt

• Venous admixture is added to the systemic circulation

• Ductal-dependent PBF

• Tetralogy of Fallot

• Pulmonary Atresia

• Tricuspid Atresia

• Single Ventricle

• Ductal-dependent SBF

• Critical Coarctation of Aorta

• Critical Aortic Stenosis

• Hypoplastic Left Heart Syndrome

• Mixing Lesions

• AVSD

• Double Outlet Right Ventricle

• TAPVR

• Transposition of the Great Arteries

• Truncus Arteriosus

Adult Congenital Heart Disease Most common congenital disorder of newborns

• 1% of live births

• Advances in cardiovascular medicine and surgery

85-95% survive to adulthood

15-25% survival of patients prior to treatment availability

Long term Survival by complexity of

CHD

95%

Simple

90 %

Moderate

80%

Severe

ASD Anamolous Pulmonary

venous drainage

Single ventricle palliation

VSD Atriaventicular canal

defect

TGA

PFO Coarctation of aorta Truncus arteriosus

PDA TOF Tricuspid atresia

Mild PS VSD with assoc Pulmonary atresia

Long term sequelae – Cardiac

• Pulmonary hypertension

• Ventricular dysfunction

• Dysrhythmias and conduction defects

• Residual shunts - Cyanosis

• Valvular lesions- Stenosis, regurgitation

• Hypertension

• Aneurysms

Long term sequelae – Non cardiac

Secondary erythrocytosis

• Cholelithiasis

• Nephrolithiasis

• Neurodevelopment

abnormalities

• CNS disease

• Seizure

• CVA (thromboembolism)

• Hearing/vision loss

• Chronic lung disease

• Hepatic dysfunction, Cirrhosis

• Renal impairment

• Coagulopathy

• Cancers

ACHD management issues:

Changing Age prevalence of CHD

Which hospital for ACHD patients?

Which anaesthetist for which ACHD patient ?

Changing age prevalence of CHD

Increasing survival in CHD has changed age distribution of CHD patients.

One of the most important improvements was achieved by Fontan and

Baudet, pioneers in the field of single ventricle palliation.

Numbers of ACHD now surpasses those of children with CHD. More than a

third of these ACHD patients are currently at least 45years old.

Which hospital for ACHD

Several recommendations and guidelines – though level of evidence is low.

Any non cardiac surgical procedure in CHD pt carries a much higher risk

than non –CHD grp of patients.

Severe/complex CHD grp mortality increase by 2 folds compared to

control, however, with minor/simple CHD no such increase in mortality.

Despite missing high level evidence, its recommended that patient with

complex CHD should be treated by specialised centres, even if surgical risks

of non-cardiac procedures may be rated as low.

Which anaesthetist for which ACHD

In 2008 ACC/AHA recommended that all general anaesthesia and

sedation in ACHD with moderate to complex CHD should be performed in

regional ACHD centre.

Enough evidence and studies done to show that, if surgical procedure

done in mod./complex CHD grown up in non-cardiac centre or

noncardiac anaesthetists- morbidity and mortality is high.

More cardiac arrests in CHD patients were reported during non cardiac

surgery in the genral operating room (54%) than during cardiac surgery

(26%) and cardiac catherization (17%).

Anaesthetic Management

3 grp of ACHD

1. Uncorrected CHD patients

2. Patients with previous palliative surgery

3. Patients with previous corrective surgery .

Anaesthetic management in ACHD patients may change completely

depending on type of repair, age at repair, associated defects with specific

long term risk factors and complications.

Preoperative Risk assessment for

anaesthesia

Individual risk of ACHD patients depends on 4 aspect:

1. Underlying nature of CHD

2. Individual course of CHD

3. Aware of substantial CHD associated noncardiac morbidity

4. Type of cardiac/noncardiac surgical procedure.

Heart Failure

Leading cause of death in ACHD

Evaluation of HF in ACHD is more tricky – rely on physical status and echo

- Biomarker like NT-proBNP – useful tool . NTproBNP >33.3pmol/l is strongly

associated with cardiovascular events and death or HF.

In CHD pt, NTproBNP levels <15.2 pmol/l , the cumulative proportion of death

and HF was below 1%.

Arrythmias and Anticoagulation

Supraventricular tachycardia is more than ventricular arrythmias

ACC/AHA guidelines in 2016 for Mx of arrythmias in ACHD

Anticoagulation – AF

scoring system CHADS2 – not predictive for thromboembolic risk in ACHD

ACHD pts aged below 55 yrs revealed a 9-12 times higher age-sex

standardized incidence rate of ischaemic stroke.

More complex CHD – more high risk of thromboembolic events, Khairy et al.

perioperative anticoagulation has to be evaluated by a MDT, carefully

opposing risks of thromboembolic complications vs haemorrhage.

Recent evidence, Bouillon et al, suggest that for non CHD patients , bridging

therapy with heparin in AF pt., is associated with more risk of bleeding and a

similar risk arterial thromboembolism compared with no bridging therapy.

-------whether this can be transferred to ACHD pt., we need further studies.

Anaesthetic Technique

Regional Anaesthesia :

Look for bony deformity, able to lie flat, anticoagulation .

Physiological changes.

- General anaesthesia :

No anaesthetic technique is prohibited in ACHD patients. However, a

profound understanding of anaesthesia induced physiological changes and

anticipation of consequences in abnormal circulation in each individual ACHD

case is crucial.

Fontan Population

Major long term problems in Fontan patients are supraventricular

arrythmias, heart failure , Fontan specific problems like protein-losing

enteropathy, pulmonary arteriovenous fistulae, as well as liver disease

including liver cirrhosis and hepatocellular carcinoma.

During GA – high risk of haemodynamic instability due to positive pressure

ventilation. (Passive lung perfusion – increase in intrathoracic pressure –

impaired transpulmonary pressure gradient – low pulmonary flow – Low CO)

Fontan hearts often reeal an impaired ventricular systolic contractile

function and a chronotropic incompetence as wellas pre-load

dependence, which is essential for intraoperative anaesthetic

management.

Tachycardia, bradycardia, hypovolemia, and positive pressure ventilation

are therefore undesirable in patients with Fontan circulation.

Shunts & Cyanosis in CHD

Haemodynamic point of views, 3 types of shunt

1. Intracardiac ( ASD, VSD)

2. Vascular shunt ( systemic to pulmonary shunt)

3. Complex shunt ( truncus arteriosus, TAPVD etc)

Most Left – Rt shunt , causing increase PBF, and if longstanding PulmHT, Rt sided heart issues.

Shunt reversal can happen during anaesthesia – systemic hypopersion – acidosis – further decrease in SVR.

Anaesthetist need to be aware of it and treat appropriately to prevent haemodynamic collapse.

Pregnancy and congenital heart

disease

Increasing number of women with complex CHD reaching child bearing

age

Women with Fontan circulation hve reached childbearing age

Anaesthesia techniques for delivery are predominantly neuraxial

catheters(86%) whereas general anaesthesia is an exception.

Most complications in this population were post partum haemorrhage and

arrythmias .

Heart failure is the most common complication during pregnancy with two

peaks – 23-30wks and around delivery .

Cardiac disease in pregnancy risk

score

Predictors of cardiovascular events Point

Prior cardiac even (Heart failure, TIA,

MI prior to surgery) or arrythmias

1

NYHA functional class at baseline > II

or Cyanosis

1

Left heart obstruction (mitral valve

area <2.0, aortic valve area <1.5, and

LV outflow tract gradient >30mmHg)

1

Reduced systolic ventricular function

( EF <40%)

1

zero point <5% risk of cardiac

complications, 1 point – 27% risk , 2 or

more >75% risk

Red flags for Anaesthesia

Cyanosis

Poor exercise tolerance

Limited mobility/ wheel chair bound

Cardiac studies shows poor EF, high pulm HTN, poor RV

Complex CHD e.g Fontan’s circulation

Allergy to common anaesthetic drugs

Conclusion

Any surgical procedure in ACHD patients carries a greater risk than in the

normal population

Growing population of ACHD – clinicians need to take care in wide range

of settings

Risk evaluation and perioperative management of CHD – associated

cardiac and noncardiac morbidity is challenging and calls for a

multidisciplinary team approach.

Questions….

Thank you ..