Autopsy Cause of death in

‘Presumed Cardiac’ aetiology

Out-of-Hospital Cardiac

Arrests in Young Adults

Presenter; Dr Conor Deasy, FACEM, FCEM

PhD Student

Deasy C, Bray J, Smith K, Harriss L,

Bernard S, Cameron P on behalf of the

VACAR Steering Committee

Background

Background

• OHCA is presumed of cardiac aetiology unless as best

determined by rescuers it is known or likely to have

been caused by;

- Trauma

- Submersion

- Drug overdose

- Asphyxia

- Exsanguination

- Other noncardiac cause

Background

• The aetiology in the young adult age group is likely to be

different to that of older adults where ischemic heart

disease is more common. Zipes et al. Sudden cardiac death. Circulation.

1998;98(21)

• Realising the aetiology of the cardiac arrest may

influence treatment decisions.

• Much attention towards structural heart abnormalities &

cardiac electrical disorders

- Genetic screening Doolan A et al. Causes of sudden cardiac death in

young Australians. Med J Aust. 2004;180(3)

Aims

We aim to describe the autopsy findings of young adults

in Melbourne where the OHCA precipitant was

‘presumed cardiac.’

Melbourne, Australia

• Population; 4 million

• 35.6% aged 16-39 years

• Area; 10,000 km2

Ambulance Victoria

Paramedics all educated to ALS

Base qualification for a paramedic

is a Bachelor's degree

Post graduate diploma conversion

course

MICA – university level

postgraduate diploma

Data

Electronic patient record (VACIS)

Victorian Ambulance Cardiac

Arrest Registry (VACAR)

- Clinical and Utstein data

elements

- Hospital data including

outcome

Methods

• VACAR was searched for all OHCAs occurring in

patients aged 16-39 years occurring 2000-2009.

• Cross checked cause of death with coroner’s office

• Excluded Patients

EMS witnessed OHCA

Drug overdoses on autopsy

• Compared autopsy confirmed ‘cardiac’ and confirmed

‘non cardiac’ OHCA

Ethics approval

Results

OHCA

• OHCAs n=842

• Discharged Alive n=86

• Survival 10.2%

Post Mortems

• PMs not done or unavailable n=278

• 551 PMs available (73%)

• Cause of death not ascertainable on PM n=98 (18%)

• Confirmed ‘Cardiac’ n=233 (42%)

• Confirmed ‘Non Cardiac’ n=220 (40%)

Results

• Years 2000-2009

• Age Median(IQR) 33(27-37) years

• 71% male

‘Cardiac’ Cause of Death (n=233)

%

53

12 10

5 4 3 3 2 1 2

0

10

20

30

40

50

60

‘Non Cardiac’ Cause of Death (n=220)

26

13 11

10 8

7 6

5 4

3 2 2

3

0

5

10

15

20

25

30

%

Unascertainable n=98

Results

‘Non Cardiac’ n=220 ‘Cardiac’ n=233

Age 32(26-37) 34(30-38)*

Male 64% 78%*

Bystander CPR 21% 34%*

Witnessed Arrest 24.6% 42%*

EMS Response Time 7(5.9-10.3) 7.95(6-9.7)

Shockable Rhythm 21.5% 78.5%*

Resuscitated 45.8% 61.2%*

ROSC 47.6% 52.4%

Discussion

• Cause of cardiac arrest in the 16-39 year old sub group

patients is challenging to predict.

• Where autopsy provided cause of death in ‘presumed

cardiac’ OHCA 49% were ‘non cardiac’

• ‘Presumed cardiac’ group was significantly different

Older, Male, Shockable, Witnessed, Received Bystander CPR.

Discussion

• Better knowledge of the causes of OHCA is important in

supporting the development of diagnostic and treatment

pathways in OHCA

Prehospital ultrasound, echo, thrombolysis

• Aetiological heterogeneity may undermine the impact of

improved EMS standards of care

Limitations

• The data does not report drug overdose

• Aetiology of OHCA in those that survived to hospital

discharge is not reported

• Decisions to perform/withhold performing a complete

autopsy are not standardised between coroner’s, states,

countries.

Conclusion

Linkage of Cardiac Arrest Registries with Coroner’s data

and hospital diagnostics may provide the key to

improved diagnostic and treatment algorhythms in

OHCA and be more sensitive to the outcome benefits of

such interventions.