Out of Hospital Treatment of STEMI Patients
James J McCarthy MD FACEP
Assistant Professor of Emergency Medicine
University of Texas Medical School – Houston
Medical Director Emergency Medical Services Memorial Hermann Hospital –
Texas Medical Center
Medical Director Emergency Medical Services – West University Place, Texas
Disclosures
None related to topic
DOD grant funding for mTBI research
NIH funding for mTBI research
DOD/NHLBI funding for hemorrhagic shock research
CDC funding for HIV surveillance
Background •
Coronary Heart Disease (CHD) caused 1 of every 5 deaths in the
United States in 2003.
•
Acute MI mortality is an underlying or contributing cause of death in
221,000 patients annually
•
CHD is the single largest killer of American males and females.
•
Every 26 seconds an American will suffer a coronary event, and about
every minute someone will die from one.
•
The annual estimated direct and indirect cost of CHD is $142.5 billion.
In God We Trust…
All others must bring data!
A beautiful theory can be slain by a single ugly fact!
STEMI Treatment:
• Reperfusion – Time is Muscle
• Every 30 minute delay results in a 7% increase in 1 year mortality. (Cannon JAMA 2000, De Luca Circulation 2003)
• ACC/AHA STEMI Guidelines in 2007
• Door to Balloon <90 minutes
• Door to Needle <30 minutes
Reperfusion
Patient
Transport
In hospital
Reperfusion
Goals
D-N ≤ 30 min
5 min
< 30 min
Media campaign
Patient education D‐B ≤ 90 min
Methods of
Speeding Time
to Reperfusion
Pre‐hospital
ECG
Greater use of 911
Pre‐hospital Rx
and
Pre‐hospital Rx
MI protocol
Critical pathway
Bolus lytics Dedicated PCI team
Relationship Between Mortality Reduction and Extent of Salvage
100
80
Potential
outcomes
E
60
%
D
A-B – no benefit
A-C – benefit
B-C – benefit
E-D – harm
C
40
B
20
A
Mortality reduction (%)
Extent of salvage (% of myocardium at risk)
0
1
3
Time to treatment is critical
Gersh JAMA 2005
6
12
Hours
24
Reducing Time From Symptom Onset
One-year mortality, %
To IRA Reperfusion is Critical
12
6 RCTs of Primary PCI by Zwolle Group
1994 – 2001 n = 1791
10
Prague II 277 min
7.3%
8
6.1%
6
ASSENT- 4 PCI 255 min
4.8%
4
CAPTIM 190 min
2
0
0
60
120
180
240
300
Symptoms to balloon inflation (minutes)
DeLuca et al. Circulation 2004;109:1223.
360
STEMI Care:
the State of the System
In contrast to the expeditious care system that has
evolved for trauma patients, treatment for STEMI
patients remains unorganized and arbitrary across
the various regions of the US.
State of the System:
400,000 STEMIs anually in the US
•
30% do not receive reperfusion therapy
•
20% are not eligible for fibrinolytic therapy
•
33 % of US Hospitals have a Cardiac Catheterization Lab
•
2/3 of 1.5 million AMI per year present to hospitals without cath labs
•
79% of the US population lives within 60 minutes of a PCI center
– yet 70% of these patients do not receive primary PCI
Hospital Statistics 2001: AHA
Treatment Strategies
Drugs vs. Hardware
PCI vs. Lysis Meta‐analysis of 23 trials
Short Term Events
P<0.0001
14
P=0.0003
P<0.0001
8
7
7
p=0.0004
5
3
P<0.0001
1 2
0.05 1
I IIa IIb III
Keeley, Lancet Jan 2003
“PCI is Worth the Wait”
(Jacobs, AK 2003 NEJM 349:798)
Not So Fast…
• Need to read the paper not just the Conclusions:
–
–
–
–
23 trials – different enrollments, different operators…
Data span 10–15 years (therapies and techniques change)
Selection bias of pts enrolled
2% mortality benefit with PCI depends on lytic –
(not significant vs. tPA if SHOCK is excluded)
– Composite endpoint is driven by reMI –
potential biases against lytic arms:
• Hard to diagnose peri‐PCI MI
• UFH used in lytic arms‐‐? Better antithrombins
• Dependent on use of PCI post‐lysis
JACC 2004;44: 671.
Circulation 2004;110: 588.
79% of the US population lives
within 60 minutes of a PCI center
However,
43 million adults do not!
Pre‐Hospital STEMI
Emergency Medical Response
• Patient recognition
• 911 response times
• STEMI recognition
– 12 lead capability
• Protocols for triaging STEMI patients
Twelve Lead Acquisition
• AHA “Essential” 1990
• Initial assessment tool
• Does not prolong scene times
• Guides protocols
• Transmission
Time to Treatment Effect of EMS EKG in AMI
With Prehospital Lead 12
W/O Prehospital 12 Lead
Kargounis
48 minutes
103 minutes
Kereiakis
30 minutes
50 minutes
Foster
22 minutes
51 minutes
Cantu
30 minutes 92 minutes (PCI)
40 minutes 115 min (PCI)
Researcher
Recognition of ST elevation by paramedics
Conclusions: UK paramedics can recognize ST elevation using a 12 lead ECG.
Radio transmission of an ECG may not be necessary to pre‐alert the hospital.
Emergency Medicine Journal. 19(1):66‐67, January 2002.
Bradley NEJM 2006
Southern California
STEMI Receiving Centers
•
•
•
•
16.8 Million Citizens in 4 Counties
>4500 Paramedics 127 Paramedic‐Receiving Hospitals
52 of 127 are designated STEMI Receiving Centers (SRCs)
– 909 patients with a PH‐ECG+ for STEMI
• 699 of 909 (77%) underwent primary PCI
– 85% rate of D2B ≤ 90 minutes
– Prior rate < 30%
What about pre‐hospital reperfusion?
Looking not just at Door to Therapy
Instead…
First Medical Contact to Therapy
% of Patients Treated with 1st rPA Bolus
TIMI 19: Time from EMS Arrival to 1st Bolus
Avg time savings 32 minutes
1° Endpoint
p < 0.0001 at 30 and 60 min.
Time from EMS Arrival (minutes)
JACC 2002; 40:71‐77
Relationship Between Mortality Reduction and Extent of Salvage
100
80
Potential
outcomes
E
60
%
D
A-B – no benefit
A-C – benefit
B-C – benefit
E-D – harm
C
40
B
20
A
Mortality reduction (%)
Extent of salvage (% of myocardium at risk)
0
1
3
Time to treatment is critical
Gersh JAMA 2005
6
12
Hours
24
Transport to Level I CV Center
PRAGUE-2: Event rate
30 day mortality (%)
Time from onset of pain
to treatment
< 3 hr
>3 hr
Thrombolysis (IV SK)
7.4
15.3
Transport for 10 PCI
7.3
6.0
(European Heart Journal (2003) 24, 94 – 104)
Reperfusion Strategy 1-Year Survival
*
N=180
N=365
N=434
N=943
* = 67% of patients had early PCI
Danchin N, et al., Circulation 2004; 110:1909-1915.
WEST
Which Early ST‐Elevation Myocardial Infarction Therapy
Armstrong PW, European Heart Journal, 2006
•
Intelligent pre‐hospital lysis vs. rapid PCI
•
121 pre‐hospital vs. 183 PCI patients
•
Pre‐hospital program resulted in PCI 1 hour earlier than “walk in”
patients
•
No significant differences in death, reinfarction, refractory ischemia, CHF, cardiogenic shock, or arrhythmia at 30 days
•
Interventions reserved for high‐risk or rescue PCI
ACS Guideline revisions support early thrombolysis and combined therapies.
The pendulum is swinging back to midline!
PCI versus Fibrinolysis with Fibrin-Specific
Agents: Is Timing (Almost) Everything?
Absolute Risk Difference in Death (%)
10 −
5 −
13 RCTs
N = 5494 P = 0.04
Favors PCI
0 −
Favors fibrinolysis with a fibrin‐specific agent
‐5 −
┬
30
┬
┬
┬
┬
┬
40 50 60 70 80
PCI‐Related Time Delay (minutes)
Nallamothu and Bates. Am J Cardiol 2003;92:824.
Patient Location
• Rural/remote vs. Urban
• Coordination between Ground and Air EMS • Predetermined community landing zones
• Destination Protocols
• Fibrinolytic facility with transfer • PCI center
• Leap frog ‐ activating HEMS to meet crew at local hospital for transfer to PCI center
Report From National Cardiovascular Data Registry:
Wang et al, American Heart Journal 2011
• Transfer patients D2B 149 minutes (10% PCI <90 minutes)
• No correlation between improving D2B in direct arrival patients D2B and Transfer Patients D2B
• <3% received d2B < 90 min
• median door‐to‐balloon time was 131 minutes (interquartile range 114 to 158 minutes)
• 49% received fibrinolysis under 30 minutes prior to transfer.
• Median door‐to‐needle time was 31 minutes (interquartile range 23 to 45)
Annals Of Emergency Medicine March 2011
Buying time in Houston
Time to Treatment for STEMI Patients
100
90
Table 3
80
Time to
treatment
<120
minutes
>120
minutes
p value
% aborted
MI
17.32
11.01
0.18
Peak CK
1765.71
2342.89
0.03
Percent Treated
70
60
50
FAST PCI
PCI
40
30
Fast PCI (n 210)
20
30 day Mortality
2.4%
Stroke
1.4%*
Gusto Major Bleed
0.95%
10
0
<60 <90 <120 <150 <180 <210 <240 <270 <300 <330 <360
Ischemic Time in Minutes
EMS Transport of STEMI Patients
Shortens Ischemic Time and is Associated
with a Higher Risk
Population: Results from the ACTION
Registry.
Methods
•
American College of Cardiology’s National Cardiovascular Data Registry
(NCDR) Acute Coronary Treatment and Intervention Outcomes Network
(ACTION) Registry–Get With The Guidelines (GWTG) Database for
STEMI patients.
•
37,715 patients from 412 sites between July 2008 and Dec 2010 were
analyzed.
•
We compared pre-hospital ischemic time (PHIT) defined as symptom onset
to hospital arrival, first medical contact time (FMCT) and D2B times for
EMS transports (EMS-T) vs. Self transports (Self-T).
•
Transfer-in patients were excluded.
Results
Symptom Onset to Hospital Arrival (min)
Self‐T
EMS‐T
Mean 233
158.4
1st Pctl
12
25
Lower Quartile
59
58
Median
118
89
Upper Quartile
268
161
99th Pctl
1416
1099
Symptom onset to 1st Medical Contact (min)
Self‐T
EMS‐T
Mean 233
123.7
1st Pctl
12
4
Lower Quatrile
59
25
Median
118
53
Upper Quartile
268.2
120
99th Pctl
1416
1052
Mode of Arrival and In-hospital
outcome
EMS-T 1st Medical Contact
vs. Self-T Hospital Arrival.
8
90
80
70
7
60
%
6
50
40
Self-T
30
EMS-T
20
10
5
0
0-60
0-120
time in minutes
0-180
% 4
Shock and CHF on Arrival
3
12
10
2
8
%
1
Self-T
6
EMS-T
4
2
0
Mortality
Shock In-hospital
Self-T
EMS-T
CHF In-hospital
0
Shock on arrival
CHF on arrival
Conclusions
• Patients who call 911 have the highest risk of death from STEMI.
• Thrombolysis can safely be performed in the pre‐hospital setting.
• EMS delivered therapy represents significant time savings for STEMI patients.
• Time savings not in rural regions alone.
• After 3 hours – incremental benefit is minimal
Questions?
james.j.mccarthy@uth.tmc.edu