Management of Acute Myocardial Infarction
Minimal Acceptable vs Optimal Care
Hussien H. Rizk, MD
Cairo University
Background
• Suspicious chest pain: extremely common
cause of ER visits
• Acute MI: the most costly cardiac cause of
ER visits
• 5-10% of acute MI patients are missed
because of errors in symptom interpretation
or missed ECG diagnosis
• Many patients do not receive proven
inexpensive effective therapy
Clinical proceedings of a suspected MI
• Symptom evaluation
– Pain characteristics
– Heart failure, syncope
– Contraindication to SK
• Relief of symptoms
– Pain
– Nausea
– Anxiety
• Physical examination
• ECG
• Aspirin
– Quick
– Interpretation correct
• ACE-I
• Lab work-up
– Basic [Sugar. CRT. K. CK
if no ST elevation]
– CXR
– Specific [Clinically
guided]
• Disposal:
–
–
–
–
Discharge
Observation
Admission
Referral
– Saves as many lives as SK
– Low dose [Captopril 6.25]
– Not if SBP<100
• BB
• Thrombolysis
– SK
– TPA: SK sensitive or recent
use
• Primary PCI:
– Who? Where?
Should everybody with acute MI have:
• Statin?
• Clopedogrel?
• Platelet GP II b/III a inhibitor?
• Primary PCI?
Timing of Statin Therapy Initiation After
ACS in Recent Clinical Studies
Atorvastatin
Pravastatin
Simvastatin
Fluvastatin
MIRACL
PROVE IT
4S
WOSCOPS
FLORIDA
L-CAD
ACS
Primary
prevention
CARE
LIPID
Secondary prevention
0
6 12 18 24 2
Hours
4
6 8 10 12 3
Days
6
Months
MIRACL
Study Outcome Measures
Primary
–Death, Non-fatal MI, Cardiac arrest
–Worsening angina + evidence of
myocardial ischemia.
Secondary
–Stroke
–Revascularization.
–Worsening CHF
–Worsening angina without evidence of ischemia
Schwartz GG et al. JAMA 2001;255:1711
MIRACL
Worsening Angina with New Objective Evidence
Primary Urgent
Efficacy
Measure
of MIRACL:
Ischemia Requiring
Hospitalisation
Risk reduction = 16%
P=0.048
15
Placebo 17.4%
Atorvastatin 14.8%
Cumulative
Incidence
10
(%)
95% CI = 0.701–0.999
Time to first occurrence of
composite
endpoint8.4%
of:
Placebo


5


Death (any cause)
Non-fatal MI
ResuscitatedAtorvastatin
cardiac arrest 6.2%
Worsening angina
withreduction
new
Risk
= 26%
objective evidence
and urgent
P=0.02
rehospitalisation
0
0
4
8
12
Time Since Randomisation (Weeks)
16
Schwartz GG et al. JAMA 2001;255:1711-8.
MIRACL: COST-BENEFIT
• Absolute risk reduction for worsening angina:
2.2%
• NNT = 100/2.2 = 45.5
• Cost of avoiding one worsening angina event
= NNT x No of Days x Daily cost
(Ignoring lab tests & treating complications)
= 45.5 x 120 X 36 = 196,364 LE
GP II b/III a inhibitors for medically
treated acute coronary syndromes
• GUSTO 4-ACS: Abciximab, no acute
revascularization. No benefit at 30D (Simoons.
Lancet 2001;357:1915) or 1Y (Ottervanger et al. CIRCULATION
2003;107:437)
• GRAPE pilot: abciximab for acute MI: TIMI 3
flow in 20% (van der Merkhof et al. JACC 1999;33:1528)
• PRISM: Tirofiban reduced total mortality
compared to heparin alone.
Tirofiban in ACS: 1.5% ARR of 30D mortality
compared to heparin alone
PRISM. NEJM 1998;338:1498
NNT = 67
Cost/event = LE 130,000
• PRISM PLUS: terminated prematurely
for excess mortality with tirofiban (4.6%
vs 1.1% for heparin alone)
DANAMI-2
COST-BENEFIT
•
•
•
•
6% Absolute risk reduction
NNT = 16.7
Procedure cost: LE 14,000
Cost of preventing ONE EVENT (MI) at 30D =
LE 233,800
MINIMAL ACCEPTABLE CARE FOR MI
• CLINICAL TRAINING COST-EFFECTIVE
• ROUTINE LAB:
FBS. BUN. K. CK. CXR
• ROUTINE Rx.
SYMPTOMS. ASA. SK.
BB. ACE-I
• NOT ROUTINE:
–
–
–
–
–
TPA
CLOPEDOGREL
STATIN
PLATELET GLYCOPROTEIN INHIBITORS
PRIMARY PCI