Veterans Affairs
Non-Q Wave Infarction
Strategies In-Hopsital
Trial
Compare outcomes of patients with non-Q wave MI, managed with an early invasive stategy vs. an early conservative strategy
Goal
Inclusion / Exclusion
Inclusion Criteria:
Clinical presentation consistent with acute MI
CK-MB > 1.5 times upper limit of normal
No Q wave on ECG (could be ST elev without Q waves)
Onset within 72 hours of randomization
Exclusion Criteria:
High risk (ongong ischemia, CHF, arrhythmias)
Recent revascularization
Treatment Strategies
Invasive:
Cardiac catheterization within 3-7 days
Revascularization if possible
(PTCA for 1 or 2VD, CABG for 3VD)
Conservative:
Mecical management
RVG
ETT / Thallium pre-discharge
Cath if ETT + or recurrent ischemia at rest with ECG changes
Statistics
Equivalence Design:
i.e, No difference in clinical outcome between the two strategies
Primary End Point: Death or non-fatal MI through follow-up (minimum 1 year)
Assumed 20% event rate in each arm.
85% power, p=0.05
Patient Flow
17 VA Hosptial
Across U.S.
Catheterization / Revascularization
Outcomes
462
29.9
17.3
12.6
4.5
12.8
9.5
Hazard Ratios
Hazard Ratio
95%
Conf. Interval
In-hosptial deaths: 21 Invasive vs. 6 Conservative
11 of 21 deaths were post CABG (13.4% perioperative mortality)
0 deaths post PTCA
Recent Ontario study - 5517 CABG patients :
Total perioperative mortality 3.14%
Patients with recent MI = mortality 12.6%
Peri-Procedural Complications
Patients with non-Q wave MI in this trial did not benefit from early invasive strategy and may be harmed.
A conservative, “ischemia-guided” management approach is both safe and effective
Conclusions
Observations from TIMI IIIB and VANQWISH
An invasive strategy did not prevent recurrent MI
Outcome of invasive strategy depends on peri-procedural complication rate, influenced by:
Procedure (PTCA vs. CABG)
Hospital
Patient population
100
$2,353,671
Cost Analysis - Invasive vs. Conservative (using TIMI IIIB as a model)
Conti CR. Clin Cardiol 1995;18:187-188
Invasive strategy $1696 per patient added cost
(1.5% lower rate of death or MI by 1 year)