Effect of Low-Dose Intracoronary Alteplase During Primary Percutaneous Coronary Intervention on Microvascular Obstruction in Patients With Acute Myocardial Infarction
Key result
Low-dose intracoronary alteplase (20 mg) given during primary PCI did not reduce microvascular obstruction compared to placebo (3.5% vs 2.3%; estimated difference 1.16%; 95% CI -0.08% to 2.41%; P=.32).
Why the study?
Microvascular obstruction commonly affects STEMI patients and is associated with adverse outcomes, but whether early low-dose intracoronary alteplase after reperfusion reduces it was unknown.
Does low-dose intracoronary alteplase infused early after coronary reperfusion reduce microvascular obstruction in patients with acute STEMI undergoing primary PCI?
Population
440 STEMI patients presenting within 6 hours of symptoms at 11 UK hospitals
Comparison
Intracoronary alteplase (10 mg or 20 mg) vs placebo during primary PCI
Design
Multicentre 1:1:1 randomized dose-ranging trial
Follow-up
3 months
Authors
Discussion
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Member takes
Implication
Does not support low-dose intracoronary alteplase during primary PCI; confirms lack of microvascular obstruction benefit.
Study Design
Type
RCT (n=440)
Randomization
1:1:1
Multicenter
Yes
Structured PICO
Does low-dose intracoronary alteplase infused early after coronary reperfusion reduce microvascular obstruction in patients with acute STEMI undergoing primary PCI?
P
Population
440 patients (mean age 60.5 years, 15% women) presenting within 6 hours of STEMI due to proximal-mid-vessel occlusion, followed up to 3 months.
I
Intervention
Alteplase 10 mg or 20 mg by manual intracoronary infusion over 5 to 10 minutes, administered early during the primary percutaneous coronary intervention (PCI) procedure, after reperfusion of the infarct-related coronary artery and before stent implant.
C
Comparator
Placebo by manual intracoronary infusion over 5 to 10 minutes during primary PCI.
O
Outcome
Amount of microvascular obstruction (% left ventricular mass) demonstrated by contrast-enhanced cardiac magnetic resonance imaging (MRI) conducted from days 2 through 7 after enrollment.surrogate
Main Result
Mean Difference: 1.16 (95% CI -0.08–2.41)
Absolute Event Rate: 3.5% vs 2.3%
p-value: p=.32
Adjunctive low-dose intracoronary alteplase administered during primary PCI for acute STEMI does not reduce microvascular obstruction and is not supported for routine clinical use.
Limitations
- Trial stopped early for futility because conditional power for the primary outcome was less than 30% in both treatment groups
Cite This Study
McCartney et al. (2019) conducted an RCT in acute ST-segment elevation myocardial infarction (STEMI) (n=440). alteplase vs. placebo was evaluated on amount of microvascular obstruction (% left ventricular mass) demonstrated by contrast-enhanced cardiac magnetic resonance imaging (MRI) (estimated difference 1.16%, 95% CI -0.08% to 2.41%, p=.32). Low-dose intracoronary alteplase (20 mg) given during primary PCI did not reduce microvascular obstruction compared to placebo (3.5% vs 2.3%; estimated difference 1.16%; 95% CI -0.08% to 2.41%; P=.32).