April 23, 2026Journal of the American College of Cardiology438 citationsOpen Access
Randomized Trial of Interleukin-6 Receptor Inhibition in Patients With Acute ST-Segment Elevation Myocardial Infarction
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Key Result
Tocilizumab increased the myocardial salvage index compared to placebo in patients with acute STEMI (adjusted difference 5.6 percentage points; 95% CI 0.2-11.3; p=0.04).
Key Points
- This trial aimed to assess the efficacy of tocilizumab in improving myocardial salvage in acute ST-segment elevation myocardial infarction (STEMI).
- Randomized, double-blind, placebo-controlled trial conducted at 3 PCI centers in Norway.
- 101 patients received tocilizumab, and 98 received placebo within 6 hours of STEMI symptoms.
- Primary endpoint was myocardial salvage index measured by MRI after 3 to 7 days.
- Myocardial salvage index was higher in the tocilizumab group (5.6 percentage points, 95% CI: 0.2 to 11.3, p = 0.04).
- Microvascular obstruction was less in the tocilizumab group; however, final infarct size showed no significant difference (7.2% vs. 9.1%, p = 0.08).
- Adverse events were similarly distributed between the treatment groups.
Study Design
Type
RCT (n=199)
Blinding
Double-blind
Randomization
1:1
Multicenter
Yes
Structured PICO
Does a single infusion of tocilizumab improve the myocardial salvage index in patients with acute STEMI presenting within 6 hours of symptom onset?
P
Population
199 patients admitted with acute ST-segment elevation myocardial infarction (STEMI) within 6 hours of symptom onset, treated at 3 high-volume PCI centers in Norway.
I
Intervention
Single infusion of 280 mg tocilizumab
C
Comparator
Matching placebo (single infusion)
O
Outcome
Myocardial salvage index as measured by magnetic resonance imaging after 3 to 7 dayssurrogate
A single infusion of tocilizumab in patients with acute STEMI significantly increased the myocardial salvage index measured by MRI at 3-7 days, though it did not significantly reduce final infarct size.
Main Result
Effect estimate: Adjusted difference 5.6 percentage points (95% CI 0.2 to 11.3)
p-value: p=0.04
Abstract
BACKGROUND: Prompt myocardial revascularization with percutaneous coronary intervention (PCI) reduces infarct size and improves outcomes in patients with ST-segment elevation myocardial infarction (STEMI). However, as much as 50% of the loss of viable myocardium may be attributed to the reperfusion injury and the associated inflammatory response. OBJECTIVES: This study sought to evaluate the effect of the interleukin-6 receptor inhibitor tocilizumab on myocardial salvage in acute STEMI. METHODS: The ASSAIL-MI trial was a randomized, double-blind, placebo-controlled trial conducted at 3 high-volume PCI centers in Norway. Patients admitted with STEMI within 6 h of symptom onset were eligible. Consenting patients were randomized in a 1:1 fashion to promptly receive a single infusion of 280 mg tocilizumab or placebo. The primary endpoint was the myocardial salvage index as measured by magnetic resonance imaging after 3 to 7 days. RESULTS: We randomized 101 patients to tocilizumab and 98 patients to placebo. The myocardial salvage index was larger in the tocilizumab group than in the placebo group (adjusted between-group difference 5.6 95% confidence interval: 0.2 to 11.3 percentage points, p = 0.04). Microvascular obstruction was less extensive in the tocilizumab arm, but there was no significant difference in the final infarct size between the tocilizumab arm and the placebo arm (7.2% vs. 9.1% of myocardial volume, p = 0.08). Adverse events were evenly distributed across the treatment groups. CONCLUSIONS: Tocilizumab increased myocardial salvage in patients with acute STEMI. (ASSessing the effect of Anti-IL-6 treatment in Myocardial Infarction ASSAIL-MI; NCT03004703).
Expert Takes5 quotes
1/5
“We're among the first to show that you can actually affect the reperfusion injury through anti-inflammatory treatment – it's sort of a new attack point for treatments in STEMI. What we do now is reperfuse as soon as we can and then add drugs in order to prevent new events, but we don't really attack the reperfusion injury that occurs when you perform PCI, which has been shown to actually account for some 50% of the final injury.”
Kaspar Broch, Cardiologist, Oslo University Hospital Rikshospitaletauto_pipelineSupportiveView source
Cite This Study
Broch et al. (2021) conducted an RCT in Acute ST-segment elevation myocardial infarction (n=199). Tocilizumab vs. Placebo was evaluated on Myocardial salvage index as measured by magnetic resonance imaging after 3 to 7 days (Adjusted difference 5.6 percentage points, 95% CI 0.2 to 11.3, p=0.04). Tocilizumab increased the myocardial salvage index compared to placebo in patients with acute STEMI (adjusted difference 5.6 percentage points; 95% CI 0.2-11.3; p=0.04).