Effect of a single dose of the interleukin-6 receptor antagonist tocilizumab on inflammation and troponin T release in patients with non-ST-elevation myocardial infarction: a double-blind, randomized, placebo-controlled phase 2 trial.

AIMS: Interleukin-6 (IL-6) contributes to atherosclerotic plaque destabilization and is involved in myocardial injury during ischaemia-reperfusion. Interleukin-6 is therefore a potential therapeutic target in myocardial infarction (MI). We hypothesized that the IL-6 receptor antagonist tocilizumab would attenuate inflammation, and secondarily reduce troponin T (TnT) release in non-ST-elevation MI (NSTEMI). METHODS AND RESULTS: In a two-centre, double-blind, placebo-controlled trial, 117 patients with NSTEMI were randomized at a median of 2 days after symptom onset to receive placebo (n = 59) or tocilizumab (n = 58), administered as a single dose prior to coronary angiography. High sensitivity (hs) C-reactive protein and hsTnT were measured at seven consecutive timepoints between Days 1 and 3. The area under the curve (AUC) for high-sensitivity C-reactive protein was the primary endpoint. The median AUC for high-sensitivity C-reactive protein during hospitalization was 2.1 times higher in the placebo than in the tocilizumab group (4.2 vs. 2.0 mg/L/h, P < 0.001). Also, the median AUC for hsTnT during hospitalization was 1.5 times higher in the placebo group compared with the tocilizumab group (234 vs. 159 ng/L/h, P = 0.007). The differences between the two treatment groups were observed mainly in (i) patients included ≤2 days from symptom onset and (ii) patients treated with percutaneous coronary intervention (PCI). No safety issues in the tocilizumab group were detected during 6 months of follow-up. CONCLUSION: Tocilizumab attenuated the inflammatory response and primarily PCI-related TnT release in NSTEMI patients.

Sequential ADP-stimulated light transmission and multiple electrode aggregometry in patients taking aspirin and clopidogrel after non ST-elevation myocardial infarction.

BACKGROUND: Fast platelet function tests can identify weak clopidogrel responders, but data on variability over time in clopidogrel responsiveness in several clinical settings are lacking. We wanted to explore long-term variability of multiple electrode aggregometry (MEA) measurements and the agreement between MEA and light transmission aggregometry (LTA) in patients with non-ST elevation myocardial infarction (NSTEMI) treated with aspirin and clopidogrel. METHODS: Parallel MEA and LTA were performed at baseline and after 6 and 12 weeks in 31 patients treated with percutaneous coronary intervention after NSTEMI. Adenosine diphosphate (ADP) concentrations 2 µM, 6.5 µM and 10 µM were used. Parallel testings in both arterial and venous blood were performed at baseline. MEA and LTA cut-off levels were applied to discriminate aggregation values suggesting presence or absence of high platelet reactivity (HPR). RESULTS: Arterial and venous MEA and LTA aggregation were similar. Within-subject variability in both MEA and LTA aggregation throughout the study was moderate. According to MEA, eight patients had HPR at baseline (MEA aggregation > 47 U). Defining > 47% as the LTA aggregation HPR cut-off level, the same number of patients (eight) had HPR according to LTA. Of the 93 MEA/LTA observations 81 (87.1%) gave the same HPR classification. MEA vs. LTA agreement at baseline was slightly inferior to that obtained after 12 weeks. CONCLUSIONS: MEA and LTA aggregation in arterial and venous blood seem similar. Within-subject variability over time was moderate, and the agreement between LTA and MEA was good, and stable in most patients.

Machine Learning Analysis of Left Ventricular Function to Characterize Heart Failure With Preserved Ejection Fraction.

BACKGROUND: Current diagnosis of heart failure with preserved ejection fraction (HFpEF) is suboptimal. We tested the hypothesis that comprehensive machine learning (ML) of left ventricular function at rest and exercise objectively captures differences between HFpEF and healthy subjects. METHODS AND RESULTS: One hundred fifty-six subjects aged >60 years (72 HFpEF+33 healthy for the initial analyses; 24 hypertensive+27 breathless for independent evaluation) underwent stress echocardiography, in the MEDIA study (Metabolic Road to Diastolic Heart Failure). Left ventricular long-axis myocardial velocity patterns were analyzed using an unsupervised ML algorithm that orders subjects according to their similarity, allowing exploration of the main trends in velocity patterns. ML identified a continuum from health to disease, including a transition zone associated to an uncertain diagnosis. Clinical validation was performed (1) to characterize the main trends in the patterns for each zone, which corresponded to known characteristics and new features of HFpEF; the ML-diagnostic zones differed for age, body mass index, 6-minute walk distance, B-type natriuretic peptide, and left ventricular mass index (P<0.05) and (2) to evaluate the consistency of the proposed groupings against diagnosis by current clinical criteria; correlation with diagnosis was good (κ, 72.6%; 95% confidence interval, 58.1-87.0); ML identified 6% of healthy controls as HFpEF. Blinded reinterpretation of imaging from subjects with discordant clinical and ML diagnoses revealed abnormalities not included in diagnostic criteria. The algorithm was applied independently to another 51 subjects, classifying 33% of hypertensive and 67% of breathless controls as mild-HFpEF. CONCLUSIONS: The analysis of left ventricular long-axis function on exercise by interpretable ML may improve the diagnosis and understanding of HFpEF.

Interleukin-6 receptor inhibition with tocilizumab induces a selective and substantial increase in plasma IP-10 and MIP-1ß in non-ST-elevation myocardial infarction.

AIM: To evaluate the effect of interleukin-6 inhibition with tocilizumab on the cytokine network in patients with acute non-ST-elevation myocardial infarction (NSTEMI). METHODS: 117 patients with acute NSTEMI were randomised to an intravenous infusion of 280 mg tocilizumab or placebo prior to coronary angiography. Blood samples were obtained at baseline, at 6 consecutive points in time during hospitalisation, and at follow-up after 3 and 6 months. Cytokines (n = 27) were analysed with a multiplex cytokine assay. RESULTS: Using a mixed between-within subjects analysis of variance, we observed a significant (p < 0.001) between-group difference in changes for interferon gamma-inducible protein (IP-10) and macrophage inflammatory protein-1ß (MIP-1ß), due to significant increases in the tocilizumab group during hospitalisation (i.e., IP-10 median change from baseline during hospitalisation (mΔ), placebo: 3 (-60, 68) pg/ml vs tocilizumab: 209 (69, 335) pg/ml; MIP-1ß mΔ, placebo: 5 (-2, 12) pg/ml vs tocilizumab: 39 (24, 63) pg/ml). MIP-1ß was inversely correlated to troponin T (r = -0.28, p < 0.05) and neutrophils (r = -0.32, p < 0.05) in the tocilizumab group. In contrast, tocilizumab had only modest or no effects on the other examined cytokines. CONCLUSIONS: Tocilizumab led to a selective and substantial increase in IP-10 and MIP-1ß during the acute phase of NSTEMI, with no or only minor effects on the other measured cytokines. ClinicalTrials.gov, NCT01491074.

Effect of interleukin-6 inhibition on coronary microvascular and endothelial function in myocardial infarction.

OBJECTIVE: Interleukin-6 (IL-6) is a driver of inflammation and associated endothelial cell activation in acute coronary syndromes. We evaluated the effect of the IL-6 receptor antagonist tocilizumab on coronary microvascular function and endothelial dysfunction measured by coronary flow reserve (CFR) and markers of endothelial cell activation in patients with non-ST-elevation myocardial infarction (NSTEMI). METHODS: This substudy was part of a two-centre, double-blind, randomised, placebo-controlled trial evaluating the effect of a single dose of tocilizumab in NSTEMI. Markers of endothelial cell activation (vascular cell adhesion molecule (VCAM)-1, intercellular adhesion molecule-1 and von Willebrand factor) were assessed in 117 patients. In 42 of these patients, 20 assigned to placebo and 22 to tocilizumab, we measured CFR. Blood samples were obtained at seven consecutive time points between day 1 and 3. CFR was measured by transthoracic echocardiography during hospitalisation and after 6 months. RESULTS: Tocilizumab did not affect CFR during hospitalisation (tocilizumab: 3.4±0.8 vs placebo: 3.3±1.2, p=0.80). CFR improved significantly in both groups at 6 months. Patients in the tocilizumab group had significantly higher area under the curve for VCAM-1 (median 622 vs 609 ng/mL/hour, tocilizumab and placebo respectively, p=0.003). There were inverse correlations between VCAM-1 and CFR in the placebo (hospitalisation: r=-0.74, p<0.01, 6 months: r=-0.59, p<0.01), but not in the tocilizumab group (hospitalisation: r=0.20, p=0.37, 6 months r=-0.28, p=0.20). CONCLUSIONS: Tocilizumab did not affect CFR during hospitalisation or after 6 months. Tocilizumab increased VCAM-1 levels during hospitalisation, but this was not associated with reduced CFR in these patients.