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- Armstrong, Paul W., et al.
(author)
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Quantitative ST-depression in Acute Coronary Syndromes : the PLATO Electrocardiographic Substudy
- 2013
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In: American Journal of Medicine. - : Elsevier BV. - 0002-9343 .- 1555-7162. ; 126:8, s. 723-
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Journal article (peer-reviewed)abstract
- BACKGROUND: We evaluated whether electrocardiogram (ECG) characteristics were aligned with clinical outcomes and the effect of ticagrelor within the diverse spectrum of non-ST-elevation acute coronary syndrome patients enrolled in the PLATelet inhibition and patient Outcomes (PLATO) trial. METHODS: There were 8884 PLATO patients who had baseline ECGs assessed by a core laboratory; of these, 4935 had an ECG at hospital discharge that also was assessed. Associations with study treatment on vascular death or myocardial infarction within 1 year were examined. RESULTS: At baseline, most patients had either no or <= 0.5 mm of ST-segment depression (57%); 26% had 1.0 mm, and 17% had more extensive depression (>1.0 mm). Across the baseline ST-segment depression strata, there was a consistent treatment benefit with ticagrelor versus clopidogrel on vascular death/myocardial infarction. The extent of residual ST-segment depression at discharge was similar in the treatment groups, and the treatment effect did not differ by the extent of discharge ST-segment depression. There was a progressive increase in vascular death/myocardial infarction with increasing extent of baseline ST-segment depression (1.0 mm [vs no/0.5 mm]: hazard ratio [HR] 1.22; 95% confidence interval [CI], 1.03-1.45; > 1.0 mm: HR 1.49; 95% CI, 1.24-1.78; P < .001) and at discharge (HR 1.28; 95% CI, 1.02-1.61; HR 2.13; 95% CI, 1.54-2.95; P <. 001). CONCLUSION: The treatment effect of ticagrelor among non-ST-segment-elevation acute coronary syndrome patients was consistently expressed across all baseline ST-segment depression strata. There was no indication of an anti-ischemic benefit of ticagrelor as reflected on the discharge ECG. Our data affirm the independent prognostic relationship of both baseline and hospital discharge ST-segment depression on outcomes within 1 year in non-ST-segment-elevation acute coronary syndrome patients.
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| 2. |
- Armstrong, Paul W, et al.
(author)
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ST Elevation Acute Coronary Syndromes in PLATO : Insights from the ECG Substudy
- 2012
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In: Circulation. - 0009-7322 .- 1524-4539. ; 125:3, s. 514-521
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Journal article (peer-reviewed)abstract
- BACKGROUND: Ticagrelor, when compared with clopidogrel, reduced the 12-month risk of vascular death/myocardial infarction (MI) and stroke in patients with ST-elevation acute coronary syndromes (ST-E ACS) intended to undergo primary percutaneous coronary intervention (PCI) in the PLATelet inhibition and patient Outcomes (PLATO) trial. This pre-specified electrocardiogram (ECG) substudy explored whether ticagrelor's association with vascular death and MI within one year would be amplified by: 1) the extent of baseline ST shift; and 2) subsequently associated with less residual ST changes at hospital discharge. METHODS AND RESULTS: ECGs were evaluated centrally in a core laboratory in 3,122 ticagrelor- and 3,084 clopidogrel-assigned patients having at least 1mm ST-E in two contiguous leads as identified by site investigators on the qualifying ECG. Patients with greater ST-segment shift at baseline had higher rates of vascular death/MI within one year. Amongst those who also had an ECG at hospital discharge (n=4,798), patients with ≥50% ∑ST-deviation (∑ST-dev) resolution had higher event-free survival than those with incomplete resolution (6.4% vs. 8.8%, adjusted hazard ratio 0.69 (0.54-0.88), p=0.003). The extent of ∑ST-dev resolution was similar irrespective of treatment assignment. The benefit of ticagrelor versus clopidogrel on clinical events was consistent irrespective of the extent of baseline ∑ST-dev (p(interaction)=0.728). When stratified according to conventional times from symptom onset i.e. ≤3 hours, 3-6 hours, >6 hours, the extent of baseline ∑ST-dev declined progressively over time. As time from symptom onset increased beyond three hours, the benefit of ticagrelor appeared to be more pronounced; however, the interaction between time and treatment was not significant (p=0.175). CONCLUSIONS: Ticagrelor did not modify ∑ST-dev resolution at discharge nor was its benefit affected by the extent of baseline ∑ST-dev. These hypothesis-generating observations suggest that the main effects of ticagrelor may not relate to the rapidity or the completeness of acute reperfusion, but rather the prevention of recurrent vascular events by more powerful platelet inhibition or other mechanisms.
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