December 24, 2011
View Full PaperAmerican College of Cardiology/American Heart Association/European Society of Cardiology/World Heart Federation Universal Definition of Myocardial Infarction Classification System and the Risk of Cardiovascular Death
Key Result
New or recurrent myocardial infarction in patients with acute coronary syndrome was associated with a 5-fold higher risk of cardiovascular death at 6 months (6.5% vs 1.3%; HR 5.0, 95% CI 3.8-7.1).
Study Design
Type
Cohort (n=13,608)
Structured PICO
Does the occurrence of new or recurrent MI by subtype increase the risk of cardiovascular death in patients with acute coronary syndrome?
P
Population
13,608 patients with acute coronary syndrome from the TRITON-TIMI 38 trial, evaluated for the risk of cardiovascular death at 6 months following a new or recurrent myocardial infarction.
E
Exposure
Occurrence of new or recurrent MI by subtype according to the Universal Definition of MI Classification System
C
Comparator
Patients without an MI
O
Outcome
Risk of cardiovascular death at 6 months (180 days after the event)hard clinical
All subtypes of MI defined by the universal classification system, including peri-PCI and stent thrombosis, are associated with a significantly increased risk of cardiovascular death at 6 months.
Main Result
Hazard Ratio: 5 (95% CI 3.8–7.1)
Absolute Event Rate: 6.5% vs 1.3%
p-value: p=<0.001
Abstract
BACKGROUND: The availability of more sensitive biomarkers of myonecrosis and a new classification system from the universal definition of myocardial infarction (MI) have led to evolution of the classification of MI. The prognostic implications of MI defined in the current era have not been well described. METHODS AND RESULTS: We investigated the association between new or recurrent MI by subtype according to the European Society of Cardiology/American College of Cardiology/American Heart Association/World Health Federation Task Force for the Redefinition of MI Classification System and the risk of cardiovascular death among 13 608 patients with acute coronary syndrome in the Trial to Assess Improvement in Therapeutic Outcomes by Optimizing Platelet Inhibition with Prasugrel-Thrombolysis in Myocardial Infarction 38 (TRITON-TIMI 38). The adjusted risk of cardiovascular death was evaluated by landmark analysis starting at the time of the MI through 180 days after the event. Patients who experienced an MI during follow-up had a higher risk of cardiovascular death at 6 months than patients without an MI (6.5% versus 1.3%, P<0.001). This higher risk was present across all subtypes of MI, including type 4a (peri-percutaneous coronary intervention, 3.2%; P<0.001) and type 4b (stent thrombosis, 15.4%; P<0.001). After adjustment for important clinical covariates, the occurrence of any MI was associated with a 5-fold higher risk of death at 6 months (95% confidence interval 3.8-7.1), with similarly increased risk across subtypes. CONCLUSIONS: MI is associated with a significantly increased risk of cardiovascular death, with a consistent relationship across all types as defined by the universal classification system. These findings underscore the clinical relevance of these events and the importance of therapies aimed at preventing MI.