ABSTRACT
Objective To explore the relationship between symptom-onset-to-balloon time and in-hospital mortality in patients with ST elevation myocardial infarction (STEMI). Methods Since October 2010, all cardiovascular intervention procedures in military hospitals were registered online, including coronary interventions. Data in this study were originated from this registry database. Primary endpoint was in-hospital mortality, and it was stratified by age and infarction location to explore the effects of these factors on the mortality rate. Results 8878 STEMI patients from 92 military medical centers were enrolled in this study. These patients were divided into 3 groups by the length of onset-to-vessel opening time: interval ≤3h (n=2999), interval between 3 and 6h (n=2369), and interval >6h (n=3510). The in-hospital mortality rate in those groups was 2.5%, 2.9% and 3.0%, respectively (P=0.405). In interval ≤3h group, mortality rate in young (70 years) patients with anterior MI was as high as 7.4% (P<0.001). ConclusionsIn-hospital mortality rate in STEMI patients is related to onset-to-vessel opening time. Patients with old age or anterior MI are a high-risk cohort.
ABSTRACT
PURPOSE: We aimed to discover clinical and angiographic predictors of microvascular dysfunction using the index of microcirculatory resistance (IMR) in patients with ST-segment elevation myocardial infarction (STEMI). MATERIALS AND METHODS: We enrolled 113 patients with STEMI (age, 56+/-11 years; 95 men) who underwent primary percutaneous coronary intervention (PCI). The IMR was measured with a pressure sensor/thermistor-tipped guidewire after primary PCI. The patients were divided into three groups based on IMR values: Low IMR [31 U (48.1+/-17.1 U), n=37]. RESULTS: The age of the Low IMR group was significantly lower than that of the Mid and High IMR groups. The door-to-balloon time was <90 minutes in all patients, and it was not significantly different between groups. Meanwhile, the symptom-onset-to-balloon time was significantly longer in the High IMR group, compared to the Mid and Low IMR groups (p<0.001). In the high IMR group, the culprit lesion was found in a proximal location significantly more often than in a non-proximal location (p=0.008). In multivariate regression analysis, age and symptom-onset-to-balloon time were independent determinants of a high IMR (p=0.013 and p=0.003, respectively). CONCLUSION: Our data suggest that age and symptom-onset-to-balloon time might be the major predictors of microvascular dysfunction in STEMI patients with a door-to-balloon time of <90 minutes.