Mortality, prognostic factor and cause of death of acute myocardial infarction in Korean patients: single center experience

Kang, Ji Hoon; Park, Jong Seon; Son, Jang Won; Jo, Hyeun Su; Bae, Jun Ho; Hong, Geu Ru; Shin, Dong Gu; Kim, Young Jo; Sim, Bong Seup

Abstract

BACKGROUND: The number of patients suffering from acute myocardial infarction is on the increase in Korea due to the westernization of life style. Recent improvement of therapeutic stratigies have shown early mortality benefits in acute myocardial infarction. But we don't have data how many patients died and what's the cause of death in these patients. This study aimed to find out the mortality rate, cause of death and it's relevant prognostic factors of myocardial infarction (MI) patients who admitted alive, and to construct a database which will be used to develop a risk stratification strategy for the implementation of new preventive therapeutic modalities, such as implantable cardioverter-defibrillator (ICD).
METHODS
Seven hundred and forty two MI patients admitted to our hospital from March, 1999 to August, 2002 were included in this study. The risk factors and survivals were evaluated by medical record searching and telephone survey in these patients.
RESULTS
The average age was 64 years-old and 67% was male. During the mean follow up 20.7+/-15.4 months, total 105 cardiac death (14.2%) was occurred and cumulative mortality rate at 1 year and 2 year was 5.69% and 10.80%, respectively. Of the total 129 death, in-hospital death was 68 (cardiac death 48, non-cardiac death 20) and out of hospital death was 60 (cardiac death 57, non-cardiac death 4). When it comes to cause of death, most common cause of cardiac death was malignant arrhythmia. The proportion of malignant arrhythmia in cardiac death was 81.3% and 72% of in-hospital and out of hospital death, respectively. Multivariate analysis showed that old age, low LV ejection fraction and no percutaneous coronary intervention (PCI) treatment were independent risk factors for cardiac mortality.
CONCLUSIONS
Myocardial infarction shows still high mortality rate despite the recent development of therapeutic strategy. As post-MI patients with low LVEF or no PCI shows high mortality, the early reperfusion therapy should be encouraged. Additionally, because malignant arrhythmia was one of the most in cause of cardiac death, ICD therapy to prevent sudden cardiac death should be considered in an active manner.