Long Term Survival Rate and Prognostic Factors of Acute Myocardial Infarction

Kim, Seok Yeon; Han, Joo Yong; Kim, Yong Jin; Sung, Ji Dong; Chae, In Ho; Kim, Hyo Soo; Shon, Dae Won; Oh, Byung Hee; Lee, Myoung Mook; Park, Young Bae; Choi, Yun Shik; Lee, Young Woo

Abstract

BACKGROUND
AND METHODS: To identify the long term survival rate and prognostic factors of acute myocardial infarction (AMI) in Korea, total 1139 patients who presented between Jan. 1980 and Dec. 1997 at Seoul National University Hospital were followed for an average of 115 months. 321 patients died during follow up periods, 238 patients were lost and 580 patients are alive till the end point of the study.
RESULTS
Overall survival rates (+/-standard error) were 88.2+/-1%, 86.8+/-1%, 85.3+/-1.1%, 82.1+/-1.2%, 79.6+/-1.3%, 75.6+/-1.5%, 73.1+/-1.6%, 70.3+/-1.7%, 67.4+/-1.8%, 64.5+/-1.9%, 60.0+/-2.2%, 56.3+/-2.5% at 1,6,12,24,36,48,60,120 months. In univariate analysis, older, history of diabetes, higher degree of Killip class, higher peak creatine kinase level, residual ischemia on treadmill test or MIBI scan, lower ejection fraction on echocardiography or gated blood pool scan, more severe extent of coronary artery disease, lower HDL-cholesterol level at least 3 months after AMI proved as poor long term prognostic factors of AMI with statistical significance (p<0.05). Sex, body mass index, history of hypertension, hsitory of angina, history of infarction, infarct site on electrocardiography, existence of Q-wave, patency of infarct related arteries, total cholesterol level, HDL-and LDL-cholesterol at the time of AMI, total cholesterol and LDL-cholesterol at least 3 months after AMI did not show statistical significance (p>0.05). In mltivariate analysis, old age and Killip class III versusIproved as independent poor long term prognostic factors of AMI with statistical significance (p<0.05) at combinations of age, sex, Killip class, existence of Q-wave, history of diabetes, ejection fraction on gated blood pool scan.
CONCLUSION
The morthality of AMI is composed of two components. At acute phase, within 1 month, the mortality reaches to about 12%, and at chronic phase, after 1 month from AMI, mortality increases by 3% a year for 10 years. The other conclusion is old patients who have poor left ventricular functions show poor prognosis.