Spectrum of Risk Factors of Myocardial Infarction and Their Associations with Age: A Cross Sectional Study from Gujranwala, Pakistan

Abstract

Objective: To determine the prevalence of various risk factors of acute ST elevation myocardial
infarction (STEMI) and their associations with age among patients admitted at tertiary care
hospital, Gujranwala, Pakistan.
Methods: It was a cross sectional study of acute STEMI patients admitted from June 2017 to
May 2018. After informed consent, data was collected by purposive sampling. Statistical analysis
was done using SPSS version 25. Various risk factors of STEMI including smoking, hypertension,
diabetes mellitus, obesity, personal H/O IHD, H/O of IHD in male family member of age <55years,
and H/O of IHD in female family member of age <45years, were the qualitative variables while age
of the patients was the only quantitative variable. Independent sample T test was used to
compare the mean age of patients in two groups of each risk factor. The multiple regression
analysis was also performed to predict the age at which STEMI may occur using different risk
factors. The prediction by a risk factor was considered statistically significant if p< 0.05.
Results: Amongst 668 patients, 54.2% were smokers, 54% hypertensive, 29.5% diabetics,
22.9% obese, 28.9% had personal H/O IHD, 12.1% had H/O of IHD in male family member of age
<55years, and 21.1% had H/O of IHD in female family member of age <45years. The mean age of
the patients was 53.81 + 12.37 years. The mean age of the patients was statistically significantly
less of smokers than non-smokers (p<0.1), diabetics than non-diabetics (p=0.047), and non-
hypertensives than hypertensives (p<0.1). The mean age of the patients had no statistically
significant association with H/O obesity (p=0.264), personal H/O IHD (p=0.134), H/O of IHD in
male family member of age <55years (p=0.700), and H/O of IHD in female family member of age
<45years (p=0.265). A multiple regression analysis suggested that age at which STEMI may
occur can be statistically significantly predicted by 4 variables (Smoking, Hypertension, Diabetes
mellitus, Obesity).
Conclusions: Smoking was the most prevalent risk factor for myocardial infarction in our
studied population. Smokers and diabetic patients who suffered STEMI were younger than non-
smokers and non-diabetic patients respectively. Among STEMI patients, hypertension was seen
in relatively older group of patients. Smoking, Hypertension, Diabetes mellitus, Obesity are those
four risk factors which significantly predict the age at which STEMI may occur.