Prevalence of Conventional Risk Factors in Acute Coronary Syndrome Patients in Eastern Part of Nepal

Background Smoking, diabetes mellitus, hypertension and dyslipidemia are known as conventional risk factors of coronary artery disease (CAD) and the prevalence of it varies across populations. There is paucity of data in our country about the prevalence of risk factors for acute coronary syndrome (ACS). This study aims to assess the prevalence of these conventional risk factors in patients who were admitted in Nobel medical college, with the diagnosis of ACS. Material & Methods In this observational study, we enrolled 102 patients diagnosed as ACS with stenosis ≥50% of any epicardial arteries as shown on angiography admitted in Nobel Medical College between September 2015 to March 2017 and evaluate the prevalence of conventional risk factors. In addition, we analyzed the lipid profiles within 24 hour of the event. Results Mean age of the patients was 59 years. Two third (66.7%) of the patients were male. Left anterior descending artery (43.13%) was the most common culprit lesion followed by RCA in 35.29%. Dyslipidemia was present in 73.5%, hypertension in 46.1%, smoking in 38.2% and diabetes in 37.3%. Prevalence of hypertension, diabetes and dyslipidemia was similar among male and female. Smoking (44.1%vs26.5%) was more common in male (P=<0.05). TG ≥150 mg/dl was seen in 52% study population and higher level of TG was seen in younger population ≤45 years compared to ≥45 years old (p=0.013). Conclusion Present study showed high prevalence of hypertension, smoking, diabetes and dyslipidemia in patients with ACS, suggesting the need of aggressive risk factor reduction in general population.


Introduction
Coronary artery disease (CAD) is a leading cause of morbidity and mortality in both developing and developed countries [1].Epidemiological studies have established cigarette smoking [2], diabetes mellitus (DM) [3], hypertension (HTN) [4], and dyslipidemia [5] as independent risk factors for CAD and have been labeled as conventional risk factors [6].Acute coronary syndrome includes unstable angina (UA), Non-ST elevation myocardial infarction (NSTEMI) and ST elevation myocardial infarction (STEMI), which needs urgent or emergency care to reduce mortality or morbidity.Reduction of these risk factors has been convincingly shown to reduce the risk of future events [2,7].Prevalence of these risk factors may vary across populations [8].Our study aims to assess the prevalence of conventional risk factors in patients who were admitted with diagnosis of ACS in Nobel medical college.

Material & Methods
It is an observational, cross-sectional, single center study conducted in Nobel Medical College Biratnagar Nepal.A total of 102 patients admitted with the diagnosis of ACS (Unstable angina, NSTEMI, and STEMI) were enrolled for the study in between September 2015 to march 2017.Performa was designed to collect patient information, which included; age, gender, diabetes, dyslipidemia, hypertension and smoking.Coronary angiography was done in all patients.Significant CAD was defined as the presence of >50% stenosis of any of the epicardial vessels.Patients only with significant CAD were included in the study.Patients with normal coronary angiography or mild disease, defined as <50% stenosis in any of the epicardial vessels, were excluded, as were patients in whom ACS was considered to be secondary to coronary embolism, arteritis, spontaneous dissection, muscular bridges, or an anomalous origin of the coronary artery.Stable angina patients were also excluded.

Prevalence of risk factors according to sex
The prevalence of CVD risk factors among the study population is summarized in Table 2. Hypertension was present in45.6% of male and 47.1% of female was the most frequently observed risk factors in Myocardial infarction and unstable angina groups with (P=0.888),whereasprevalence of smoking was seen in 44.1% male vs 26.5% in female (P<0.05).Among the risk factors T2DM was present in 38.2% in male vs35.3% in female with (P=0.77),respectively among 102 study populations.4. TC, LDL-C and TG all three levels were higher in women than men and HDL-C was seen higher in men compared to women though the difference were non-significant (p≥0.05).When the lipid profile was differentiated by age, older patient have higher percentage of LDL-C ≤130 mg/dl, TC ≤200 mg/dl as compared to age≤45 years old.In this study one third (33%) of the patients were female.The incidence of acute coronary syndrome (ACS) is lower in women than men in all age group [10], which is consistent with our study , having lower percentage 33.3% of total population.The finding that ACS event is more common in male patients is consistent with report from multinational observational Global Registry of Acute Coronary Events (GRACE) [11].We found high prevalence of Dyslipidemia (73.5%),Hypertension (46.1%),Smoking (38.2%),Diabetes (37.3%) in our study population.In study done by Adhikari et al [9] have lower prevalence of dyslipidemia 45.5% compared to our 73.5% which is much higher, it is s because we included TG in the definition of dyslipidemia [12].Cigarette smoking plays a critical role in the development of CHD (Coronary heart disease).Smoking is considered one of the most important modifiable risk factors for increasing cardiovascular disease.In our study, the prevalence of current smoking was 44.1% in male and 26.5% in female.Smoking was significantly higher in male population in overall as well as among all age group in our study.These results are  [8].The higher prevalence of diabetes in women than in men is not consistent in our study (F 35.3% vs M 38.2%)with other studies that have shown that diabetes is a powerful risk factors in women, though our study did not show any sex disparity in prevalence which were non-significant and also one of the factors effecting the ratio could be higher number of subject for ACS being male.In previous observational study [26], every 1 mg/dl increment in HDL-C was reported to be associated with 2%-3% decrease risk of CVD in adult.In our study 52.9% of population has HDL-C ≤ 40 mg/dl, which co-relates that HDL-C level is strong biomarker and one of the conventional and important risk factors for ACS.Elevated levels of TG are independent risk factors for CHD [27].Even our study demonstrated that TG level ≥150 are statistically significant (P=0.013)risk factors for ACS.For a reduction of 1% in TC has been shown to reduce the risk for coronary artery disease[28] assuming that reverse is true, our study does not correlates to previous studies as our study 57% of population have TC level ≤ 200 mg/dl, and suffered acute coronary syndrome event.LDL-C ≥130 mg/dl is seen in smaller percentage of 36.3% compared to 63.7% of LDL-C ≤130 mg/dl.This may point out that even lower level of LDL-C can be a risk factor for ACS event [29,30] and future study needs to validate more accurate event.Our study clearly shows that conventional risk factors occur in most of the ACS patients in cluster.Adhikari CM et.al [9] Study showed that 70% population had more than 2 risk factors which is same in our study too.All the above data from studies shows that most of the ACS patients have cluster of conventional risk factors and primary prevention against all of the four conventional cardiovascular risk factors should be address by education, diet, exercise and pharmacologically.

Conclusion
Present study showed high prevalence of hypertension, smoking, diabetes and dyslipidemia in patients with ACS, suggesting the need of aggressive risk factor reduction in general population.

Limitations
This study has some limitations, such as its observational design and small sample size.Doses of atorvastatin taken by patient vary and many are not documented and Lipid profile was taken at variable time within 24 hours.Factors that can impact the cardiovascular risk (eg, obesity, Inactivity, familial history) were not evaluated separately which might change the results if taken into consideration.
71 mg/dl to 188 mg/dl.Mean value for Triglyceride (TG) was 167.29 mg/dl, which ranged from 79 mg/dl to 400 mg/dl.Mean value for High-density lipoprotein-cholesterol (HDL-C) was 39.14 mg/dl, which ranged from 19 mg/dl to 98 mg/dl.Anterior wall myocardium was the

Table 7 .
10.7% are without any conventional risk factors for ACS, which is negligible compared to 89% patients with at least one or more risk factors for cardiovascular disease.

Table 4 .
Pattern of Lipid profiles in study populations by sex