Relationship between Cardiovascular Risk Factors and Development of Acute Coronary Syndrome

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Acute coronary syndrome (ACS), a subcategory of ischemic heart disease, is considered a major cause of mortality.1In Saudi Arabia, the prevalence of ACS among the population is 8.2%, most of them diagnosed with unstable angina (19.2%).2ACS comprise a group of disorders that arise from acute myocardial ischemia.3These disorders include UA, NSTEMI , and STEMI.3-5Risk factors of coronary artery disease include non-Modifiable RFs which comprise family history, race, age, and gender; modifiable like type2 diabetes mellitus, hypertension, smoking, dyslipidemia, chronic kidney disease, Obesity, and metabolic syndrome.6.7 Prevention and early detection of risk factors diminished the rate of morbidity and mortality associated with CAD.In spite of the fact that Saudi Arabia is known for its ethnic, and socioeconomic diversity which may contribute to ACS, there is a lack of studies about ACS.Therefore, this study aims to evaluate the prevalence of cardiovascular RFs among patients admitted to Prince Sultan cardiac center, King Saud Hospital, and Bukayriyah General Hospital and to determine their association with different ACS subtypes.

Study design
A retrospective multi-center crosssectional study was conducted on 170 patients admitted to Prince Sultan cardiac center, King Saud Hospital, and Bukayriyah General Hospital in Al Qassim, KSA.The ACS patients were classified into UA, NSTEMI, and STEMI.Patients with stable angina or previous MI were excluded from the study.Participants' data was retrieved from patients' medical records in a predesigned data collection form focusing on demographic characteristics and RFs such as family history, hypertension, diabetes mellitus, and smoking.Ethical approval for this study was obtained from Al-Qassim Regional Ethical Committee.

Statistical analysis
The collected data was fed to IBM SPSS software version 22 (SPSS, Inc.Chicago, IL).All statistical analysis was done using two-tailed tests.Descriptive analysis performed for all variables including patients' socio-demographic data, weight, height, and nationality.Different risk factors of ACS were also displayed such as diabetes, hypertension, smoking, dyslipidemia, and IHD history.Crosstabulation was used to evaluate the distribution of ACS subtypes by reported risk factors and patients' data.Pearson chi-square test and exact probability test for small frequency distributions were used to assess the associations.P-value less than 0.05 was statistically significant.
Table2 shows a significant difference regarding smoking status by patient age as all patients aged 70 years or more were non-smokers compared to 41.9% of the age group less than 50 years were active smokers (P=.001).All other risk factors were insignificantly associated with patients' age but all of them were higher among old aged patients (70 years or more) except for IHD.
Table3 shows the distribution of different ACS subtypes by age, gender, and BMI.65.1% of young aged patients (< 50 years) had STEMI while 40% of old aged patients (70+) had NSTEMI with no statistical significance (P=.188).A total of 52.8% of males had STEMI versus 46.7% of female patients (P=.375).Also, 61.1% of patients with normal body weight had STEMI compared to 52.4% of overweight and 42.3% of obese patients (P=.229).
Regarding Association between different ACS subtypes and cardiovascular risk factors (Table4).The exact 65.6% of active smokers had STEMI compared to 48.2% of non-smokers with no statistical significance (P=0.190).Also, 50% of patients with hypertension complained of STEMI versus 54.4% of non-hypertensive (P=0.158).STEMI was diagnosed among 52.6% of nondiabetic patients compared to 50.4% of diabetic patients (P=0.542).Additionally, 54.5% of patients with dyslipidemia complained of STEMI versus 46.5% of others without (P=0.308).Family history of IHD was associated with developing NSTEMI (42.9%) compared to 28.6% of patients without (P=0.550).A total of 52.2% of patients with IHD developed STEMI compared to 51% of others without (0.351).

DiScuSSion
Out of the total number of patients included in the current study, 51.2% of them presented with STEMI, while 27.6% and 21.2% of them presented with NSTEMI and UA respectively.The distribution of ACS subtypes was as expected according to previous studies which reported that STEMI was the most common presentation in ACS patients, followed by NSTEMI, and UA. 8,9STARS-1 Program (The first survey of the Saudi Acute Myocardial Infarction Registry Program ) reported that among 2233 patients with ACS, 65.9% of them had STEMI and 34.1% had NSTEMI.They attributed this distribution to the relatively young age of ACS appearance in their sample. 10However, in contrast to their findings, the current study revealed that younger patients have the lowest risk factors.
According to the current study, 73.5% of the patients were males, while 26.5% were females.These findings align with various studies that have indicated a higher prevalence of all risk factors among males. 11,12,13,14Despite the fact that more than half of male patients present with STEMI, the occurrence of NSTEMI is lower compared to female patients, as confirmed by multiple studies. 15,16However, the gender association with ACS progression remains uncertain.
Most of the ACS patients in the current study were 50 years old or older (74.7%), and among all age groups, STEMI was higher in the younger age.In agreement with this finding, earlier studies documented inverse relationship between STEMI and patients' age. 9,17.Based on the patients' BMI data our results showed that obese and overweight patients were N: number P-value < 0.05 considered significant a, STEMI: ST elevation myocardial infarction b, NSTEMI: non ST elevation myocardial infarction at higher risk for ACS compared to normal-weight patients and most of them presented with STEMI..Interestingly our results showed that overweight patients were at higher risk of ACS (48.2%) compared to obese patients (30.6%).However, unexpectedly normal weight patients were the most diagnosed with STEMI (61.1%) compared to both overweight and obese patients.In our study, the BMI relationship with UA has a predictable pattern which exhibits that with each increase in BMI the percentage of UA cases increases.
We generally recognize risk factors through epidemiological findings. 25The high prevalence of the cardiovascular disease is due to specific lifestyle characteristics and related risk factors.Many cardiovascular risk factors contribute to ACS.These factors are classified into modifiable and non-modifiable risk factors. 26In Saudi Arabia according to the Prospective Urban Rural Epidemiology study (PURE-Saudi) which focus on the epidemiology of cardiovascular disease risk factors demonstrated that the most common risk factor was physical inactivity (69.4%) followed by obesity 34.4%, unhealthy eating 32.1%, dyslipidemia (32.1%), hypertension (30.3%), diabetes (25.1%) and low percentage of the population were active smokers (12.2%). 27n the present study, a significant percentage of ACS patients had DM (66%) and HTN (66%) as risk factors, followed by dyslipidemia with a percentage of 58%.However, we observed a low percentage of active smokers among the patients.This could be due to the fact that the average age of our sample is 58 years old, with the majority of patients being above 40 years old.Previous studies conducted in Saudi Arabia have shown that the younger age group (40 years old or younger) has the highest percentage of smokers, reaching 84.8%. 28he main concern of our study was to find the association between cardiovascular risk factors and ACS subtypes, and we focus on six main risk factors.Starting with smoking which is considered a crucial risk factor. 29Most of the smokers' patients in our sample were at higher risk for developing STEMI (65.6%) compared to non-smokers.Out of studies that have supported this association, one study showed that smoking raises the risk of developing ACS even in those who smoke less than 5 cigarettes per day. 30,31 N along with DM appears to be higher in NSTEMI compared with other ACS subtypes.These results were consistent with some previous studies.An epidemiological study conducted on patients with NSTEMI shows that two-thirds of the population was suffering from chronic HTN. 32ccording to the Saudi Project for Assessment of Coronary Events (SPACE) study HTN was the second most risk factor found in CAD patients in Saudi Arabia with a percent of 48%. 8Hypertension prevalence increases with age. 33Seeing that most of our patients were older, it is no strange that HTN was one of the most risk factors along with DM according to our results.
In Saudi Arabia according to the latest edition of "IDF Diabetes Atlas" the prevalence of adults with diabetes currently is 18.7%.And Saudi Arabia classified as the seventh-highest country with new cases of diabetes type 1. 34 In general, men with diabetes were twice more susceptible to CVD than nondiabetic .Among diabetic women, the prevalence of CVD was about three times that those who were nondiabetic . 35Dyslipidemia also appeared to be a critical risk factor for ACS according to our findings and previous studies. 33,36y comparing dyslipidemia presence with ACS subtypes it showed an increased presentation of patients with STEMI and NSTEMI.These outcomes were compatible with earlier studies. 36,37  one study that was conducted on ACS patients with a mean age of 59 years old which is similar to what we got (58 years) shows that most of them presented mostly with STEMI (61%) followed by NSTEMI (25.7%) and with a lower percentage of UA (13.3%). 37Finally Based on our results, having an IHD or a family history of IHD was associated with a higher percentage of UA but particularly IHD as a risk factor was associated with a higher occurrence of STEMI unlike the family history of IHD where most patients presented with NSTEMI.

concluSion
To conclude, out of 170 patients with ACS included in the study most of them were males, at the age of 50 years old or more, with elevated BMI.Furthermore, 51.21% of them presented with STEMI followed by 27.6% with NSTEMI and 21.2% with UA.Among the cardiovascular risk factors, HTN, DM, and dyslipidemia were presented in more than half of the patients which strongly suggests an association with developing ACS.

table 1 .
Bio-demographic data of study participants Fig. 1.Distribution of acute coronary syndromes subtypes among study participants

table 2 .
Association between risk factors and different age groups P: Pearson X2 test $: Exact probability test N: number P-value < 0.05 considered significant a, IHD: ischemic heart disease Fig. 2. Prevalence of risk factors among study participants

table 3 .
Distribution of acute coronary syndrome subtypes by age, gender, BMI P: Pearson X2 test.

table 4 .
Association between different acute coronary syndrome subtypes and cardiovascular risk factors