mong these independent factors, diabetes mellitus was the strongest risk factor (multiple regression coefficient: 6.7, p < 0.001) (Table 3).
Table 1. Baseline characteristics.
Abbreviations: HTN, hypertension; DM, diabetes mellitus; BMI, body mass index.
Table 2. SX score comparison between populations with and without each risk factor.
Abbreviations: HTN, hypertension; DM, diabetes mellitus; HPL, hyperlipidemia. Data are expressed as mean ± SD, median and IQR, or number (percentage).
Table 3. Univariate and multivariate regression analyses of risk factors for SYNTAX score.
Abbreviations: HTN, hypertension; DM, diabetes mellitus; HPL, hyperlipidemia; BMI, body mass index.
Figure 1. A scatterplot of age against SYNTAX score among the study population.
Figure 2. A scatterplot of BMI against SYNTAX score among the study population.
The SYNTAX trial is the origin from which the SX score was developed. It was used as an index for assessment of lesion complexity in patients with left main trunk lesion or three-vessel disease for whom CABG treatment is indicated . Conventional risk factors of CAD such as age, male gender, hypertension, dyslipidaemia, BMI, diabetes and smoking have been linked to more severe forms of CAD . A higher patient’s risk status is expected to be accompanied by a more severe and advanced form of the disease and a higher SX score. The evidence regarding such statement is still not that sufficient .
The aim of this work was to study the correlation between SX score and pattern of risk factors in patients referred for coronary angiography in Cardiology Department―Menoufia University. The study enrolled 52 cardiac patients. All patients were subjected to history taking, full clinical examination, angiographic analysis and SX score. The data was collected and statistically analyzed.
In this study, aging, having diabetes mellitus and smoking were significant independent risk factors of the complexity of CAD and high SX score results. So, patients with these factors are expected to have a more complicated CAD than that in patients without these factors. In the SYNTAX trial, rates of MACE and cerebrovascular events were similar in patients with low or intermediate scores in both the CABG group as well as in the PCI group. However this wasn’t the case in patients with high scores, in which, patients in the PCI group had significantly increased event rate . Based on this finding, it is recommended to avoid PCI in patients with high SX score as a result of expected high complexity of CAD in those patients, and this is also why CABG should be considered.
It is known that vascular endothelium function decreases and arterial sclerosis progresses with aging . In our study, it was found that advanced age is an independent risk factor of the complexity of CAD.
In this study, being a male wasn’t a statistically significant risk factor for the complexity of CAD. It is known from a previous study that estrogen shows antiarteriosclerotic effects and that’s why women develop CAD after menopause . It was previously thought that CAD in men is more complex and severe than in women. However, several studies reported that women with CAD have a smaller reference diameter of coronary artery, as well as more frequent diffuse stenosis not suitable for PCI, calcification and coronary artery dissection than men . Besides, it was also found in a previous study that except for female hormonal status, no risk factor has been recognized as acting on one gender and not on the other. This finding indicates that the pathogenesis of CAD is very similar for men and women .
It is now universally well established that cigarette smoke exposure is an important cause of cardiovascular morbidity and mortality. This is because either active or passive exposure leads to vasomotor dysfunction, atherogenesis, and thrombosis in multiple vascular beds . In our study smoking is found to be an independent risk factor of the complexity of CAD.
Diabetes mellitus is found to be associated with the complexity of CAD . In our study, we found that diabetes mellitus is an independent risk factor for the complexity of CAD.
Lastly, in this study, the conventional risk factors of CAD were not totally concordant with those of CAD complexity. We found that factors, such as male gender, hypertension, increased BMI and hypercholesterolemia were not significant independent risk factors for the complexity of CAD.
5. Study Limitations
Although the number of patients enrolled in our study is relatively small, the results are quite comparable to larger studies. This study was observational and single-institutional in nature, which possibly restricted us from identifying and analyzing all potential confounding factors. There was some sort of selection bias because the choice between PCI and CABG as a treatment is dependent on the treating physician. Exclusion of acute MI because SX score is not yet valid in such condition, is considered one of the study limitations. Lastly, we didn’t demonstrate the effect of treating different modifiable risk factors on CAD lesion complexity.
Regarding conventional risk factors of CAD, being an advanced age, having diabetes mellitus and cigarette smoking are considered to be independent risk factors for the complexity of CAD. Therefore, presence of these risk factors will lead to the expectation of a highly complex CAD which in turn requires a careful management and a more tendency for CABG as a method of revascularization. Further studies in larger cohorts are needed for the validation of these findings to better define the role of conventional risk factors in clinical decision making in patients with CAD.
Declaration of Conflicting Interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
The author(s) received no financial support for the research, authorship, and/or publication of this article.