|Year : 2019 | Volume
| Issue : 1 | Page : 167-171
Platelet to lymphocyte ratio as a predictor of severity of coronary artery disease
Ahmad A Reda, Mohammad A Moharram, Ali ElGhareeb Rasheed
Department of Cardiology, Faculty of Medicine, Menoufia University, Menoufia, Egypt
|Date of Submission||25-Jun-2017|
|Date of Acceptance||08-Sep-2017|
|Date of Web Publication||17-Apr-2019|
Ali ElGhareeb Rasheed
Department of Cardiology, Faculty of Medicine, Menoufia University, Menoufia
Source of Support: None, Conflict of Interest: None
The objective was to research the value of platelet to lymphocyte ratio (PLR) as an indicator of severity of coronary atherosclerosis.
Cardiovascular disease is the commonest cause of death worldwide. The process of coronary atherosclerosis is greatly dependent on several factors. New inflammatory markers were believed to be valuable as indicators of severity of coronary atherosclerosis.
Patients and methods
We conducted a randomized prospective observational study in our Coronary Intervention Unit, Menoufia University hospital. One hundred and thirty patients qualified for elective coronary angiography were arranged into three groups based on their Gensini score. Group I patients with normal coronary angiography, group II patients with mild atherosclerotic coronary disease, and group III included patients with severe atherosclerotic coronary disease.
There was a significant positive correlation between PLR and severity of coronary atherosclerosis estimated by Gensini score. Regarding group I, the mean PLR value is 102.8 whereas in group II, the mean PLR value is 114.98 and in group III, the mean PLR value is 141, providing a cut-off value of PLR 126.5 that predicts severe coronary atherosclerosis.
PLR is a powerful marker for the prediction of severity of coronary atherosclerosis and should be widely used for risk stratification of ischemic patients. Moreover, PLR should be considered when choosing the management strategy of such patients either conservatively or interventionally.
Keywords: coronary atherosclerosis, Gensini, lymphocyte, platelet
|How to cite this article:|
Reda AA, Moharram MA, Rasheed AE. Platelet to lymphocyte ratio as a predictor of severity of coronary artery disease. Menoufia Med J 2019;32:167-71
|How to cite this URL:|
Reda AA, Moharram MA, Rasheed AE. Platelet to lymphocyte ratio as a predictor of severity of coronary artery disease. Menoufia Med J [serial online] 2019 [cited 2019 May 21];32:167-71. Available from: http://www.mmj.eg.net/text.asp?2019/32/1/167/256115
| Introduction|| |
Amazing progress in the diagnosis and management could not change the fact that ischemic heart disease is the principal cause of mortality all over the world . The procedure of coronary atherosclerosis is significantly reliant on several components. New inflammatory markers emerged to be profitable as indicators of seriousness of coronary atherosclerosis . Platelets are considered a basic supply for the inflammatory mediators . Platelet activation was demonstrated to start atherosclerosis and actually has a fundamental role in its advancement . Ongoing inflammatory processes cause increased synthesis of platelets through proliferation in megakaryocytic series and that finishes with relative thrombocytosis. Elevated number of platelets in the peripheral blood is usually associated with high possibility of undesired cardiac and vascular outcomes . Studying lymphocytes and their impact in regulating the immunologic reaction at nearly all pathophysiologic phases of atherosclerotic process raises the level of significance of applying them as indicators of atherosclerosis . The relationship between lymphocytopenia and major undesired cardiac and vascular outcomes appeared in several reviews ,. At the time of sustained inflammation, lymphocyte count decreases significantly due to increased rate of lymphocyte apoptosis. Lymphocytes represent a more convenient immune response. Meanwhile neutrophils create a damaging inflammatory response. Lymphcytopenia was learned to be incredibly connected with low survival in a population-based analysis of patients having known stable coronary artery disease (CAD). Additionally, they propose that lymphocytopenia is a potential risk factor and a free crucial prognostic marker in stable CAD . However, it is confirmed that the lymphocyte count represents a valuable early marker of physiologic 'stress' and systemic inflammatory reaction . Previous reviews confirmed the fundamental relation between numerous hematologic variables especially neutrophil to lymphocyte ratio and CAD. Predictive and more notable prognostic significance of the neutrophil to lymphocyte ratio has been clearly shown in several cardiac and vascular diseases . Platelet to lymphocyte ratio (PLR) is a novel prognostic marker which includes the predictive risk of both platelet count and lymphocyte count. It can anticipate both inflammation and aggregation cascades; therefore, it is more valuable than either platelet or lymphocyte counts alone in revealing the burden of coronary atherosclerosis.
| Patients and methods|| |
This is a prospective study that was conducted at the Coronary Intervention Unit, Cardiology Department, Menoufia University Hospital during the period from February 2015 to March 2016 including 130 individuals planned for elective diagnostic coronary angiography, excluding patients with significant valvular or rheumatic heart disease, hematological disease, malignancy, severe liver or renal disease, systemic inflammatory disease, active infection, autoimmune disease, decompensated heart failure or cardiogenic shock and patients on steroid therapy whatever be the cause. Patients were subdivided into three groups according to the result of their coronary angiography and their Gensini scores. Group I: patients with completely normal coronary angiography with zero Gensini score. Group II: patients with mild degree atherosclerotic CAD with Gensini scores of less than 25 points. Group III: patients with severe degree atherosclerotic CAD with Gensini scores of 25 points or more. The study was approved by the Ethical Committee of the Faculty of Medicine, Menoufia University and the patient gave an informed consent.
Careful history was taken from all participants especially that of previous myocardial infarction, hypertension, diabetes mellitus, smoking, dyslipidemia, and family history of CAD. A thorough general and local cardiac examination was done for every patient.
Resting 12-leads ECG and laboratory investigations were done including complete blood picture on presentation measuring the total and differential leukocyte numbers, serum level of creatinine, blood glucose fasting level, and lipid profile. Elective coronary angiography was performed for all participants enlisted in the study by Judkin's technique. All of the coronary angiograms were carefully evaluated by two experienced interventionists. A precise review of each coronary angiogram established the lesion location and percentage of arterial stenosis among all coronary artery lesions. The Gensini scoring system was used to identify the degree of severity of CAD. This method classifies and scores the degree and sites of the stenosis of coronary arteries . The correlation between PLR and severity of atherosclerosis in CAD was performed. The cut-off value of PLR that predicts severe CAD was calculated.
| Results|| |
The study included 130 patients, men represented 43.8% and women represented 56.2%. They were arranged into three groups. Group I: patients with completely normal coronary angiography (n = 26, with an average age of 52.43 years), group II: patients with mild degree of atherosclerotic CAD (n = 46, with an average age of 59.91 years), and group III: patients with severe degree of atherosclerotic CAD (n = 58, with an average age of 64.6 years).
A sum of 104 patients with confirmed CAD and 26 controls were enlisted in our study.
Smoking and diabetes were predominant in the group of mild atherosclerosis, whereas hypertension was predominant in the group of severe atherosclerosis [Table 1] and [Table 2].
|Table 2: Hypertension, diabetes mellitus, smoking, and serum creatinine in relation to disease state of the recruited participant (n=130)|
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The mean serum level of creatinine was significantly higher in the group of severe atherosclerosis (P < 0.001) [Table 2].
Concerning the lipid profile, serum total cholesterol, low-density lipoprotein, and triglycerides levels did not differ between the study groups (P = 0.81, 0.69, 0.10, respectively) unlike high-density lipoprotein (HDL), which significantly varies among the study groups (P < 0.001). The group of severe atherosclerosis and the group of mild atherosclerosis had considerably lower HDL levels compared with controls (P < 0.001 for both). The HDL level in the group of severe and mild atherosclerosis did not reach a statistically significant difference (P = 0.08) [Table 3].
White blood cell (WBC) numbers were significantly higher in the group of severe atherosclerosis than in the other two groups (P < 0.001), while there was no significant difference between the group of mild atherosclerosis and control group (P = 1.00) [Table 4].
|Table 4: Comparing laboratory data and blood indices between the study groups|
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The group of severe atherosclerosis had significantly higher numbers of platelets when compared with mild atherosclerosis and control groups (P = 0.006) [Table 4].
PLR was significantly higher in the group of severe atherosclerosis than the other two groups (P < 0.001) [Table 4].
PLR shows a significant positive correlation with Gensini scores (r = 0.87, P < 0.001) [Table 5].
|Table 5: Correlation between platelet to lymphocyte ratio of the participants and the Gensini score|
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PLR was also demonstrated to predict severe coronary atherosclerosis with a cut-off value of 126.5 with a sensitivity of 86% and specificity of 84% [Figure 1].
|Figure 1: The receiver operating characteristic curve analysis of platelet to lymphocyte ratio for predicting severe atherosclerosis. A cut-off value of platelet to lymphocyte ratio predicting severe atherosclerosis is 126.5 with a specificity of 84% and sensitivity of 86%. CI, confidence interval; ROC, receiver operating characteristic curve|
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| Discussion|| |
Cardiovascular disease is nowadays the first worldwide cause of death, accounting for more than 17.3 million deaths per year in 2013, a number that is expected to grow to more than 23.6 million by 2030 . This study was conducted to find out the value of PLR as an indicator of severity of atherosclerosis in CAD.
In our present study, the group of severe atherosclerosis had significantly higher numbers of platelets when compared with the other two groups (P = 0.006). Sayin et al.  studied 90 patients with stable CAD who underwent coronary angiography. There was no correlation between Gensini score and platelet numbers. This difference may be due to the small number of patients in the study by Sayin et al.  According to our present study, WBC numbers were significantly higher in the group of severe atherosclerosis than in the other two groups. This is in agreement with Amaro et al.  who focused in his study on the relationship between WBC number and CAD in 152 men, without myocardial infarction or clear infection in the 6 months before the review. There was a reasonable positive correlation between WBC number and Gensini score, and it was significantly higher in patients with multivessel disease . This is also in agreement with Kostis et al. , patients with CAD demonstrated by coronary angiography had significantly higher WBC numbers than patients with normal coronary angiograms. There was a clear positive correlation between the WBC count and the severity of CAD .
In this study, the PLR value in the group of severe atherosclerosis was significantly higher than the other two groups (P < 0.001). The information given by our present study is concordant with the Yüksel et al.  study results, where 388 individuals who performed coronary angiography were evaluated retrospectively. Patients with CAD were arranged as mild and severe atherosclerosis, based on their Gensini score. The mean PLR value of the group of severe atherosclerosis was considerably higher than that of the other two groups. Moreover, the PLR value gives a clear positive correlation with Gensini score in CAD patients. In multivariate analysis, preprocedural PLR value was freely correlated with Gensini score analysis . In Sari et al.  study, 180 successive participants underwent elective coronary angiography, whereas 100 of them demonstrated to have abnormal coronary angiography, the other 80 revealed normal coronaries. Patients with abnormal Coronary angiography (CAG) had considerably higher PLR values when compared with those with normal CAG. Patients with CAD had significantly higher PLR values when compared with those having normal coronary artery angiography which is concordant with the present study .
The Kurtul et al.  study also questioned the association of PLR with the severity and complexity of coronary atherosclerosis as assessed by the Syntax score in patients with acute coronary syndrome (ACS) who underwent urgent Coronary angiography (CA). PLRs were significantly higher in patients with intermediate to high Syntax scores compared with those with low Syntax scores. In multivariate analysis, the independent predictors of intermediate to high Syntax score were PLR together with the left ventricular ejection fraction and age. A PLR greater than or equal to 116 had 71% sensitivity and 66% specificity in predicting intermediate to high Syntax score. Increased PLR is an independent predictor of higher Syntax score .
| Conclusion|| |
In conclusion, PLR is believed to be a simple, basic, and promptly accessible method to predict the severity and extent of CAD in patients planned for coronary angiography.
This study pronounces that a high PLR value has to be viewed as an extra marker to conventional risk factors and daily used biomarkers in predicting severe coronary atherosclerosis and that the PLR value has a fundamental positive correlation with the measured Gensini score. When we consider that PLR is an estimation of routine complete blood picture parameters with no additional cost and it is a promptly achievable, easily done marker, it can help to find out participants at relatively high risk of advanced CAD, who might need a more forceful therapeutic approach and closer clinical follow-up.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]