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ORIGINAL ARTICLE
Year : 2021  |  Volume : 34  |  Issue : 3  |  Page : 1139-1144

Coronary atherosclerotic plaque extent in hypertensive patients detected by computed tomographic angiography


1 Department of Cardiology, ElAgoza Hospital, Giza, Egypt
2 Department of Cardiology, Police Academy Hospital, Cairo, Egypt
3 Department of Cardiology, Faculty of Medicine, Menoufia University, Menoufia, Egypt

Date of Submission09-Jun-2020
Date of Decision27-Jul-2020
Date of Acceptance28-Jul-2020
Date of Web Publication18-Oct-2021

Correspondence Address:
Ehab M Elewa
ElAgoza Hospital, AlAgoza, Giza
Egypt
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/mmj.mmj_190_20

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  Abstract 


Objective
To evaluate the extent of coronary artery calcium in hypertensive patients using multislice computed tomography.
Background
Uncontrolled hypertension is one of the most common determinants for hospital admissions owing to acute coronary events. Computed tomographic (CT) coronary calcium scoring has been established as the best noninvasive predictor of atherosclerotic cardiovascular risk available today.
Patients and methods
The present study was conducted on 90 patients with recurrent chest pain referred for coronary multislice computed tomography angiography at Kobry El-Kobba Military Hospital. Patients comprised 69 hypertensive patients and 21 normotensive patients. Full history taking, laboratory investigation, coronary CT angiography, coronary plaque distribution, and coronary artery calcium scoring (CACS) were done.
Results
There was no statistically significant difference between the studied groups regarding mid left anterior descending (LAD) obstruction, distal LAD obstruction, proximal left circumflex (LCX) obstruction and distal LCX obstruction, proximal right coronary artery (RCA) obstruction, mid RCA obstruction, and distal RCA obstruction. However, hypertensive patients had significantly higher rate of 1–49% proximal LAD obstruction (P = 0.015) and mid LCX 1–49% and more than or equal to 50% obstruction (P = 0.034). Moreover, nonhypertensive patients had significantly higher number of patients with nonaffected vessels. Hypertensive patients had significantly higher rate of two-vessel affection. Moreover, hypertensive patients had significantly higher CACS, atheroma burden obstructive score, segment involvement score, and segment stenosis scored syntax I score compared with nonhypertensive patients.
Conclusion
Hypertension is associated with higher rate of coronary artery stenosis as shown by CT angiography. Hypertension is associated with increasing CACS.

Keywords: cardiovascular disease, computed tomographic, coronary artery calcium, hypertension


How to cite this article:
Elewa EM, Mostafa AA, Kamal AM. Coronary atherosclerotic plaque extent in hypertensive patients detected by computed tomographic angiography. Menoufia Med J 2021;34:1139-44

How to cite this URL:
Elewa EM, Mostafa AA, Kamal AM. Coronary atherosclerotic plaque extent in hypertensive patients detected by computed tomographic angiography. Menoufia Med J [serial online] 2021 [cited 2024 Mar 28];34:1139-44. Available from: http://www.mmj.eg.net/text.asp?2021/34/3/1139/328311




  Introduction Top


Cardiovascular disease (CVD) is the leading cause of death worldwide. Hypertension is the most important modifiable risk factor accounting for nearly half of all CVD events globally [1]. Unfortunately, the prevalence of high blood pressure (BP) is increasing. Given the aging population and epidemic of obesity, the prevalence is projected to further increase over the next decade [2],[3]. Although control rates in the world have improved, recent data demonstrate that nearly half of all hypertensive individuals still have BP levels above goals [3]. Medical treatment of severe and stage 2 hypertension is well established to reduce CVD events and universally recommended [4],[5]. An additional critically important unanswered question is how to best assess overall CVD risk, including the evaluation of target organ damage, in patients with hypertension to optimally tailor treatment decisions [6].

'Guidelines recommend several routine tests (e.g., ECG, creatinine, and urinalysis) and assessing for other CVD risk factors (e.g., diabetes). However, unlike with cholesterol management' [7], guidance regarding the usage of global risk scores and the incorporation of advanced imaging test results, such as coronary artery calcium score (CACS), into clinical decision making have not been well delineated [2],[3]. Coronary artery calcium (CAC) is a marker of subclinical atherosclerosis and ranks among the most important independent predictors of future CVD events [myocardial infarctions (MI) and strokes] as well as all-cause mortality [8],[9].

Recent evidence supports that a CAC-based treatment algorithm of hyperlipidemia would likely be highly effective owing to its accuracy in stratifying patients regarding absolute CVD risk [9]. In a similar fashion, meta-analyses demonstrate that overall CVD risk (rather than just BP level) is the most predictive factor regarding the treatment benefits derived from antihypertensive therapy. Little data are available regarding coronary plaque composition and semiquantitative scores in individuals with hypertension, and the extent to which hypertension my affect the extent of CAC needs more evaluation. Considering that this information may be of great value in formulating preventive interventions in this population [9]. The aim of this study was to evaluate the extent of CAC in hypertensive patients using multislice computed tomography (MSCT).


  Patients and methods Top


The present study was conducted on 90 patients with recurrent chest pain referred for coronary MSCT angiograph at Kobry El-Kobba Military Hospital. Patients comprised 69 hypertensive patients and 21 normotensive patients.

Ethical consideration

All participants signed a written informed consent with explaining the aim of study before the study initiation. Approval of the study protocol was obtained by Ethical Scientific Committee of Menoufia University Hospital.

Patients included in this study were selected according to the following criteria:

Inclusion criteria were patients with recurrent chest pain and fulfilling the following criteria: sinus rhythm, their heart rate less than 70 bpm spontaneously or beta blocker induced, they can hold breath for more than 20 s, weight less than 150 kg, and documented coronary artery disease (CAD) by MSCT.

Exclusion criteria were respiratory failure, decompensated heart failure, presence of arrhythmias, hypersensitivity to iodinated contrast agent, history of allergies or allergic reactions to other medications, impaired renal function (serum creatinine ≥1.5 mg/dl), hyperthyroidism morbid obesity, previous coronary stenting, previous coronary artery bypass grafting, diabetes, and liver cell failure.

All patients were subjected to the following: full history taking, including age; sex; hyperlipidemia; smoking; hypertension, defined as a self-reported history of high BP or had a documented BP more than or equal to 140/90 mmHg or use of antihypertensive medication; and diabetes, defined as baseline use of antidiabetic medication or had a history of elevated blood glucose measurement of more than 126 mg/dl. Physical examination included vital data and hemodynamic stability. Lead ECG included rhythm, rate, interval, and QRS duration. Routine laboratory investigations included blood glucose level, renal function tests, and lipid profile.

Coronary computed tomography angiography (cCTA) was performed for all patients utilizing a dual-source scanner (Somatom Definition Flash; Siemens Company, Munich, German) using two radiograph sources.

Coronary plaque distribution was divided into 17 segments according to the modified American Heart Association classification. The presence of coronary plaques was evaluated visually using axial images and curved multiplanar reconstructions. One coronary plaque was assigned per coronary segment. Plaques were classified as obstructive and nonobstructive, using a 50% threshold of luminal narrowing. The presence of coronary plaques on MSCT, the presence of obstructive CAD in general and if located in the left main/left anterior descending (LAD) coronary artery, and the presence of obstructive CAD in one vessel (single-vessel disease) or two or three vessels (multivessel disease) were evaluated.

CACS was defined as lesions with attenuations greater than 130 Hounsfield Units in more than four adjacent pixels. For quantification of CACS, the Agatston score was calculated as the product of the lesion's surface area and a weighting factor ranging from one to four, which was assigned according to the peak attenuation of the lesion. Agatston score used as risk modifier CAC indicates risk of CAD as low CAC less than 400, moderate 400–1000, and severe more than 1000.

The atheroma burden obstructive score (ABOS): the ABOS was defined as the number of plaques with more than 50% stenosis in the entire coronary artery tree.

Segment involvement score (SIS): the SIS was calculated as the total number of coronary artery segments exhibiting plaque, irrespective of the degree of luminal stenosis within each segment (minimum = 0; maximum = 16).

Segment stenosis scored (SSS) syntax I score: the SSS was used as a measure of the overall coronary artery plaque extent. To determine the SSS, each individual coronary segment was graded as having no to severe plaque (i.e., scores from 0 to 3) based on the extent of the obstruction of the coronary luminal diameter. Then, the extent scores of all 16 individual segments were summed to yield a total score ranging from 0 to 48.

Statistical analysis

Data entry, coding, and analysis were conducted using SPSS for Windows, Version 22 (IBM Corp., Armonk, New York, USA). Description of quantitative variables was in the form of mean ± SD), χ2 test, Student t test, or Mann–Whitney U test. P value less than or equal to 0.05 was set to be statistically significant.


  Results Top


In the current study, there was no statistically significant difference between the studied groups regarding age (P = 0.018), sex (P = 0.56), and the rate of left main obstruction (P = 0.33). However, there was a significantly higher frequency of smoking in the nonhypertensive group. Moreover, hypertensive patients had significantly higher rate of dyslipidemia [Table 1]. In the current study, there was no statistically significant difference between the studied groups regarding mid LAD obstruction (P = 0.051), distal LAD obstruction (P = 0.38), proximal left circumflex (LCX) obstruction (P = 0.42), and distal LCX obstruction (P = 0.62). However, hypertensive patients had significantly higher rate of 1–49% proximal LAD obstruction (P = 0.015) and mid LCX 1–49% and more than or equal to 50% obstruction (P = 0.034) when compared with nonhypertensive patients [Table 2]. There was no statistically significant difference between the studied groups regarding proximal right coronary artery (RCA) obstruction (P = 0.49), mid RCA obstruction (P = 0.13), and distal RCA obstruction (P = 0.32), [Table 3]. Our results showed that nonhypertensive patients had significantly higher number of patients with nonaffected vessels. Hypertensive patients had significantly higher rate of 2-vessel affection. Moreover, hypertensive patients had significantly higher CACS, ABOS, SIS, SSS, and syntax I scores when compared with nonhypertensive patients [Table 4].
Table 1: Comparison between the studied groups regarding the basic data and left main obstruction

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Table 2: Comparison between the studied groups regarding left anterior descending and left circumflex obstruction

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Table 3: Comparison between the studied groups regarding right coronary artery obstruction

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Table 4: Total number of vessels affected and coronary disease severity scores in the studied groups

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  Discussion Top


CAD remains the leading cause of mortality and morbidity worldwide, and hypertension is its most prevalent modifiable risk factor. Patients with CAD and concomitant hypertension are a special population with distinct physiologic and structural alterations [10]. Pathophysiologic links of hypertension to acute MI include endothelial dysfunction, autonomic nervous system dysregulation, impaired vasoreactivity, and a genetic substrate [11]. Uncontrolled hypertension is one of the most common determinants for hospital admissions owing to acute coronary events. Markedly high BP levels are also frequently observed during the acute phase of coronary syndromes (both ST-segment and non-ST-segment elevation MI and unstable angina) [12]. Computed tomographic (CT) coronary calcium scoring has been established by large prospective, population-based studies as the single best noninvasive predictor of atherosclerotic cardiovascular risk available today. The calcium score correlates highly with the total burden of coronary atherosclerosis demonstrated at autopsy [13]. CAC is a powerful independent predictor of future cardiovascular events. However, the clinical utility of calcium score testing specifically among patients with hypertension is not well defined [14]. So, the present study aimed to evaluate the extent of CAC in hypertensive patients using MSCT. The study recruited 90 patients with recurrent chest pain referred for coronary MSCT angiography. They comprised 69 hypertensive patients and 21 normotensive patients. All patients were subjected to careful history taking, thorough clinical examination, and laboratory investigations. CT angiography was performed for all patients, and CACS was calculated. Comparison between hypertensive and nonhypertensive patients regarding the CT angiographic data revealed that patients with hypertension had significantly higher rate of 1–49% proximal LAD obstruction when compared with nonhypertensive patients. In addition, they had significantly higher rate of mid LCX 1–49% and more than or equal to 50% obstruction when compared with nonhypertensive patients. Moreover, it was shown that nonhypertensive patients had significantly higher number of patients with nonaffected vessels. Hypertensive patients had significantly higher rate of 2-vessel affection. These results are in harmony with the study of Hou et al. [15] who aimed to document the prevalence of CAD and major adverse cardiac events (MACE) in patients younger than 45 years of age with intermediate pretest likelihood of CAD and to determine whether cCTA is useful for risk stratification of this cohort. In their work, hypertension, smoking, and significant CAD in cCTA were significant predictors of MACE in univariate analysis. Moreover, cCTA remained a predictor of events after multivariate correction.

In another study, the authors proposed to evaluate risk factors associated with CAD extension documented by cCTA. The study found that these patients were older, more often male and had higher prevalence of diabetes, hypertension, and dyslipidemia [16]. Otaki et al. [17] also examined the relationship between cardiovascular risk factors and prevalence and severity of coronary atherosclerosis in a large, prospective, multinational registry of consecutive young individuals undergoing cCTA. Of 27, 125 patients undergoing cCTA, 1635 young (<45 years) individuals without known CAD or coronary anomalies were identified. Coronary plaque was assessed for any CAD, obstructive CAD (≥50% stenosis), and presence of calcified plaque and noncalcified plaque (NCP). Any CAD, obstructive CAD, and NCP were higher for young individuals with diabetes, hypertension, dyslipidemia, current smoking, or family history of CAD. Moreover, the study of Barros et al. [18] assessed the potential of cCTA in the prediction of cardiac adverse events in patients with suspected CAD. During the follow-up, there were 37 MACE. In multivariate Cox proportional hazards model, hypertension and cCTA were independent predictors of MACE.

The relation between adverse cardiac events detected by cCTA was even reported in patients with white coat hypertension. It was found that patients with white coat hypertension had a higher coronary atherosclerotic burden compared with patients with normal BP for all markers [19]. In another work, hypertension among other clinical factors was incorporated in prediction model with the extent of nonobstructive CAD determined by cCTA. The dedicated risk scoring system for nonobstructive CAD using clinical factors and cCTA findings accurately predicted prognosis [20]. Most recently, the study of van Rosendael et al. [21] examined the prognostic value of risk factors and atherosclerotic extent. In their study, 3547 patients were included, experiencing 460 MACE during 5.4 years of follow-up. Age, BMI, hypertension, and diabetes were the clinical variables associated with increased MACE risk, but the magnitude of risk was higher for cCTA-defined atherosclerotic extent; adjusted hazard ratio for diabetes and hypertension were 1.7 and 1.4, respectively.

In the current study, it was also found that hypertensive patients had significantly CACS, ABOS, SIS, SSS, and syntax I scores when compared with nonhypertensive patients. These findings are in agreement with the study of Rasmussen et al. [22]. In their study, participants were categorized into five CACS risk classification groups according to the CACS. In addition to age, male sex, hypertension, hypercholesterolemia, continued smoking, and COPD according to GOLD classification were independent predictors of a higher CACS risk classification group in multivariable analysis. In addition, the study of Im et al. [23] aimed to investigate the prevalence, severity, and plaque characteristics of coronary atherosclerosis according to grade of BP using cCTA. Patients were classified according to JNC 7 guidelines [normal, systolic BP/diastolic BP <120/80; prehypertension (PH), 120–139/80–89; hypertension stage 1 (H1), 140–159/90–99; and hypertension stage 2 (H2) >160/100]. Isolated systolic hypertension (systolic BP >140, diastolic BP <80) was additionally categorized. After adjustment for clinical risk factors, the risk of subclinical atherosclerosis, NCP, and CACS more than 100 gradually increased from PH stage (all P values for trend <0.05), whereas the risk of obstructive CAD increased from the H1 stage (AORs of H1 and H2: 1.70 and 2.33, respectively). In the isolated systolic hypertension group, the AOR of subclinical atherosclerosis (1.64) was higher than in the H1 group (1.55), whereas the AOR of obstructive CAD (2.58) was higher than in the H2 group (2.33). Moreover, the study of Jang et al. [24] tried to identify the distribution of CACS by age group and cardiovascular risk factors and to evaluate the association between cardiovascular risk factors and CACS classification. The study included 31 545 asymptomatic Koreans, over 20 years of age with no previous history of malignancy, proven CAD, or stroke, who underwent CACS computed tomography. When analyzed according to sex, in males, the adjusted odds ratio for CACS increased with the presence of hypertension, diabetes mellitus, obesity, chronic kidney disease, and smoking status. However, in females, the adjusted odds ratio for CACS increased with the presence of hypertension, diabetes mellitus, and obesity. Furthermore, the study of Tay et al. [25] determined the proper use of contributing risk factors and CACS using cCTA. Patients were grouped based on CACS into 'zero,' 'minimal,' 'mild,' 'moderate,' and 'excessive.' It was found that males over 45 years old with diabetes mellitus and hypertension had a higher risk of significant coronary stenosis. In multivariate analysis, age, sex, hypertension, and diabetes mellitus remained significant predictors of stenosis.


  Conclusion Top


Hypertension is associated with higher rate of coronary artery stenosis as shown by CT angiography. Hypertension is associated with increasing CACS.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
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