Hindawi

BioMed Research International

Volume 2020, Article ID 6471098, 8 pages
https://doi.org/10.1155/2020/6471098

Research Article
Ankle-Brachial Index as the Best Predictor of First Acute
Coronary Syndrome in Patients with Treated
Systemic Hypertension

Wojciech Myslinski ,1 Agata Stanek ,2 Marcin Feldo ,3 and Jerzy Mosiewicz 1

1
Department of Internal Medicine, Medical University of Lublin, Staszica 16, 20-081 Lublin, Poland
2
Department of Internal Medicine, Angiology and Physical Medicine, Faculty of Medical Sciences in Zabrze, Medical University
of Silesia, Batorego 15 St., 41-902 Bytom, Poland
3
Department of Vascular Surgery and Angiology, Medical University of Lublin, Staszica 16, 20-081 Lublin, Poland

Correspondence should be addressed to Agata Stanek; astanek@tlen.pl

Received 20 June 2020; Accepted 26 June 2020; Published 17 July 2020

Academic Editor: Raffaele Serra

Copyright © 2020 Wojciech Myslinski et al. This is an open access article distributed under the Creative Commons Attribution
License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is
properly cited.

Objective. The objective of our study was to evaluate the incidence of target organ damages (TOD) in patients with arterial
hypertension and the first ever episode of myocardial infarction (N-STEMI or STEMI) and to determine which of the analyzed
kinds of TOD had the highest predictive value for the assessment of the likelihood of acute coronary syndrome (ACS). Material
and Methods. The study group consisted of 51 patients with treated systemic hypertension, suffering from the first episode of
myocardial infarction (N-STEMI or STEMI), confirmed by coronary angiography and elevation of troponin. The control group
consisted of 30 subjects with treated hypertension and no history of myocardial ischaemia. In all subjects’ measurements of
blood lipids, hsCRP and eGFR were measured. TOD, such as intima-media thickness (IMT), presence of atherosclerotic plaques,
ankle-brachial index (ABI), and left ventricular hypertrophy, were assessed. Results. Age, BMI, blood pressure, and time since
diagnosis of hypertension did not differ between the study groups. There were no differences regarding blood lipids and eGFR,
while hsCRP was significantly increased in the study group. The left ventricular mass index was similar in both groups. Patients
with myocardial infarction had significantly increased IMT and decreased ABI. The statistical analysis revealed that only ABI
was the most significant predictor of ACS in the study group. Conclusion. Among several TOD, ABI seems to be the most
valuable parameter in the prediction of ACS.

1. Introduction (LVH), atherosclerotic plaque, carotid intima-media thick-

ness (IMT), ankle-brachial index (ABI), pulse wave velocity
Arterial hypertension is one of the most important modifi- (PWV), and renal injury features are the best determinants
able risk factors for cardiovascular complications [1]. In clin- of the condition of the cardiovascular system [3]. In the
ical practice, we often find that the extent of cardiovascular ESC/ESH guidelines, each TOD has equivalent weight,
damage implies that the actual duration of arterial hyperten- meaning that slight thickening of the intima-media complex
sion is longer than that declared by the patient, possibly due has the same score as advanced left ventricular hypertrophy
to the long-term asymptomatic course of the disease as well or hemodynamically significant stenosis within the carotid
as the cooccurrence of other risk factors for cardiovascular or lower limb arteries [1].
diseases. Therefore, in addition to the presence of risk factors, The objective of our study was to evaluate the incidence
an important role in global cardiovascular risk assessment is of TOD in patients with arterial hypertension and the first
played by identification of subclinical target organ damage ever episode of myocardial infarction (N-STEMI or STEMI)
(TOD) [2]. TOD such as left ventricular hypertrophy and to determine which of the analyzed kinds of TOD had
2 BioMed Research International

Table 1: General characteristics of the study group and the control group subjects.

Study group (n = 51) Control group (n = 30) p

Mean age (years) 64:84 ± 9:83 64:2 ± 9:34 NS
Mean age, females (years) 69:6 ± 8:73 68:5 ± 6:02 NS
Mean age, males (years) 61:9 ± 9:33 60:4 ± 10:23 NS
BMI (kg/m2) 27:73 ± 5:06 28:47 ± 5:04 NS
Diabetes 14 (27.45%) 11 (36.6%) NS
Time since the diagnosis of hypertension (years) 8:54 ± 6:82 8:37 ± 6:9 NS
Smokers 13 (25.49%) 9 (30%) NS
Systolic blood pressure (mmHg) 129:3 ± 8:2 127:1 ± 7:8 NS
Diastolic blood pressure (mmHg) 77:7 ± 6:1 79:2 ± 6:4 NS
NS: nonsignificant.

the highest predictive value for the assessment of the likeli- approved by the Bioethics Committee at the Medical Univer-
hood of acute coronary syndrome. sity of Lublin.
The characteristics of the study groups are given in
2. Material and Methods Table 1.

2.1. Study Subjects. The study was conducted in a group of 51 2.2. Biochemical Analysis
patients aged 47 to 80 years, including 32 men and 19 women
with arterial hypertension who had experienced their first 2.2.1. Laboratory Parameters. Blood samples of all the sub-
acute coronary episode. Study group inclusion criteria jects were collected in the morning before the first meal.
included the age of ≤80 years, typical anginal pain or changes Samples of whole blood (5 ml) were collected from the
in ECG records, increased troponin I or T levels, and no his- basilic vein into tubes containing ethylenediaminetetraace-
tory of previous acute coronary syndrome (ACS) episodes. tic acid tripotassium salt (Sarstedt, S-Monovette with
Coronary angiography was performed in all patients con- 1.6 mg/ml EDTA-K3) and into tubes with a clot activator
firming the presence of coronary lesions; the time elapsed (Sarstedt, S-Monovette).
since the ACS was not longer than 4 days. All patients had Total cholesterol, HDL cholesterol, and LDL cholesterol
been diagnosed with arterial hypertension. The diagnosis of (T-Chol, HDL-Chol, and LDL-Chol) and triglyceride (TG)
arterial hypertension was based on the use of 1 or more anti- concentrations in serum were estimated using routine tech-
hypertensive drugs. The average age in the study group was niques (COBAS INTEGRA 400 plus analyzer, Roche Diagnos-
64.8 years, including 69.6 years in women and 61.9 years in tics, Mannheim, Germany). Concentrations were expressed in
men. The mean BMI was 27.7 kg/m2; overweight or obesity mg/dl. The inter- and intra-assay coefficients of variations
was diagnosed in 34 (66.6%) patients, including 16 (31.37%) (CV) were, respectively, 2.8% and 5.4% for T-Chol, 3.2% and
patients diagnosed with obesity. Thirteen (25.49%) patients 5.4% for HDL-Chol, 2.6% and 6.5% for LDL-Chol, and 2.5%
smoked, and 14 (27.45%) received antidiabetic treatment. and 7.6% for TG. Estimated GFR (eGFR) and hsCRP levels
The control group consisted of 30 subjects aged 45 to 78, were also determined in all patients.
including 16 men and 14 women treated for arterial hyper-
tension with no history of episodes of myocardial infarction. 2.3. Estimation of the Ankle-Brachial Index. A Vivid 4 ultra-
Just as in the study group, the diagnosis of arterial hyperten- sound system equipped with a 7–10 MHz adjustable fre-
sion was based on the use of 1 or more antihypertensive quency vascular transducer was used for ABI assessments.
drugs. The average age in the study group was 64.2 years, The ABI values were measured after a 5-minute rest in a
including 68.5 years in women and 60.4 years in men. The recumbent position. At the first stage, a color Doppler tech-
mean BMI was 28.4 kg/m2; overweight or obesity was diag- nique was used to visualize blood flow within the dorsal
nosed in 22 (73.3%) patients, including 12 (40.0%) patients artery of the foot or, in cases of visualization problems,
with BMI of 30 kg/m2 or higher. There were 9 (30%) smokers within the posterior tibial artery. Next, the cuff of a mercury
in the control group. Antidiabetic treatment was received by sphygmomanometer previously placed above the ankle of the
11 (36.6%) subjects. right lower limb was inflated until the blood flow in the visu-
As it was not possible to unambiguously determine the alized artery stopped. Upon slow deflation of the sphygmo-
duration of arterial hypertension, time since the diagnosis manometer cuff, the value of systolic blood pressure at
of arterial hypertension was taken into account and was sim- which the return of blood flow was observed in the examined
ilar in both groups. artery was recorded. In order to verify the measured systolic
All subjects in the study and the control group received pressure value, a second measurement was made using the
statins as part of primary or secondary prevention. pulsed-wave Doppler method to assess the return of blood
Qualified patients were informed of the study objectives flow. Immediately after the color Doppler and pulsed-wave
and expressed their consent to participate. The study was Doppler measurements were completed within the lower
BioMed Research International 3

limb, the value of systolic blood pressure at which blood flow jects within the study groups. The same test was used to
returned to the right brachial artery was also recorded. Sim- verify whether the compared groups differed in terms of the
ilar measurements were made on the arteries of the left lower incidence of comorbidities, smoking, and atherosclerotic
limb and the left upper limb. ABIs were calculated as ratios of plaque being present in the carotid arteries.
the systolic pressure values for ipsilateral lower and upper The Mann-Whitney U test (unequal sample sizes) was
limb arteries. Separate ABI values were determined for color performed to assess whether subjects from the study group
Doppler and pulsed-wave Doppler measurements. Lower differed from those in the control group in terms of measure-
ABI values were used for statistical purposes, with subjects ment variables.
presenting with ABI > 1:3 not being included in statistical At the next stage of the statistical analysis, potential
analysis [4]. significant correlations between the study variables were
verified using Pearson’s correlation coefficient.
2.4. Echocardiography. Echo scans were acquired on a Vivid 4 The final step consisted in a logistic regression analysis
ultrasound system with a 2 MHz transducer. During the scan, with myocardial infarction status as the dependent vari-
patients were lying on their left sides. The transducer was able and the measurement variables as predictors (quanti-
placed above the 4th intercostal space near the left edge of tative scale).
the sternum to produce a 2D image of the heart in the para- Differences at the significance level of p < 0:05 were
sternal longitudinal view. The following cardiac chamber size considered statistically significant.
and wall thickness measurements were made in M-mode to
evaluate the left ventricular mass: 3. Results
LVEDD: left ventricular end diastolic dimension (mm),
IVSD: interventricular septal thickness at end diastole The Mann-Whitney U test was performed in order to verify
(mm), whether the patients with the history of ACS differed from
PWD: posterior left ventricular wall thickness at end those with no history of coronary incidents in terms of
diastole (mm). measurement variables.
The left ventricular mass (LVM) was calculated using the Patients with the history of ACS were found to present
following formula[5, 6]: with increased hsCRP levels, decreased ABI values, and
carotid intima-media complex thickness. The results of the
LVM = 1:04 × ½ðLVEDD + IVSD + PWDÞ3 − LVEDD3 − 13:6 statistical analysis of the results are presented in Table 2.
A statistically significant difference in the incidence of
ð1Þ
atherosclerotic plaque was observed. In the study group, the
presence of one or more atherosclerotic plaque(s) was
The left ventricular mass index (LVMI) was calculated observed in 47 patients (92.15%) as compared to 21 patients
by dividing the left ventricular mass (in grams) by the body (70%) in the control group (Figure 1).
surface area (in square meters). The mean LVMI value in the study group was 120:49 ±
2.5. Estimation of Intima-Media Thickness. The final stage of 32:21 g/m2 as compared to 113:53 ± 25:19 g/m2 in the con-
the study consisted of ultrasound measurements of the trol group; the difference was not statistically significant.
carotid intima-media thickness (IMT). Measurements were Significant gender-specific LVMI differences were also
made using a Vivid 4 ultrasound system with a 7–10 MHz sought as different normal LVMI values had been adopted
vascular transducer. During the examination, patients were for men and women. No statistically significant differences
lying on their backs with their heads facing backwards and were observed for the examined variables between the study
away from the examination side. groups. Results of echocardiographic LVH assessments are
IMT was assessed at the common carotid artery, carotid presented in Table 3.
bulb, and internal carotid artery on the right and the left. Pearson’s correlation analysis was used to check whether
Due to better repeatability, measurements were made on dis- there were any statistically significant relationships between
tal arterial walls. First, a measurement was made within the the examined variables.
common carotid artery about 2 cm distally from the bifurca- The analysis of Pearson’s correlation coefficients for the
tion site; then, measurements were made at bifurcation and study group revealed a negative correlation between ABI
within the internal carotid artery 2 cm proximally from the and IMT (r = −0:40, p < 0:05). Data are presented in Figure 2.
carotid bulb. The average IMT was calculated separately for In order to determine potential correlations between the
the left and the right side from all the above measurements. study variables and the occurrence of myocardial infarction,
The presence of atherosclerotic plaque was also assessed, the Logistic Regression Variable Selection Method was used
with 1.5 mm being taken as the minimum atherosclerotic with myocardial infarction status as the dependent variable
plaque thickness. and the measurement variables as predictors. Due to the
small number of subjects, predictors were entered into the
2.6. Statistical Analysis. Statistical analysis was carried out model using the forward selection (Wald) method.
using the SPSS 14 software package for the MS Windows They proved to match the data well: χ2 = 9:77 and
operating system. p = 0:282. It explained approximately 27.8% of the observed
The chi-square compliance test was performed to verify variance of the dependent variable. The model introduced
any statistically significant differences in the numbers of sub- two predictors, CRP and ABI, in two steps (Table 4).
4 BioMed Research International

Table 2: Results of measured laboratory and ultrasonography variables.

Mean range Mean range

Parameters Study group (n = 51) Control group (n = 30) p
(study group) (control group)
hsCRP (mg/l) 14:70 ± 23:81 5:78 ± 9:26 47.19 30.48 0.002
Total cholesterol (mg/dl) 186:39 ± 40:65 174:23 ± 42:75 40.65 42.75 0.231
LDL cholesterol (mg/dl) 111:57 ± 29:5 116:13 ± 61:6 41.74 39.75 0.714
Triglycerides (mg/dl) 141:96 ± 80:96 131:23 ± 111:14 43.82 36.20 0.159
T-Chol/HDL cholesterol 4:20 ± 1:15 3:75 ± 1:41 44.75 34.62 0.061
eGFR (ml/min) 83:22 ± 31:91 78:74 ± 30:39 42.12 39.10 0.577
ABI 0:89 ± 0:25 1:05 ± 0:13 34.68 51.75 0.002
IMT (mm) 1:11 ± 0:13 1:00 ± 0:18 46.31 31.97 0.008
IMT/ABI 1:45 ± 0:87 0:96 ± 0:2 47.44 30.05 0.001
Mean plaque thickness (mm) 2:27 ± 0:99 1:79 ± 1:34 43.33 37.03 0.243
The average thickness of plaque or plaques (if more than one is present) was taken into account for calculation purposes.

100 and hypertension societies [1]. Cardiovascular risk assess-

90 ment scales included in these guidelines are based on
80 population-based studies and facilitate the classification of
70 patients into different risk categories. Organ-related compli-
60 cations of arterial hypertension included in the global cardio-
vascular risk assessment, i.e., left ventricular hypertrophy,
(%)

50
40 carotid intima-media thickness, ankle-brachial index, and
30
renal injury features, are taken into account as equivalent to
20
one another. This means that a patient with extensive athero-
sclerotic lesions within the carotid arteries and reduced ABI
10
is categorized into the same group as a patient with mild left
0
ventricular hypertrophy and eGFR of 50 ml/min/1.73 m2.
Study group Control group
The intuitive evaluation of both patients, however, suggests
Study group that particular attention should be paid to the patient pre-
Control group senting with features of the extensive atherosclerotic process
in the imaging studies. Therefore, it is interesting to answer
Figure 1: Prevalence of atherosclerotic plaque in carotid arteries the question of which kinds of target organ damage due to
(p = 0:021). arterial hypertension can be best used to differentiate the
group of patients who have experienced an ACS episode
Table 3: Mean LVMI values in the study and control groups from the group of patients who have hitherto not experi-
according to gender.
enced such an episode.
LVMI (study group) LVMI (control group) The main objective of the study was to answer the ques-
p tion of whether any differences can be found in the intensity
(g/m2) (g/m2)
112:63 ± 26:15 106:79 ± 22:32
of asymptomatic target organ damage between the two study
Females 0.689
groups otherwise homogeneous in terms of anthropometric
Males 125:16 ± 34:87 119:44 ± 26:75 0.562 variables and the incidence of risk factors and comorbidities.
Another objective of the study was to identify a potential tar-
get organ damage parameter characterized by the highest
The statistical analysis revealed that only ABI was an ACS predictive strength. The selected parameters of target
important predictor of ACS in the study group. The ExpðBÞ organ damage, highly valued in clinical practice mainly due
factor indicates that higher ABI values reduce the likelihood to their ease of use as well as to the availability of diagnostic
of ACS. tools such as echocardiography and vascular ultrasound,
were assessed.
4. Discussion As confirmed by the results, the analysis of generally
accepted cardiovascular risk factors such as diabetes, smok-
Along with strokes, acute coronary syndromes belong to the ing, lipid disorders, overweight, or obesity may by itself not
most dramatic episodes in the long-term process of athero- be sufficient for a reliable evaluation of ACS risk level. There-
sclerosis. The risk factors and organ-related complications fore, the current risk assessment scales have been expanded
associated with higher cardiovascular risk are well defined to include modules that take into account the presence of
in the current guidelines of European and American cardiac target organ damage and comorbidities [7].
BioMed Research International 5

1.4

1.2

IMT (mm)
0.8

0.6

0.4

0.2

0
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6
ABI

Figure 2: Pearson’s correlation between IMT and ABI (r = −0:40, p < 0:05).

Table 4: Predictors of acute coronary syndrome.

the presence of atherosclerotic lesions within the lower
ACS predictors (study group) B Wald p ExpðBÞ extremity arterial bed expressed as ABI of <0.9 should not
hsCRP 0.05 3.14 0.076 1.055
be considered an isolated disease but rather an indicator of
similar lesions being present in other parts of the circulatory
ABI -5.89 7.15 0.007 0.003
system [8]. The relationships between peripheral arterial dis-
ease and cardiovascular mortality are independent of age,
BMI, smoking, LDL and HDL cholesterol levels, blood pres-
As shown by the analysis of the study results, the study sure, glycemia, or the history of symptoms of angina pectoris,
and the control groups differed in a statistically significant myocardial infarction, and stroke [11, 12].
manner in terms of ABI, carotid IMT, and IMT/ABI ratio However, no explanation is provided by the above data as
values. A statistically significant difference in the incidence to why the low ABI values rather than, for example, carotid
of atherosclerotic plaque within the carotid arteries was iden- intima-media thickening had the highest correlation with
tified; the difference, however, did not apply to the average the incidence of ACS in our study group. In addition, the
thickness of atherosclerotic plaque. Another finding which mean ABI in the study group was 0.89 and thus was only
emerged following the analysis of the measurement variables slightly below the value decisive for confirmation or rejection
was that subjects with a history of myocardial infarction pre- of PAD diagnosis. Perhaps the answer to this question can be
sented with significantly higher levels of C-reactive protein provided by demands made by some researchers regarding
compared to subjects within the control group, suggesting the arbitrary character of the ABI threshold for the diagnosis
the involvement of inflammation within the vascular wall of peripheral arterial disease. In normal conditions, systolic
and atherosclerotic plaque. However, no statistically signifi- blood pressure at the ankle level is 8–15% higher than that
cant intergroup differences were observed concerning the at the shoulder level, and therefore, ABI values are consid-
LVMI values. ered to be normal when greater than 1.0. In the MESA,
In order to determine the factor(s) most strongly associ- SHS, and CHS studies where ABI values in ranges 0.9–0.99
ated with ACS, a logistic regression analysis was performed and 1.0–1.09 were considered, respectively, as borderline
with myocardial infarction status as the dependent variable and low normal, these values were also shown to be associ-
and measurement variables as predictors. As shown by the ated with an increased risk of death for cardiac reasons
statistical method used for that purpose, ABI values of <0.9 [12–14]. The results of these studies suggest that despite the
are associated with high risk of ACS. The second predictor, absence of the diagnosis of peripheral arterial disease,
albeit of a low prognostic value, was the elevation of C- patients with ABI values between 0.9 and 1.09 are nonethe-
reactive protein levels. less burdened with mild to moderate atherosclerosis which
Numerous studies showed that reduced ABI is associated indicates a risk of lesions being present, e.g., in the coronary
with the presence of atherosclerotic lesions in the carotid and arteries. In the light of the aforementioned results from large
coronary arteries. According to Criqui and Denenberg, as studies, it appears that the stage of atherosclerosis within
well as to Dormandy et al., the incidence of coronary artery the lower limb arteries, and therefore in the coronary
disease in patients with ABI < 0:9 ranges from 20 to 60% if arteries, of the study group patients was much higher than
the diagnosis was based on physical examination, history, that suggested by the ABI value used to define peripheral
and electrocardiogram to as much as 90% in patients sub- arterial disease (PAD).
jected to angiographic diagnostics [8–10]. Unfortunately, An attempt to demonstrate the relationship between ABI
the sensitivity of ABI is too low for the presence of, e.g., cor- and the extent of lesions in the coronary arteries was made by
onary disease to be excluded on the basis of its correct value Papamichael et al. [15]. They performed coronary angiogra-
alone. On the other hand, ABI is specific enough to indicate phy examinations and calculated ABI values in 165 patients
elevated cardiovascular risk at low ABI values. Therefore, to assess the advancement of lesions in patients with stable
6 BioMed Research International

coronary disease. The results of this study provided evidence the Mann-Whitney U test revealed an intergroup difference
for the existence of correlation between reduced ABI and the at the significance level of p = 0:001 which means that the
extent of lesions in coronary arteries. Of 44 people with IMT/ABI ratio was significantly lower in the control group
three-vessel disease as diagnosed by angiography, 13 had as compared to the study group. At present, it is difficult to
ABI of <0.9; for the sake of comparison, only 4 out of 37 sub- conclude whether the predictive value of this “complex”
jects with confirmed one-vessel disease presented with ABI parameter could be higher than the predictive value of either
values providing the grounds for the diagnosis of peripheral parameter assessed separately. No mention has been found in
arterial disease. The logistic regression analysis carried out the available literature on the use of complex risk assessment
by the study authors led to the final conclusion that ABI of markers that would simultaneously describe the stage of ath-
<0.9 was a predictor of cardiovascular incidents. This result erosclerosis at different levels of the arterial bed. Instead,
coincides with our findings obtained in a much smaller attempts were made to create a scoring system based on
group. However, does identification of a correlation ABI and IMT values. On the basis of their research, Hayashi
between low ABI and three-vessel disease justify coronary et al. assumed that correct ABI and IMT values would be
angiography being performed on a routine basis in each assigned the score of 0 while abnormal values would be
patient with ABI < 0:9? While the answer remains unclear, assigned the score of 1. Next, they divided their study popu-
it seems that such patients should be subject to special lation into 3 groups depending on the score. A total score of 0
monitoring, active screening for other kinds of TOD, and was assigned when the patient had presented with unremark-
possible qualification for noninvasive studies, such as able ABI and IMT values, a total score of 2 was assigned when
angio-CT of the coronary arteries. both markers were abnormal, and a total score of 1 was
Another factor identified in the logistic regression analy- assigned when only one of the marker values was unremark-
sis as being correlated with the risk of ACS was the elevated able. The conclusion stemming from the use of this simple
concentration of C-reactive protein. For many years, the scoring system was that the incidence of cardiovascular dis-
CRP levels have been associated with the presence of general- eases was statistically significantly higher in subjects who
ized inflammation. CRP is synthesized mainly in the liver, scored 1 or 2 points [22]. This means that the lesion on the
but also in smooth muscles, including those within the walls arterial bed should be sought at many levels, as identification
of the coronary arteries [16]. Ridker et al. claim that of all the of their absence in only one part of the cardiovascular system
acute phase proteins, elevated CRP levels have the strongest may lead to incorrect evaluation of a patient’s condition and,
association with elevated cardiovascular risk [17]. Pasceri therefore, to a failure to implement appropriate management.
and other researchers demonstrated that C-reactive protein The results are indicative of the high value of ABI mea-
directly contributes to the initiation of the atherogenesis by surements in the assessment of ACS risk in patients with
inducing adhesion molecules on the endothelial cell, opso- arterial hypertension. Notably, none of the subjects within
nizing LDL molecules for their subsequent absorption by the study or the control group reported any signs of intermit-
macrophages leading to the formation of foam cells, and tent claudication or had previously undergone diagnostic
stimulating and activating monocytes to produce various screening for peripheral arterial disease. This is due to the
growth tissue factors [18]. Goldstein et al. observed that fact that the symptomatic course of the disease is observed
elevated CRP levels as determined during hospitalization in patients with very advanced atherosclerotic lesions due
due to ACS were related to a larger extent of coronary athero- to the development of collateral circulation. Postexercise
sclerotic lesions, increased risk of death, and higher incidence drops in systolic blood pressure values as observed in exercise
of recurrent myocardial infarction and need for revasculari- tests are even better for identification of disturbed supply of
zation [19]. These observations were consistent with those blood to the lower limbs [23]. Perhaps postexercise ABI
obtained in a multicenter study conducted in 1773 patients values would be the strongest predictor of ACS in our study
with acute coronary syndrome. Patients with CRP > 10 mg/l group. However, sensitive postexercise assessment of blood
had significantly higher risk of death within 30 days of the pressure within the lower limb arteries is also a method
coronary incident, regardless of troponin levels [20]. There which cannot be used in general clinical practice, particularly
are 3 levels of risk for cardiovascular events based on hsCRP in primary care.
concentration, namely, low risk for hsCRP < 1:0 mg/l, With no doubt, very interesting information could be
medium risk for hsCRP of 1.0 to 3.0 mg/l, and high risk for provided by prospective observation of patients with arterial
hsCRP > 3 mg/l. On the basis of data from the FHS study, hypertension and by identification of target organ damage
Wilson et al. concluded that only hsCRP > 3:0 mg/l is associ- parameter that would, either alone or combined, ensure the
ated with increased cardiovascular risk [21]. However, it best prediction of future coronary episodes. It cannot be
should be noted that the mean CRP levels in our control ruled out that acute coronary episodes would occur in the
group were higher than 3 mg/l. Perhaps higher cut-off values near future in all control group subjects. However, it is
should be adopted for prognostic purposes as observed in the important to demonstrate that despite the same risk factors,
study by Oltrona et al. [20]. arterial beds may differently respond to the same damaging
When evaluating the results of our study, we also decided stimuli, obviously as a consequence of individual traits. Thus,
to verify whether the combined use of two hypertension- “individualization” of cardiovascular risk assessments
related target organ damage markers, i.e., ABI and carotid becomes particularly important today. Further studies are
IMT, would differentiate the study group from the control needed to assess the predictive strength of individual TOD
group in a statistically significant manner. The analysis using parameters, possibly facilitating the development of new
BioMed Research International 7

scales which would differentiate the predictive values of adverse events from coronary artery disease,” Vascular
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ankle-brachial index has a very high ACS predictive value. sclerosis as a reflection of a systemic process: implications for
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Index,” Journal of the American Geriatrics Society, vol. 45,
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Data Availability [13] M. M. G. McDermott, et al.K. Liu, M. H. Criqui et al., “Ankle-
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All data are included in the tables within the article. American Journal of Epidemiology, vol. 162, no. 1, pp. 33–41,
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Conflicts of Interest [14] A. M. O’Hare, R. Katz, M. G. Shlipak, M. Cushman, and A. B.
Newman, “Mortality and cardiovascular risk across the ankle-
The authors declare that there are no conflicts of interests arm index spectrum: results from the Cardiovascular Health
regarding the publication of this paper. Study,” Circulation, vol. 113, no. 3, pp. 388–393, 2006.
[15] C. M. Papamichael, J. P. Lekakis, K. S. Stamatelopoulos et al.,
Acknowledgments “Ankle-brachial index as a predictor of the extent of coronary
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