“FLOW MEDIATED DILATATION, CAROTID INTIMA MEDIA THICKNESS, ANKLE BRACHIAL PRESSURE INDEX AND PULSE PRESSURE IN YOUNG MALE POST MYOCARDIAL INFARCTION PATIENTS”

artery, ABPI and PP were measured in the cases and compared with healthy control Results: The FMD was lower among young patients of MI than controls . CIMT was higher among cases than controls . ABI was lower among cases than controls . Compared to controls, PP was higher among cases . In all subjects, a negative correlation between FMD and CIMT and a positive correlation between FMD and ABPI was found. A statistically significant negative correlation was found between endothelial dependent FMD and PP among cases and control groups Conclusion: Biophysical parameters were deranged in young post MI patients. Majority of our young male patients fell in low risk Framingham risk score but still they manifested with CAD. Despite 3 days of treatment among young male patients of MI, various biophysical parameters were stillderanged


ISSN: 2320-5407
Int. J. Adv. Res. 9 (10), 1449-1463 1450 atherosclerotic process and population at risk, at the earliest. Various biophysical methods include -Flow Mediated Dilatation (FMD) for assessment of endothelial function, Carotid Intima Media Thickness (CIMT) which is considered as a surrogate marker of atherosclerosis and Ankle Brachial Pressure Index (ABI) to diagnose Peripheral Vascular Disease (PVD).
Brachial artery reactivity is a non-invasive ultrasonographic assessment of FMD. It is used to measure endotheliumdependent response to shear stress [4]. Studies have shown that FMD is a marker for increased cardiovascular risk. It has been observed that FMD correlates with impaired endothelium-dependent relaxation in the coronary arteries [5]. CIMT is a non-invasive tool that can be used for cardiovascular risk stratification in individuals [6].
ABI is a useful tool for prediction of overt atherosclerosis and marker of cardiovascular risk (<0.9)ABI is strongly associated with cardiovascular diseases. Previous studies have found that those with lower extremity arterial disease are 1.5 to 2 times more likely to experience a clinical cardiovascular event [7]. As shown in studies, ABI has an inverse association with mortality [8]. Many prospective studies have shown that a low ABI (<0.9) can predict CVD. ABI, particularly in elderly men with morbidities as hypertension and type II diabetes can be used to predict mortality [9].
Pulse Pressure (PP) is an index of morphologic deterioration reflecting arterial thickening, fibrosis and calcification of blood vessels. Amongst PP, systolic or diastolic blood pressure, PP was found to be a better predictor of cardiovascular events [10].
Various studies have been done on biophysical parameters among the MI patients. However, there is scarce data on biophysical parameters among the young patients of MI in India The objectives of this study were:

Primary:
To compare the FMD, CIMT, ABI and PP in young male patients of Myocardial Infarction (MI) with age and sex matched healthy controls.

Secondary:
To correlate FMD with CIMT, ABI and PP among cases and control

Materials and Methods:-
We consecutively recruited the patients of MI aged ≤ 45 yrs [11] whopresented to iccu of Department of Medicine Indira Gandhi medical college Nagpur India,, from 2018 to August 2019. The study was a case control study. Those who qualified the criteria of inclusion and exclusion and gave consent for the study were enrolled. The post MI survivors were followed up in preventive cardiac clinic and OPDs of medicine. After 3 days or more of MI -FMD, CIMT and ABI were measured. The controls were age and sex matched volunteers from hospital staff and unrelated attendants of patient.
Healthy controls were recruited based on history, examination including blood pressure and investigations including lipid profile, blood sugar, HbA1c and ECG, only healthy controls were recruited. Controls with any risk factor for CAD were excluded. All ultrasound measurements were performed in the morning by a single immensely experienced radiologist. Cases were on their regular therapy (ecospirin, ramipril, atorvastatin, propranolol, clopidogrel) and had taken their usual dose of morning medicine. The smokers abstained from smoking. Finally the data of 50 male patients of MI and same number of age and sex matched healthy controls were analysed. The study was approved by Institution Review Board and ethical clearance was obtained. The informed consent was taken from the patients. The diagnosis of MI was made by -Revised Definition of MI [12].

Discussion:-
Our This Hospital based Descriptive Case Control Study was carried out from Jan 2018 to August 2019 (18 months) to assess the Flow Mediated Dilatation, Carotid Intima Media Thickness, Ankle Brachial Pressure Index and Pulse Pressure in Young Male Post Myocardial Infarction Patients We studied 50 cases 50 controls who fulfilled the eligibility criteria. Case record form was duly filled, clinical examination was done and appropriate samples were taken. The study was undertaken to assess the biophysical parameters in post MI young male patients at three days of follow-up. We assessed and compared the biophysical parameters i.e., FMD of brachial artery, CIMT and ABPI in young male post MI patients with age-sex matched healthy controls. Controls were taken as healthy i.e., without any risk factor. We also assessed various risk factors associated with young CAD. Biophysical parameters were assessed at three days to determine the usefulness of these parameters in follow-up of patients of MI. Since these parameters remain deranged post MI, they may be used for patient follow-up and aggressive treatment of CAD. 3 days was taken as an arbitrary period so that these parameters may be assessed as early as possible and may be an indicator for an aggressive management.We took patients below the age of 45years as there have been previous studies in India as Narsingan SN who defined young CAD as CAD occurring in patients less than 45years of age in Indian population [15]. CAD among young population is on the rise. Various Indian studies report that the patients suffering from acute MI below 45years to be 25%-40% [16].
It was observed that various risk factors as smoking, hypertension, diabetes, dyslipidemia and central obesity were significantly associated with premature CAD in male patients. In our study, the percentage of smokers in young CAD was observed to be 86.2%.
Increased CIMT is conventionally considered to be a marker of subclinical atherosclerosis. In our study, we observed that mean CIMT was significantly higher among cases as compared to controls. In our study, 43 cases(86%) cases had average CIMT value ≥ 0.08 cm, which is taken to be significant for cardiovascular risk [17,18].
FMD correlates with impaired endothelium-dependent relaxation in the coronary arteries [5]. In our study, we observed the mean value of endothelium dependent dilatation i.e., FMD after inflation of cuff among cases was significantly lower than the control group. These results were comparable to previous study as reported by Otikunta A. Naidu et al., who demonstrated significantly decreased flow mediated dilatation in patients when compared to control (9.42 ± 7.20% vs. 21.11 ± 9.16% p<0.01) [19]. FMD improves in response to drugs that have proven benefit on cardiovascular outcomes such as statins, anti-hypertensive drugs (including ACE-Inhibitors, angiotensin I receptor blockers, and calcium channel blockers) [20,21]. Despite the fact that our patients were on most of the above mentioned drugs for 3 days, the endothelial dependent dilatation was still significantly lower among cases than controls.
Various studies have shown the role of ABI in predicting cardiovascular risk. In our study, mean value of ABI was significantly lower amongst the cases as compared with controls. Previous studies have found that those with lower extremity arterial disease are 1.5 to 2 times more likely to experience a clinical CVD event [14]. Our results were in concordance with previously done studies by Erzen et al., and Gopal Premlatha et al., [10,22].

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PP has been shown to be a risk factor for cardiovascular disease in many studies. High PP signifies an increased atherosclerotic process among the vessels. In our study, we found a statistically significant higher PP among cases as compared to controls. PP was found to be a better predictor of cardiovascular events than either systolic or diastolic blood pressure in the Framingham Heart Study [23].
As large artery stiffness increases, SBP rises and DBP falls, with a resulting increase in PP [24]. DBP falls with central artery stiffness and thus, may negative association with CAD [25].
Both PP and SBP components rise with increase in vascular resistance and large artery stiffness and hence, are correlated to each other. It was seen that increments in PP at a fixed SBP was associated with a greater risk for CHD than was increment in SBP at a fixed PP [23].
Majority of our young male patients fell in low risk Framingham risk score. Despite this finding, our young male patients with various risk factors suffered MI. This may be due to the fact that Framingham risk score is heavily dependent on age, which underestimates CV risk in young individuals [26] as shown in studies.
CAD is an overt manifestation of atherosclerosis. Atherosclerosis being a generalized process affects all the vessels. Thus, many patients with CAD develop other complications of atherosclerosis, one being the Peripheral Artery Disease (PAD). Patients with PAD have attenuated flow-mediated dilatation of the brachial artery, which suggests the loss of nitric oxide activity [27]. Thus, atherosclerosis forms a common basis of impairment of endothelium function, increased thickness of carotid intima and PAD. In this present study, a highly significant negative correlation (r= -0.220, p=0.005) was found between FMD and CIMT among all the subjects (cases and control). In all subjects together (cases and controls), Erzen et al [10] also found a significant negative correlation between FMD and CIMT. In our study, a highly significant positive correlation was also found between FMD and ABI among cases and control groups. A statistically significant negative correlation was found between endothelial dependent FMD and PP among cases and control groups. These results were significant despite six weeks of regular medications for CAD which might have improved endothelial function in these patients.
A multivariate regression analysis was done between various risk factors and FMD, CIMT and ABI among cases. However, none of the risk factor correlated with these biophysical parameters significantly. Thus, these risk factors in our cases did not contribute significantly to FMD, CIMT, ABI and PP and thus to the atherosclerotic process. Thus taking controls with no risk factors did not create a bias to the values of FMD, CIMT, ABI and PP.
Some authors have measured endothelial dysfunction as an additional marker of coronary risk. They estimated the risk on the basis of endothelial dysfunction and found that endothelial dysfunction has a higher predictive value than risk estimated from the presence of classical risk factors [28][29][30]. from the presence of classical risk factors (212-214)           Figure 6:-Comparison of ankle systolic between case and control.        1460 Table 10:-Comparison of ankle brachial pressure index between case and control.   Figure 11:-Comparison of pulse pressure between case and control.