Group Of Myocardial Infarction Patients Research Articles

Opioid administered prior to onset of myocardial infarction is associated with atypical symptoms of acute coronary ischemia in emergency calls

Abstract Background Acute identification and treatment of myocardial infarction (MI) is crucial for survival. MI symptom presentation is typically characterized by chest pain. Regular use of opioids to relief pain of chronic diseases is common. However, it has not been investigated whether opioid administered prior to onset of MI is associated more with atypical presentation of ischemia compared to non-opioid users. Purpose To investigate if opioid therapy is associated with atypical symptoms of MI. Methods The study is registry-based. MI is defined as patients with the ICD-10 discharge diagnoses I20.0 and I21 as primary diagnosis <24 hours after a call to the Capital Emergency Medical Services, including the Emergency Number (1–1-2) and Out-of-hours Service (OOHS). MI patients with opioid treatment prior to onset of MI are compared with a control group of MI patients without opioid treatment. The primary symptom of MI is registered in calls to the Capital Emergency Medical Services, from 2014 to 2018. Opioid treatment includes opioid prescribed and picked up <30 days prior to onset of MI. Results In total, 866 MI patients with opioid treatment and 10,061 MI patients without opioid treatment were included. The median age was 72.0 vs 67.8 years, 50.5% vs 34.5% were women, 61.0% vs 54.7% called the Emergency Number (1–1-2), ischemic heart disease was present in 48.5% vs 34.3% and type 2 diabetes in 23.1% vs. 16.2%. Atypical symptoms of MI were associated with opioid treatment and most prevalent in calls to OOHS, in women and by higher age. Acute symptoms of MI are visualized in Figure 1 and 2. Conclusion Opioid treatment prior to onset of MI was associated with increased atypical symptoms of MI, especially dyspnea, and increased in calls to the OOHS, in women and by higher age. This might challenge the clinician in early diagnose of MI in patients with opioid treatment and thereby delay acute lifesaving treatment. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): The Danish Heart Foundation

Relationship of Midkine in Myocardial Infarction patients and some biochemical parameters

Objectives: This study aims to estimate the concentrations of MK, hs-CRP, TnI, AST, ALT and ALP in serum for MI in comparison to wholesome controls, in an effort to check the quantity of this impact at the pathological condition, in addition to understanding the position of MK in MI sufferers and its relationship to liver function tests and may be used as biochemical markers to decide the severity of MI in sufferers.
 Methods: The studying include the investigation of midkine (MK), High-sensitivity C-reactive protein (hs-CRP), Troponin I (TnI), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) and alkaline phosphatase (ALP) levels in myocardial infarction (MI) patients. The study includes (84) samples: 34 of myocardial infarction patients (19 male and 15 female) and 50 sample of apparently healthy as control group (25 male and 25 female). Samples were collected during the period from Jan. 2021 to July 2021 from in-patients of Cardiac Surgery Center admitted at Ibn Sina Teaching Hospital and Mosul General Hospital, Mosul, Iraq with matching age ranged between 26-86 years. The clinical diagnosis in each case is made according to a cardiovascular specialist.
 Results: The results showed that there was a significant increase in MK, TnI, GOT, GPT and ALP for all studied groups (males and females) of MI patients compared with control groups, and there was no any a significant in hs-CRP. Beside of, showed significant positive correlation between MK with BMI, hs-CRP, TnI, AST, ALT and ALP in control and patients group. Whereas there were no any correlation between MK with age, in patients and control under study.
 Conclusion: The study indicated that the MK increased in patients with myocardial infarction, and it’s increased in males more than female patients, and that may act as a good markers for diagnosis of myocardial infarction disease.

УРОВЕНЬ ВЕЩЕСТВ СРЕДНЕЙ И НИЗКОЙ МОЛЕКУЛЯРНОЙ МАССЫ И ОЛИГОПЕПТИДОВ У БОЛЬНЫХ ИНФАРКТОМ МИОКАРДА НА ФОНЕ ХРОНИЧЕСКОЙ ОБСТРУКТИВНОЙ БОЛЕЗНИ ЛЁГКИХ С ОДНО- И МНОГОСОСУДИСТЫМ ПОРАЖЕНИЕМ КОРОНАРНЫХ АРТЕРИЙ

Introduction. The presence of endogenous intoxication syndrome in somatic pathology worsens the course and prognosis of diseases. It is especially urgent to study this syndrome in comorbid pathology, in particular, in myocardial infarction development in patients with chronic obstructive pulmonary disease. The objective markers of endogenous intoxication are medium and low molecular weight substances and oligopeptides. Aim. The aim is to estimate the severity of endogenous intoxication syndrome by studying the levels of medium and low molecular weight substances and oligopeptides in patients with myocardial infarction developed against the background of chronic obstructive pulmonary disease depending on the number of coronary arteries affected. Material and meth- ods. 225 patients with myocardial infarction were examined. In 130 of them the infarction developed as monosomal disease, and in 195 - against the background of previously documented chronic obstructive pulmonary disease. Among patients with myocardial infarction as monoinflammation, 71 (64.5%) had a single-vessel lesion and 59 (35.5%) had a multivessel lesion. Among patients with myocardial infarction against chronic obstructive pulmonary disease, lesion of the 1st coronary artery was found in 50 patients (25.6%), and multivessel lesion was found in 145 (74.4%). The comparison group included 110 somatically healthy subjects. We used direct spectrometry (according to M.Y. Malakhova, 1995) to determine the levels of medium and low molecular weight substances and oligopep- tides. Statistical data processing was carried out using software package SPSS 26.0. Results and discussion. In the group of patients with myocardial infarction the levels of medium and low molecular weight substances and oligopeptides and calculated indices showed significant differences in single- and multivessel lesions. In the 1st coronary artery lesion, the indices in most cases were comparable with the values in the control group. In the group of myocardial infarction patients with multivessel lesions, the values of medium and low molecular weight substances and oligopeptides increased significantly. In patients with myocardial infarction against the background of chronic obstructive pulmonary disease, all intoxication parameters were significantly higher compared not only with the control, but also with patients with myocardial infarction as monoinflammation. However, the values in the subgroups with single and multivessel lesions did not demonstrate statistical reliability. Conclusion. The number of affected vessels, and hence the volume of ischemic myocardium, affects the severity of endogenous intoxication in patients with myocardial infarction as mononasal. In this case, the elimination function of the excretory organs is not impaired, which means that the level of intoxication is due to the production of toxins in conditions of ischemia and myocardial necrosis. In conditions of cardiorespiratory comorbidity chronic obstructive pulmonary disease con- tributes significantly to the development of endogenous intoxication, aggravating it and levelling the differences occurring in monosensing.

Improving smoking cessation after myocardial infarction by systematically implementing evidence-based treatment methods: a prospective observational cohort study

Abstract Background For smokers who suffer a myocardial infarction (MI), smoking cessation is the most effective measure to reduce recurrent event risk. Still, evidence-based treatment methods for aiding smoking cessation post-MI are underused. Purpose To compare the odds of smoking cessation at two-months post-MI before and after implementing a set of pre-specified routines for optimization of evidence-based treatment methods for smoking cessation, with start during admission. Methods Structured routines for early smoking cessation counselling and treatment optimization were implemented at six cardiac rehabilitation (CR) centres in Sweden. The routines included CR nurses providing current smokers hospitalized for acute MI with short consultation, written material, and optimal dosage of nicotine replacement therapy during admission, increasing early prescription of varenicline for eligible patients, and contacting the patients by telephone 3–5 days after discharge, after which usual care CR follow-up commenced. Centres were also encouraged to strive for continuity in nurse-patient care. Patient data was retrieved from the SWEDEHEART registry and medical records. Using logistic regression, we compared the odds for smoking cessation at two-months post-MI for currently smoking patients admitted with MI (a) before (n=188, median age 60 years, 23% females) and (b) after (n=195, median age 60 years, 29% females) routine implementation. Secondary outcomes included adherence to implemented routines and the association of each routine with smoking cessation odds at two-months. Results In total, 159 (85%) and 179 (92%) of enrolled patients attended the two-month CR follow-up, before and after implementation of the new routines. After implementation, a significantly larger proportion of patients (65% vs 54%) were abstinent from smoking at two-months (crude OR 1.60 [1.04–2.48], p=0.034) (Figure 1). Including only those counselled during admission (n=89), 74% (vs 54%) were abstinent at two-months (crude OR 2.50 [1.42–4.41], p=0.002). After the new routine implementation patients were counselled more frequently during admission (50% vs 6%, p<0.001), prescribed varenicline at discharge or during follow-up (23% vs 7%, p<0.001), and contacted by telephone during the first week post-discharge (18% vs 2%, p<0.001), compared to before implementation. Crude and adjusted associations between each routine and smoking cessation at two-months are shown in Table 1. Entering all routines into the regression model simultaneously, being prescribed varenicline before discharge or during follow-up had the strongest independent association with smoking abstinence at two-months (adjusted OR 4.09 [1.68–10.00], p=0.002). Conclusion Our results support that readily available methods for aiding smoking cessation can be implemented effectively in routine practice, with possible beneficial effects on smoking cessation for the high-risk group of smoking MI patients. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): The Swedish Heart and Lung AssociationPfizer AB

Cognitive dysfunction after out-of-hospital cardiac arrest: Rate of impairment and clinical predictors

BackgroundThe purpose of this study was to evaluate the rate and domains of cognitive impairment in out-of-hospital cardiac arrest (OHCA) survivors, as compared to patients who experienced a myocardial infarction (MI), and to explore mechanisms and predictors of this impairment. Methods and resultsOHCA survivors with “good” neurological recovery (i.e., Cerebral Performance Categories Scale ≤ 2) (n = 79), as well as a control group of MI patients (n = 69), underwent a comprehensive neuropsychological assessment. Forty-three percent of OHCA survivors were cognitively impaired (in the lowest decile on a global measure of cognitive functioning). Rates of impairment were approximately six times higher in the OHCA group than the MI group. Attention, memory, language and executive function were affected. Downtime was a significant predictor of cognitive impairment; the interaction between downtime and immediate intervention was significant such that, at short downtimes, receiving cardiopulmonary resuscitation (CPR) or defibrillation within 1 min of collapse predicted less cognitive impairment. ConclusionsOHCA survivors – even those with seemingly good neurological recovery – are at risk for cognitive impairment. Cognitive rehabilitation may be an important consideration post-OHCA.

Insulin-like growth factor-binding protein 7 (IGFBP 7) as a new biomarker in coronary heart disease

PurposeThe role of insulin-like growth factor-binding protein-7 (IGFBP-7) in atherosclerosis is still not well-known. The objective of this study was to find out the following: 1) whether IGFBP-7 may act as a biomarker of coronary artery disease (CAD) occurrence and extent; 2) whether IGFBP-7 is potentially related to the classical and new markers of cardiovascular risk (carotid intima-media thickness - cIMT); 3) whether IGFBP-7 may be a marker of mortality in the group of patients with myocardial infarction (MI). Materials/MethodsThe study group consisted of 212 patients with MI and 75 patients with stable CAD, the control group included 100 healthy volunteers. IGFBP-7 serum concentration was measured. ResultsIGFBP-7 value was considerably higher in the study group (MI and CAD patients - 35.1 ng/ml (P = 0.000001) and 32.7ng/ml (P = 0.0001), respectively), than in the controls – 25.2ng/ml. No statistically significant differences between IGFBP-7 concentrations in the MI and CAD group were found. No relationship between IGFBP-7 and the coronary lesions advancement in the study group was observed. No changes in IGFBP-7 concentration in the MI patients during hospitalization were observed. In the group of MI patients who died during follow-up, a considerably higher cIMT values were found whereas no statistically significant difference was observed in relation to IGFBP-7 (34.6 vs. 35.2 ng/ml). ConclusionsIGFBP-7 is a good biomarker of CAD occurrence but not of its advancement. We demonstrated the existence of the relation between higher IGFBP-7 concentration and the selected classical risk factors of cardiovascular events as well as cIMT values. IGFBP-7 cannot serve as a marker of acute ischemia. Also, IGFBP-7 was not confirmed as a predictor of mortality in the MI patients.

Association between paraoxonase-1 gene promoter -108C/T polymorphism and myocardial infarction in the Tunisian male population / Tunuslu erkek populasyonunda miyokard enfarktüs ile paraoksonaz -1 gen başlatıcı -108C/T polimorfizmi arasındaki ilişki

Abstract Objective: Human paraoxonase 1 (PON1) is an HDL-associated enzyme with anti-oxidant/anti-inflammatory properties that has been suggested to play an important protective role against coronary artery disease (CAD). The PON1 promoter -108C/T polymorphism has been analyzed in numerous association studies as a genetic marker for CAD, however, with controversial results. The aim of this study was to evaluate the association of PON-1 promoter -108C/T polymorphism with the risk of myocardial infarction (MI) in the Tunisian male population. Methods: A total of 815 subjects were recruited, including 318 healthy controls and 497 MI patients. Genotypes were determined by PCR-RFLP method. Genotype/allele frequencies were compared in patients and controls using the chi-square test. Results: Genotype distributions and allele frequencies of PON-1 promoter -108C/T polymorphism were different among the control and MI groups. Patients with MI had significantly higher frequency of the TT genotype compared to controls [29.2% vs. 25.5%; OR (95% CI), 1.67 (1.52-2.49); p=0.010]. The MI patient group showed a significant higher frequency of the T allele compared to the controls [0.56 vs. 0.51; χ2=8.61, p=0.013]. The association between the PON-1 promoter -108C/T polymorphism and MI remained significant after adjustment for other well-established cardiovascular risk factors. Conclusion: The present study showed a significant and independent association between the PON-1 promoter -108C/T polymorphism and MI in the Tunisian male population.

Predictive value of Galectin-3 for the occurrence of coronary artery disease and prognosis after myocardial infarction and its association with carotid IMT values in these patients: A mid-term prospective cohort study

ObjectiveThe role of Galectin-3(Gal-3) in atherosclerosis progression has not been definitely acknowledged. The aim of the study was to establish the following: whether Gal-3 may act as an independent risk factor of coronary artery disease (CAD) occurrence and its advancement, if Gal-3 has potential relations with classical and new markers of cardiovascular risk (carotid intima-media thickness (cIMT), and whether Gal-3 may be a marker of mortality in the group of patients with myocardial infarction (MI) during mid-term follow-up. Patients and MethodsThe study group was composed of 233 patients with MI and 100 patients with a stable CAD. Selected risk factors were assessed, Gal-3 concentrations and cIMT were measured. The control group was composed of 100 healthy individuals. ResultsIn the study group (MI and CAD patients) Gal-3 concentration was significantly higher than in the controls – median 7.9 ng/ml (p = 0.0001) and 10.7 ng/ml (p = 0.00001) vs. 5.5 ng/ml, respectively. Patients with 3-vessel disease had higher levels of Gal-3 than patients with 1-or 2-vessel disease (9.2 ng/ml vs 7.4 ng/ml, p = 0.003). In the group of MI patients who died during the follow-up (average period – 2.8 years), we found a significantly higher concentration of Gal-3 (20.0 ng/ml vs 8.0 ng/ml, p = 0.0005) and cIMT values (common carotid artery(CCA): 1.4 ± 0.4 mm vs. 1.0 ± 0.3 mm, p = 0.03; carotid bulb(CB): 2.3 ± 0.5 mm vs. 1.9 ± 0.4 mm, p = 0.009). In the model of multivariate logistic regression analysis, the variables influencing the mortality after MI during follow-up were: age>65years, Gal-3 concentration>8.7 ng/ml, IMT values and plaque occurrence in CB, previous MI and EF<40%. ConclusionsGal-3 is an independent risk factor of CAD occurrence, but cIMT values are better markers of CAD advancement. Both Gal-3 concentration>8.7 ng/ml and IMT values in CB were an independent predictive indicators of increased risk of all-cause mortality in patients after MI during mid-term follow up.

0183: A common polymorphism in CD40 Kozak sequence (-1C/T) is associated with myocardial infraction in the Tunisian male population

Coronary artery disease is influenced by both environmental and genetic factors. Current evidence shows that the CD40-CD40 ligand (CD40-CD40L) system plays a crucial role in the development, progression and outcome of acute coronary syndrome. A single nucleotide polymorphism (SNP) located at position –1 in the Kozak sequence of the CD40 gene (rs1883832; C>T) has been associated with the development of acute coronary syndrome. The purpose of the study was to explore the association between the C/T (–1) single nucleotide polymorphism in the CD40 gene and myocar-dial infarction (MI) in the Tunisian male population. A total of 273 unrelated Tunisian patients with MI and 219 healthy controls were genotyped using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Clinical parameters such as fasting serum total cholesterol, high-density lipoprotein cholesterol (HDL-C), triglycerides, and plasma glucose were detected by autoanalyzer assay. Weight, height and blood pressure (BP) were measured and body mass index (BMI) was calculated. Patients with MI had significantly higher frequency of the TT genotypes compared to controls (12.5% vs. 5.9%; OR=1.43, 95% CI: 1.08 – 1. 89, p=0.011). The MI patient group showed a significant higher frequency of the T allele compared to the controls (0.33 vs. 0.26; OR=1.45, 95% CI: 1.09 – 1.94, p=0.008). The association between the C/T (–1) single nucleotide polymorphism in the CD40 gene and MI remained significant after adjustment for other well-established cardiovascular risk factors. Our study suggests that C/T (–1) single nucleotide polymorphism in the CD40 gene might contribute to the susceptibility to MI in the Tunisian male population. Further replication with larger numbers, and populations of different ethnicities, are needed to confirm our finding.

0501: Association of Cys311Ser polymorphism of paraoxonase-2 gene with myocardial infarction in the Tunisian male population

Paraoxonase 2 (PON2) has antioxidant properties similar to paraoxonase-1 and paraoxonase-3. However, in contrast to paraoxonase-1 and paraoxonase-3, paraoxonase-2 is not associated with high-density lipoproteins and may only exert its antioxidant function at the cellular level. PON2 may also play a role in the pathogenesis of arterial thrombosis and atherosclerosis. The purpose of the present study was to investigate the possible association between the Cys311Ser polymorphism of PON2 gene and myocardial infarction (MI) in the Tunisian male population A total of 700 unrelated Tunisian subjects including 321 patients with MI and 379 healthy controls were included in this study. Genomic DNA was extracted from peripheral blood leukocytes according to standard methods. PON2 genotypes were determined by PCRRFLP method. A significant difference in genotype distribution and allele frequencies was observed between MI patients and controls. Patients with MI had a frequency of 17.1% for CC genotype, 45.8% for the CS genotype and 37.1% for the SS genotype. The controls had a frequency of 26.1% for the CC genotype, 45.6% for the CS genotype and 28.2% for the SS genotype (χ 2 =10.58; p=0.005). The MI patient group showed a significantly higher frequency of the S allele compared to the controls (0.60 vs 0.51; χ 2 =11.16; p<0.001). In multivariate analysis, C311S polymorphism was independently associated with MI (p<0.001). Our results showed a significant and independent association between the PON2 C311S polymorphism (presence of S allele) and MI in the Tunisian male population.

Beat-to-beat QT interval variability and T-wave amplitude in patients with myocardial infarction

The purpose of this study was to investigate the effects of T-wave amplitude and ECG lead on beat-to-beat QT interval variability (QTV) in patients with myocardial infarction (MI) compared to healthy subjects. Standard resting 12-lead ECGs of 79 MI patients and 69 healthy subjects were investigated. Beat-to-beat QT intervals were measured separately for each lead using a template matching algorithm. In addition, we extracted the beat-to-beat T-wave amplitude in each lead. We computed the standard deviation of beat-to-beat QT intervals as a marker of QTV for both healthy subjects and MI patients. Significant QTV differences were observed between the 12 ECG leads as well as between the groups of healthy subjects and MI patients. Beat-to-beat QTV was significantly higher in MI patients than in healthy subjects for half of the leads. Furthermore, significant T-wave amplitude differences across leads and between groups were observed. A significant inverse relation between beat-to-beat QTV and T-wave amplitude was demonstrated. The group differences in QTV remained significant after co-varying for the T-wave amplitude. In conclusion, the increase in beat-to-beat QTV that has been repeatedly reported in patients with MI is partly due to the lower T-wave amplitudes. However, QTV remains significantly increased in MI patients after covarying for this effect.

‘I am still a bit unsure how much of a heart attack it really was!’ Patients presenting with non ST elevation myocardial infarction lack understanding about their illness and have less motivation for secondary prevention

There are considerable differences in the type of treatments offered to patients presenting with acute myocardial infarction (AMI), in terms of the speed and urgency with which they are admitted, treated and discharged from hospital. The impact of these different treatment experiences on patients' illness perception and motivation for behavioural changes is unknown. The aim of this study was to explore and compare patients' illness perception and motivation for behavioural change following myocardial infarction (MI) treated by different methods. Semi-structured, domiciliary interviews (n=15) based on the common sense model of self regulation, were conducted with three groups of MI patients within four weeks of diagnosis: (a) primary percutaneous coronary intervention (PPCI) (n=5); (b) thrombolysis (n=5); (c) non ST elevation MI (NSTEMI) (n=5). Framework analysis was used to identify and compare themes between groups. Patients presenting with a ST-elevation MI (STEMI) receiving either PPCI or thrombolysis had similar perceptions of their illness as a serious, life-threatening event and were determined to make lifestyle changes. In contrast, patients with a NSTEMI experienced uncertainty about symptoms and diagnosis, causing misconceptions about the severity of their condition and less determination for lifestyle changes. Patients with NSTEMI in this study expressed very different perceptions of their illness compared to those experiencing STEMI. Patients' clinical presentation and treatment experience during an AMI can impact on their illness perception, motivation for behavioural change and uptake of cardiac rehabilitation. Nurses should consider the patients' illness experience and perception when planning secondary prevention interventions.

Neuropsychological Deficits, Depression and Type a Behavior Pattern in Patients with Myocardial Infarction

In cardiovascular disease, which is one of the leading causes of death in developing countries, the majority of deaths are due to myocardial infarction (MI). Myocardial infarction occurs when the blood supply to parts of the heart is interrupted causing some heart cells to die. Myocardial infarction may lead to cognitive deficits. The main causes or risk factors of myocardial infarction are hypertension, diabetes mellitus and tobacco use. Psychosocial factors such as Type A behavior pattern or coronary prone behavior and depression have been reported to be associated with myocardial infarction. The aim of the present study was to examine the presence of depression and neuropsychological deficits in patients with myocardial infarction. In addition, Type A behavior pattern or coronary prone behavior of patients with MI was also examined. The sample consisted of 40 MI patients and the tests were administered within one week after hospitalization. A healthy normal comparison group of 40 subjects, who were matched with respect to age, education, gender, place and state of residence with the MI patient group, was also selected for the study. The tools used were Beck depression inventory, Edinburgh Handedness inventory, Type A/B behaviour pattern scale, General Health Questionnaire, and tests from NIMHANS Neuropsychological test battery. The results showed that neuropsychological performances of the MI patient group were significantly poor in the domains of mental speed and information processing; sustained attention; executive functions: category fluency, phonemic fluency, verbal working memory and response inhibition; verbal learning and memory; visual learning and memory; and visuo-spatial ability compared to the healthy normal matched group. Moreover, 52.5% of the MI patients were depressed. Type A behavior was significantly linked to myocardial infarction. The cognitive deficits and depression which are seen in the present study might have resulted from the disruption of neural networks that connect cortical and subcortical regions of the brain. Index Terms—Myocardial infarction, type a behavior, depression.

234: Association of the porothrombin 20210GA variant with myocardial infarction in Tunisian population

The prothrombin is the precursor of the serine protease thrombin, a key enzyme in hemostasis and thrombosis. Prothrombin 20210GA polymorphism was described as a moderate risk factor for venous thrombosis because this mutation is associated with prothrombin elevated levels which may lead to an imbalance between the procoagulant, anticoagulant and fibrinolytic system. 20210GA curriers have an increased risk of thrombosis. In this study, we propsed to determine the prevalence of 20210GA prothrombin variant among Tunisian population, and to evaluate the potential relevance of this variant with myocardial infarction (MI). This study included 1007 unrelated male Tunisians divided into 399 MI patients and 608 healthy controls. Both groups were aged between 35-70 years. The prothrombin 20210GA polymorphism was carried out by polymerase chain reaction/restriction fragment length polymorphism (PCR-RFLP) analysis. The distribution of genotypes was in accordance with Hardy-Weinberg equilibrium (P >0.05). A significant difference in genotype distribution and allele frequency was observed between patients and controls. Patients with MI had a frequency of 97% for GG genotype and 3% for GA + AA genotype. The control group had a frequency of 99% for the GG genotype and 1% for the GA + AA genotype (χ2=6.95, p=0.031). The MI patient group showed a significant higher frequency of the 20210A allele compared to the controls 0.02 vs. 0.01 [OR=3.60 (95% CI=1.29-10.53), p =0.005]. Our work showed a significant association between the 20210GA polymorphism of the prothrombin gene and MI in the Tunisian population.

Selection of optimal dose of beta-blocker treatment in myocardial infarction patients based on changes in synchronization between 0.1 Hz oscillations in heart rate and peripheral microcirculation

Selection of the optimal dose of beta-blocker treatment in myocardial infarction (MI) patients is problematic because of a lack of well-established guidelines. We evaluated changes in synchronization between 0.1 Hz oscillations in heart rate (HR) and plethysmographic peripheral microcirculation in response to a tilt-table test and to 3-month treatment with the highest tolerated beta-blocker (metoprolol) dose in 43 patients aged between 41 and 77 years with acute MI 6 months prior to the start of the study. Before the study the patients were treated with small doses of beta-blocker. Phase differences between HR and peripheral microcirculation oscillations were used to measure the degree of synchronization (S), and relative change in S from horizontal position was used to characterize the response to vertical tilt. Two groups of MI patients matched for clinical characteristics were identified on the basis of the results. The first group was composed of patients with decreased S as a response to vertical tilt at the beginning of the study. The patients with increased S during vertical tilt before treatment with the highest tolerated beta-blocker dose were attributed to the second group. The response to vertical tilt in the first group of patients was postulated to indicate the need to increase beta-blocker dose, and in turn, the response in the second group to indicate an already adequate beta-blocker dose. Assessment of synchronization of 0.1 Hz HR and peripheral microcirculation oscillations as a response to a tilt test can possibly be used as a guideline for selecting beta-blocker dose in post-MI patients.

Association of a DNA polymorphism of the apolipoprotein AI–CIII–AIV gene cluster with myocardial infarction in a Tunisian population

Background Apolipoproteins AI–CIII–AIV play important roles in the metabolism of triglycerides and high-density lipoprotein cholesterol. However, whether genetic variations in the ApoAI–CIII–AIV gene cluster are associated with the risk of myocardial infarction (MI) remains uncertain. In the present study, we examined a possible association of the ApoCIII SacI polymorphism in the ApoAI–CIII–AIV gene cluster with lipid parameters and MI in a sample of the Tunisian population. Methods A total of 326 Tunisian patients with MI and 361 controls were included in the study. Genotypes were determined by polymerase chain reaction — restriction fragment length polymorphism (PCR-RFLP) analysis. Results A significant difference in genotype distribution and allele frequency was observed between patients and controls. At the multivariate analysis after adjustment for traditional vascular risk factors, the ApoCIII SacI polymorphism was significantly associated with MI, according to co-dominant and dominant models (co-dominant model odds ratio [OR]: 1.53, 95% confidence interval [CI]: 1.0–2.35, p = 0.04; dominant model OR: 2.02, 95% CI: 1.11–3.67, p = 0.02). The MI patient group showed a significant higher frequency of the S2 allele compared to the controls (10.2% vs. 6.5%; OR: 1.64, 95% CI: 1.10–2.47, p = 0.01). There was no statistically significant association between ApoAI–CIII–AIV cluster gene polymorphism and lipid, lipoprotein, and apolipoprotein levels in both MI patients and controls. Conclusion In the current study, a significant association between the ApoCIII SacI polymorphism (presence of S2 allele) and MI in the Tunisian population was found.

A bounded random process model and its application in heart rate variability analysis

A bounded random process (BRP) model was developed in this paper to interpret why approximate entropy (ApEn) can not describe the stochastic characteristic of Brownian motion time series correctly. Low ApEn value, generally implying presence of determinacy, also existed in Brownian motion series, a stochastic process. The BRP model investigated this phenomenon through quantifying the relationship between ApEn and a parameter of BRP model. BRP model was then applied to analyze electrocardiograph (ECG) time series from 60 healthy subjects and 60 myocardial infarction (MI) patients. ApEn of the healthy group had a close relationship with the parameter of BRP model, while this relationship could not be found in MI patient group. Grounded on combination of BRP and ApEn, a classifier was designed to assist to diagnose the MI patients. ROC curve and classification figures verified the classifier. Key words: Bounded random process, approximate entropy, Brownian motion, heart rate variability.

Risk assessment of ventricular arrhythmia using new parameters based on high resolution body surface potential mapping

SummaryBackgroundThe effective screening of myocardial infarction (MI) patients threatened by ventricular tachycardia (VT) is an important issue in clinical practice, especially in the process of implantable cardioverter-defibrillator (ICD) therapy recommendation. This study proposes new parameters describing depolarization and repolarization inhomogeneity in high resolution body surface potential maps (HR BSPM) to identify MI patients threatened by VT.Material/MethodsHigh resolution ECGs were recorded from 64 surface leads. Time-averaged HR BSPMs were used. Several parameters for arrhythmia risk assessment were calculated in 2 groups of MI patients: those with and without documented VT. Additionally, a control group of healthy subjects was studied. To assess the risk of VT, the following parameters were proposed: correlation coefficient between STT and QRST integral maps (STT_QRST_CORR), departure index of absolute value of STT integral map (STT_DI), and departure index of absolute value of T-wave shape index (TSI_DI). These new parameters were compared to known parameters: QRS width, QT interval, QT dispersion, Tpeak-Tend interval, total cosines between QRS complex and T wave, and non-dipolar content of QRST integral maps.ResultsSTT_DI, TSI_DI, STT_QRST_CORR, QRS width, and QT interval parameters were statistically significant (p≤0.05) in arrhythmia risk assessment. The highest sensitivity was found for the STT_DI parameter (0.77) and the highest specificity for TSI_DI (0.79).ConclusionsArrhythmia risk is demonstrated by both abnormal spatial distribution of the repolarization phase and changed relationship between depolarization and repolarization phases, as well as their prolongation. The proposed new parameters might be applied for risk stratification of cardiac arrhythmia.

251 Renin-angiotensin-aldosterone system polymorphisms: a role or a hole in occurrence and long-term prognosis of acute myocardial infarction at Tunisian older people

Myocardial infarction (MI) is one of the major causes of death all over the world. Because MI frequently occurs suddenly without any preceding clinical symptoms, the prediction of MI is clinically of great importance. Angiotensin II is produced primarily by angiotensin I-converting enzyme (ACE) within atherosclerotic lesions and ACE level correlates with the severity of vessel wall damage. We analyzed the evolution with age of the frequencies of the I/D polymorphism of the ACE, A1166C of the angiotensin II AT1 receptor (AT1R), and M235T of the angiotensinogen (AGT) gene in a healthy population and he subsequent comparison to age- and sex-matched groups of MI patients. To investigate the influence of increasing age on the incidence and remaining lifetime risk of myocardial infarction in a cohort of older men. Polymorphisms of the AGT, ACE (I/D) and AGTR1 (A1166C) genes in patients and controls were analyzed using allele-specific PCR, and PCR-rflp. A total of 140 healthy subjects and 119 individuals with MI were divided into two groups < 65 and > 65 years old. The evolution with age showed that the AGT M allele (P < 0.001) and the ACE I allele (P < 0.05) frequency decreased with age. The TT genotype frequency increased in patients with MI > 65 years (OR = 3.52; 95% CI; 3.12–5.54). The AA genotype showed a similar behaviour (OR = 2.9; 95% CI; 1.11–5.6). The DD genotype increased in the MI > 65 group (OR = 6.66; 95% CI; 2.02–21.9). Serum ACE activity was positively associated to age (r = 0.38, p = 0.000). Patients with DD genotype > 65 years was significantly higher (119.7 ± 50.8 U/L) than in patients with DD genotype < 65 years (96.9 ± 31.4 U/L, p = 0.039). The incidence of new cardiovascular disease continued to increase after age 65 but was most often diagnosed at death. These findings suggest that people aged 60 and older have a substantial amount of undiagnosed disease. We propose that the study of the allele frequency evolution in an healthy population at different ages is essential to determine risk factors for MI in case-control studies.

The paraoxonase L55M and Q192R gene polymorphisms and myocardial infarction in a Tunisian population

Objectives In the present study, we examined a possible association between the PON1 Q192R and L55M polymorphisms and myocardial infarction (MI) in a sample of the Tunisian population. Design and methods Three hundred and ten patients with MI and 375 controls were recruited. Paraoxonase gene polymorphisms at codon 192 and 55 were analyzed by PCR-RFLP. Results Genotype distributions and allele frequencies of L55M were similar among the control and MI groups. For the Q192R polymorphism patients with MI had significantly higher frequency of the RR genotype compared to controls [17.1% vs. 10.9%; OR (95% CI), 1.93 (1.24–3.02); p = 0.004]. The MI patient group showed a significantly higher frequency of the R allele compared to the controls [38% vs. 30%; χ 2 = 10.74, p = 0.001]. The association between the PON1 Q192R polymorphism and MI remained significant after adjustment for other well-established cardiovascular risk factors. Conclusions The present study showed a significant and independent association between the PON1 Q192R polymorphism (presence of R allele) and MI in the Tunisian population.