Probability Of Coronary Heart Disease Research Articles

Overestimation of the pretest probability of coronary heart disease with the Diamond and Forrester algorithm in low prevalent Mediterranean area

Abstract Funding Acknowledgements Type of funding sources: None. Background Initial diagnostic approach for chest pain includes: nature of pain (non coronary, typical or atypical), sex and age. This probabilistic Bayesian method is called the Diamond and Forrester algorithm. It uses as benchmarks coronariography and autopsy, but strongly depends of ischemic heart disease (IHD) prevalence. In low prevalent countries of IHD, as Mediterranean area, the very high negative predictive value of cardiac CT could overcome Diamond and Forrester algorithm. Objective To compare pre-test probability of IHD in patients with atypical chest pain using the algorithm of Diamond and Forrester. (expected) opposite to cardiac computed tomography (observed). Methods Patients examined with cardiac CT. All patients were pretreated with metoprolol 5–20 mg. e.v., unless contraindications, to obtain sinus rhythm <60 bpm and 0.4 mg of sublingual nitro-glycerine. Prospective studies or retrospective at fixed phase at 75% of RR interval when appropriated were used for standardized reconstruction. Postprocessing accomplished with double reading. Results A subset of 175 consecutive PP submitted for atypical chest pain was compared according to its expected prevalence (Diamond and Forrester) and that observed. Mean age 66 ± 12 years, 54% male, prevalence of hypertension was 50%, hypercholesterolemia 36%, diabetes 19% and smoking 11%. CHD was demonstrated in 37% vs 58% expected from the method of Diamond and Forrester (p <0.05). Age related dichotomic analysis of the expected probability disclosed the highest difference when age <60 yo. (expected 42% vs. observed 11%; p<0.05) and lesser when ≥60 yo (expected 64% vs. observed 47%; p<0.09). Conclusion In low prevalent Mediterranean area, clinical evaluation of patients with a history of atypical chest pain using Bayesian calculation overestimates the true prevalence of coronary heart disease, especially in those less than 60 year old. Our results would remark the crescent role of cardiac CT as an efficient, gatekeeper tool for overwhelming and costly health systems.

Diagnostic significance of myocardial and multimodal contrast exercise stress echocardiography in the detection of hemodynamically significant coronary artery stenosis in stable angina pectoris

Aim. To evaluate the diagnostic significance of myocardial contrast stress echocardiography (MCSE) and multimodal contrast stress echocardiography (MMSE) with dosed exercise in detecting hemo­dynamically significant coronary artery stenosis in patients with stable coronary heart disease (CAD) without impaired regional left ventricular contractility at rest.Material and methods. MCSE and MMSE were performed in 61 pa­­tients with suspected or stable CAD (mean age, 62,9±8,9 years). All patients underwent coronary angiography. During MCSE, perfusion and regional contractility were assessed. With MMSE, regional contractility was assessed. Sensitivity, specificity, and positive (LR+) and negative (LR-) likelihood ratios for MCSE and MMSE were assessed in com­parison with coronary angiography.Results. The sensitivity of MCSE with perfusion assessment was 82% (CI, 67-92%) with specificity of 70% (35-92%), LR+ — 2,74, LR- — 0,26. Sensitivity of MCSE with assessment of perfusion and regional contractility was 67% (50-81%) with specificity of 90% (65-99%), LR+ — 6,67, LR- — 0,37. The sensitivity of MCSE with an estimate of regional contractility of 74% (58-87%) with a specificity of 90% (56-98%), LR+ — 7,4, LR- — 0,28. The sensitivity of MMSE in the mode of cavitary and myocardial contrasting was 72% (55-85%) with a specificity of 90% (56-99%), LR+ — 7,18, LR- — 0,31.Conclusion. MCSE with an assessment of regional contractility and MMSE are of diagnostic importance in the detection of CAD, a positive result of which increases the post-test probability of hemodynamically significant coronary artery stenosis. A positive result of MCSE with dosed exercise with isolated perfusion assessment does not have a diagnostically significant effect on the post-test probability of CAD.

Using Machine Learning to Identify Risk Factors and Establishing a Clinical Prediction Model to Predict Atherosclerosis Complications in Idiopathic Membranous Nephropathy.

Clinically, it has been observed that patients with idiopathic membranous nephropathy (IMN) have a higher probability of coronary heart disease. We aim to investigate the risk factors associated with coronary heart disease in IMN patients using a mechanomics approach and establish a clinical diagnosis model. We collected sixty-nine clinical data points from patients undergoing phospholipase A2 receptor (anti-PLA2R) tests at the Affiliated Hospital of Qingdao University between July 9, 2019 and March 15, 2021. We excluded patients with cancer, hepatitis B, recent injuries or surgeries, and those under 18. Finally, 162 patients were considered for our study, which included 73 patients with coronary heart disease. The patients were split into test and validation groups at a 7:3 ratio. We utilized the Mann-Whitney U test for initial factor screening and the least absolute shrinkage and selection operator (LASSO) regression for further index screening. Eventually, the effectiveness of the clinical model was evaluated through visual statistical methods. Age, lymphocyte count, the sum of high-density lipoprotein (HDL) and low-density lipoprotein (LDL), serum creatinine, and antithrombin III were risk factors for coronary heart disease in patients with idiopathic membranous nephropathy in a multivariate regression (p < 0.1). In the training group, 14 clinical features were finally screened by the LASSO regression, and the area under the curve (AUC) of the training group was 0.90 (95% CI 0.877-0.959), accuracy (ACC) was 0.85, sensitivity was 0.76, specificity was 0.91, and precision was 0.85. F1 scored 0.80. In the verification group, AUC was 0.84 (0.743-0.927), ACC was 0.80, sensitivity was 0.67, specificity was 0.87, precision was 0.75, and F1 scored 0.71. We then visualized them using a nomogram based on multivariate regression. The C index and clinical decision curve evaluated them. The C index was 83.8%, and the clinical decision curve was also excellent. We've established an effective clinical prediction model for patients with IMN who also have coronary heart disease. This model holds significant potential for enhancing clinical decision-making.

Using a machine learning-based risk prediction model to analyze the coronary artery calcification score and predict coronary heart disease and risk assessment

ObjectivesTo calculate the coronary artery calcification score (CACS) obtained from coronary artery computed tomography angiography (CCTA) examination and combine it with the influencing factors of coronary artery calcification (CAC), which is then analyzed by machine learning (ML) to predict the probability of coronary heart disease(CHD). MethodsAll patients who were admitted to the Affiliated Hospital of Traditional Chinese Medicine of Southwest Medical University from January 2019 to March 2022, suspected of CHD, and underwent CCTA inspection were retrospectively selected. The degree of CAC was quantified based on the Agatston score. To compare the correlation between the CACS and clinical-related factors, we collected 31 variables, including hypertension, diabetes, smoking, hyperlipidemia, among others. ML models containing the random forest (RF), radial basis function neural network (RBFNN),support vector machine (SVM),K-Nearest Neighbor algorithm (KNN) and kernel ridge regression (KRR) were used to assess the risk of CHD based on CACS and clinical-related factors. ResultsAmong the five ML models, RF achieves the best performance about accuracy (ACC) (78.96%), sensitivity (SN) (93.86%), specificity(Spe) (51.13%), and Matthew's correlation coefficient (MCC) (0.5192).It also has the best area under the receiver operator characteristic curve (ROC) (0.8375), which is far superior to the other four ML models. ConclusionComputer ML model analysis confirmed the importance of CACS in predicting the occurrence of CHD, especially the outstanding RF model, making it another advancement of the ML model in the field of medical analysis.

A COMBINATION OF HYPERTENSION AND A HIGH ATHEROGENIC INDEX OF PLASMA AS AN INDICATOR OF A CORONARY HEART DISEASE RISK

Objective: Our study demonstrated the changes in the prevalence of coronary heart disease (CHD) depending on hypertension and atherogenic index of plasma Design and method: The atherogenic index of plasma (AIP) is a common logarithm of a ratio of triglycerides and HDL-cholesterol molar concentrations. According to M. Dobiasova (2006), at AIP &lt; 0.10, cardiovascular risk is low; at the range of 0.10 to 0.24, the risk is medium, and if AIP is higher than 0.24, the risk is high. For the randomized sample of the ESSE-RF study, which included 1603 Krasnoyarsk Krai inhabitants, we used a standard questionnaire, anthropometry, office blood pressure measurement, and biochemical blood analyses to find a prevalence of known cardiovascular diseases and their risk factors. We registered hypertension if a person took antihypertensive medications or their measured blood pressure was at 140/90 mm Hg or higher. Coronary heart disease was diagnosed with a Rose angina questionnaire and 12-lead rest ECG encoded by the Minnesota system (the authors wish to thank the National Medical Research Center for Therapy and Preventive Medicine for assistance in laboratory tests and ECG encoding). Results: In 14.7% (95% CI = 13.8%-15.6%) of the study participants, we found CHD. Along with it, 73.5% of people had a low risk by AIP; in 10.4%, AIP indicated a medium risk, and 16.1% of the study participants had a high risk. People with normal blood pressure had no significant interrelation between the prevalence of CHD and AIP level (p = 0.669). Contrary, hypertensives with low risk by AIP had 23.2% (95% CI = 19.5%-27.0%) cases of CHD; at the medium risk, the prevalence of CHD was at 31.5% (95% CI = 21.8%-41.1%), and in the group of high risk, there were 17.5% (95% CI = 11.9%-23.1%) people with CHD. Chi-square was for trend at p = 0.036. Conclusions: The atherogenic index of plasma and coronary heart disease had no interrelation in normal blood pressure. In hypertension, however, the atherogenic index of plasma at a medium level may indicate a higher probability of coronary heart disease.

718 Cardiac injury following immunization with mRNA SARS-CoV-2 vaccines

AimsCardiac involvement as myocarditis and/or pericarditis is now recognized as a rare but possible adverse event following SARS-CoV-2 mRNA vaccines. In this brief report we describe a series of four subjects: three of them with myocarditis and one with pericarditis probably due to hypersensitivity and developed in temporal association with COVID-19 mRNA vaccination.Methods and resultsDuring last summer, we observed a series of four young Caucasian male [median (range) age, 25 (18–32) years] presenting to the Emergency Department with severe acute chest pain within few days after second dose COVID-19 mRNA vaccine administration [median (range), 3 (2–5) days]. All of these were previously healthy and fitness males. All patients had abnormal electrocardiogram (EKG) and three of them had elevated high sensitive cardiac I troponin (hs-cTnI) levels. These latter three were diagnosed as having myocarditis and undergone cardiac magnetic resonance imaging (CMR). None had acute or prior COVID-19 or pulmonary disease on chest X-ray. Moreover, ischaemic injury, other infections, adverse drug reactions or any autoimmune diseases were excluded by appropriate tests. All patients underwent ecocardiography which showed preserved ejection fraction and no wall motion abnormalities and it excluded coronary origin abnormalities in each patient. The hospital course was uneventful for all four patients and they were discharged within few days of hospitalization [median (range), 6 (3–8) days] after a conservative treatment. The four patients met CDC criteria for probable myocarditis and pericarditis. To date, it is recognized a possible clinical correlation between cardiac injury and SARS-CoV-2 mRNA vaccination. The following elements support this hypothesis: (i) short time lapse between vaccine administration and symptoms onset; (ii) onset after the second dose suggesting an immune-mediated pathogenesis needing a previous sensibilization; (iii) exclusion of other possible damage causes (ischaemia, infections, other immune-mediated diseases, toxicity). In particular, we did not perform coronary angiography given the low pre-test probability of coronary heart disease. Although compending a small sample, our report includes a patient series with clinical features similar to those frequently encountered into other papers: i.e. a prevalence in young males without risk factors; symptoms onset within few days second dose administration; an eventful clinical course. This benign course, seen in the majority of cases in literature, raises the question of the need for specific therapy or an empirical one for symptoms control only. Our report suggest that possible cardiac involvement can range from isolated pericarditis to myocarditis with significant hs-cTnI raise and signs of acute inflammation at CMR or even a myocardial injury with a mild hs-cTnI raise in absence of pathological signs at CMR. This latter case suggests also a possible cardiac injury with subclinical course.ConclusionsTo date, we are observing a temporal association linking mRNA SARS-CoV-2 vaccines administration and cardiac involvement. According to the majority of papers, our experience suggests an acute benign course of such cardiac involvement; a longer follow-up will also reveal a long-term benign course or conversely the presence of any sequelae. Clinicians should adequately inform patients when receiving vaccine to ensure prompt symptoms recognition and consequently put in place the best management of myocarditis/pericarditis. Finally, it is important to keep in mind that the benefits of vaccines far outweigh the risks.

A system for predicting the development of coronary heart disease in miners with anthracosilicosis

Introduction. Among underground miners, the pathology of the cardiovascular system is much more common than among workers on the surface, which indicates the negative role of the impact of harmful production factors. There is evidence of a high prevalence of traditional risk factors for the development of coronary heart disease among miners with dust pathology of the lungs. Preventive measures for coronary heart disease exist for the timely detection and elimination of risk factors. In this regard, it is relevant to optimize methods for predicting the risk of developing coronary heart disease in coal mine workers. The study aims to develop a system for predicting the probability of developing coronary heart disease in miners with anthracosilicosis based on determining the most significant risk factors. Materials and methods. The experts studied the frequency of coronary heart disease and its risk factors in 139 employees of the primary professions of coal mines. The scientists performed daily ECG monitoring, bicycle ergometry according to the Rose questionnaire. They also studied the indicators of lipid metabolism, hemostasis, the level of homocysteine, C-reactive protein, glycemia, the presence of excess body weight, constitutional and morphological types according to Rice-Eysenck and Tanner. The experts developed a predictive system using the Bayes method. We calculated a predictive coefficient for each factor. Scientists determined the probability of coronary heart disease by the value of the sum of prognostic coefficients. Results. Workers aged 45 years and older have the highest risk of developing coronary heart disease. The experience of working in harmful working conditions for 20 years or more, the presence of arterial hypertension, metabolic syndrome, respiratory failure, andromorphic constitutional-morphological type according to the Tanner index, as well as the presence of hyperhomocysteinemia, hyperfibrinogenemia, increased levels of soluble fibrin-monomer complexes and C-reactive protein - all these are the risks of developing coronary heart disease in miners with anthracosilicosis. Conclusions. The developed system of personalized prediction of the probability of developing coronary heart disease in miners with anthracosilicosis allows us to identify a group of high-risk workers for timely treatment and preventive measures for them.

Coronary heart disease probability in familial hypercholesterolemia patients

Background and Aims: Cardiovascular risk assessment in patients with familial hypercholesterolemia (FH) is complicated. Aim: to create the formula for estimating the probability of cardiovascular heart disease (CHD) in FH patients.

The place of echocardiography with physical activity in the diagnosis of stable coronary heart disease: State of the Art

Ischemic heart disease is the most common cause of death in developed countries. Diagnostic methods for ischemic heart disease can be classified into functional (stress tests: echocardiography with physical or pharmacological stress, perfusion myocardial scintigraphy with physical or pharmacological stress, magnetic resonance imaging of the heart with physical or pharmacological stress) and imaging (computed tomographic coronary angiography and selective coronary angiography) methods. An algorithm has been developed for assessing the pretest probability of coronary heart disease, according to the clinical picture of the disease, complaints, age and sex of the patient that simplifies the procedure for making a decision regarding the diagnostic method. As per the data from previous studies, stress tests have shown comparable sensitivity and specificity, making it possible to choose a diagnostic method based on other factors, such as method safety, operator dependence, physiology and availability. This study focuses on stress echocardiography as the safest and most affordable diagnostic method. We present an algorithm for performing echocardiography with exercise as per the data from European and national Russian guidelines. Received 2 March 2020. Revised 27 April 2020. Accepted 27 April 2020.Funding: The study did not have sponsorship.Conflict of interest: Authors declare no conflict of interest.

Multifocal atherosclerosis in practice family doctor: modern look on the problem and the results of personal observation

The aim of this review is to analyze the possibility of diagnostics of multifocal atherosclerosis (MFA) in the practice of the General practitioner taking into account available in real clinical activity diagnostic and treatment strategies based on evidence based medicine. At the moment there are no standardized guidelines for the management of patients with MFA. Considering the severe MFA complications (stroke, myocardial infarction, acute thrombosis of peripheral arteries) diagnostic of this disease in early stages in patients with risk factors is an important step in the prevention of these complications. For effective cooperation with specialists General practitioner should be widely used scales of cardiovascular risk stratification and the methodology of pre test probability of coronary heart disease. Based on the analysis of literature data and own experience the indications for additional observation and surgical intervention treatment of patients with atherosclerosis of different vessels are summarized.

Single-centre cohort study of gender influence in coronary CT angiography in patients with a low to intermediate pretest probability of coronary heart disease

BackgroundIn ‘real-world’ patient populations undergoing coronary CT angiography (CCTA), it is unclear whether a correlation exists between gender, coronary artery calcium (CAC) score and subsequent referral for invasive coronary angiography...

The state of coronary arteries in perimenopausal women with chest pain.

BackgroundThe goal of the study was to assess the state of coronary arteries in perimenopausal women undergoing examination before prescription of hormonal replacement therapy.MethodsOne hundred ninety-three patients were screened, and 43 of them were selected for inclusion to the study. Pretest probability of coronary heart disease (CHD) was 47% for patients with typical angina pain and 20.5% with atypical pain. Patients with typical and atypical pain syndromes had no essential differences in terms of age, but had different hormonal status assessed by follicle stimulating hormone level and different menopause durations.ResultsAtherosclerotic lesion causing luminal occlusion by more than 50% was detected in 13 (61.9%) patients with typical pain syndrome and in eight (36.4%) patients with atypical pain syndrome manifestations. Numbers of patients with intact coronary arteries were six (28.6%) and 10 (45.5%) in groups with typical and atypical pain syndrome, respectively. Myocardial bridges were found in five (23.8%) patients with typical pain syndrome and seven (31.8%) patients with atypical manifestations.ConclusionIn spite of modest pretest CHD probability in the group with typical pain syndrome and low pretest CHD probability in the group with atypical manifestations, patients with major atherosclerotic lesions were detected in both groups. Use of this approach to assessment of the state of coronary arteries allows detecting patients at high risk of cardiovascular complications and avoiding the use of hormonal replacement therapy in them.

Achievement of Goals in U.S. Diabetes Care, 1999–2010

BackgroundTracking national progress in diabetes care may aid in the evaluation of past efforts and identify residual gaps in care.MethodsWe analyzed data for adults with self-reported diabetes from the National Health and Nutrition Examination Survey and the Behavioral Risk Factor Surveillance System to examine risk-factor control, preventive practices, and risk scores for coronary heart disease over the 1999–2010 period.ResultsFrom 1999 through 2010, the weighted proportion of survey participants who met recommended goals for diabetes care increased, by 7.9 percentage points (95% confidence interval [CI], 0.8 to 15.0) for glycemic control (glycated hemoglobin level <7.0%), 9.4 percentage points (95% CI, 3.0 to 15.8) for individualized glycemic targets, 11.7 percentage points (95% CI, 5.7 to 17.7) for blood pressure (target, <130/80 mm Hg), and 20.8 percentage points (95% CI, 11.6 to 30.0) for lipid levels (target level of low-density lipoprotein [LDL] cholesterol, <100 mg per deciliter [2.6 mmol per liter]). Tobacco use did not change significantly, but the 10-year probability of coronary heart disease decreased by 2.8 to 3.7 percentage points. However, 33.4 to 48.7% of persons with diabetes still did not meet the targets for glycemic control, blood pressure, or LDL cholesterol level. Only 14.3% met the targets for all three of these measures and for tobacco use. Adherence to the recommendations for annual eye and dental examinations was unchanged, but annual lipid-level measurement and foot examination increased by 5.5 percentage points (95% CI, 1.6 to 9.4) and 6.8 percentage points (95% CI, 4.8 to 8.8), respectively. Annual vaccination for influenza and receipt of pneumococcal vaccination for participants 65 years of age or older rose by 4.5 percentage points (95% CI, 0.8 to 8.2) and 6.9 percentage points (95% CI, 3.4 to 10.4), respectively, and daily glucose monitoring increased by 12.7 percentage points (95% CI, 10.3 to 15.1).ConclusionsAlthough there were improvements in risk-factor control and adherence to preventive practices from 1999 to 2010, tobacco use remained high, and almost half of U.S. adults with diabetes did not meet the recommended goals for diabetes care.

Attenuated associations between increasing BMI and unfavorable lipid profiles in Chinese Buddhist vegetarians.

Obesity is related to hyperlipidemia and risk of cardiovascular disease. Health benefits of vegetarian diets have well-documented in the Western countries where both obesity and hyperlipidemia were prevalent. We studied the association between BMI and various lipid/lipoprotein measures, as well as between BMI and predicted coronary heart disease probability in lean, low risk populations in Southern China. The study included 170 Buddhist monks (vegetarians) and 126 omnivore men. Interaction between BMI and vegetarian status was tested in the multivariable regression analysis adjusting for age, education, smoking, alcohol drinking, and physical activity. Compared with omnivores, vegetarians had significantly lower mean BMI, blood pressures, total cholesterol, low density lipoprotein cholesterol, high density lipoprotein cholesterol, total cholesterol to high density lipoprotein ratio, triglycerides, apolipoprotein B and A-I, as well as lower predicted probability of coronary heart disease. Higher BMI was associated with unfavorable lipid/lipoprotein profile and predicted probability of coronary heart disease in both vegetarians and omnivores. However, the associations were significantly diminished in Buddhist vegetarians. Vegetarian diets not only lower BMI, but also attenuate the BMI-related increases of atherogenic lipid/ lipoprotein and the probability of coronary heart disease.

Reclassification of Cardiovascular Risk in Patients With Normal Myocardial Perfusion Imaging Using Heart Rate Response to Vasodilator Stress

Previous studies have shown that patients with normal vasodilator myocardial perfusion imaging (MPI) findings remain at a greater risk of future cardiac events than patients with normal exercise MPI findings. The aim was to assess improvement in risk classification provided by the heart rate response (HRR) in patients with normal vasodilator MPI findings when added to traditional risk stratification. We retrospectively studied 2,000 patients with normal regadenoson or adenosine MPI findings. Risk stratification was performed using Adult Treatment Panel III framework. Patients were stratified by HRR (percentage of increase from baseline) into tertiles specific to each vasodilator. All-cause mortality and cardiac death/nonfatal myocardial infarction (MI) ≤2 years from the index MPI were recorded. During follow-up, 11.8% patients died and 2.7% patients experienced cardiac death/nonfatal MI in the adenosine and regadenoson groups, respectively. The patients who died had a greater Framingham risk score (12 ± 4 vs 11 ± 4, p= 0.009) and lower HRR (22± 16 vs 32 ± 21, p <0.0001). In an adjusted Cox model, the lowest tertile HRR was associated with an increased risk of mortality (hazard ratio 2.1) and cardiac death/nonfatal MI (hazard ratio 2.9; p <0.01). Patients in the highest HRR tertile, irrespective of the Adult Treatment Panel III category, were at low risk. When added to the Adult Treatment Panel III categories, the HRR resulted in net reclassification improvement in mortality of 18% and cardiac death/nonfatal MI of 22%. In conclusion, a blunted HRR to vasodilator stress was independently associated with an increased risk of cardiac events and overall mortality in patients with normal vasodilator MPI findings. The HRR correctly reclassified a substantial proportion of these patients in addition to the traditional risk classification models and identified patients with normal vasodilator MPI findings, who had a truly low risk of events.

Accuracy of general practitioners' assessment of chest pain patients for coronary heart disease in primary care: cross-sectional study with follow-up.

To estimate how accurately general practitioners' (GP) assessed the probability of coronary heart disease in patients presenting with chest pain and analyze the patient management decisions taken as a result. During 2005 and 2006, the cross-sectional diagnostic study with a delayed-type reference standard included 74 GPs in the German state of Hesse, who enrolled 1249 consecutive patients presenting with chest pain. GPs recorded symptoms and findings for each patient on a report form. Patients and GPs were contacted 6 weeks and 6 months after the patients' visit to the GP. Data on chest complaints, investigations, hospitalization, and medication were reviewed by an independent panel, with coronary heart disease being the reference condition. Diagnostic properties (sensitivity, specificity, and predictive values) of the GPs' diagnoses were calculated. GPs diagnosed coronary heart disease with the sensitivity of 69% (95% confidence interval [CI], 62-75) and specificity of 89% (95% CI, 87-91), and acute coronary syndrome with the sensitivity of 50% (95% CI, 36-64) and specificity of 98% (95% CI, 97-99). They assumed coronary heart disease in 245 patients, 41 (17%) of whom were referred to the hospital, 77 (31%) to a cardiologist, and 162 (66%) to electrocardiogram testing. GPs' evaluation of chest pain patients, based on symptoms and signs alone, was not sufficiently accurate for diagnosing or excluding coronary heart disease or acute coronary syndrome.

Optimizing the Start Time of Statin Therapy for Patients with Diabetes

Clinicians often use validated risk models to guide treatment decisions for cardiovascular risk reduction. The most common risk models for predicting cardiovascular risk are the UKPDS, Framingham, and Archimedes models. In this article, the authors propose a model to optimize the selection of patients for statin therapy of hypercholesterolemia, for patients with type 2 diabetes, using each of the risk models. For each model,they evaluate the role of age, gender, and metabolic state on the optimal start time for statins. Using clinical data from the Mayo Clinic electronic medical record, the authors construct a Markov decision process model with health states composed of cardiovascular events and metabolic factors such as total cholesterol and high-density lipoproteins. They use it to evaluate the optimal start time of statin treatment for different combinations of cardiovascular risk models and patient attributes. The authors find that treatment decisions depend on the cardiovascular risk model used and the age, gender, and metabolic state of the patient. Using the UKPDS risk model to estimate the probability of coronary heart disease and stroke events, they find that all white male patients should eventually start statin therapy; however, using Framingham and Archimedes models in place of UKPDS, they find that for male patients at lower risk, it is never optimal to initiate statins. For white female patients, the authors also find some patients for whom it is never optimal to initiate statins. Assuming that age 40 is the earliest possible start time, the authors find that the earliest optimal start times for UKPDS, Framingham, and Archimedes are 50, 46, and 40, respectively, for women. For men, the earliest optimal start times are 40, 40, and 40, respectively. In addition to age, gender, and metabolic state, the choice of cardiovascular risk model influences the apparent optimal time for starting statins in patients with diabetes.

Cytochrome P450 and gene activation—from pharmacology to cholesterol elimination and regression of atherosclerosis

Lipoproteins are closely associated with the atherosclerotic vascular process. Elevated levels of high-density lipoprotein cholesterol (HDL-C) and apolipoprotein AI (apo AI) in plasma indicate a low probability of coronary heart disease (CHD) together with enhanced longevity, and elevated levels of low-density lipoprotein-cholesterol (LDL-C) and apo B indicate an increased risk of CHD and death. Studies linking gene activation and the induction of cytochrome P450 with elevated plasma levels of apo AI and HDL-C and lowered plasma levels of LDL-C presented a new potential approach to prevent and treat atherosclerotic disease. This is a review aimed at clarifying the effects of P450-enzymes and gene activation on cholesterol homeostasis, the atherosclerotic vascular process, prevention and regression of atherosclerosis and the manifestation of atherosclerotic disease, particularly CHD, the leading cause of death in the world. P450-enzymes maintain cellular cholesterol homeostasis. They respond to cholesterol accumulation by enhancing the generation of hydroxycholesterols (oxysterols) and activating cholesterol-eliminating mechanisms. The CYP7A1, CYP27A1, CYP46A1 and CYP3A4 enzymes generate major oxysterols that enter the circulation. The oxysterols activate-via nuclear receptors-ATP-binding cassette (ABC) A1 and other genes, leading to the elimination of excess cholesterol and protecting arteries from atherosclerosis. Several drugs and nonpharmacologic compounds are ligands for the liver X receptor, pregnane X receptor and other receptors, activate P450 and other genes involved in cholesterol elimination, prevent or regress atherosclerosis and reduce cardiovascular events. P450-enzymes are essential in the physiological maintenance of cholesterol balance. They activate mechanisms which eliminate excess cholesterol and counteract the atherosclerotic process. Several drugs and nonpharmacologic compounds induce P450 and other genes, prevent or regress atherosclerosis and reduce the occurrence of non-fatal and fatal CHD and other atherosclerotic diseases.

Anthropometric indices and their relationship with diabetes, hypertension and dyslipidemia in Australian Aboriginal people and Torres Strait Islanders

Australian indigenous people have a body shape and cardiovascular risk profiles different from that of other ethnic populations. This present study aims to examine the association of anthropometric indices with diabetes, hypertension and dyslipidemia, and to determine what indices can best predict these individual risk factors for the risk of cardiovascular disease (CVD). A cross-sectional study of Australian Aboriginal people and Torres Strait Islanders. A total of 747 Australian Aboriginal people and 439 Torres Strait Islanders aged 25 years and over were examined between 1993 and 1997. Body weight, height, waist and hip circumferences, blood pressure, plasma glucose, triglycerides, total and high-density lipoprotein cholesterol were measured. The best predictor of hypertension among five anthropometric indices was waist : height ratio for Australian Aboriginal people and waist circumference for Torres Strait Islanders. Waist : hip ratio (WHR) was the best predictor for both diabetes and dyslipidemia in both populations. In multivariate regression analyses, WHR and body mass index were independently associated with the 10-year predicted absolute probability of coronary heart disease (CHD) for Torres Strait Islanders. However, overall WHR appeared to be the best predictor of the estimated CHD risk for both populations. This study shows that WHR was the best predictor for diabetes, dyslipidemia and absolute CHD risk in Australian Aboriginal people and Torres Strait Islanders. Incorporating WHR into routine health examinations in Australian indigenous people will enhance the evaluation of CVD risk.

29.11

29.11