Mild hypercholesterolemia and premature heart disease: do the national criteria underestimate disease risk?

Modifiable and Non-Modifiable Risk Factors for Premature Coronary Heart Disease (PCHD): Systematic Review and Meta-Analysis

AIM

We aimed to compare the prevalence of modifiable and non-modifiable coronary heart disease (CHD) risk factors among those with premature CHD and healthy individuals.

METHODS

PubMed, CINAHL, Embase, and Web of Science databases were searched (review protocol is registered in PROSPERO CRD42020173216). The quality of studies was assessed using the National Heart, Lung and Blood Institute tool for cross-sectional, cohort and case-control studies. Meta-analyses were performed using Review Manager 5.3. Effect sizes for categorical and continuous variables, odds ratio (OR) and mean differences (MD)/standardised mean differences (SMD) with 95% confidence intervals (CI) were reported.

RESULTS

A total of n=208 primary studies were included in this review. Individuals presenting with premature CHD (PCHD, age ≤65 years) had higher mean body mass index (MD 0.54 kg/m2, 95% CI 0.24, 0.83), total cholesterol (SMD 0.27, 95% CI 0.17, 0.38), triglycerides (SMD 0.50, 95% CI 0.41, 0.60) and lower high-density lipoprotein cholesterol (SMD 0.79, 95% CI: -0.91, -0.68) compared with healthy individuals. Individuals presenting with PCHD were more likely to be smokers (OR 2.88, 95% CI 2.51, 3.31), consumed excessive alcohol (OR 1.40, 95% CI 1.05, 1.86), had higher mean lipoprotein (a) levels (SMD 0.41, 95% CI 0.28, 0.54), and had a positive family history of CHD (OR 3.65, 95% CI 2.87, 4.66) compared with healthy individuals. Also, they were more likely to be obese (OR 1.59, 95% CI 1.32, 1.91), and to have had dyslipidaemia (OR 2.74, 95% CI 2.18, 3.45), hypertension (OR 2.80, 95% CI 2.28, 3.45), and type 2 diabetes mellitus (OR 2.93, 95% CI 2.50, 3.45) compared with healthy individuals.

CONCLUSION

This meta-analysis confirms current knowledge of risk factors for PCHD, and identifying these early may reduce CHD in young adults.

Risk factors, lab parameters, angiographic characteristics and outcomes of coronary artery disease in young South Asian patients: a systematic review

This systematic review provides a qualitative summary of the risk factors, angiographic characteristics, treatment, and complications of young South Asians with coronary artery disease (CAD). PubMed, Embase, and Google Scholar were searched to identify research articles published between 1 January 2010 and 13 November 2022. Studies in patients aged 18 to 45 years that were conducted in South Asian countries, were published in the English language, and included information on patients' clinical profiles and at least two risk factors for young CAD were included in the review. Smoking, dyslipidemia, high body mass index, increased high-sensitivity C-reactive protein, and hyperhomocysteinemia were observed in high proportions in young patients with CAD. Single-vessel disease was more common than multi-vessel disease in young CAD. The complications of CAD such as arrhythmias, cardiogenic shock, and heart failure were also commonly observed in young patients. Large-scale health promotion activities that curb modifiable risk factors such as smoking, obesity, and a sedentary lifestyle should be conducted in South Asian countries.

Clusters of the Risk Markers and the Pattern of Premature Coronary Heart Disease: An Application of the Latent Class Analysis

Background: Coronary heart disease (CHD) is the major cause of mortality in the world with a significant impact on the younger population. The aim of this study was to identify prematurity among patients with coronary artery bypass graft surgery (CABG) based on the clustering of CHD risk factors.

Methods: Patients were recruited from an existing cohort of candidates for CABG surgery named Tehran Heart Center Coronary Outcome Measurement (THC-COM). A latent class analysis (LCA) model was formed using 11 potential risk factors as binary variables: cigarette smoking, obesity, diabetes, family history of CHD, alcohol use, opium addiction, hypertension, history of stroke, history of myocardial infarction (MI), peripheral vascular disease (PVD), and hyperlipidemia (HLP). We analyzed our data to figure out how the patients are going to be clustered based on their risk factors.

Results: For 566 patients who were studied, the mean age (SD) and BMI of patients were 59.1 (8.9) and 27.3 (4.1), respectively. The LCA model fit with two latent classes was statistically significant (G2 = 824.87, df = 21, p < 0.0001). The mean (SD) age of patients for Class I and Class II was 55.66 (8.55) and 60.87 (8.66), respectively. Class I (premature) was characterized by a high probability of smoking, alcohol consumption, opium addiction, and a history of MI (P < 0.05), and class II by a high probability of obesity, diabetes, and hypertension.

Conclusion: Latent class analysis calculated two groups of severe CHD with distinct risk markers. The younger group, which is characterized by smoking, addiction, and the history of MI, can be regarded as representative of premature CHD.

Risk factors of premature coronary artery disease in Iran: A systematic review and meta-analysis

BACKGROUND

The aim of this study was to determine the mean age at which coronary artery disease (CAD) hase decreased in recent years in Iran. This systematic review and meta-analysis compares the prevalence of different risk factors of premature CAD (PCAD) in patients vs healthy individuals.

METHODS

Medline, Web of Science, Embase and Scientific Information Database were searched for studies about PCAD risk factors in Iran until 28 October 2017. Observational studies of Iranians, comparing risk factors between patients with PCAD and age- and sex-matched healthy subjects, were included. Fixed-effects and random-effects model were used for pooling data. Odds ratio (OR) with 95% CI and mean difference were used for effect size estimation among studies.

RESULTS

Twelve studies were eligible for meta-analysis. Diabetes mellitus (OR: 2.4, 95% CI: 1.9-3.03; P = 0.0001, I²  = 25.5%; P = 0.2), family history of CAD (OR: 2.09, 95% CI: 1.22-3.6; P = 0.007, I²  = 86%; P = 0.0001), dyslipidaemia (OR: 2.05, 95% CI: 1.15-3.64; P = 0.01, I²  = 54%; P = 0.08), smoking (OR: 1.65, 95% CI: 1.11-2.46; P = 0.01, I²  = 77.2%; P = 0.000) and hypertension (OR: 1.35, 95% CI: 1.21 to-1.50; P < 0.001, I²  = 31%, P = 0.1) associated with PCAD. Sensitivity analysis demonstrated that patients with PCAD had significantly lower levels of high-density lipoprotein (HDL) cholesterol and significantly higher levels of triglycerides compared to healthy subjects (MD: -2.56, 95% CI: -3.54 to -1.58, P < 0.001, I²  = 42%, P = 0.01 and MD: 21.17, 95% CI: 14.73-27.62, P < 0.001, I²  = 80.12%, P < 0.001, respectively). It should be noted that although high levels of heterogeneity in LDL and HDL values among the studies were observed, when dyslipidaemia was studied as a binary variable, no significant heterogeneity among studies was observed.

CONCLUSION

Diabetes mellitus, family history of CAD, dyslipidaemia, smoking, and hypertension were significantly and positively associated with CAD in young adults compared to healthy age- and sex-matched population in Iran.

Familial hypercholesterolemia in very young myocardial infarction

Familial hypercholesterolemia (FH) is one of the most common causes of premature myocardial infarction (MI). However, The patterns of FH remained unrecognized in clinical care, especially in very young patients (VYPs, ≤35 years) with MI. The present study enrolled a total of 1,093 VYPs (≤35 years) presenting a first MI. Clinical diagnosis of FH was made using Dutch Lipid Clinic Network criteria. Coronary severity was assessed by Gensini score (GS). Patients were followed for a median of 40-months with cardiac death, stroke, MI, post-discharge revascularization or unstable angina as primary endpoints. The detected rates of definite/probable FH were 6.5%. The prevalence reached up to 10.3% in patients ≤25 years. The FH had similar levels of comorbidities but was younger, more likely to be very high risk (VHR) and had higher GS (p < 0.05) than unlikely FH. Notably, the FH on prior lipid-lowering medication presented a lower GS compared to those untreated. Differences in event rates were similar in FH as unlikely FH (11.8% vs. 8.1%, adjusted hazard ratio 1.35 [0.64–2.86], p = 0.434) but patients on treatment improved outcome (6.5% vs. 10.5%, adjusted hazard ratio 0.35[0.13–0.95], p = 0.039). The early identification and treatment might be critical to reduce cardiovascular risk in VYPs with MI.

Cardiovascular Disease Prevention in Men with Vascular Erectile Dysfunction: The View of the Preventive Cardiologist

Vascular erectile dysfunction is a powerful marker of increased cardiovascular risk. However, current guidelines lack specific recommendations on the role that the evaluation of vascular erectile dysfunction should play in cardiovascular risk assessment, as well on the risk stratification strategy that men with vascular erectile dysfunction should undergo. In the last 3 years, erectile dysfunction experts have made a call for more specific guidance and have proposed the selective use of several prognostic tests for further cardiovascular risk assessment in these patients. Among them, stress testing has been prioritized, whereas other tests are considered second-line tools. In this review, we provide additional perspective from the viewpoint of the preventive cardiologist. We discuss the limitations of current risk scores and the potential interplay between erectile dysfunction assessment and the use of personalized prognostic tools, such as the coronary artery calcium score, in the cardiovascular risk stratification and management of men with vascular erectile dysfunction. Finally, we present an algorithm for primary care physicians, urologists, and cardiologists to aid clinical decision-making.

Coronary Heart Disease Mortality Declines in the United States From 1979 Through 2011: Evidence for Stagnation in Young Adults, Especially Women

BACKGROUND

Coronary heart disease (CHD) mortality rates have fallen dramatically over the past 4 decades in the Western world. However, recent data from the United States and elsewhere suggest a plateauing of CHD incidence and mortality among young women. We therefore examined recent trends in CHD mortality rates in the United States according to age and sex.

METHODS AND RESULTS

We analyzed mortality data between 1979 and 2011 for US adults ≥25 years of age. We calculated age-specific CHD mortality rates and compared estimated annual percentage changes during 3 approximate decades of data (1979-1989, 1990-1999, and 2000-2011). We then used Joinpoint regression modeling to assess changes in trends over time on the basis of inflection points of the mortality rates. Adults ≥65 years of age showed consistent mortality declines, which became even steeper after 2000 (women, -5.0%; men, -4.4%). In contrast, young men and women (<55 years of age) initially showed a clear decline in CHD mortality from 1979 until 1989 (estimated annual percentage change, -5.5% in men and -4.6% in women). However, the 2 subsequent decades saw stagnation with minimal improvement. Notably, young women demonstrated no improvements between 1990 and 1999 (estimated annual percentage change, 0.1%) and only -1% estimated annual percentage change since 2000. Joinpoint analyses provided consistent results.

CONCLUSIONS

The dramatic decline in CHD mortality since 1979 conceals major heterogeneities. CHD death rates in older groups are now falling steeply. However, young adults have experienced frustratingly small decreases in CHD mortality rates since 1990. The drivers of these major differences in CHD mortality trends by age and sex merit urgent study.

Acute myocardial infarction as the first presentation of thyrotoxicosis in a 31-year old woman - case report

A 31-year old woman, previously fit & well was admitted with pressing retrosternal chest pain and palpitations of sudden onset. Her body weight was normal (BMI 20.5 kg/m²) and there was no significant family history of cardiac disease. She smoked, however, about 15 cigarettes a day and she had been taking combined oral contraceptive pill (Cilest^®) for about three years. On admission she appeared sweaty and in pain, blood pressure 130/70 mmHg, heart rate about 110/min, mild lid-lag sign. Heart sounds were normal and chest was clear. ECG revealed 2-3 mm ST segment elevations in II, III, aVF as well as V2 to V5. Troponin I was raised and she was qualified to an emergency coronary angiography. This revealed a massive spasm of left anterior descending (LAD) coronary artery that responded to intracoronary glyceryl trinitrite administration, however, with the presence of critical narrowing of the LAD apical segment with possible superimposed thrombus. Cardiac ultrasound revealed akinesis of 1/2 of apical area consistent with myocardial infarction

Treatment and progress

She was started on Aspirin, Simvastatin, and Diltiazem, but continued to have persistent tachycardia and tremor. Thyroid function tests were ordered and showed thyrotoxicosis [free T4-46.9 pmol/l (ref. range 9-25), free T3-11.9 pmol/l (2-5), TSH - 0.02 mIU/l (0.27-4.2)]. She was referred for an endocrine opinion and started on Thiamazole. Other investigations revealed elevated anti-TPO and anti-TSH receptor antibodies consistent with Graves' disease. Thrombophilia screen was negative. She had remained euthyroid on a "block & replace" regimen (Thiamazole plus L-Thyroxine) that was discontinued after 18 months. She denies any anginal symptoms, but continues to smoke against medical advice.

Conclusions

Our case highlights the possibility of development of an acute myocardial infarction in a young subject with thyrotoxicosis. We speculate that patient's smoking habit combined with subtle thyrotoxicosis-induced prothrombotic state and/or coronary-artery spasm had lead to the above-mentioned acute coronary event.

The relative value of metabolic syndrome and cardiovascular risk score estimates in premature acute coronary syndromes

BACKGROUND

To compare the relative value of metabolic syndrome (MetS) and cardiovascular risk score estimates in patients with acute coronary syndromes (ACS) aged <45 years.

PATIENTS AND METHODS

Two hundred consecutive patients (183 men, mean age 40.8 +/- 3.5 years) presented with a first-ever ACS, and 200 age-and sex-matched controls were evaluated. Metabolic syndrome diagnostic criteria, European Risk SCORE estimation function, and the Framingham Risk Score (FRS) were assessed in all participants.

RESULTS

The prevalence of the MetS was significantly higher in the patients' group compared with the control group (51.5% vs 26.0%, P < .001). No subjects with a SCORE >1.0% were identified. The mean 10-year FRS for patients and controls was 13.03% +/- 7.96% and 10.02 +/- 8.10%, respectively (P < .001), whereas only 22.5% of ACS patients had a 10-year risk >20.0% compared with 14.5% of controls (P = .04). After controlling for potential confounders, MetS was associated with 1.93 (95% CI 1.13-3.28, P = .01) higher odds of having an ACS. Moreover, the odds had a positive association with the increasing cumulative number of MetS components. Crude and adjusted ORs for the FRS were 1.05 (95% CI 1.029-1.08, P = .001) and 0.98 (95% CI 0.92-1.05, P = NS), respectively.

CONCLUSION

Metabolic syndrome is highly associated with ACS in subjects <45 years of age and seems to be more valuable than established cardiovascular risk calculators.

National Cholesterol Education Panel III performance in preventing myocardial infarction in young adults

BACKGROUND

Only one published trial has directly evaluated the utility of the new National Cholesterol Education Program (NCEP) guidelines in young adults and that study population consisted of young Americans. We examined the utility of the latest NCEP Adult Treatment Panel III (ATP III) guidelines in a group of young Lebanese adults.

METHODS

A group of 234 young adults admitted for myocardial infarction at a Lebanese teaching hospital over a 2-year period were evaluated retrospectively. The Framingham risk predictor model was used to calculate the 10-year risk for coronary events in all subjects.

RESULTS

Two hundred young Lebanese adults with a mean age of 49.7+/-7.6 years were included in the analysis. The majority of the study population had a history of smoking (67%) and LDL cholesterol <130 mg/dL (70.5%) and were considered overweight and obese (80.5%). As a group, 80% did not meet the criteria to qualify for antilipemic pharmacotherapy prior to their presentation.

CONCLUSION

The predictive model did not detect the majority of these patients. Clinicians should treat modifiable risk factors with the same intensity given to cholesterol even if the patient has a normal lipid profile.

Prognostic significance of zero coronary calcium scores on cardiac computed tomography

BACKGROUND

Most unexpected cardiovascular events occur in persons at intermediate risk of coronary artery disease (10%-20% 10-year risk). Coronary artery calcium (CAC) has been shown to be highly specific for atherosclerosis, occurring only in the intima of the coronary arteries. Evidence shows that elevated coronary calcium scores (CCSs) are predictive of future cardiovascular events, both independently of and incrementally to conventional cardiovascular risk factors. Several studies reported event rates of zero for those persons without CAC by cardiac computed tomography (CT).

OBJECTIVES

We sought to evaluate the event rates in persons with negative calcium scores from the reported literature to establish whether these patients may be considered at low risk for hard cardiovascular events (myocardial infarction and death).

METHODS

English-language studies from January 1, 1975, through February 1, 2007, were retrieved using MEDLINE and Current Contents databases, bibliographies, and expert consultation.

RESULTS

Summary data show that in a total follow-up of 35,765 asymptomatic persons, 16,106 (45%) had scores of zero. Pooled sensitivity for CAC to detect a cardiovascular event was 98.1% [95% confidence interval (CI), 95.1%-99.9%], and negative predictive value was 99.9% (95% CI, 98.9%-100%). There were 48 hard events in this population, with an annual event rate of 0.027%.

CONCLUSION

These large observational cohorts show that the absence of CAC by cardiac CT is associated with a low adverse event risk and therefore could be used as a tool to counsel patients about their risk of such events.

Prevalence of metabolic syndrome in young patients with acute MI: does the Framingham Risk Score underestimate cardiovascular risk in this population?

To assess the prevalence of metabolic syndrome (MS) and estimates of global risk by Framingham Risk Score in young subjects with acute myocardial infarction (MI), we assessed metabolic parameters and global risk assessment in 165 consecutive subjects who presented with myocardial infarction prior to 45 years of age. Nearly 80% of subjects were overweight or obese and at least one cardiovascular risk factor was present in 96% of patients. MS with or without overt diabetes was present in nearly two thirds of subjects. Excluding subjects with diabetes, the mean 10-year Framingham Risk Score estimate in the total cohort was 9.3%, with only 17.1% of subjects having a 10-year risk greater than 20%. Only 28% of subjects with MS had a Framingham Risk Score greater than 20%. Although MS is present in nearly two thirds of young patients with premature myocardial infarction, the Framingham Risk Score appears to underestimate global cardiovascular risk in this population.

Metabolic Syndrome and Coronary Heart Disease Equivalent Conditions in Predicting Cardiovascular Events in Young to Middle-Aged Adults

There are questions concerning the validity of the metabolic syndrome as a diagnostic entity and whether the syndrome predicts coronary heart disease (CHD) better than global risk stratification. The use of the metabolic syndrome as a potential adjunct to improve global risk stratification has received less attention. The authors evaluated the relationship between the metabolic syndrome and cardiovascular disease compared with coronary heart disease equivalent. Two hundred thirty-six subjects undergoing elective coronary angiography had bilateral carotid ultrasound studies and global risk scores calculated. Mean total, low-density lipoprotein, and high-density lipoprotein cholesterol and triglyceride values were normal. The metabolic syndrome was associated with carotid atherosclerosis (odds ratio, 2.3; confidence interval, 1.2-4.2), coronary disease (odds ratio, 2.9; confidence interval, 1.6-5.4), and future cardiovascular events. Rates for future events and coronary and carotid atherosclerosis were similar for subjects with the metabolic syndrome compared with coronary heart disease equivalent. Combined, the two conditions identified 70% of subjects who developed events. The metabolic syndrome is associated with cardiovascular disease and provides additive information to clinical risk stratification.

Coronary calcium scanning

While there is no doubt that high-risk patients (those with more than a 20% 10-year risk of a future cardiovascular event) need more aggressive preventive therapy, a majority of cardiovascular events occur in individuals at intermediate risk (10%-20% 10-year risk). Data suggest that it will be most cost-effective to concentrate screening efforts on this group of patients. Coronary artery calcium has been shown to be highly specific for atherosclerosis, occurring only in the intima of the coronary arteries. There is evidence to show that elevated coronary calcium scores are predictive of cardiovascular events, both independently of and incrementally to conventional cardiovascular risk factors. Based on current available data, patients with increased plaque burdens (increased coronary calcium scores) are approximately 10 times more likely to suffer a cardiac event over the next 3-5 years. Coronary calcium scores have outperformed conventional risk factors, high sensitivity C-reactive protein, and carotid intima-media thickness as a predictor of cardiovascular events. Both electron beam tomography and multidetector computed tomography can accurately detect and quantify the coronary calcium scores. In summary, coronary calcium detection significantly improves the accuracy of global cardiovascular risk prevention, the noninvasive tracking of the atherosclerotic burden, and the prediction of cardiovascular events.

[Five-year follow up of lipid profile in children in the Rivas-Vaciamadrid study]

OBJECTIVE

To evaluate lipid balance in children after a 5-year follow-up and tracking between initial and final levels.

METHODS

Two hundred eighty-one children included in the Rivas-Vaciamadrid study were evaluated at the ages of 6 and 11 years. In all children, total cholesterol (TC), triglycerides (TG), high-density lipoprotein-cholesterol (HDL-C), and apoproteins A1 (Apo A) and B100 (Apo B) were measured. Low-density lipoprotein-cholesterol (LDL-C) was determined and the Apo B/Apo A, TC/HDL-C, and LDL-C/HDL-C ratios and the atherogenic index were calculated.

RESULTS

At 11 years of age, lipid balance was worse in girls than in boys. Levels of TG and HDL-C were significantly higher at the age of 11 years than those at the age of 6 years, but levels of the remaining variables analyzed were lower, except for Apo A and TC, which showed a non-significant increase. The correlation coefficients between values at the ages of 6 and 11 years were significant for all variables and the highest was LDL-C in girls (0.711). Kappa and Nishio tracking indexes were significant for all variables and were highest for the atherogenic index (0.431 and 6.71 respectively) and lowest for TG (0.129 and 2.85 respectively). Subjects in the highest quartile at 6 years old had a relative risk of 8.04 (CI 4.34-14.88) for having the same atherogenic index at the age of 11 years and a relative risk of 1.91 (CI 1.05-3.46) for having the same TG value.

CONCLUSION

There is a significant correlation between lipid profile values in children at the ages of 6 and 11 years. The best tracking was found in the atherogenic index.

Preventing myocardial infarction in the young adult in the first place: how do the National Cholesterol Education Panel III guidelines perform?

OBJECTIVES

The purpose of this study was to investigate the utility of the new National Cholesterol Education Program (NCEP) III guidelines in a group of young adults.

BACKGROUND

These guidelines have been hailed as an improvement in their potential to identify individuals at risk for coronary heart disease (CHD) complications. Compared with the NCEP II, the new guidelines will increase the number of patients who qualify for medical management. However, the effectiveness of these guidelines to identify young adults at risk for a cardiac event is yet to be studied.

METHODS

A retrospective review of clinical data from young adults (age <or=55 years for men and <or=65 years for women) hospitalized for acute myocardial infarction over a three-year period was conducted. Patients with a history of CHD or CHD equivalent were excluded. Using the NCEP III guidelines, we calculated a 10-year risk for coronary events on all patients.

RESULTS

A total of 222 patients met criteria for inclusion. The mean age was 50 years and 25% were women. Mean lipid levels were all within the normal range; however, rates of smoking and obesity were high. When the 10-year risk of these patients was stratified by the number of risk factors and low-density lipoprotein cholesterol level, only 25% met criteria to qualify for pharmacotherapy. For women in this population, only 18% met criteria for treatment.

CONCLUSIONS

The new guidelines offer multiple new features but have a tendency to underappreciate the risk for disease in young adults. To improve performance in young adults, statistical adjustments may be necessary.

Coronary angiographic findings in patients with cocaine-associated chest pain

Patients who present to the Emergency Department (ED) with chest pain associated with cocaine use are a common problem. The incidence and predictors of underlying significant coronary disease in patients with and without myocardial infarction (MI) has not been well described. Patients who underwent coronary angiography within 5 weeks of an ED evaluation for cocaine-associated chest pain were studied. Significant disease was defined as > or = 50% stenosis of a coronary artery or major branches or bypass graft. A total of 90 patients underwent coronary angiography. Significant disease was present in 45 (50%), with 1-vessel disease in 32%, 2-vessel disease in 10%, 3-vessel disease in 6%, with significant graft stenosis in 3%. Significant disease was present in 77% of patients with MI or troponin I elevations, compared to only 35% of patients without myonecrosis. Predictors of significant coronary disease included MI or troponin I elevations, prior MI, known coronary disease (prior MI or revascularization), and elevated cholesterol. Only 7 of the 39 patients (18%) without myonecrosis or a history of coronary disease had significant disease on angiography. In conclusion, significant disease is found in the majority of patients with cocaine-associated MI or troponin elevations. In contrast, only a minority of those without myonecrosis have significant coronary disease.

Association of lipids, lipoproteins, apolipoproteins and paraoxonase enzyme activity with premature coronary artery disease

BACKGROUND AND DESIGN

The association of serum apolipoprotein (apo) A-I and apo B concentrations and paraoxonase (PON) enzyme activity with angiographically determined coronary artery disease (CAD) was investigated in Iranian non-diabetic patients with premature CAD and control participants in a sex- and age-matched case-control study.

METHODS

The study population consisted of 59 non-diabetic patients with premature CAD and 55 CAD control participants. Premature CAD was defined as the presence of angiographically proven coronary stenosis (> or =50% involvement) in men and women younger than 55 and 65 years, respectively. Apolipoprotein concentrations were measured by immunoturbidometric assay and paraoxonase/arylesterase activities by spectrophotometric assay of p-nitrophenol/phenol production following addition of paraoxon/phenylacetate to serum.

RESULTS

In CAD patients, increased concentrations of total cholesterol (215 +/- 43 compared with 193 +/- 43, P < 0.001), low-density lipoprotein cholesterol (137 +/- 46 compared with 116 +/- 39, P < 0.05) and apo B (102 +/- 24 compared with 84 +/- 17, P < 0.001) and a decreased ratio of apo A-I/apo B (1.7 +/- 0.4 compared with 2.0 +/- 0.6, P < 0.001) were observed compared to the control group. Other study variables were not significantly different between the two groups. On multiple logistic regression analysis, the only marker for discrimination between the CAD+ group and the CAD- control group was apo B level.

CONCLUSIONS

In Iranian non-diabetic patients with premature CAD, the concentration of apo B is a better marker than traditional lipids in discriminating between CAD+ and CAD- patients. The lack of significant difference in PON activity between CAD patients and control participants supports the concept of interethnic variability in PON activity and gene polymorphism observed in other studies.

Myocardial infarction in young adults with low-density lipoprotein cholesterol levels < or = 100 mg/dL: clinical profile and 1-year outcomes

STUDY OBJECTIVES

To define the clinical profile of young adults with optimal low-density lipoprotein (LDL) cholesterol levels who present with acute myocardial infarctions (MIs); to compare and contrast differences in the clinical profiles of young adults admitted to the hospital with MIs who have LDL cholesterol levels < or = 100 mg/dL and those with LDL cholesterol values > or = 160 mg/dL; and to evaluate the clinical outcomes for the two groups at 1 year.

DESIGN

A retrospective chart review was conducted on all young men (55 years) and women (65 years) admitted to the hospital for MIs within a 2-year period (n = 232). A history of cardiovascular risk factors and 1-year outcomes were obtained.

SETTING

Rural community medical center serving a tri-state area in the midwestern United States.

PATIENTS

Patients were included in this analysis if (1) a lipid profile was drawn within 24 h of hospital admission and (2) the patient was not receiving a statin medication on hospital admission.

MEASUREMENTS AND RESULTS

Of the 183 patients who met the inclusion criteria, as many as 68% (124 patients) had LDL cholesterol levels of < or = 130 mg/dL, 29% (53 patients) had LDL cholesterol level of < or = 100 mg/dL, and only 14% (26 patients) had LDL cholesterol levels of > or = 160 mg/dL. Patients were categorized into group 1 if their LDL cholesterol level was < or = 100 mg/dL and were categorized into group 2 if their LDL cholesterol level was > or = 160 mg/dL. In group 2, 92% of patients were placed on a statin medication. By 1 year, the mean LDL cholesterol level had decreased from 188 to 106 mg/dL. The rate of coronary artery bypass graft and percutaneous coronary intervention procedures was similar between groups. Hospital readmission rates (43.4% vs 50%, respectively) and 1-year mortality rates (9% vs 8%, respectively) were not different between groups group 1 and 2.

CONCLUSIONS

Young adults experiencing acute MIs typically have acceptable cholesterol levels (ie, < or = 130 mg/dL) or optimal values (ie, < or = 100 mg/dL). In those patients with abnormal cholesterol levels, a combined strategy of aggressive intervention and adherence to secondary prevention protocols including lipid control is successful in improving outcomes.

Assessing patients with possible heart disease using scores

Multivariable analysis of clinical and exercise test data has the potential to become a useful tool for assisting in the diagnosis of coronary artery disease, assessing prognosis, and reducing the cost of evaluating patients with suspected coronary disease. Since general practitioners are functioning as gatekeepers and decide which patients must be referred to the cardiologist, they need to use the basic tools they have available (i.e. history, physical examination and the exercise test), in an optimal fashion. Scores derived from multivariable statistical techniques considering clinical and exercise data have demonstrated superior discriminating power compared with simple classification of the ST response. In addition, by stratifying patients as to probability of disease and prognosis, they provide a management strategy. While computers, as part of information management systems, can run complicated equations and derive these scores, physicians are reluctant to trust them. Thus, these scores have been represented as nomograms or simple additive tables so physicians are comfortable with their application. Their results have also been compared with physician judgment and found to estimate the presence of coronary disease and prognosis as well as expert cardiologists and often better than nonspecialists. However, the discriminating power of specific variables from the medical history and exercise test remains unclear because of inadequate study design and differences in study populations. Should expired gases be substituted for estimated metabolic equivalents (METs)? Should ST/heart rate (HR) index be used instead of putting these measurements separately into the models? Should right-sided chest leads and HR in recovery be considered? There is a need for further evaluation of these routinely obtained variables to improve the accuracy of prediction algorithms especially in women. The portability and reliability of these equations must be demonstrated since access to specialised care must be safe-guarded. Hopefully, sequential assessment of the clinical and exercise test data and application of the newer generation of multivariable equations can empower the clinician to assure the cardiac patient access to appropriate and cost-effective cardiological care.

Population-based screening with the Coronary Heart Disease Risk Factor Calculator

Data from the Framingham Heart Study and risk-appraisal models were used to develop a Coronary Heart Disease (CHD) Risk Factor Calculator for early identification of high-risk individuals. The Calculator was tested at an employee health fair for a large northeastern US corporation. Of the 590 employees who registered for cholesterol screening, 514 had their CHD risk calculated, and 134 (26.1%) of this group had a relative risk greater than 2. Elevated risk increased with age, ranging from 26.2% of those younger than 35 years to 75% of the over-64 group. Of special concern was the percentage of individuals below 45 years of age whose relative risk of CHD in the next 10 years was more than twice that of coevals with standard risk. The program also estimates and visually demonstrates possible benefits of interventions, allows monitoring of progress, and serves as an educational aid to motivate behavior modification. In this test, the software functioned as designed, and graphic demonstration of individual risk estimations appeared to motivate several participants to seek medical follow-up.

Global risk assessment for lipid therapy to prevent coronary heart disease

Randomized clinical trials have established that lipid- lowering pharmacologic therapy can substantially reduce morbidity and mortality in patients with known coronary artery disease (CAD). Researchers are now working to define the role of lipid-lowering agents in the primary prevention of CAD to extend their benefit to patients at increased risk for future coronary events. The risk assessment models presently used for secondary prevention are not sufficient to identify high-risk, asymptomatic patients. Building on the accumulated data about the physiologic mechanisms and metabolic factors that contribute to CAD, novel serum markers and diagnostic tests are being critically studied to gauge their utility for the assessment of high-risk patients and occult vascular disease. New risk prediction models that combine traditional risk factors for CAD with the prudent use of new screening methods will allow clinicians to target proven risk reduction therapies at high-risk patients before they experience a cardiac event.