Selected Presentations of Interest from AHA 2007

Table of Contents:

No Change in Rate of Occurrence of Acute Myocardial Infarction Among Young Individuals Continuous Increase in Prevalence of Hypertension in USA in the Last Decade High Levels of Physical Activity is Associated with Exceptional Longevity High Discontinuation Observed Among Statin Users Coronary Artery Calcium Predicts Heart Disease in Vulnerable Asymptomatic Young Men Considered Low Risk by Framingham Risk Score SHAPE Guidelines Identify High Risk Individuals more Accurately than Framingham Score Based CHD Risk Assessment Increased Burden of Coronary Artery Calcium Scores is a Strong Predictor of CHD Among Those with Metabolic Syndrome as Well Diabetic Mellitus Improved CHD Risk Prediction with Carotid IMT Among Women Underestimated by Framingham Risk Score Absence of Absent Coronary Artery Calcium and Carotid Plaque is a Powerful Predictor of Absence of Coronary Heart Disease. Peripheral Arterial Disease Associated with High All Cause Mortality

No Change in Rate of Occurrence of Acute Myocardial Infarction Among Young Individuals Wilson AC et al, UNDMJ Robert Wood Johnson Med School   Aim: To assess the trend of acute myocardial infarction in the last 2 decades Methods: The study used the New Jersey statewide myocardial infarction data acquisition system to assess the rates of acute infarction hospitalization across different age groups from 1986-89 to 2000-04 Results: A overall reduction in acute myocardial infarction rates were assessed over time More reduction was observed in men (31%) compared to in women (24%) Major reduction in acute MI cases were seen in those aged 60-85 years However, no improvement in heart rate incidence was reported among the young (<60 years). On the other hand an increase in acute MI was seen in those ≥85 years of age (16% women & 11% in men)  SHAPE Perspective: The annual occurrence of new events from heart disease has been stable in the last 15 years and improvement in CHD prevention has been mainly limited to those 60-85 years of age Primary prevention based on risk factor assessment has fared poorly in reducing the risk of acute myocardial infarction among high risk young individuals, especially women. Top   Continuous Increase in Prevalence of Hypertension in USA in the Last Decade Finkelstein J et al, University of Maryland Aim: The aim of the study assessed the trends related to presence of hypertension prevalence among US Population Methods: The authors assessed the national health interview survey (NHIS) from 1997-2005 and identified the rate of presence of hypertension in a randomly selected portion of US population Results: The prevalence of hypertension was 19.1% in 1997 in USA; and this rose to 22.4% in 2004 Across the 9 year span the adjusted prevalence rose to 17% SHAPE Perspective: Hypertension is among the leading cause of cardiovascular disease and death worldwide with significant evidence that good control is associated with marked reduction in risk of heart disease. The study's findings suggest that more aggressive preventive efforts are required to curb the rising increase of hypertension and call for more aggressive screening and treatment of these vulnerable patients.  Top   High Levels of Physical Activity is Associated with Exceptional Longevity Cheng S et al, Brigham & Women Hospital Boston MA Aim: To assess whether improved physical activity results in increased life span. Methods: In a prospective study of over 2000 physicians, the authors assessed the relationship of longevity defined as living over 90 years of age with leisure time exercise. Results: Nearly 1/3 of this cohort lived over 90 years of age (36%). As compared to those with sedentary life style those participating in any regular exercise had at least 2 years more life expectancy at age 65 years (22 vs. 20 years, p<0.0001). Those exercising regularly were significantly less likely to die in the follow-up compared to those reported a sedentary lifestyle, even after taking into account heart disease risk factors. SHAPE Perspective: In recent years, a significant proportion of adult population in both developing and developed world is likely to lead a sedentary life style. The findings of this study demonstrate that even in the presence of cardiovascular risk factors, indulging in regular exercise results in better survival and longevity. Significant advocacy is needed on part of health care professionals to encourage the public to increase their adherence to regular exercise programs to reduce risk of future heart diseases. Top   High Discontinuation Observed Among Statin Users Davidson M et al, Radiant Research Inc, Chicago, IL Aim: To assess the rate of statin continuation as well as factors associated with increased/reduced adherence Methods: Using a retrospective cohort study design, prescription records from the pharmacy claim database of a large national retail pharmacy chain over period of 6 months and was followed for 1 year. Results: More than 700,000 individuals were studied. Discontinuation of statin increased by the time of follow-up (28% at 3 months, 41% at 6 months and 59% at 1 year). Risk factors for discontinuation were a) those on higher dose, b) those who paid high co-payments & c) those that speak Spanish Factors associated with likelihood of continuation were a) those who used the internet, b) those that had hypertension and/or c) CHD. SHAPE Perspective: Statins and lipid lowering therapy are the main stay of reducing CHD events in high risk populations. In spite of well documented effect of CHD, the rates of continuation as well prescription rates remain low in high risk individuals. This very large study supports the fact that more than 50% of statin users discontinue its use within one year. Among major risk factors are high doses, socioeconomic issues and ethnic barriers. It is imperative that policy makers target these issues in order to improve compliance of these potentially live saving therapies. Top   Coronary Artery Calcium Predicts Heart Disease in Vulnerable Asymptomatic Young Men Considered Low Risk by Framingham Risk Score Taylor A et al, Walter Reed Army Medical Center, Washington DC Aim: The study was aimed to assess whether a higher coronary artery calcium (CAC) scores can high identify young men at risk of coronary heart disease (CHD) at low FRS Methods: The study population consist of 1624 young men (mean age 42 years) free of CHD followed for 5 and half years. CAC by non contrast CT and FRS were calculated in all individuals. Results: This was a very low risk group as considered by current risk stratification methods (FRS=4.6%) 22% men had CAC at baseline In the follow up duration 22 men suffered a CHD event, of which majority were considered low risk (FRS<10%) Presence of any CAC was associated with six fold higher risk of a hard CHD event (hazard ratio: 6.1; 95% CI: 2.6-14.5, p<0.0001) SHAPE Perspective: Presence of CAC even in apparently health and low risk men per current guidelines had a significant risk of CAC. According to AHA guidelines, CAC testing should be limited to those with at least 10 year risk of CHD of 10-20% by FRS, which would potentially miss these young and high risk vulnerable asymptomatic individuals that may benefit from aggressive preventive strategies. There is an urgent need to expand the scope of atherosclerotic screening eligibility in asymptomatic individuals to detect underlying CHD. Top   SHAPE Guidelines Identify High Risk Individuals more Accurately than Framingham Score Based CHD Risk Assessment Berman DS et al; Cedar Sinai Medical Center, Los Angeles CA Aim: To compare the prevalence of individuals qualifying for lipid lowering management according to Framingham risk score (FRS) and national cholesterol education program (NCEP) vs. Society of Heart Attack Prevention & Eradication (SHAPE) guidelines Methods: This study consisted of asymptomatic individuals 2119 free of CHD who were not currently on any lipid lowering therapy (LLT). All individuals were assessed for eligibility for LLT based on FRS/NCEP as well SHAPE guidelines. Results: One third of the population were considered low risk (33%) by FRS and only 3% were classified as high risk; women were less likely to be in the low risk category. On the other hand CAC was observed in 52% with 8% having very high CAC burden (≥400). Based on FRS, only 26% individuals qualified for LLT as compared to 47% based on SHAPE guidelines. With increasing CAC scores, fewer women qualified for pharmacotherapy according to FRS, whereas more than 90% of women with high CAC scores qualified for LLT. SHAPE Perspective: The finding provide further evidence that FRS appears to significantly underestimate risk in young and women Based on SHAPE guidelines, more individuals with higher CHD risk will qualify for LLT. SHAPE guidelines did not discriminate against high risk women; both men and women with high CAC scores were eligible for LLT Top   Increased Burden of Coronary Artery Calcium Scores is a Strong Predictor of CHD Among Those with Metabolic Syndrome as Well Diabetic Mellitus Malik S et al; University of California, Irving, CA Aim: The study assessed the value of measuring of coronary artery calcium ( CAC) scores in asymptomatic individuals with metabolic syndrome (MS) and diabetes mellitus (DM) beyond current risk stratification methods. Methods: This study consisted of nearly 7000 asymptomatic individuals in one of the largest prospective studies in USA. All individuals underwent Framingham risk score (FRS) assessment as well CAC & carotid IMT testing at baseline. These individuals were followed for nearly 3 years for the occurrence of cardiovascular disease (CVD) as well coronary heart disease (CHD) events. Results: Overall 29% and 15% of study participants had MS & DM, respectively. MS and DM were more likely to have higher CACS and CIMT at baseline. Among individuals with MS with and without DM, a very high CAC score (>400) was associated with a risk of heart disease event of 9-13 fold. In absence of CAC, both MS and DM were not at a higher risk of CVD/CHD event as compared to those without these conditions. SHAPE Perspective: This study provides a strong evidence that CAC can risk stratify even high risk individuals, i.e those with MS and or DM. In presence of a higher CAC burden, these individuals require more aggressive treatment as well frequent evaluation to assess efficacy of these therapeutic regimens. In absence of CAC, these high risk group is not associated with a worse outcome. Atherosclerosis screening is potentially an important tool ot further risk stratifying CHD risk among those with MS as well DM. Top   Improved CHD Risk Prediction with Carotid IMT Among Women Underestimated by Framingham Risk Score Akosah KO et al, University of Virginia Aim: The study aimed to compare the utility of Framingham risk score (FRS) and carotid intimal thickness (CIMT) in predicting CHD in high risk women Methods: 136 young women (<65 years) with no previous and not currently on anti lipid therapy who were scheduled for elective coronary angiography underwent FRS and CIMT assessment. Results: Severe CHD was diagnosed in 39 (28%) women on coronary angiography. Majority of the women (80%) were considered low risk and not eligible for preventive medications by FRS Presence of high CIMT (≥ 1mm) was observed in 2/3 of these women (74%) In 50 months follow-up 6 women had a major cardiovascular event (CVE); no difference was found in FRS among those with and without event. Women with high CIMT were more likely to have CVE compared to those with normal (225 vs. 9%, p=0.046). SHAPE Perspective: Women are historically under diagnosed and treated based on risk factor assessment approach. Majority of women in this study with significant CHD were considered low risk by FRS CIMT testing was able to identify high risk women for heart disease and a normal level was associated with a low cardiovascular disease risk, thus improving on current risk factor based approaches. Top   Absence of Absent Coronary Artery Calcium and Carotid Plaque is a Powerful Predictor of Absence of Coronary Heart Disease Konno K et a, University School of Medicine, Tokyo Japan Aim: To assess the negative predictive value of various non invasive testing for ruling out significant coronary heart disease (CHD). Methods: The study population consisted of 80 patients (mean age 65 years, 51% men) undergoing elective coronary angiography. All the subjects were also assessed for coronary artery calcium (CAC), carotid plaque as well ankle brachial pulse wave velocity (PWV). Significant CHD was defined as reduction in ≥50% diameter of one of the major coronary arteries. Results: CAC was a better predictor of CHD compared to PWV and carotid plaque. None of the study participant with absence of CAC & carotid plaque had significant CHD (negative predictive value of 100%). SHAPE Perspective: The study highlights that a combination of simple and easy to perform non-invasive test can easily rule of significant CHD is high risk individuals and provides support for assessing atherosclerosis in multiple vascular beds. Top   Peripheral Arterial Disease Associated with High All Cause Mortality Diehm C et al, Karlsbad Germany Aim: Identify if presence of peripheral arterial disease (PAD) is associated with reduced survival among elderly individuals. Methods: The study is part of a large prospective cohort in Germany of nearly 7000 patients ≥65 years of age who underwent ankle brachial index (ABI). Relationship of PAD defined as reduced ABI (<0.9) with all cause mortality was studied in a 5 year follow up in this study. Results: At baseline 18% individuals had reduced ABI. In 5 years, 24% and 19% with symptomatic and asymptomatic PAD were dead. As compared only 9% all cause mortality were seen in those with normal ABI. After taking into account all risk factors, PAD was associated with a 40% increase in mortality (hazard ratio: 1.4, 95% CI: 1.3-1.5, p<0.001). SHAPE Perspective: Presence of significant atherosclerosis as determined by a simple test such as ABI improves ability to identify high risk individuals. This data strongly supports the use of ABI in primary care prevention to identify those requiring more aggressive and comprehensive treatment of these vulnerable patients. Top