Recognition, diagnosis and management of obesity after myocardial infarction

Mechanisms of adverse cardiometabolic consequences of obesity

Obesity is an epidemic that threatens the health of millions of people worldwide and is a major risk factor for cardiovascular diseases, hypertension, diabetes, and dyslipidemia. There are multiple and complex mechanisms to explain how obesity can cause cardiovascular disease. In recent years, studies have shown some limitations in the way we currently define obesity and assess adiposity. This review focuses on the mechanisms involved in the cardiometabolic consequences of obesity and on the relationship between obesity and cardiovascular comorbidities, and provides a brief review of the latest studies focused on normal weight obesity and the obesity paradox.

Evaluation of anthropometric indices of patients with left ventricle dysfunction fallowing first acute anterior myocardial infarction

INTRODUCTION

In the current study, we evaluated the effect of anthropometric indices on ejection fraction following first acute anterior myocardial infarction.

METHODS

In an analytic-cross sectional study, 50 patients with acute anterior myocardial infarction and abnormal anthropometric indices (Body Mass Index (BMI) ≥ 30, Waist Hip Ratio (WHR) ≥ 1 and ≥ 0.85 in males and females respectively and Waist Circumference (WC) ≥ 102 cm and ≥ 88 cm in males and females respectively) were recruited as case group and 50 patients with acute anterior myocardial infarction and normal anthropometric indices as control group. Subsequently, the relation between anthropometric indices and left ventricle dysfunction was evaluated and compared between two groups.

RESULTS

77 people of the studied patients were male and 23 female with the mean age of 59± 1.2 years and an age range of 32-90 years. To evaluate the left ventricle function, the mean ejection fraction of the patients was measured as 34.3± 7.2 % and 44.8± 6.3% in patients with abnormal anthropometric indices and patients with normal anthropometric indices respectively (P= 0.0001). Calculation of the correlation coefficient between ejection fraction and BMI, WHR and WC in males and females revealed a moderate reverse (r=-0.521 to r=-0.691) and statistically significant (P= 0.0001) relations which was of more strength in females.

CONCLUSION

Anthropometric indices including BMI and waist circumference influence cardiac function following myocardial infarction.

The impact of obesity on critical care resource use and outcomes

Obese patients in the ICU present unique challenges to the health care team and specific challenges to nurses. This article reviews the science and art of resource use for obese patients in the ICU. Staff nurses and advanced practice nurses can make important contributions in evaluating optimal resource use and improving outcomes in this population of vulnerable patients.

Metabolic syndrome and its components are underdiagnosed in cardiology clinics

BACKGROUND

Although metabolic syndrome (MetS) is an important clinical condition, evidence is scarce on how often doctors successfully diagnose this syndrome.

AIMS

To assess the extent of doctors' diagnosis of MetS and its components in cardiology outpatient setting and whether such diagnosis affects the way patients are counselled on lifestyle modification.

METHODS

This is a multicentre cross-sectional study on randomly selected clinical notes at ambulatory cardiology clinics in three academic centres in the USA. We abstracted data on cardiovascular risk factors, and examined whether doctors documented a diagnosis of MetS and its components.

RESULTS

Of 511 participants who satisfied our inclusion criteria, the MetS was present in 246 participants (48%). The proportions with which a doctor correctly documented diagnoses were: MetS 9.3% (23/246), obesity 60% (119/197), elevated blood pressure 74% (305/412), elevated fasting glucose 17% (49/291), reduced high density lipoprotein cholesterol 10% (18/190) and elevated triglycerides 20% (32/164). This pattern of diagnoses, less frequent with dyslipidaemia and elevated fasting glucose compared with the rest, was persistently observed regardless of sex, age, and presence or absence of MetS. Those diagnosed were more likely to receive a recommendation of weight loss or increase in physical activity than those undiagnosed: 91% (21/23) versus 37% (82/223) for weight loss, and 83% (19/23) versus 26% (58/223) for increase in physical activity (P < 0.001 for both).

CONCLUSIONS

Our data indicate that MetS and its components are commonly underdiagnosed in cardiology outpatient setting. Better diagnosis may lead to better counselling on lifestyle changes and improvement in the quality of care.

Physician diagnosis of overweight status predicts attempted and successful weight loss in patients with cardiovascular disease and central obesity

INTRODUCTION

Despite the association of central obesity with adverse outcomes, most patients with cardiovascular disease (CVD) are unable to successfully lose weight. We undertook this analysis to evaluate the effect of motivational factors, and clinical factors, including physician diagnosis of overweight, on weight loss in patients with CVD and central obesity in the United States.

METHODS AND RESULTS

We used data from the National Health and Nutrition Examination Survey 1999 to 2004. Waist circumference ≥ 102 cm in men and ≥ 88 cm in women were used to classify central obesity. We examined demographic, motivational and clinical determinants of attempted and successful weight loss using multivariable logistic regression. Successful weight loss was defined as ≥ 5% weight loss in the preceding year. There were 907 respondents with CVD and central obesity of which 78% were aware of their overweight status and 80% were desirous to weigh less. Despite this awareness and desire, only 49% of centrally obese adults had attempted weight loss in the last year. Only 62% (n = 584) reported that they had been informed that they were overweight by a physician. On multivariable analysis, physician diagnosis of overweight was a significant predictor of weight loss attempts (OR 2.42, 95% CI 1.44-4.09, P = .006) and successful weight loss (OR 2.70, 95% CI 1.40-5.19, P = .001).

CONCLUSION

In a nationally representative sample of adults with CVD and central obesity, physician diagnosis of overweight status emerged as a significant predictor of attempted and successful weight loss.

Medically diagnosed overweight and weight loss in a US national survey

BACKGROUND

Impact of physician diagnosis of overweight on successful weight loss in community-based patients is not known. We analyzed data from NHANES 1999-04 to assess if self-reported physician diagnosis of overweight was associated with attempted and successful weight loss in the preceding year.

METHODS

We determined if physician-rendered diagnosis of overweight was associated with attempted and successful weight loss in multivariable Poisson regression models that adjusted for age, gender, ethnicity, education, income, insurance status, BMI, central obesity, self-rated health, number of office/emergency room visits, hyperlipidemia, hypertension, diabetes and cardiovascular disease. Successful weight loss was defined as intentional loss of > or = 5% body weight over the last year.

RESULTS

We included 8767 adults with BMI > or = 25 kg/m(2) who met the criteria for this analysis. In multivariate models physician-rendered diagnosis of overweight was associated with attempted weight loss (PrR 1.39; 95% CI, 1.30-1.48) and successful weight loss (PrR 2.09; 95% CI, 1.72-2.55). Female gender, self-rated health, number of office/emergency room visits in preceding year, severity of overweight and presence of overweight-related co-morbidities were all significantly associated with physician diagnosis of overweight.

CONCLUSION

In a nationally representative sample of community dwelling adults, self-reported physician diagnosis of overweight was associated with successful weight loss.

Documentation of body mass index and control of associated risk factors in a large primary care network

BACKGROUND

Body mass index (BMI) will be a reportable health measure in the United States (US) through implementation of Healthcare Effectiveness Data and Information Set (HEDIS) guidelines. We evaluated current documentation of BMI, and documentation and control of associated risk factors by BMI category, based on electronic health records from a 12-clinic primary care network.

METHODS

We conducted a cross-sectional analysis of 79,947 active network patients greater than 18 years of age seen between 7/05 - 12/06. We defined BMI category as normal weight (NW, 18-24.9 kg/m2), overweight (OW, 25-29.9), and obese (OB, >or= 30). We measured documentation (yes/no) and control (above/below) of the following three risk factors: blood pressure (BP)

RESULTS

BMI was documented in 48,376 patients (61%, range 34-94%), distributed as 30% OB, 34% OW, and 36% NW. Documentation of all three risk factors was higher in obesity (OB = 58%, OW = 54%, NW = 41%, p for trend <0.0001), but control of all three was lower (OB = 44%, OW = 49%, NW = 62%, p = 0.0001). The presence of cardiovascular disease (CVD) or diabetes modified some associations with obesity, and OB patients with CVD or diabetes had low rates of control of all three risk factors (CVD: OB = 49%, OW = 50%, NW = 56%; diabetes: OB = 42%, OW = 47%, NW = 48%, p < 0.0001 for adiposity-CVD or diabetes interaction).

CONCLUSIONS

In a large primary care network BMI documentation has been incomplete and for patients with BMI measured, risk factor control has been poorer in obese patients compared with NW, even in those with obesity and CVD or diabetes. Better knowledge of BMI could provide an opportunity for improved quality in obesity care.

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MESH Headings

• Adult
• Body Mass Index
• Cardiovascular Diseases/epidemiology
• Cross-Sectional Studies
• Diabetes Mellitus/epidemiology
• Documentation
• Electronic Health Records
• Female
• Humans
• Male
• Massachusetts/epidemiology
• Middle Aged
• Obesity/prevention & control
• Primary Health Care/organization & administration
• Quality Indicators, Health Care
• Risk Factors

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Grants

• T32 HL007609 NHLBI NIH HHS
• #5 T32 HP11001-19 PHS HHS
• K23 DK067452 NIDDK NIH HHS
• K24 DK080140 NIDDK NIH HHS

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Affiliation(s)

Stephanie A Rose Division of General Internal Medicine, University of Kentucky, 740 South Limestone Street, Kentucky Clinic K507, Lexington, KY 40536, USA
Alexander Turchin Clinical Informatics Research and Development, Harvard University, and Division of Endocrinology, Brigham and Women's Hospital, 221 Longwood Avenue, Boston, MA, 02115, USA
Richard W Grant General Medicine Division, Massachusetts General Hospital, 50 Staniford Street, Boston, MA, 02114, USA
James B Meigs General Medicine Division, Massachusetts General Hospital, 50 Staniford Street, Boston, MA, 02114, USA

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Targeting abdominal obesity in cardiology: can we be effective?

Obesity has reached epidemic proportions in much of the industrialized world, and is also increasing in prevalence in the developing world. In the later decades of the 20th century until present, there have been numerous epidemiological studies reporting the relationship between excess weight and total, or all-cause, mortality. Obesity is associated with a wide variety of comorbidities such as type 2 diabetes, systemic hypertension, cardiovascular disease, certain cancers and sleep apnea, most of which may lead to disability or death. In general, the risk of developing comorbidities such as diabetes and cardiovascular disease rises as body mass index (BMI) increases. Using BMI, an indicator of relative weight for height (kg/m(2)) and a frequently used surrogate for assessing excess body fat, epidemiological studies have found linear, U- or J-shaped relationships between total mortality and BMI. However, obesity is remarkably heterogeneous. Obese patients considered to be 'at risk' are mostly characterized by features associated with the metabolic syndrome. The aim of the present paper is to review the cardiovascular consequences of obesity and to review some of the literature emphasizing why the cardiologist should measure other indices of adiposity in order to refine clinical assessment of obese individuals.

Obesity and age of first non-ST-segment elevation myocardial infarction

OBJECTIVES

Because excess adiposity is one of the most important determinants of adipokines and inflammatory factors associated with coronary plaque rupture, we hypothesized that obesity was associated with myocardial infarction at earlier ages.

BACKGROUND

The developing obesity pandemic of the past 50 years has gained considerable attention as a major public health threat.

METHODS

The CRUSADE (Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes with Early Implementation of the American College of Cardiology/American Heart Association Guidelines) registry was a voluntary observational data collection and quality improvement initiative that began in November 2001, with retrospective data collection from January 2001 to January 2007. The CRUSADE initiative included high-risk patients with unstable angina and non-ST-segment elevation myocardial infarction (NSTEMI). We retrospectively examined, among 189,065 patients with acute coronary syndrome (between January 2001 and September 2006) in the CRUSADE initiative, the relationship of body mass index (BMI) with patient age of first NSTEMI.

RESULTS

A total of 111,847 patients with NSTEMI were included in the final analysis. There was a strong, inverse linear relationship between BMI and earlier age of first NSTEMI. The mean patient ages (+/- SD) of first NSTEMI were 74.6 +/- 14.3 years and 58.7 +/- 12.5 years for the leanest (BMI <or=18.5 kg/m(2)) and most obese (BMI >40.0 kg/m(2)) cohorts, respectively (p < 0.0001). After adjustment for baseline demographic data, cardiac risk factors, and medications, the age of first NSTEMI occurred 3.5, 6.8, 9.4, and 12.0 years earlier with ascending levels of adiposity (BMI 25.1 to 30.0, 30.1 to 35.0, 35.1 to 40.0, and >40.0 kg/m(2), respectively; referent 18.6 to 25.0 kg/m(2)) (p < 0.0001 for each estimate).

CONCLUSIONS

Excess adiposity is strongly related to first NSTEMI occurring prematurely.

Attacking Obesity

For the first time since the Civil War, American life expectancy is projected to decrease, owing to the diseases associated with obesity such as diabetes, ultimately causing cardiovascular death. In the past 30 years, the prevalence of obesity among U.S. adults has doubled, as has the incidence of type 2 diabetes. Enough data. The Surgeon General should attack obesity the same way as smoking in 1964, with: 1) Advisory Council creation of public statements; 2) warning labels and menu information in all restaurants; 3) legislation for tax incentives for industry to promote worksite health; and 4) consideration of taxation of fatty food; the cigarette tax is now 42%. It is abundantly clear that in short order, obesity will kill more people than smoking. The time has come for the country to get serious about obesity and take lessons from our nation's campaign to reduce smoking. As patient advocates, scientists, and medical professionals, cardiologists should appropriately take the lead.

Effect of weight loss on predicted cardiovascular risk: change in cardiac risk after bariatric surgery

OBJECTIVE

Our goal was to assess the effect of bariatric surgery on cardiovascular risk estimations of preventable, long-term adverse outcomes.

RESEARCH METHODS AND PROCEDURES

We performed a population-based, historical cohort study between 1990 and 2003 of 197 consecutive patients from Olmsted County, MN, with Class II to III obesity (defined as BMI > or = 35 kg/m2) treated with Roux-en-Y gastric bypass and 163 non-operative patients assessed in a weight-reduction program. We used the observed change in cardiovascular risk factors and risk models derived from data from the National Health and Nutrition Examination Survey (NHANES) I and the NHANES I Epidemiological Follow-up Study (NHEFS) to calculate the predicted impact on cardiovascular events and mortality for the operative and non-operative groups.

RESULTS

Mean follow-up was 3.3 years. Hypertension, diabetes, and dyslipidemia all improved after bariatric surgery. The estimated 10-year risk for cardiovascular events for the operative group decreased from 37% at baseline to 18% at follow-up, while the estimated risk for the non-operative group did not change from 30% at baseline to 30% at follow-up. Risk modeling to predict 10-year outcomes estimated 4 overall deaths and 16 cardiovascular events prevented by bariatric surgery per 100 patients compared with the non-operative group.

CONCLUSIONS

Bariatric surgery induces an improvement in cardiovascular risk factors in patients with Class II to III obesity. Weight loss predicts a major, 10-year reduction in cardiovascular events and deaths. Bariatric surgery should be considered as an alternative approach to reduce cardiovascular risk in patients with Class II to III obesity.

Association of bodyweight with total mortality and with cardiovascular events in coronary artery disease: a systematic review of cohort studies

BACKGROUND

Studies of the association between obesity, and total mortality and cardiovascular events in patients with coronary artery disease (CAD) have shown contradictory results. We undertook a systematic review to determine the extent and nature of this association.

METHODS

We selected cohort studies that provided risk estimates for total mortality, with or without cardiovascular events, on the basis of bodyweight or obesity measures in patients with CAD, and with at least 6 months' follow-up. CAD was defined as history of percutaneous coronary intervention, coronary artery bypass graft, or myocardial infarction. We obtained risk estimates for five predetermined bodyweight groups: low, normal weight (reference), overweight, obese, and severely obese.

FINDINGS

We found 40 studies with 250,152 patients that had a mean follow-up of 3.8 years. Patients with a low body-mass index (BMI) (ie, <20) had an increased relative risk (RR) for total mortality (RR=1.37 [95% CI 1.32-1.43), and cardiovascular mortality (1.45 [1.16-1.81]), overweight (BMI 25-29.9) had the lowest risk for total mortality (0.87 [0.81-0.94]) and cardiovascular mortality (0.88 [0.75-1.02]) compared with those for people with a normal BMI. Obese patients (BMI 30-35) had no increased risk for total mortality (0.93 [0.85-1.03]) or cardiovascular mortality (0.97 [0.82-1.15]). Patients with severe obesity (> or =35) did not have increased total mortality (1.10 [0.87-1.41]) but they had the highest risk for cardiovascular mortality (1.88 [1.05-3.34]).

INTERPRETATION

The better outcomes for cardiovascular and total mortality seen in the overweight and mildly obese groups could not be explained by adjustment for confounding factors. These findings could be explained by the lack of discriminatory power of BMI to differentiate between body fat and lean mass.

Obesity: a risk factor for acute myocardial infarction with angiographically patent epicardial coronary vessels in an adolescent

OBJECTIVE

Toreport a causal relationship between myocardial infarction (MI) and obesity in an adolescent in the absence of the well-known risk factors for MI.

CASE PRESENTATION AND INTERVENTION

A morbidly obese 17-year-old male, a nonsmoker, nondiabetic and normotensive patient, who sustained acute inferior MI with no family history of coronary artery disease, presented with central chest pain. ECG showed low voltage, normal sinus rhythm and ST segment elevation in the inferior leads; cardiac enzymes were elevated. Screening for ethanol and cocaine were negative. He was admitted to the coronary-care unit as a case of inferior MI with late presentation. Cardiac catheterization revealed patent epicardial coronary arteries; short- and long-term plans for weight reduction and family counseling were started. The hospital stay was uneventful, and the patient was discharged home on the fourth day.

CONCLUSION

Based on clinical and laboratory findings, we assume that the MI might partly be secondary to coronary artery spasm or invisible premature atherosclerotic plaques. Public education and awareness for this complication in a young obese patient are warranted.