Risk of myocardial infarction and stroke in bipolar disorder: a systematic review and exploratory meta-analysis.

OBJECTIVE: To review the evidence on and estimate the risk of myocardial infarction and stroke in bipolar disorder. METHOD: A systematic search using MEDLINE, EMBASE, PsycINFO, Web of Science, Scopus, Cochrane Database of Systematic Reviews, and bibliographies (1946 - May, 2013) was conducted. Case-control and cohort studies of bipolar disorder patients age 15 or older with myocardial infarction or stroke as outcomes were included. Two independent reviewers extracted data and assessed quality. Estimates of effect were summarized using random-effects meta-analysis. RESULTS: Five cohort studies including 13 115 911 participants (27 092 bipolar) were included. Due to the use of registers, different statistical methods, and inconsistent adjustment for confounders, there was significant methodological heterogeneity among studies. The exploratory meta-analysis yielded no evidence for a significant increase in the risk of myocardial infarction: [relative risk (RR): 1.09, 95% CI 0.96-1.24, P = 0.20; I(2)  = 6%]. While there was evidence of significant study heterogeneity, the risk of stroke in bipolar disorder was significantly increased (RR 1.74, 95% CI 1.29-2.35; P = 0.0003; I(2)  = 83%). CONCLUSION: There may be a differential risk of myocardial infarction and stroke in patients with bipolar disorder. Confidence in these pooled estimates was limited by the small number of studies, significant heterogeneity and dissimilar methodological features.

Do cardiovascular risk factors confer the same risk for cardiovascular outcomes in rheumatoid arthritis patients as in non-rheumatoid arthritis patients?

OBJECTIVE: To compare the frequency of traditional cardiovascular (CV) risk factors in rheumatoid arthritis (RA) compared to non-RA subjects, and examine their impact on the risk of developing selected CV events (myocardial infarction (MI), heart failure (HF) and CV death) in these two groups. METHODS: We examined a population-based incidence cohort of subjects with RA (defined according to the 1987 American College of Rheumatology criteria), and an age- and sex-matched non-RA cohort. All subjects were followed longitudinally through their complete community medical records, until death, migration, or 1 January 2001. Clinical CV risk factors and outcomes were defined using validated criteria. The chi2 test was used to compare the frequency of each CV risk factor at baseline. Person-years methods were used to estimate the rate of occurrence of each CV risk factor during follow-up. Cox models were used to examine the influence of CV risk factors on the development of CV outcomes. RESULTS: A total of 603 RA and 603 non-RA subjects (73% female; mean age 58 years) were followed for a mean of 15 and 17 years (total: 8842 and 10,101 person-years), respectively. At baseline, RA subjects were significantly more likely to be former or current smokers when compared to non-RA subjects (p<0.001). Male gender, smoking, and personal cardiac history had weaker associations with CV events among RA subjects, compared to non-RA subjects. There was no significant difference between RA and non-RA subjects in the risk imparted with respect to the other CV risk factors (ie, family cardiac history, hypertension, dyslipidaemia, body mass index, or diabetes mellitus). CONCLUSION: While some traditional CV risk factors imparted similar risk among RA compared with non-RA subjects, others (ie, male gender, smoking and personal cardiac history) imparted significantly less risk for the development of CV disease. These differences in the overall impact of traditional CV risk factors suggest that strategies to prevent CV disease and mortality focused solely on controlling traditional CV risk factors may be relatively less beneficial in RA subjects than in the general population. Further research is needed to determine optimal approaches to reducing CV morbidity and mortality in persons with RA.

Patient-Centered Network of Learning Health Systems: Developing a resource for clinical translational research.

INTRODUCTION: The Learning Health System Network clinical data research network includes academic medical centers, health-care systems, public health departments, and health plans, and is designed to facilitate outcomes research, pragmatic trials, comparative effectiveness research, and evaluation of population health interventions. METHODS: The Learning Health System Network is 1 of 13 clinical data research networks assembled to create, in partnership with 20 patient-powered research networks, a National Patient-Centered Clinical Research Network. RESULTS AND CONCLUSIONS: Herein, we describe the Learning Health System Network as an emerging resource for translational research, providing details on the governance and organizational structure of the network, the key milestones of the current funding period, and challenges and opportunities for collaborative science leveraging the network.

Severe aortic stenosis with low transvalvular gradient and severe left ventricular dysfunction:result of aortic valve replacement in 52 patients.

BACKGROUND: The outcome of aortic valve replacement in patients with severe aortic stenosis, low transvalvular gradient, and severe left ventricular dysfunction is not well known. METHODS AND RESULTS: Between 1985 and 1995, 52 patients with left ventricular ejection fraction (EF) < or =35% and aortic stenosis with transvalvular mean gradient <30 mm Hg underwent aortic valve replacement. The mean (+/-SD) preoperative characteristics included EF, 26+/-8%; aortic valve mean gradient, 23+/-4 mm Hg; aortic valve area, 0.7+/-0.2 cm(2); and cardiac output, 3.7+/-1.2 L/min. Simultaneous coronary artery bypass graft surgery was performed in 32 patients (62%). Perioperative (30-day) mortality was 21% (11 of 52 patients). Ten additional patients died during follow-up. Advanced age (P=0.048) and small aortic prosthesis size (P=0.03) were significant predictors of hospital mortality by univariate analysis. By multivariate analysis, the only predictor of surgical mortality was smaller prosthesis size. The only predictor of postoperative survival was improvement in postoperative functional class (P=0.04). Postoperative functional improvement occurred in most patients. Postoperative EF was assessed in 93% of survivors; 74% demonstrated improvement. Positive change in EF was related to smaller preoperative aortic valve area and female sex. CONCLUSIONS: Despite severe left ventricular dysfunction, low transvalvular mean gradient, and increased operative mortality, aortic valve replacement was associated with improved functional status. Postoperative survival was related to younger patient age and larger aortic prosthesis size, and medium-term survival was related to improved postoperative functional class.

Identification of multivessel coronary artery disease by exercise echocardiography.

OBJECTIVES: This study examined the ability of exercise echocardiography to identify multivessel coronary artery disease and ascertain its incremental value when combined with clinical and exercise test variables. BACKGROUND: Although exercise echocardiography has been shown to be accurate for the detection of coronary artery disease, little is known about its utility for identifying multivessel involvement, and its incremental value when combined with clinical and exercise test variables has not been studied. METHODS: One hundred fifty consecutive patients were selected on the basis of having had an exercise echocardiographic and a coronary angiographic study within 6 months without any revascularization procedure. Significant coronary artery disease (> or = 50% diameter stenosis in any major coronary artery) was present in 117 patients, and multivessel (two- or three-vessel) disease was present in 90 patients. The exercise echocardiographic studies were reviewed by an experienced observer unaware of the results of the coronary angiogram. RESULTS: The overall sensitivity and specificity of exercise echocardiography for the identification of multivessel disease were 73% and 70%, respectively. A stepwise logistic regression analysis identified the number of abnormal regions on the postexercise images as the strongest independent predictor of multivessel disease; also significant were a history of myocardial infarction and ST segment depression of at least 2 mm on the peak exercise electrocardiogram. CONCLUSIONS: Exercise echocardiography adds independent and incremental information to clinical and exercise test variables for identifying multivessel coronary artery disease.

Paradoxical sinus deceleration during dobutamine stress echocardiography: description and angiographic correlation.

OBJECTIVES: This report characterizes the paradoxical sinus deceleration occasionally observed during dobutamine stress testing and determines its relation to myocardial ischemia. BACKGROUND: Dobutamine stress echocardiography is widely accepted as a noninvasive tool for evaluating coronary artery disease. With infusion of dobutamine, there is typically a dose-dependent increase in heart rate. However, in some patients, a paradoxical decrease in heart rate has been observed during high dose dobutamine infusion. METHODS: In 181 consecutive patients undergoing both dobutamine stress echocardiography and coronary angiography, electrocardiographic (ECG) data collected during dobutamine infusion were reviewed to identify patients with a decrease in heart rate. The clinical, stress echocardiographic, hemodynamic and angiographic correlates of patients with a decrease in heart rate were reviewed. RESULTS: A decrease in heart rate ranging from 7 to 64 beats/min occurred during high dose dobutamine infusion in 14 patients (8%, 95% confidence interval [CI] 6% to 10%), including 3 in whom a junctional rhythm developed. The decrease was sudden in five patients (36%, 95% CI 13% to 65%) and gradual in nine (64%, 95% CI 35% to 87%). A decrease in blood pressure (12 patients [86%], 95% CI 57% to 98%) with simultaneous chest pain (7 patients [50%], 95% CI 23% to 77%) and nausea (5 patients [36%], 95% CI 13% to 65%) was common. Significant coronary artery disease (> or = 50% diameter stenosis) was present in 8 (57%) of 14 patients (95% CI 29% to 82%). Two patients (14%, 95% CI 2% to 43%) had no clinical, ECG or echocardiographic evidence of ischemia and no significant coronary artery disease by angiography. There was no increased incidence of right coronary artery stenosis in patients with paradoxical sinus deceleration. CONCLUSIONS: Paradoxical sinus deceleration occurs in 8% of patients during dobutamine stress testing. Although most often observed in patients with coronary artery disease, it can occur in the absence of ischemia and coronary artery disease, and in some patients may be due to a vasodepressor reflex.

Comparison of ischemic response during exercise and dobutamine echocardiography in patients with left main coronary artery disease.

OBJECTIVES: This study sought to compare manifestations of myocardial ischemia evoked by exercise and dobutamine echocardiography in patients with left main coronary artery disease. BACKGROUND: During exercise testing, left ventricular cavity dilation, marked ST segment depression and blood pressure decrease indicate severe coronary artery disease. Whether these signs are comparably evoked by dobutamine echocardiography has not been described. METHODS: Fifty-four patients who underwent stress echocardiography (36 exercise, 18 dobutamine) and coronary angiography showing > or = 50% left main stenosis were analyzed. Electrocardiographic and blood pressure changes, symptoms, wall motion score indexes and sensitivity for coronary artery disease were compared. In 47 patients, the left ventricular endocardium was traced to quantify volumes and ejection fraction. RESULTS: Stress-induced regional wall motion abnormalities developed in 91% of patients; this was not different on exercise (89%) or dobutamine echocardiography (94%). Rate-pressure product and wall motion score index, similar at rest, tended to be higher after exercise than after dobutamine stress (p = 0.07 and p = 0.05, respectively). ST segment depression > or = 1 mm was more common with exercise (p = 0.005). Ejection fraction and end-systolic and end-diastolic volume indexes were comparable at rest in both groups. With exercise, ejection fraction decreased in 87% of patients, and end-systolic and end-diastolic volume indexes increased in 80%. In contrast, with dobutamine, decreased ejection fraction and increased volume indexes were infrequent. Ejection fraction was lower ([mean +/- SD] 45 +/- 19% vs. 54 +/- 12%, p = 0.007) and end-diastolic (69 +/- 26 vs. 50 +/- 17 ml/m2, p =0.02) and end-systolic (39 +/- 20 vs. 24 +/- 13 ml/m2, p = 0.02) volume indexes were higher after exercise than after dobutamine stress. CONCLUSIONS: On the basis of changes in regional wall motion both dobutamine and exercise echocardiography have a comparable high sensitivity in diagnosing myocardial ischemia in left main coronary artery disease. However, conventional signs of severe myocardial ischemia, including left ventricular cavity dilation and marked ST segment depression, occur more often with exercise than with dobutamine echocardiography.

Atropine augmentation in dobutamine stress echocardiography: role and incremental value in a clinical practice setting.

OBJECTIVES: This study sought to evaluate the role and incremental value of atropine in a large patient group undergoing dobutamine stress echocardiography. BACKGROUND: The use of atropine to potentiate dobutamine stress is not standard practice. Although the utility of atropine has been described, data on its incremental value remain limited and do not exist for a routine clinical practice setting. METHODS: Dobutamine stress echocardiography was performed in 1,171 patients with use of a standard protocol. Atropine (maximal dose 2.0 mg) was given to 299 patients (26%) who did not attain target heart rate. Coronary angiography was performed in 183 patients (46 received atropine), 148 of whom were found to have significant coronary artery disease (> or = 70% diameter stenosis in a major epicardial vessel, > or = 50% stenosis for left main coronary artery disease). All tests were reviewed independently by experienced observers. RESULTS: There were no major adverse events. Patients receiving atropine had a lower rest heart rate (65 vs. 74 beats/min, p < 0.0001) and more often received beta-adrenergic blocking agents (49% vs. 14%, p < 0.0001). Of 444 patients in whom stress-induced ischemia developed, 70 (16%) required atropine before ischemia became evident. Sensitivity for detection of significant coronary artery disease was 90% with dobutamine alone and 95% after the addition of atropine. In 66 patients with normal wall motion at rest, test sensitivity was 65% before and 84% after atropine was given. Atropine use did not compromise test specificity. New diagnostic information was obtained in 20 (50%) of 40 patients with angiographic coronary artery disease given atropine. Proportionately more patients with single-vessel disease required atropine before an ischemic response was observed; this effect appeared related to the higher ischemic threshold in these patients. CONCLUSIONS: Augmentation of heart rate had a modest influence on the overall diagnostic sensitivity of dobutamine stress echocardiography in our study cohort. However, it was particularly helpful in patients receiving beta-blockers and those with milder coronary disease. Despite the use of > or = 1 mg of atropine in some patients, this incremental value was not achieved at the expense of safety.

Assessment of cardiac risk before nonvascular surgery: dobutamine stress echocardiography in 530 patients.

OBJECTIVE: This study evaluated the incremental value of dobutamine stress echocardiography (DSE) for assessment of cardiac risk before nonvascular surgery. BACKGROUND: Limited information exists regarding the preoperative assessment of cardiac risk in patients with known or suspected coronary artery disease who are to undergo nonvascular surgery. METHODS: All patients (303 men, 227 women) who underwent DSE before nonvascular surgery and did not sustain an intervening event (coronary revascularization or cardiac event) were studied. Clinical, electrocardiographic and rest and stress echocardiographic variables were evaluated to identify predictors of postoperative cardiac events. RESULTS: Events occurred in 6% of patients: 1 cardiac death and 31 nonfatal myocardial infarctions. All of these patients had inducible ischemia on DSE (sensitivity 100%, specificity 63%). Multivariate predictors of postoperative events in patients with ischemia were history of congestive heart failure (p = 0.006; odds ratio = 4.66; confidence interval 1.55 to 14.02) and ischemic threshold less than 60% of age-predicted maximal heart rate (p = 0.0001; odds ratio 7.002; confidence interval 2.79 to 17.61). Clinical variables of Eagle's index identified 21% of patients as low, 68% as intermediate and 11% as high risk preoperatively; the postoperative event rates were 3%, 6%, and 14%, respectively. Dobutamine stress echocardiography identified 60% of patients as low (no ischemia), 32% as intermediate (ischemic threshold 60% or more) and 8% as high risk (ischemic threshold < 60%); postoperative event rates were 0%, 9% and 43%, respectively. CONCLUSIONS: In this population of patients with known or suspected coronary artery disease evaluated before nonvascular surgery, DSE had incremental value over clinical, electrocardiographic and rest echocardiographic variables for identifying patients at low, intermediate and high risk for postoperative cardiac events. Ischemia occurring at less than 60% of age-predicted maximal heart rate identified patients at highest risk.

Gender differences in use of stress testing and coronary heart disease mortality: a population-based study in Olmsted County, Minnesota.

OBJECTIVES: We sought to examine the utilization of exercise stress testing in relation to age and gender in a population-based setting. BACKGROUND: The utilization of noninvasive procedures has been shown to be associated with the subsequent use of invasive procedures. Yet, there are no population-based data on the utilization of stress testing; in particular, although gender differences in the use of invasive procedures have been reported, the use of noninvasive procedures has not been examined in relation to gender. METHODS: In Olmsted County, Minnesota, passive surveillance of the medical care of the community is provided through the Rochester Epidemiology Project. A population-based cohort of Olmsted County residents undergoing exercise tests was identified. The medical records of residents with prevalent and incident exercise tests in 1987 and 1988 were reviewed. For persons with an initial test (incidence cohort), data on clinical presentation, test indications and results were abstracted. Stress test utilization rates were calculated, and crude rates were directly adjusted to the age distribution of the 1980 U.S. population. To help interpret patterns of use at the population level, coronary heart disease mortality rates (International Classification of Diseases, 9th revision, codes 410 to 414) were calculated (crude and directly adjusted to the overall age distribution of the 1980 U.S. population) and used as an indicator of coronary disease burden. RESULTS: A total of 2,624 tests were performed. The crude utilization rate (per 100,000) was 1,888 for men and 703 for women (rate ratio for men over women 2.7, 95% confidence interval [CI] 2.5 to 2.9); it remained significantly higher in men across all age strata. The crude incidence rate (per 100,000) of initial stress tests was 1,112 for men and 517 for women (rate ratio 2.2, 95% CI 1.9 to 2.4). For both men and women, the incidence increased with age; however, incidence remained lower in women in all age strata. At the time that they underwent an initial test, women were more symptomatic and had poorer exercise performance than men. The rate ratio of men over women for coronary heart disease mortality was 1.1 (95% CI 0.9 to 1.2). The age-adjusted rate ratios for stress test utilization were 2.8 (95% CI 2.5 to 3.0), and that for coronary heart disease mortality was 1.9 (95% CI 1.7 to 2.2). CONCLUSIONS: These population-based data show that during the study period, the utilization of stress testing in Olmsted County was lower in women than in men. Women in the incidence cohort were older and more symptomatic and had poorer exercise performance than men. Such differences should be considered when examining the utilization of subsequent invasive procedures according to gender.

Prognostic value of exercise echocardiography in 2,632 patients > or = 65 years of age.

OBJECTIVES: We sought to determine the prognostic value of exercise echocardiography in the elderly. BACKGROUND: Limited data exist regarding the prognostic value of exercise testing in the elderly, a population which may be less able to exercise and is at increased risk of cardiac death. METHODS: Follow-up (2.9 +/- 1.7 years) was obtained in 2,632 patients > or = 65 years who underwent exercise echocardiography. RESULTS: There were 1,488 (56%) men and 1,144 (44%) women (age 72 +/- 5 years). The rest ejection fraction was 56 +/- 9%. Rest wall motion abnormalities were present in 935 patients (36%). The mean work load was 7.7 +/- 2.3 metabolic equivalents (METs) for men and 6.5 +/- 1.9 METs for women. New or worsening wall motion abnormalities developed with stress in 1,082 patients (41%). Cardiac events included cardiac death in 68 patients and nonfatal myocardial infarction in 80 patients. The addition of the exercise electrocardiogram to the clinical and rest echocardiographic model provided incremental information in predicting both cardiac events (chi-square = 77 to chi-square = 86, p = 0.003) and cardiac death (chi-square = 71 to chi-square = 86, p < 0.0001). The addition of exercise echocardiographic variables, especially the change in left ventricular end-systolic volume with exercise and the exercise ejection fraction, further improved the model in terms of predicting cardiac events (chi-square = 86 to chi-square = 108, p < 0.0001) and cardiac death (chi-square = 86 to chi-square = 99, p = 0.004). CONCLUSIONS: Exercise echocardiography provides incremental prognostic information in patients > or = 65 years of age. The best model included clinical, exercise testing and exercise echocardiographic variables.

Gender differences and temporal trends in clinical characteristics, stress test results and use of invasive procedures in patients undergoing evaluation for coronary artery disease.

OBJECTIVES: This study examined gender differences and temporal changes in the clinical characteristics of patients referred for nuclear stress imaging, their imaging results and subsequent utilization of coronary angiography and revascularization. BACKGROUND: Gender bias may influence resource utilization in patients with coronary artery disease (CAD). No study has analyzed gender differences and time trends in patients referred for noninvasive testing and subsequent use of invasive procedures. METHODS: Between January 1986 and December 1995, 14,499 patients (5,910 women and 8,589 men) without established CAD underwent stress myocardial perfusion imaging. The clinical characteristics, imaging results, coronary angiograms and revascularization outcomes were compared in women and men over time. RESULTS: The mean pretest probability of CAD was lower in women (45%) than in men (70%) (p < 0.001). More women (69%) than men (42%) had normal nuclear images (p < 0.001). Men (17%) were more likely than women (8%) to undergo coronary angiography (p < 0.001). Male gender was independently associated with referral for coronary angiography (multivariate model: chi-square = 16, p < 0.001) but was considerably weaker than the imaging variables (summed reversibility score: chi-square = 273, p < 0.001). Revascularization was performed in more men (46% of the population undergoing angiography) than women (39%) (p = 0.01), but gender was not independently associated with referral to revascularization. There were no significant differences in clinical, imaging or invasive variables between the genders over time. CONCLUSIONS: There was little evidence for a bias against women in this study. Women were somewhat less likely to undergo coronary angiography but were referred for stress perfusion imaging more liberally. Practice patterns remained constant over this 10-year period.

Influence of coronary artery disease on morbidity and mortality after abdominal aortic aneurysmectomy: a population-based study, 1971-1987.

The prognostic importance of coronary artery disease at the time of elective abdominal aortic aneurysmectomy was evaluated among 131 residents of Olmsted County, Minnesota who underwent elective aneurysmectomy from 1971 to 1987 and were followed up to 1988 for death and cardiac events (cardiac death, myocardial infarction, coronary bypass surgery and angioplasty). Before aneurysmectomy, 75 patients (Group 1) had no clinically recognized coronary disease, 47 patients (Group 2) had suspected or overt uncorrected coronary artery disease (history of prior myocardial infarction, angina or a positive stress test) and 9 patients (Group 3) had undergone coronary artery bypass grafting or coronary angioplasty. The 30 day operative mortality rate was 3% (2 of 75) in Group 1 and 9% (4 of 47) in Group 2 (p = 0.15). According to Kaplan-Meier analysis, estimated survival 8 years after aneurysmectomy was 59% (expected rate 68%, p = 0.29) in Group 1 versus 34% (expected rate 61%, p = 0.01) in Group 2. The cumulative incidence rate of cardiac events at 8 years was 15% and 61%, respectively, for patients without and with suspected/overt coronary artery disease (p less than 0.01). Using multivariable proportional hazards analysis, uncorrected coronary artery disease was associated with a nearly twofold increased risk of death (hazard ratio 1.79, 95% confidence interval 1.06 to 3.00) and a fourfold increased risk of cardiac events (hazard ratio 3.71, 95% confidence interval 1.79 to 7.69). These population-based data support an aggressive life-long approach to the management of coronary artery disease in patients undergoing abdominal aortic aneurysmectomy.

Outcome after normal exercise echocardiography and predictors of subsequent cardiac events: follow-up of 1,325 patients.

OBJECTIVES: This study sought to examine the outcome of a large group of patients after normal exercise echocardiography and to identify potential predictors of subsequent cardiac events. BACKGROUND: Earlier studies suggested that prognosis after normal exercise echocardiography is favorable, with a low subsequent cardiac event rate. These studies involved a small number of patients and did not have sufficient statistical power to stratify risk. METHODS: The outcomes of 1,325 patients who had normal exercise echocardiograms were examined. End points were overall and cardiac event-free survival. Cardiac events were defined as cardiac death, nonfatal myocardial infarction and coronary revascularization. Patient characteristics were analyzed in relation to time to first cardiac event in a univariate and multivariate manner to determine which, if any, were associated with an increased hazard of subsequent cardiac events. RESULTS: Overall survival of the study group was significantly better than that of an age- and gender-matched group obtained from life tables (p < 0.0001). The cardiac event-free survival rates at 1, 2 and 3 years were 99.2%, 97.8% and 97.4%, respectively. The cardiac event rate per person-year of follow-up was 0.9%. Subgroups with an intermediate or high pretest probability of having coronary artery disease also had low cardiac event rates. Multivariate predictors of subsequent cardiac events were angina during treadmill exercise testing (risk ratio [RR] 4.1, 95% confidence interval [CI] 1.5 to 11.0), low work load (defined as < 7 metabolic equivalents [METs] for men and < 5 METs for women; RR 3.2, 95% CI 1.4 to 7.6), echocardiographic left ventricular hypertrophy (RR 2.6, 95% CI 1.1 to 6.3) and advancing age (RR 1.04/year, 95% CI 1.0 to 1.1). CONCLUSIONS: The outcome after normal exercise echocardiography is excellent. Subgroups with an intermediate or high pretest probability of having coronary artery disease also have a favorable prognosis after a normal exercise echocardiogram. Characteristics predictive of subsequent cardiac events (i.e., patient age, work load, angina during exercise testing and echocardiographic left ventricular hypertrophy) should be considered in the clinical interpretation of a normal exercise echocardiogram.

Cardiac rehabilitation after myocardial infarction: a review to understand barriers to participation and potential solutions.

As survival after myocardial infarction (MI) improves, secondary prevention is becoming increasingly important. Cardiac rehabilitation (CR) is one modality for delivery of secondary prevention, whose ultimate goal is to help patients receive appropriate preventive therapies that will help them optimize health and reduce the risk of future cardiac diseases. However, participation rates in CR are less than optimal: in the United States, only 29.5% of MI survivors participated, in Japan 21% of those with acute MI, and in Australia 29% of those eligible were referred, and only 1/3 of those referred acutally attended CR; moreover, there does not appear to be a trend towards increasing participation over time. After reviewing the components of CR and the benefits of participation, this paper will focus on the barriers to participation in CR: from a theoretical framework to consider barriers at patient, provider, health system, and societal levels. We then explore the possible solutions to overcome them and finally propose recommendation for future research.

Time trends in the prevalence of atherosclerosis: a population-based autopsy study.

PURPOSE: Mortality from coronary heart disease is declining but little is known about trends in the prevalence of atherosclerosis. Autopsy rates in Olmsted County, Minnesota, are higher than the national average, offering an opportunity to address this matter. In this study, we determined the prevalence of anatomic coronary disease among autopsied Olmsted County residents and examined the generalizability of these findings. SUBJECTS AND METHODS: Reports of the 2,562 autopsies performed between 1979 and 1994 on Olmsted County residents > or =20 years of age were reviewed for the presence of coronary disease. RESULTS: Among autopsied decedents less than 60 years old at death and among coroner's cases, the prevalence of anatomic coronary disease declined with time (P for trend = 0.05); no trend was detected among older persons or noncoroner's cases. By logistic regression analysis, the crude odds ratio ([OR] per 5 years) for the association between time and anatomic coronary disease was 0.94 (95% confidence interval [CI]: 0.86 to 1.03; P = 0.18]. Age, sex, and antemortem diagnosis of heart disease were also strongly related to the presence of disease. After adjustment for sex and antemortem diagnosis of heart disease, the prevalence of anatomic coronary disease decreased more in younger people than in older people (age 40 years: OR 0.43 [95% CI: 0.24 to 0.80]; age 60 years: OR 0.62 [95% CI: 0.45 to 0.87]; age 80 years: OR 0.89 [95% CI: 0.64 to 1.23]). CONCLUSION: The prevalence of anatomic coronary disease at autopsy decreased between 1979 and 1994, particularly among younger people, supporting the notion that the burden of coronary disease has shifted toward the elderly. These results suggest that the decreased incidence of coronary artery disease has contributed to the recent decrease in coronary mortality, particularly among younger people.

Safety of performing dobutamine stress echocardiography in patients with abdominal aortic aneurysm > or = 4 cm in diameter.

Dobutamine stress echocardiography is frequently used for preoperative assessment of cardiac risk before major vascular surgical procedures. Dobutamine increases myocardial contractility, heart rate, and rate of increase of left ventricular pressure and has a variable effect on blood pressure. These effects could potentially increase the likelihood of rupture of a vascular aneurysm. The safety of performing dobutamine stress echocardiography in patients with vascular aneurysms has not been adequately addressed. Of 1,968 consecutive patients who underwent dobutamine stress echocardiography at our institution, 98 patients with abdominal aortic aneurysms > or = 4 cm in diameter were identified. Records were reviewed to determine whether there was any evidence of aneurysm rupture or adverse vascular events as a result of the stress test. There was no case of aneurysm rupture or hemodynamic instability precipitated by dobutamine stress echocardiography. In addition, dobutamine stress echocardiography that was negative for ischemia identified patients at very low risk of perioperative cardiac events. The positive predictive value of ischemia during dobutamine echocardiography was 29%. Dobutamine stress echocardiography may be performed safely in patients with aortic aneurysms. Precipitation of an aneurysmal complication, including rupture, by the test is unlikely. In addition, preoperative dobutamine stress echocardiography can identify patients at very low risk of perioperative cardiac events.

Assessment of the exercise electrocardiogram in women versus men using tomographic myocardial perfusion imaging as the reference standard.

The exercise electrocardiogram (ECG) is widely believed to be less accurate in women, primarily due to a high prevalence of false-positive tests. The purpose of this study was to examine the relative accuracy of the exercise ECG in women versus men in 8,671 patients (3,213 women, 5,458 men) using myocardial perfusion imaging as the reference standard. More women (14%) than men (10%) had a false-positive ECG (p <0.001), but the absolute difference was relatively small. The false-negative rate was considerably lower in women (17% vs 32%, p <0.001). Compared with men, women had lower test sensitivity (30% vs 42%, p <0.001) and positive predictive value (34% vs 70%, p <0.001) but higher specificity (82% vs 78%, p = 0.002), negative predictive value (78% vs 52%, p <0.001), and accuracy (69% vs 58%, p <0.001). In patients with a false-negative exercise ECG, "high-risk" scans were less prevalent in women (12% vs 19%, p <0.001). In the smaller subset of patients referred for coronary angiography (205 women, 838 men), the false-positive electrocardiographic rate was again higher in women (13% vs 7%, p = 0.003), but neither specificity (69% vs 74%, p = NS) nor accuracy (60% vs 66%, p = NS) was different between the sexes. Thus, the percentage of patients with a false-positive exercise ECG was higher in women than men but low in absolute terms (<15%) for both sexes. Test specificity was not lower in women. These results suggest that gender should not be a major determinant for selecting stress imaging over standard treadmill testing.

Normal stroke volume and cardiac output response during dobutamine stress echocardiography in subjects without left ventricular wall motion abnormalities.

Dobutamine stress echocardiography has become widely utilized for evaluation of coronary artery disease, but the expected responses of stroke volume and cardiac output to the high doses of dobutamine administered in these studies are not known. To determine these responses, stroke volume and cardiac output were measured with 2-dimensional Doppler echocardiography at each stage of dobutamine stress echocardiography and after administration of atropine in 47 patients without resting or inducible wall motion abnormalities. Heart rate increased significantly at each stage of dobutamine infusion and after atropine. Mean blood pressure decreased at the 5 micrograms/kg/min dose, then showed little change. Stroke volume increased 27 +/- 18% from baseline, with significant increases occurring at both the 5 and 10 micrograms/kg/min doses (p < 0.00001). With higher doses of dobutamine, stroke volume tended to plateau or decrease. Mean changes in stroke volume were not significant between the doses of 10, 20, and 30 micrograms/kg/min. The mean change in stroke volume from the 30 to the 40 micrograms/kg/min dose was a significant decrease of 6.3% (p = 0.004); the decrease from the 40 micrograms/kg/min dose to atropine approached statistical significance (p = 0.06). Cardiac output increased throughout dobutamine infusion. Stroke volume during dobutamine stress echocardiography is commonly maximum at a dose of 20 micrograms/kg/min and tends to decline at higher infusion rates. At higher doses, increases in cardiac output are mediated primarily by increases in heart rate.