David M. Mirvis

Postmenopausal estrogen use and coronary atherosclerosis

STUDY OBJECTIVE To determine whether estrogen replacement therapy affects the prevalence of severely obstructive coronary arterial lesions defined by selective coronary arteriography. DESIGN Case-control study. SETTING Large, urban, university-affiliated referral hospital. PATIENTS From a consecutive sample of 6452 women having coronary arteriography between 1972 and 1984, 2188 patients were eligible for study; others were excluded because they were nonmenopausal, had congenital heart defects, valvular heart disorders, primary myocardial disease, or no more than mild to moderate coronary artery disease. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS Hospital nurses routinely obtained medication histories. Staff invasive cardiologists interpreted coronary arteriograms. Clinical, laboratory, and angiographic data were abstracted from the cardiac catheterization reports and entered into a computerized registry. Postmenopausal estrogen use for 1444 cases of coronary artery disease (70% stenosis) was compared to that 744 controls (0% stenosis). The odds ratio estimate of the risk of coronary artery disease for estrogen users relative to the risk of coronary artery disease for nonusers was 0.44 (95% confidence interval, 0.29 to 0.67) after adjustment for age, cigarette smoking, diabetes, cholesterol, and hypertension. Postmenopausal estrogen replacement was a significant independent protective factor for coronary artery disease in a multivariate logistic regression model (P = 0.037). CONCLUSION The data suggest that postmenopausal estrogen treatment reduces the risk for angiographically significant coronary artery disease.

AHA/ACCF/HRS Recommendations for the Standardization and Interpretation of the Electrocardiogram Part V: Electrocardiogram Changes Associated With Cardiac Chamber Hypertrophy: A Scientific Statement From the American Heart Association Electrocardiography and Arrhythmias Committee, Council on Clinical Cardiology; the American College of Cardiology Foundation; and the Heart Rhythm Society: Endorsed by the International Society for Computerized Electrocardiology

This is the sixth and final section of the project to update electrocardiography (ECG) standards and interpretation. The project was initiated by the Council on Clinical Cardiology of the American Heart Association (AHA). The rationale for the project and the process for its implementation were described in a previous publication.1 The ECG is considered the single most important initial clinical test for diagnosing myocardial ischemia and infarction. Its correct interpretation, particularly in the emergency department, is usually the basis for immediate therapeutic interventions and/or subsequent diagnostic tests. The ECG changes that occur in association with acute ischemia and infarction include peaking of the T waves, referred to as hyperacute T-wave changes, ST-segment elevation and/or depression, changes in the QRS complex, and inverted T waves. The ST-segment changes are produced by the flow of currents, referred to as “injury currents,” that are generated by the voltage gradients across the boundary between the ischemic and nonischemic myocardium during the resting and plateau phases of the ventricular action potential, which correspond to the TQ and ST segments of the ECG.2,3 Current guidelines suggest that when these ST-segment shifts reach

Left ventricular hypertrophy: Effect on survival

OBJECTIVES The aim of the study was to determine whether left ventricular hypertrophy has an independent adverse effect on survival. BACKGROUND Left ventricular hypertrophy is considered to be a significant risk factor for coronary heart disease mortality; however, the impact of coexisting coronary artery stenosis on survival statistics is not clear. METHODS The relations among electrocardiographic (ECG) left ventricular hypertrophy, ST-T segment abnormality, coronary artery disease and survival were examined in 18,969 patients undergoing coronary arteriography between 1972 and 1985. Patients were excluded if they underwent coronary revascularization or had unstable angina, rheumatic or congenital heart disease, cardiomyopathy, pericardial disease or ECG changes other than left ventricular hypertrophy or repolarization abnormalities, leaving 4,824 patients for analysis. RESULTS Left ventricular hypertrophy was present in 249 patients, whereas 4,575 were free of left ventricular hypertrophy. Five-year survival was 90.2% in the group without left ventricular hypertrophy and was significantly lower (81.9%, p < 0.001) in the group with left ventricular hypertrophy. Five-year survival was significantly lower in patients with left ventricular hypertrophy, regardless of whether coronary artery disease was present: 84.4% versus 94.5% (p = 0.016) in the absence of coronary artery disease and 81.0% versus 87.7% (p < 0.001) in the presence of coronary artery disease. The presence of ST segment abnormalities was not associated with a significant reduction in survival in patients without coronary disease, although mortality was less in those without ST changes who had coronary disease (p = 0.012). CONCLUSIONS It is concluded that ECG left ventricular hypertrophy has an adverse effect on survival, even in patients who are free of coronary artery disease.

AHA/ACCF/HRS recommendations for the standardization and interpretation of the electrocardiogram: Part V: Electrocardiogram changes associated with cardiac chamber hypertrophy: A scientific statement from the American Heart Association Electrocardiography and Arrhythmias Committee, Council on Clinical Cardiology; The American College of Cardiology Foundation; And the Heart Rhythm Society

The detection and assessment of cardiac chamber hypertrophy has long been an important objective of clinical electrocardiography. Its importance has increased in recent years with the recognition that hypertrophy can be reversed with therapy, and that by doing so, adverse clinical outcomes can be

Variation in utilization of cardiac procedures in the Department of Veterans Affairs health care system: Effect of race

OBJECTIVES Utilization rates for cardiac catheterization and cardiac surgery in the Department of Veterans Affairs (VA) health care system were studied to determine whether racial differences existed in a delivery plan in which access is not determined by patient finances. BACKGROUND Prior studies have demonstrated significant differences in utilization of cardiac diagnostic and therapeutic resources by white and black patients. Reasons for the reduced utilization by black patients include socioeconomic, biologic and sociocultural effects. METHODS Computerized discharge records of 30,300 patients with coronary artery disease and 1,335 patients with valvular heart disease who were discharged from any of 172 VA Medical Centers between October 1, 1990 and September 30, 1991 were studied. RESULTS For patients with coronary artery disease, utilization rates of cardiac catheterization were significantly greater for white patients (503.4 procedures/1,000 patients) than for black patients (433.2/1,000 patients), with a relative odds ratio of 1.33. Rates for surgery (179.0 vs. 124.5/1,000 patients) were also greater for whites than for blacks, with a relative odds ratio of 1.53. For the subset with valve disease, the catheterization rate was significantly greater for whites than for blacks (575.4 vs. 432.6 procedures/1,000 patients), with a relative odds ratio of 1.78. Surgical rates were not significantly different (423.8 vs. 354.6 operations/1,000 patients). Racial differences for both catheterization and surgery varied widely as a function of geographic region and the level of complexity of the local VA facility. CONCLUSIONS Racial differences in resource utilization exist in a health care system in which economic influences are minimized. The pattern of these differences depends on numerous variables and suggests both biologic and sociocultural factors as underlying causes.

Association between the severity of diabetes mellitus and coronary arterial atherosclerosis

The relation between the severity of diabetes mellitus (DM) and the risk of significant coronary artery lesions were studied in 7,655 patients undergoing coronary arteriography for suspected coronary artery disease (CAD) between 1972 and 1982. The principal treatment regimen for DM was used to estimate the severity of DM. DM treated with insulin was defined as the most severe (n = 244), followed by DM treated with oral agents (n = 344) and with diet only (n = 380); 6,687 patients did not have DM. Severity of DM in patients with CAD (70% or greater diameter stenosis) was compared with that in control subjects without CAD (0% stenosis) for each of 9 anatomic locations (proximal, middle and distal portions of right, anterior descending and circumflex coronary arteries) using a retrospective case-control approach. The risk of CAD was highest in patients with DM treated with insulin (odds ratio estimate of the relative risk [OR = 3.0]), followed by patients with DM treated with oral agents (OR = 1.8) and lastly in those treated with diet alone (OR = 1.4). Severity of DM was a significant (p less than 0.05) independent predictor of CAD in a multivariate logistic regression model, whereas age at onset and duration of DM were not. The relative risk of CAD was the same (p greater than 0.05) for each of the 9 coronary segments. The data suggest that the risk of CAD increases with the severity of DM, which was a stronger predictor of CAD than duration of DM.(ABSTRACT TRUNCATED AT 250 WORDS)

Regional blood flow correlates of ST segment depression in tachycardia-induced myocardial ischemia.

Tachycardia produces subendocardial ischemia and ST segment abnormalities after coronary obstruction. To determine whether a quantitative relationship exists between these ST shifts and transmural blood flow, 19 dogs were studied. Coronary obstruction was produced by ameroid constriction of the left circumflex artery, and tachycardia was generated by atrial pacing at 90 to 210 beats/min. ST shifts were studied by body surface isopotential mapping with an 84-electrode torso grid, and blood flow was quantitated by serial radiolabeled microsphere injections. Isopotential maps at each paced rate, 40 msec into the ST segment, were classified as normal or ischemic based on spatial patterns of voltages. Pacing after 3 weeks of ameroid constriction reduced endocardial/epicardial flow ratios in 11 dogs from 1.16 +/- 0.22 at rest to 0.41 +/- 0.18 at 210 beats/min. Abnormal ST depression developed in these dogs at a rate of 184.0 +/- 16.5 beats/min. Endocardial/epicardial ratios with ST depression (0.45 +/- 0.15) were lower than at those without ST depression (1.05 +/- 0.19; p less than .01). Logistic regression analysis demonstrated that ST depression corresponded to an endocardial/epicardial ratio of 0.67 or less (p less than .01). With this model, 95.5% of data sets were correctly classified. Neither heart rate nor perfusion bed size were significant independent predictors of an ischemic electrocardiographic response. The magnitude of abnormal ST segment shift was significantly correlated (r = .87) with the transmural flow ratio. Thus development of electrocardiographic changes indicative of ischemia corresponds to a predictable degree of flow redistribution and the magnitude of the ST shift is correlated with the intensity of the flow abnormality.

Preliminary Evidence for an Emerging Nonmetropolitan Mortality Penalty in the United States

We discovered an emerging non-metropolitan mortality penalty by contrasting 37 years of age-adjusted mortality rates for metropolitan versus nonmetropolitan US counties. During the 1980s, annual metropolitan-nonmetropolitan differences averaged 6.2 excess deaths per 100,000 nonmetropolitan population, or approximately 3600 excess deaths; however, by 2000 to 2004, the difference had increased more than 10 times to average 71.7 excess deaths, or approximately 35,000 excess deaths. We recommend that research be undertaken to evaluate and utilize our preliminary findings of an emerging US nonmetropolitan mortality penalty.

Trends in burnout and related measures of organizational stress among leaders of Department of Veterans Affairs medical centers.

Psychological burnout significantly and detrimentally affects individuals and the organizations for which they work. Leaders with burnout often display characteristics that are the opposite of those required to implement major organizational change. This study was undertaken to assess the level of psychological burnout of leaders of the Department of Veterans Affairs (VA) medical centers during a period of rapid change. The objective was to quantify trends in the level of burnout and associated measures of psychological stress. Surveys of medical center directors, associate medical center directors, and chiefs of staff of each VA medical center were conducted in 1989, 1992, and 1997 to evaluate burnout, role characteristics, and job satisfaction. Burnout was measured using the Maslach Burnout Inventory and scored using the phase model of burnout. Findings demonstrated higher prevalences of more advanced levels of burnout in the 1992 and 1997 surveys than in the 1989 survey. Role clarity, perceived adequacy of resources to complete assigned tasks, and several measures of job satisfaction were lower in the 1997 survey compared to the earlier survey data. Therefore, psychological burnout and other indicators of stress increased during the 1989 to 1997 study period. These findings suggest cause for concern as the largest integrated healthcare system in the United States undertakes major organizational change to meet present and future challenges.

Impact of High-Deductible Health Plans on Health Care Utilization and Costs

BACKGROUND High-deductible health plans (HDHPs) are of high interest to employers, policy makers, and insurers because of potential benefits and risks of this fundamentally new coverage model. OBJECTIVE To investigate the impact of HDHPs on health care utilization and costs in a heterogeneous group of enrollees from a variety of individual and employer-based health plans. DATA Claims and member data from a major insurer and zip code-level census data. STUDY DESIGN Retrospective difference-in-differences analyses were used to examine the impact of HDHP plans. This analytical approach compared changes in utilization and expenditures over time (2007 versus 2005) across the two comparison groups (HDHP switchers versus matched PPO controls). RESULTS In two-part models, HDHP enrollment was associated with reduced emergency room use, increases in prescription medication use, and no change in overall outpatient expenditures. The impact of HDHPs on utilization differed by subgroup. Chronically ill enrollees and those who clearly had a choice of plans were more likely to increase utilization in specific categories after switching to an HDHP plan. CONCLUSIONS Whether HDHPs are associated with lower costs is far from settled. Various subgroups of enrollees may choose HDHPs for different reasons and react differently to plan incentives.