Racial and ethnic differences in access to medical care

The authors' review of the health services literature since the release of the landmark Report of the Secretary's Task Force Report of Black and Minority Health in 1985 revealed significant differences in access to medical care by race and ethnicity within certain disease categories and types of health services. The differences are not explained by such factors as socioeconomic status (SES), insurance coverage, stage or severity of disease, comorbidities, type and availability of health care services, and patient preferences. Under certain circumstances when important variables are controlled, racial and ethnic disparities in access are reduced and may disappear. Nonetheless, the literature shows that racial and ethnic disparities persist in significant measure for several disease categories and service types. The complex challenge facing current and future researchers is to understand the basis for such disparities and to determine why disparities are apparent in some but not other disease categories and service types.

Alterations of phasic coronary artery flow velocity in humans during percutaneous coronary angioplasty

BACKGROUND AND OBJECTIVES

Studies using Doppler catheters to assess blood flow velocity and vasodilator reserve in proximal coronary arteries have failed to demonstrate significant improvement immediately after coronary angioplasty. Measurement of blood flow velocity, flow reserve and phasic diastolic/systolic velocity ratio performed distal to a coronary stenosis may provide important information concerning the physiologic significance of coronary artery stenosis. This study was designed to measure these blood flow velocity variables both proximal and distal to a significant coronary artery stenosis in patients undergoing coronary angioplasty.

METHODS

A low profile (0.018-in.) (0.046-cm) Doppler angioplasty guide wire capable of providing spectral flow velocity data was used to measure blood flow velocity, flow reserve and diastolic/systolic velocity ratio both proximal and distal to left anterior descending or left circumflex coronary artery stenosis. These measurements were made in 38 patients undergoing coronary angioplasty and in 12 patients without significant coronary artery disease.

RESULTS

Significant improvement in mean time average peak velocity was noted in distal coronary arteries after angioplasty (before 19 +/- 12 cm/s; after 35 +/- 16 cm/s; p less than 0.01). Increases in proximal average peak velocity after angioplasty were less remarkable (before 34 +/- 18 cm/s; after 41 +/- 14 cm/s; p = 0.04). Mean flow reserve remained unchanged after angioplasty both proximal (1.5 +/- 0.5 vs. 1.6 +/- 1; p greater than 0.10) and distal (1.6 +/- 1 vs. 1.5 +/- 0.8; p greater than 0.10) to a coronary stenosis. Before angioplasty, mean diastolic/systolic velocity ratio measured distal to a significant stenosis was decreased compared with that in normal vessels (1.3 +/- 0.5 vs. 1.8 +/- 0.5; p less than 0.01). After angioplasty, distal abnormal phasic velocity patterns generally returned to normal, with a significant increase in mean diastolic/systolic velocity ratio (1.3 +/- 0.5 vs. 1.9 +/- 0.6; p less than 0.01). Phasic velocity patterns and mean diastolic/systolic velocity ratio measured proximal to a coronary stenosis were not statistically different from values in normal vessels (1.8 +/- 0.8 vs. 1.8 +/- 0.5; p greater than 0.10) and did not change significantly after angioplasty (1.8 +/- 0.8 vs. 2.13 +/- 0.9; p greater than 0.10).

CONCLUSIONS

Flow velocity measurements may be performed distal to a coronary stenosis with the Doppler guide wire. Phasic velocity measurements made proximal to a coronary stenosis differed from those in the distal coronary artery. Both proximal and distal flow reserve measurements made immediately after angioplasty were of limited utility. Changes in distal flow velocity patterns and diastolic/systolic velocity ratio appeared to be more relevant than the hyperemic response in assessing the immediate physiologic outcome of coronary angioplasty.

Assessment of angiographically intermediate coronary artery stenosis using the Doppler flowire

Determination of the clinical and hemodynamic significance of coronary stenoses is often difficult and inexact. Angiography and coronary vasodilator reserve have been shown to be imperfect tools to determine the physiologic significance of coronary stenoses. Spectral flow velocity data, both proximal and distal to coronary stenoses, using an 0.018-in intracoronary Doppler-tipped angioplasty guidewire, were compared to translesional pressure gradients and angiography during cardiac catheterization. Patients were divided into 2 groups based on resting translesional gradients: Group 1 had gradients < 20 mm Hg and group 2 had gradients > or = 20 mm Hg. Proximal average peak velocity, diastolic velocity integral, and total velocity integral were statistically significantly lower in Group 1. The distal average peak velocity, and diastolic and total velocity integrals were all significantly (p < 0.01) decreased in patients with gradients > 20 mm Hg (group 2). The ratio of proximal-to-distal total flow velocity integral was also higher in group 2 patients (2.3 +/- 0.9) compared with group 1 (1.1 +/- 0.2; p < 0.001). There was a strong correlation between translesional pressure gradients and the ratios of the proximal-to-distal total flow velocity integrals (r = 0.8, p < 0.001) with a weaker relationship between quantitative angiography and pressure gradients (r = 0.6, p < 0.001). Angiography was a poor predictor of translesional gradients in angiographically intermediate stenoses (range 50-70%; r = 0.2, p = NS), while the flow velocity ratios continued to have a strong correlation (r = 0.8, p < 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Reversal and Preventive Pleiotropic Mechanisms Involved in the Antipsychotic-Like Effect of Taurine, an Essential β-Amino Acid in Ketamine-Induced Experimental Schizophrenia in Mice

Schizophrenia is a life disabling, multisystem neuropsychiatric disease mostly derived from complex epigenetic-mediated neurobiological changes causing behavioural deficits. Neurochemical disorganizations, neurotrophic and neuroimmune alterations are some of the challenging neuropathologies proving unabated during psychopharmacology of schizophrenia, further bedeviled by drug-induced metabolic derangements including alteration of amino acids. In first-episode schizophrenia patients, taurine, an essential β-amino acid represses psychotic-symptoms. However, its anti-psychotic-like mechanisms remain incomplete. This study evaluated the ability of taurine to prevent or reverse ketamine-induced experimental psychosis and the underlying neurochemical, neurotrophic and neuroinmune mechanisms involved in taurine's clinical action. The study consisted of three different experiments with Swiss mice (n = 7). In the drug alone, mice received saline (10 mL/kg/p.o./day), taurine (50 and 100 mg/kg/p.o./day) and risperidone (0.5 mg/kg/p.o./day) for 14 days. In the preventive study of separate cohort, mice were concomitantly given ketamine (20 mg/kg/i.p./day) from days 8 to 14. In the reversal study, mice received ketamine for 14 days before taurine or risperidone treatments from days 8 to 14 respectively. Afterwards, stereotypy behaviour, social, non-spatial memory deficits, and body weights were assessed. Neurochemical (dopamine, 5-hydroxytryptamine, glutamic acid decarboxylase, (GAD)), brain derived-neurotrophic factor (BDNF) and pro-inflammatory cytokines [tumor necrosis factor-alpha, (TNF-α), interleukin-6, (IL-6)] were assayed in the striatum, prefrontal-cortex and hippocampal area. Taurine attenuates ketamine-induced schizophrenia-like behaviour without changes in body weight. Taurine reduced ketamine-induced dopamine and 5-hydroxytryptamine changes, and increased GAD and BDNF levels in the striatum, prefrontal-cortex and hippocampus, suggesting increased GABAergic and neurotrophic transmissions. Taurine decreases ketamine-induced increased in TNF-α and IL-6 concentrations in the striatum, prefrontal-cortex and hippocampus. These findings also suggest that taurine protects against schizophrenia through neurochemical modulations, neurotrophic enhancement, and inhibition of neuropathologic cytokine activities.

Superior accuracy of anatomic positioning with echocardiographic- over fluoroscopic-guided endomyocardial biopsy

To assess the superior anatomic positioning of echocardiographic-guided endomyocardial biopsy compared to traditional fluoroscopic-guided technique, these two modalities were compared in a blinded fashion during femoral sheath endomyocardial biopsy in 21 patients, 19 being evaluated after orthotopic cardiac transplantation. The simultaneous fluoroscopic and echocardiographic imaging indicated that traditional fluoroscopic positioning of the bioptome against the septum is inaccurate in over half of patients undergoing biopsy. This finding should be considered in cardiomyopathy patients or those at high risk for biopsy-related complications.

The prevention of cardiovascular disease in blacks

Cardiovascular disease (CVD) in black patients involves a complex interplay of risk, geographic, socioeconomic, and cultural factors. Modifiable risk factors such as high blood pressure, diabetes, cigarette smoking, high blood cholesterol, and physical inactivity contribute to the excess CVD mortality and morbidity in blacks. Health perceptions, health care seeking behavior, and willingness to submit to long-term preventive therapies are significantly influenced by cultural and socioeconomic factors. Early detection and control of these risk factors are particularly important because blacks tend to have multiple cardiovascular risks. The importance of churches and religious organizations in the black community should be harnessed by long-term strategies of CVD prevention. Emphasis on training of minority health care professionals who are most likely to practice in medically underserved areas should involve minority health professional schools. In the final analysis, CVD prevention in blacks should focus on control of risk factors; however, the role of environmental factors should be recognized, including socioeconomic status on access to health care and prevention. Long-term strategies of CVD prevention must involve active collaboration of health care providers and researchers to develop and test effective strategies. Churches and other religious organizations are effective but underutilized partners in CVD prevention in blacks.

Surgical timing for mitral valve regurgitation

Advances in diagnostic and surgical techniques in the management of mitral regurgitation have resulted in improved survival rates and clinical outcomes. Echocardiography is a valuable noninvasive diagnostic tool in the determination of the timing of surgical correction of mitral regurgitation. Improved surgical techniques, the growing role of mitral valve repair, low operative mortality rates, and improved long-term survival rates are important considerations for earlier surgical intervention in symptomatic patients and in asymptomatic patients with echocardiographic criteria of left ventricular dilatation. Intraoperative transesophageal echocardiography is very useful in mitral valve repair and valve replacement with preservation of chordal structures.

The paradox of coronary heart disease in African-American women

Coronary heart disease is the leading cause of death in the United States in both men and women. Much has been written on the ill effects of this disease in the general population; however, its ramifications in African-American women have been overlooked. Without a doubt, this group has a higher mortality and morbidity than African-American men and white women below the age of 55. Despite the lower angiographic prevalence of disease, when symptomatic coronary heart disease develops, the outlook is dismal. Today's research must concentrate on the ramifications of coronary heart disease in this population to improve the health standard of the general populace.

Ethnic disparities in cardiovascular health

Disparities in the cardiovascular outcomes of African-American patients is evident from national, regional, and local statistical data, as well as from the daily practice of medicine. This discussion highlights the complexity of ethnic disparities using a case-based approach with two typical cases from a cardiology practice. These cases underscore the complex interplay of the following factors in ethnic disparities. 1. Excess burden of cardiovascular risk factors in African Americans, with particular emphasis on high blood pressure, diabetes, obesity, physical inactivity, and psychosocial stress. 2. Inadequate knowledge of how personal risk factors are directly linked to atherosclerosis and heart disease. 3. Cultural factors in symptom recognition and health-care seeking behavior. 4. Economic factors influencing access to health care including prevention, diagnosis, and treatment. 5. A combination of psychosocial stress, racism, and frustration leading to sub-optimal interactions with the health care system. 6. Genetics of disease and predisposition to vascular disease and atherosclerosis. We must come to terms with these fundamental factors in the causation and, therefore, the resolution of ethnic disparities in cardiovascular health. Successful strategies must include: 1) partnerships for long-term, sustainable, population-wide strategies on risk factor modification; 2) models of culturally competent health care delivery; and 3) research on the gene-environment interactions, which cause the susceptibility of ethnic minorities to cardiovascular disease.

Managing hypertension in the southeastern United States: applying the guidelines from the Sixth Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC VI)

The southeastern United States has the highest occurrence of heart disease and stroke and among the highest rates of congestive heart failure and renal failure in the country. The Consortium for Southeastern Hypertension Control (COSEHC) is cooperating with other organizations in implementing initiatives to reduce morbidity and mortality from hypertension-related conditions in the southeastern United States. This article outlines for clinicians special consideration for implementation of the Sixth Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC VI) in the southeastern United States. Clinicians are encouraged to adapt the recommendations of JNC VI to their own patient groups, paying attention to these specific areas: (1) Ensure screening for hypertension in your practice and community. (2) Evaluate all patients for accompanying risk factors and target organ damage. (3) Promote lifestyle management for individual patients and populations for prevention and treatment of hypertension. (4) Set a goal blood pressure for each patient, and monitor progress toward that goal. (5) Recognize that many patients will be candidates for blood pressure goals of <130/85 mm Hg. (6) Pay attention to compelling and special indications such as diabetes, congestive heart failure, and renal dysfunction. (7) Consider combination therapy. (8) Maximize staff contributions to enhance patient adherence. (9) Encourage patient, family, and community activities to promote healthy lifestyles and blood pressure control.