Unstable angina: specialty-related disparities in implementation of practice guidelines

BACKGROUND

The agency for Health Care Policy and Research (AHCPR) has published practice guidelines to improve the quality of care patients with unstable angina. Prior to publication, studies demonstrated that when compared with cardiologists, internists were less likely to use effective pharmacologic therapies or revascularization in patients with unstable angina.

HYPOTHESIS

The study was undertaken to determine whether the AHCPR guideline publication abolished specialty-related disparities in care.

METHODS

We performed a chart review of consecutive patients hospitalized at a university-affiliated institution with an admission diagnosis of chest pain in the absence of myocardial infarction and a noncardiac etiology. Treatment and diagnostic cardiac testing were compared between risk-stratified patients cared for by a generalist (n = 125) and those whose care was guided by a cardiologist (n = 211).

RESULTS

In those with low-risk unstable angina, generalists were less likely to prescribe recommended aspirin (71 vs. 88%, p < 0.01) and beta blockers (9 vs. 37%, p < 0.001), and heparin (20 vs. 49%, p < 0.001), and to perform a recommended diagnostic stress test or cardiac catheterization (28 vs. 60%, p < 0.001). In those with at least intermediate risk, generalists were less likely to prescribe beta blockers (19 vs. 52%, p < 0.001), heparin (19 vs. 66%, p < 0.001), and nitrates (77 vs. 96%, p < 0.001), and to refer for diagnostic testing (19 vs. 65%, p < 0.001). Generalists' care was associated with significantly lower hospital charges.

CONCLUSIONS

AHCPR guidelines for the evaluation and treatment of unstable angina are implemented more effectively, but not uniformly, by cardiologists at our institution. Further studies are necessary to evaluate the barriers to implementation of the AHCPR guidelines.

Estrogen acutely abolishes abnormal cold-induced coronary constriction in men

BACKGROUND AND STUDY OBJECTIVE

Ambient cold exposure may induce myocardial ischemia by precipitating coronary artery constriction and a decrease in coronary blood flow. Estrogen has vasoactive properties that may prevent abnormal coronary constriction in a sex-independent manner. The purpose of this study is to determine whether estrogen acutely abolishes abnormal coronary responses to cold exposure in men.

DESIGN

Randomized, double-blinded placebo-controlled clinical trial.

SETTING

Cardiac catheterization laboratory.

PATIENTS

Men referred for routine diagnostic coronary angiography who exhibit abnormal coronary artery constriction in response to a 90-s cold pressor test (CPT).

INTERVENTION

Intravenous conjugated estrogens (1.25 mg) vs. placebo.

MEASUREMENTS AND RESULTS

Rate-pressure product, coronary cross-sectional area (CSA), and coronary blood flow responses to the CPT were measured before and 15 min after intervention. In 12 men with CPT-induced coronary constriction who were assigned to estrogen, CPT induced a mean 21.8% decrease in coronary CSA (p < 0.01) and a nonsignificant change in coronary flow. After estrogen, the repeated CPT induced a 16.3% increase in CSA (p < 0.01) and a 54.9% increase in flow (p < 0.01). CSA and coronary flow responses to CPT were significantly different before and after estrogen (p < 0.01). In contrast, placebo was not associated with changes in CSA or coronary flow responses to CPT in eight men.

CONCLUSIONS

In men, conjugated estrogens acutely abolish abnormal coronary constriction and improve coronary blood flow responses to an exogenous cold stimulus. These results suggest that estrogen favorably alters coronary vasoreactivity in men.

Conjugated estrogens acutely abolish abnormal cold-induced coronary vasoconstriction in male cardiac allografts

BACKGROUND

Transplant-associated coronary arteriopathy is manifested in its early stages by paradoxical coronary artery constriction in response to endothelium-dependent vasodilator stimuli such as the cold pressor test (CPT) and is a major cause of death or retransplantation. Estrogen has vasoactive properties that abolish coronary artery endothelial dysfunction in native hearts. We hypothesized that estrogen attenuates inappropriate coronary artery constriction in cardiac allografts.

METHODS AND RESULTS

Coronary artery diameter and systemic hemodynamic responses to a 90-second CPT were measured before and 15 minutes after double-blind, randomized administration of intravenous conjugated estrogens (1.25 mg) or placebo in men with male cardiac allografts. Before estrogen, 9 men exhibited an abnormal 15.1 +/- 3.0% CPT-induced decrease in coronary artery diameter. However, repeat CPT did not induce significant coronary artery constriction when performed 15 minutes after estrogen. CPT responses before and after estrogen were significantly different (P=.02). Placebo did not influence coronary artery responses to CPT in 6 men. Systemic hemodynamic responses to CPT were not influenced by estrogen or placebo. Estrogen was the only significant determinant of changes in coronary artery responses to CPT.

CONCLUSIONS

Conjugated estrogens acutely abolish abnormal CPT-induced coronary artery constriction in male cardiac allografts. This favorable vasomotor effect suggests that estrogen may prevent inappropriate coronary artery constriction in men with cardiac transplants.

Treatment of patients admitted to the hospital with congestive heart failure: specialty-related disparities in practice patterns and outcomes

OBJECTIVES

This study sought to define specialty-related differences in the care and outcome of patients admitted to the hospital with congestive heart failure (CHF).

BACKGROUND

Congestive heart failure is the leading diagnosis-related group (DRG) discharge diagnosis in the United States and accounts for an estimated annual hospital cost in excess of $7 billion. The clinical impact of aggressive CHF management and the importance of the subspecialist in guiding this care have not been evaluated.

METHODS

To define differences in physician practice patterns, we performed a chart review of consecutive patients admitted to a university teaching hospital with a primary DRG discharge diagnosis of CHF. We compared treatment and outcome of patients cared for by a generalist (n = 160) and those whose care was guided by a cardiologist (n = 138) during their index hospital period with CHF and over the next 6 months.

RESULTS

At our institution, > 50% of patients admitted to the hospital with CHF cared for by generalists alone had minimal (New York Heart Association functional class I or II) symptoms, compared with < 15% of those cared for by a cardiologist (p < 0.01). Although generalists' patients underwent significantly fewer in-hospital diagnostic tests and had shorter lengths of stay, they had a 1.7-fold increased risk of readmission for CHF within 6 months (p < 0.05). Six-month cardiac and all-cause mortality were not significantly different between the groups. The type of physician caring for the patient and a history of diabetes, previous CHF or myocardial infarction were independent predictors of readmission for CHF.

CONCLUSIONS

Involvement of a cardiologist in the care of patients admitted to the hospital with CHF is associated with increased use of diagnostic testing, longer hospital stays and improved clinical outcome. These results substantiate practice guidelines that suggest a role for cardiologists in the care of symptomatic patients with CHF.

Syndrome X: a discussion of angina and normal coronary arteries

Syndrome X was diagnosed in a female patient who presented with typical angina and a non-Q wave myocardial infarction, yet demonstrated normal coronary arteries. Syndrome X has been described as an impairment in normal endothelial function of the coronary microvasculature, resulting in inappropriate vasoconstriction and inadequate coronary flow reserve. In this article we review pathophysiology, diagnosis, treatment, and prognosis in a single case.

Syndrome X: a discussion of angina and normal coronary arteries

Syndrome X was diagnosed in a female patient who presented with typical angina and a non-Q wave myocardial infarction, yet demonstrated normal coronary arteries. Syndrome X has been described as an impairment in normal endothelial function of the coronary microvasculature, resulting in inappropriate vasoconstriction and inadequate coronary flow reserve. In this article we review pathophysiology, diagnosis, treatment, and prognosis in a single case.