Deborah A Chyun

Abstract

OBJECTIVE - To assess the prevalence and clinical predictors of silent myocardial ischemia in asymptomatic patients with type 2 diabetes and to test the effectiveness of current American Diabetes Association screening guidelines. RESEARCH DESIGN AND METHODS - In the Detection of Ischemia in Asymptomatic Diabetics (DIAD) study, 1,123 patients with type 2 diabetes, aged 50-75 years, with no known or suspected coronary artery disease, were randomly assigned to either stress testing and 5-year clinical follow-up or to follow-up only. The prevalence of ischemia in 522 patients randomized to stress testing was assessed by adenosine technetium-99m sestamibi single-photon emission-computed tomography myocardial perfusion imaging. RESULTS - A total of 113 patients (22%) had silent ischemia, including 83 with regional myocardial perfusion abnormalities and 30 with normal perfusion but other abnormalities (i.e., adenosine-induced ST-segment depression, ventricular dilation, or rest ventricular dysfunction). Moderate or large perfusion defects were present in 33 patients. The strongest predictors for abnormal tests were abnormal Valsalva (odds ratio [OR] 5.6), male sex (2.5), and diabetes duration (5.2). Other traditional cardiac risk factors or inflammatory and prothrombotic markers were not predictive. Ischemic adenosine-induced ST-segment depression with normal perfusion (n = 21) was associated with women (OR 3.4). Selecting only patients who met American Diabetes Association guidelines would have failed to identify 41% of patients with silent ischemia. CONCLUSIONS - Silent myocardial ischemia occurs in greater than one in five asymptomatic patients with type 2 diabetes. Traditional and emerging cardiac risk factors were not associated with abnormal stress tests, although cardiac autonomic dysfunction was a strong predictor of ischemia.

Abstract

Unless action is directed to address the multiple influences on coronary heart disease (CHD) risk reduction behaviors, across all population groups, the aims of Healthy People 2010 with regard to CHD will not be realized. Health-promotion and disease-prevention models, including a framework for primordial, primary, and secondary prevention provided by an American Heart Association task force, and a model for interventions to eliminate health disparities are reviewed. The role of culture, ethnicity, race, and socioeconomic status and how these concepts have been studied in recent lifestyle interventions aimed at CHD risk reduction is explored. Finally, these findings are synthesized to provide suggestions for nursing care delivery in primary and tertiary care settings.

Abstract

Effective diagnosis and treatment of coronary artery disease (CAD) are key to the management of patients with diabetes. Although the use of specialized cardiac testing for CAD screening in asymptomatic patients varies widely and is the source of current controversy, evidence is emerging on the prevalence and predictors of asymptomatic ischemia in diabetic patients. Accurate diagnosis and risk stratification are essential in symptomatic patients with known or suspected CAD. Noninvasive cardiac testing has an important role in these patients, although evaluation for revascularization with cardiac catheterization is warranted in high-risk circumstances. This article reviews recent information that may help guide the clinician in the appropriate use of cardiac testing in diabetic patients.

Abstract

The purpose of this pilot study was to explore the relationships between spiritual well-being, emotional distress, HbA1c values, and blood pressure levels in a convenience sample of 22 Black women with type 2 diabetes. Results revealed significant inverse correlations between diastolic blood pressure (BP) and both total spiritual well-being (r=-.51, P=.02) and religious well-being (RWB) (r=-.55, P=.01). Women with higher RWB scores tended to have lower diastolic BP, as compared to their counterparts with lower RWB scores (z=2.78, P=.005). Emotional distress was positively related to systolic BP (r=.48, P=.03). These findings suggest that holistic care, addressing the spiritual and emotional dimensions, may foster improved BP levels among Black women with type 2 diabetes, thereby potentially reducing their high risk for secondary complications.

Abstract

OBJECTIVE: Diabetes mellitus (DM) has been associated with an elevated, short-term risk of death after myocardial infarction (MI). Among the studies of DM, however, few studies have included elderly subjects. The purpose of the present investigation was to determine if non-insulin-treated DM (NIRxDM) and insulin-treated DM (IRxDM) were associated with specific comorbid conditions, clinical findings on arrival, and MI characteristics, as well as a higher 30-day mortality rate in elderly patients with acute MI. DESIGN: The study design was a retrospective medical record review and secondary data analysis of previously collected data from the Cooperative Cardiovascular Project. SETTING: Study setting was Connecticut from June 1, 1992, through February 28, 1993. PATIENTS: Subjects included the entire Medicare population (n = 2050), aged 65 years or older who were hospitalized for acute MI. OUTCOME MEASURES: Mortality rate at 30 days after MI was measured. RESULTS: A history of DM was observed in 29% of the study population. DM status was associated with previous comorbid conditions, poorer functional status, higher body mass index, heart failure on arrival, non-Q-wave MI, and development of atrial fibrillation and oliguria during hospitalization. Patients with DM were less likely to have chest pain on arrival to the hospital. Diabetic status was not a significant predictor of short-term mortality; at 30 days after MI, 17% (n = 242) of the subjects without DM, 19% (n = 71) of those with NIRxDM, and 18% (n = 39) of the subjects with IRxDM died (P = .460). After adjustment for other prognostic factors, it was noted that MI characteristics present on hospital arrival predicted mortality at 30 days in both patients with NIRxDM and patients with IRxDM. CONCLUSIONS: The slightly, but not significantly, increased mortality risk in patients with DM should not minimize the importance of monitoring DM in the acute MI setting. Hospitalization for MI provides an opportunity to provide aggressive lipid and blood pressure management, optimize blood glucose, control heart failure, and institute other secondary preventive interventions in the elderly population with DM.

Abstract

• OBJECTIVES: To examine the association between (1) comorbid conditions related to diabetes mellitus, clinical findings on arrival at the hospital, and characteristics of the myocardial infarction and (2) risk of heart failure, recurrent myocardial infarction, and mortality in the year after myocardial infarction in elderly 30-day survivors of myocardial infarction who had non-insulin-or insulin-treated diabetes. • METHODS: Medical records for June 1, 1992, through February 28, 1993, of Medicare beneficiaries (n = 1698), 65 years or older, hospitalized for acute myocardial infarction in Connecticut were reviewed by trained abstractors. • RESULTS: One year after myocardial infarction, elderly patients with non-insulin- and insulin-treated diabetes mellitus had significantly greater risk for readmission for heart failure and recurrent myocardial infarction than did patients without diabetes mellitus, and risk was greater in patients treated with insulin than in patients not treated with insulin. Diabetes mellitus, comorbid conditions related to diabetes mellitus, clinical findings on arrival, and characteristics of the myocardial infarction, specifically measures of ventricular function, were important predictors of these outcomes. Mortality was greater in patients not treated with insulin than in patients treated with insulin; the increased risk was mostly due to comorbid conditions related to diabetes mellitus and poorer ventricular function. • CONCLUSIONS: Risk of heart failure, recurrent myocardial infarction, and mortality is elevated in elderly patients who have non-insulin-or insulin-treated diabetes mellitus. Comorbid conditions related to diabetes mellitus and ventricular function at the time of the index myocardial infarction are important contributors to poorer outcomes in patients with diabetes mellitus.

Abstract

Insulin-induced hypoglycemia occurs commonly in intensively treated patients with type 1 diabetes, but the cardiovascular consequences of hypoglycemia in these patients are not known. We studied left ventricular systolic [left ventricular ejection fraction (LVEF)] and diastolic [peak filling rate (PFR)] function by equilibrium radionuclide angiography during insulin infusion (12 pmol·kg-1·min-1) under either hypoglycemic (∼2.8 mmol/l) or euglycemic (∼5 mmol/l) conditions in intensively treated patients with type 1 diabetes and healthy nondiabetic subjects (n = 9 for each). During hypoglycemic hyperinsulinemia, there were significant increases in LVEF (ΔLVEF = 11 ± 2%) and PFR [ΔPFR = 0.88 ± 0.18 end diastolic volume (EDV)/s] in diabetic subjects as well as in the nondiabetic group (ΔLVEF = 13 ± 2%; ΔPFR = 0.79 ± 0.17 EDV/s). The increases in LVEF and PFR were comparable overall but occurred earlier in the nondiabetic group. A blunted increase in plasma catecholamine, cortisol, and glucagon concentrations occurred in response to hypoglycemia in the diabetic subjects. During euglycemic hyperinsulinemia, LVEF also increased in both the diabetic (ΔLVEF = 7 ± 1%) and nondiabetic (ΔLVEF = 4 ± 2%) groups, but PFR increased only in the diabetic group. In the comparison of the responses to hypoglycemic and euglycemic hyperinsulinemia, only the nondiabetic group had greater augmentation of LVEF, PFR, and cardiac output in the hypoglycemic study (P < 0.05 for each). Thus intensively treated type 1 diabetic patients demonstrate delayed augmentation of ventricular function during moderate insulin-induced hypoglycemia. Although diabetic subjects have a more pronounced cardiac response to hyperinsulinemia per se than nondiabetic subjects, their response to hypoglycemia is blunted.