Coronary Artery Disease Controls Research Articles

Glutathione Peroxidase Activity Is Altered in Vascular Cognitive Impairment-No Dementia and Is a Potential Marker for Verbal Memory Performance

Background:Coronary artery disease (CAD) increases risk for vascular cognitive impairment-no dementia (VCIND), a precursor to dementia, potentially through persistent oxidative stress.Objective:This study assessed peripheral glutathione peroxidase activity (GPX), which is protective against oxidative stress, in VCIND versus cognitively normal CAD controls (CN). GPX activity was also evaluated as a biomarker of cognition, particularly verbal memory.Methods:120 CAD patients with VCIND (1SD below norms on executive function or verbal memory (VM)) or without (CN) participated in exercise rehabilitation for 24 weeks. Neurocognitive and cardiopulmonary fitness (VO2 peak) assessments and plasma were collected at baseline and 24-weeks.Results:GPX was higher in VCIND compared to CN (F1,119 = 3.996, p = 0.048). Higher GPX was associated with poorer baseline VM (β= –0.182, p = 0.048), and longitudinally with VM decline controlling for sex, body mass index, VO2 peak, and education (b[SE] = –0.02[0.01], p = 0.004). Only CN participants showed improved VM performance with increased fitness (b[SE] = 1.30[0.15], p < 0.005).Conclusion:GPX was elevated in VCIND consistent with a compensatory response to persistent oxidative stress. Increased GPX predicted poorer cognitive outcomes (verbal memory) in VCIND patients despite improved fitness.

Increased left ventricular mass and decreased left ventricular systolic function have independent pathways to ventricular arrhythmogenesis in coronary artery disease

Following myocardial infarction, individual patients can have wide variations in the extent of left ventricular systolic dysfunction (LVSD) and increased left ventricular (LV) mass. Both affect the risk for sudden cardiac death, but only LV ejection fraction is used for risk prediction. The purpose of this study was to evaluate the independent as well as the additive contributions of increased LV mass and decreased LV ejection fraction to sudden cardiac death in the general population. In the ongoing Oregon Sudden Unexpected Death Study, we studied consecutive SCD cases (n = 191) and coronary artery disease controls (n = 203) from the Portland, Oregon, metropolitan area (population approximately 1,000,000; 2002-2008). Comparisons of echocardiographic LV mass obtained prior and unrelated to sudden cardiac death (SCD) were conducted, and a logistic regression model was used to evaluate the relationship between SCD, severe LVSD, LV mass, and other relevant clinical variables. In a multivariate model, both severe LVSD and left ventricular hypertrophy (LVH) were associated with increased SCD risk (odds ratio [OR] 1.9, 95% confidence interval [CI] 1.1-3.2 for severe LVSD; OR 1.8, 95% CI 1.1-2.9 for LVH). In patients with coexisting severe LVSD and LVH, risk of SCD was additive (OR 3.5, 95% CI 1.7-7.2). In the same model, increased age, atrial fibrillation/flutter, elevated creatinine, and diabetes independently increased risk, and use of angiotensin receptor blockers attenuated risk. Reduced LV ejection fraction and increased LV mass had independent and additive effects on risk of sudden death. Despite the significant overlap between the two conditions, these findings point toward the existence of independent mechanistic pathways for ventricular arrhythmias that occur due to LVSD and LVH.

Abstract 3144: Prevalence Of Insulin Resistance Among Non-diabetic Chronic Heart Failure Patients And Its Relation To Disease Severity

Body: Background Purpose- There is increasing evidence of a reciprocal interrelationship between chronic heart failure (CHF) and insulin resistance (IR) such that IR may be pathophysiologically linked to the evolution of the disease in CHF. However, the prevalence of IR in the CHF population has not been fully defined. The purpose of this study was to establish the prevalence of IR among non-diabetic CHF patients and to assess its relation to disease severity. Methods- The homeostatic model of insulin resistance (HOMA-IR) was assessed in a cohort of 129 CHF patients; mean age (69.2±10.4 yrs) [range 30 –90 yrs], males 76%, CHF of ischemic etiology 82.2% and BMI (27.4±4.4kg/m2). All were on regular CHF medication. Patients underwent cardiopulmonary exercise testing and peripheral endothelial function testing by reactive hyperemia peripheral arterial tonometry (RH-PAT). Results- Prevalence of IR as defined by Fasting Insulin Resistance Index &gt;2.7 was 61% in CHF and was significantly higher than in the 23 subjects who were coronary artery disease controls without HF(P&lt;0.05). The degree of IR was not related to the etiology of CHF. There was a significant correlation between IR and serum triglyceride (r = 0.333, P&lt;0.01), HDL cholesterol (r = − 0.275, p&lt;0.05), impaired fasting glucose (r = 0.358, P&lt;0.01) and central obesity (r = 0.232, p&lt;0.01). The degree of IR was related to the exercise capacity and peak oxygen consumption (VO 2 ). Mean of IR increased significantly with worsening functional NYHA Classes I, II, III and IV [2.1, 2.9, 4.8, 8.9], (r = 0.437, p&lt;0.01). The IR patients had a significantly lower exercise duration (340 ±168.3 vs. 601 ±265.9 s, p&lt; 0.01) and peak VO 2 (6.4 ± 2.3 vs. 14.5 ±1.7 ml/kg per min, p&lt; 0.05). Exercise peak cardiac output determined by the inert gas re-breathing method was lower in patients with IR (5.2 ±1.2 vs. 9.2 ± 0.89 l/min, p&lt;0.05). Endothelial function as measured by RH-PAT decreased significantly in patients with IR compared to the patients with normal insulin sensitivity (1.64 ± 0.36 vs. 2.0 ± 0.53, p&lt;0.05I). Conclusion - These findings suggest that IR is highly prevalent among CHF patients and is associated with decreased exercise effort and capacity in patients with CHF. Targeting IR might represent a new strategy in the treatment of CHF.

Insulin Resistance in Heart Failure: Prevalence and Relation to Disease Severity

Insulin Resistance in Heart Failure: Prevalence and Relation to Disease Severity