Predictors of appropriate therapies delivered by the implantable cardioverter-defibrillator in patients with coronary artery disease during long-term period.

This prospective study aimed to investigate the ability of cardiac autonomic nervous system (CANS) activity assessment to predict appropriate implantable cardioverter-defibrillator (ICD) therapy in patients with coronary artery disease (CAD) during long-term follow-up period. We enrolled patients with CAD and ICD implantation indications that included both secondary and primary prevention of sudden cardiac death. Before ICD implantation CANS was assessed by using heart rate variability (HRV), myocardium scintigraphy with 123I-meta-iodobenzylguanidine (123I-MIBG) and erythrocyte membranes ß-adrenoreactivity (EMA). The study's primary endpoint was the documentation of appropriate ICD therapy. Of 45 (100.0%) patients, 15 (33.3%) had appropriate ICD therapy during 36 months follow-up period. Patients with appropriate ICD therapy were likely to have a higher summed 123I-MIBG score delayed (p < 0.001) and lower 123I-MIBG washout rate (p = 0.008) indicators. These parameters were independently associated with endpoint in univariable and multivariable logistic regression. We created a logistic equation and calculated a cut-off value. The resulting ROC curve revealed a discriminative ability with AUC of 0.933 (95% confidence interval 0.817-0.986; sensitivity 100.00%; specificity 93.33%). Combined CANS activity assessment is useful in prediction of appropriate ICD therapy in patients with CAD during long-term follow-up period after device implantation.

Potential Mechanisms for Organoprotective Effects of Exogenous Nitric Oxide in an Experimental Study.

Performing cardiac surgery under cardiopulmonary bypass (CPB) and circulatory arrest (CA) provokes the development of complications caused by tissue metabolism, microcirculatory disorders, and endogenous nitric oxide (NO) deficiency. This study aimed to investigate the potential mechanisms for systemic organoprotective effects of exogenous NO during CPB and CA based on the assessment of dynamic changes in glycocalyx degradation markers, deformation properties of erythrocytes, and tissue metabolism in the experiment. A single-center prospective randomized controlled study was conducted on sheep, n = 24, comprising four groups of six in each. In two groups, NO was delivered at a dose of 80 ppm during CPB ("CPB + NO" group) or CPB and CA ("CPB + CA + NO"). In the "CPB" and "CPB + CA" groups, NO supply was not carried out. NO therapy prevented the deterioration of erythrocyte deformability. It was associated with improved tissue metabolism, lower lactate levels, and higher ATP levels in myocardial and lung tissues. The degree of glycocalyx degradation and endothelial dysfunction, assessed by the concentration of heparan sulfate proteoglycan and asymmetric dimethylarginine, did not change when exogenous NO was supplied. Intraoperative delivery of NO provides systemic organoprotection, which results in reducing the damaging effects of CPB on erythrocyte deformability and maintaining normal functioning of tissue metabolism.

Ventricular tachycardia incidence and erythrocyte membranes ß-adrenoreactivity in patients with implanted cardioverter-defibrillator.

BACKGROUND: In patients with high risk of ventricular tachycardia (VT) the proven beneficial therapy is the implantable cardioverter defibrillator (ICD). It has been shown that the coronary artery disease (CAD) and VT development are accompanied by a persistent change of the sympathoadrenal system activity. This leads to a decrease in the total density of the erythrocyte membrane ß-adrenergic receptors. The purpose of this study was to identify the relationship of the erythrocyte membranes ß-adrenoreactivity (EMA) with VT development in patients with CAD and ICD. METHOD: Sixty-three patients (male - 53, age - 66.6 ± 9.2 years) with CAD and ICD were included to the study. EMA was studied using a method for assessing erythrocyte osmoresistance increase as a result of ß-adrenergic receptors blockade by a selective ß-adrenergic blocker. VT and ventricular fibrillation (VF) events recorded by ICD were evaluated. RESULTS: The 1st group consist of 23 patients with VT/VF events recorded by ICD during 27.0 [14.0; 53.0] months follow-up period. EMA indicator in this group was 41.54% [27.15; 51.26]. The 2nd group consist of 40 patients without VT/VF events and the same indicator was significantly higher - 55.42% [35.67; 62.33] (p = .04). The ROC-analysis (AUC = 0.657; Sen = 78.26; Spe = 55.00; p = .031) and binary logistic regression (OR = 0.9679; 95% CI: 0.9384-0.9983; p = .038) showed that EMA indicator 51.26% or lower was the independent predictor of VT events. CONCLUSIONS: In patients with CAD and ICD erythrocyte membranes ß-adrenoreactivity indicator 51.26% or lower is the predictor of VT episodes.

Nonpharmacological Correction of Hypersympatheticotonia in Patients with Chronic Coronary Insufficiency and Severe Left Ventricular Dysfunction.

BACKGROUND: Control of sympathetic hyperactivity is pivotal for treatment of heart failure (HF) in patients with coronary artery disease (CAD). Our earlier studies demonstrated that the auricular pulsed electrical stimulation of the vagus nerve (VNS) beneficially affected condition of CAD patients with HF. The aim of our study was to evaluate changes in heart rate (HR) and the levels of heat shock proteins in peripheral blood lymphocytes in patients with CAD in the course of VNS. METHODS: The study comprised 70 individuals aged 50-68 years with chronic coronary insufficiency, severe left ventricular dysfunction, and NYHA functional class (FC) III-IV HF. Main group included 63 patients who received VNS course (group 1). Control patients (n = 7) received sham therapy (group 2). RESULTS: According to the results of 6-minute walk test and 24-hour ECG monitoring, administration of VNS improved clinical condition of 58 of 63 patients, decreased HF FC, and attenuated HR. Clinical condition in sham therapy group did not change. Immunoenzyme method demonstrated that hsp70 and hsp60 contents in peripheral blood lymphocyte lysate increased by 58% and 48% (P < 0.05), respectively, in patients who initially had HR < 80 bpm. The hsp70 level significantly increased and hsp60 level remained unchanged in patients with initial HR > 80 bpm. CONCLUSIONS: Correction of autonomous nervous status by VNS attenuated HR and improved functional state of the heart in CAD patients. Cardiotropic effect of VNS was the most pronounced in patients with preserved endogenous stress-limiting systems associated with hsp60 and/or hsp70.