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.

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.