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.

A predictive model of super response to cardiac resynchronization therapy in short-term period.

BACKGROUND: The left bundle branch block, nonischemic heart failure (HF) and female gender are the most powerful predictors of a super response to cardiac resynchronization therapy (CRT). It is important to identify super responders who can derive most benefits from CRT. We aimed to establish a predicting model that could be used for prognosis of a super response to CRT in short-term period. METHODS: Patients with QRS ≥ 130 ms, New York Heart Association (NYHA) II-III class of HF, left ventricle ejection fraction (LVEF) ≤ 35% and indications for CRT were included in the study. Before and 6 month after CRT the electrocardiography, echocardiography and cardiac scintigraphy were performed. The study's primary endpoint was the NYHA class improvement ≥ 1 and left ventricle end systolic volume decrease > 30% or LVEF improvement > 15% after 6 month CRT. Based on collected data, we developed a predictive model regarding a super response to CRT. RESULTS: Of 49 (100.0%) patients, 32 (65.3%) had a super response to CRT. Patients with a super response were likelier to have a lower cardiac index (p = 0.007), higher rates of interventricular delay (IVD) (p = 0.003), phase standard deviation of left ventricle anterior wall (PSD LVAW) (p = 0.009) and ∆QRS (p = 0.02). Only IVD and PSD LVAW were independently associated with a super response to CRT in univariate and multivariate logistic regression. We created a logistic equation and calculated a cut-off value. The resulting ROC curve revealed a discriminative ability with AUC of 0.812 (sensitivity 90.62%; specificity 70.59%). CONCLUSION: Our predictive model is able to distinguish patients with a super response to CRT.

The Value of Left Ventricular Mechanical Dyssynchrony and Scar Burden in the Combined Assessment of Factors Associated with Cardiac Resynchronization Therapy Response in Patients with CRT-D.

BACKGROUND: Cardiac resynchronization therapy (CRT) improves the outcome in patients with heart failure (HF). However, approximately 30% of patients are nonresponsive to CRT. The aim of this study was to determine the role of the left ventricular (LV) mechanical dyssynchrony (MD) and scar burden as predictors of CRT response. METHODS: In this study, we included 56 patients with HF and the left bundle-branch block with QRS duration ≥ 150 ms who underwent CRT-D implantation. In addition to a full examination, myocardial perfusion imaging and gated blood-pool single-photon emission computed tomography were performed. Patients were grouped based on the response to CRT assessed via echocardiography (decrease in LV end-systolic volume ≥15% or/and improvement in the LV ejection fraction ≥5%). RESULTS: In total, 45 patients (80.3%) were responders and 11 (19.7%) were nonresponders to CRT. In multivariate logistic regression, LV anterior-wall standard deviation (adjusted odds ratio (OR) 1.5275; 95% confidence interval (CI) 1.1472-2.0340; p = 0.0037), summed rest score (OR 0.7299; 95% CI 0.5627-0.9469; p = 0.0178), and HF nonischemic etiology (OR 20.1425; 95% CI 1.2719-318.9961; p = 0.0331) were the independent predictors of CRT response. CONCLUSION: Scar burden and MD assessed using cardiac scintigraphy are associated with response to CRT.

Isolated Atrial Fibrillation, Inflammation and Efficacy of Radiofrequency Ablation: Preliminary Insights Based on a Single-Center Endomyocardial Biopsy Study.

The aim of the study was to evaluate the inflammatory changes in the myocardium, based on endomyocardial biopsy (EMB) data in patients undergoing radiofrequency ablation (RFA) for idiopathic atrial fibrillation (AF). A total of 67 patients with idiopathic AF were enrolled in the study. Patients underwent the intracardiac examination, RFA of AF, and EMB with histological and immunohistochemical studies. The catheter-treatment effectiveness, and occurrence of early and late recurrences of atrial tachyarrhythmias, were assessed depending on the identified histological changes. Nine patients (13.4%) did not have any histological changes in the myocardium according to EMB. Fibrotic changes were detected in 26 cases (38.8%). Inflammatory changes according to the Dallas criteria were observed in 32 patients (47.8%). The follow-up period for patients averaged 19.3 ± 3.7 months. The effectiveness rates of primary RFA were 88.9% in patients with the intact myocardium, 46.2% in patients with fibrotic changes of varying severity, and 34.4% in patients with the presence of criteria for myocarditis. No early recurrence of arrhythmias was observed in patients with unchanged myocardia. The presence of inflammatory and fibrotic changes in the myocardium increased the rates of early and late arrhythmia recurrences and accordingly halved the effectiveness RFA of AF.

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.

How to get the optimal defibrillation lead parameters using myocardial perfusion scintigraphy in patients with coronary artery disease.

The conventional criteria for a defibrillation lead (DL) implantation don't take into account presence of scar or deep ischemia in the myocardium. This may impair a proper functioning of the DL. We sought to optimize the DL implantation placement using rest myocardial perfusion scintigraphy (MPS), which allow detecting areas of myocardial hypoperfusion (MH). To study the influence of MH and scarring, detected by MPS, on the DL parameters in patients with coronary artery disease (CAD). 69 patients (male-65, age 64.8 ± 7.7 years) with CAD and indications for ICD implantation were enrolled. Two days before ICD implantation all patients underwent MPS at rest. Then patients were divided in 2 groups. In the 1st group DL was implanted considering MPS results: to the septal position, if the most significant MH were detected in the apical segments, and to the apical position, if MH were in the septal segments. In the 2nd group DL was implanted using the conventional approach without considering MPS results. Clinical 12 months follow-up was performed with ICD interrogation. Patients of both groups were comparable by clinical and scintigraphic parameters. In the same time, in the 1st group pacing threshold was lower (p < 0.0001) and ventricle signal amplitude was higher (p < 0.0001) comparing with the 2nd group at all control points. The presence of MH detected by MPS in the area of the DL placement worsens its parameters. The results of MPS in patients with CAD can be useful for optimization of DL placement.

Radionuclide Assessment of Cardiac Function and Dyssynchrony in Children with Idiopathic Ventricular Tachycardia.

BACKGROUND: The aim of the study was to evaluate the impact of idiopathic ventricular tachycardia and premature ventricular beats on cardiac function and dyssynchrony and to elucidate relationships between data of scintigraphic and intracardiac electrophysiology studies (EPSs). METHODS: The study comprised 64 patients with idiopathic ventricular arrhythmias (VAs; median age of 14 years ranging from 8 to 18 years). The control group comprised 20 patients (median age of 12 ranging from 7 to 16 years) without cardiac arrhythmias. EPS and radiofrequency ablation (RFA) procedure for VA were performed in 21 children according to indications. The functional state of both ventricles was assessed by gated blood pool single photon emission computer tomography (GBP-SPECT) before and after RFA in all patients. RESULTS: Patients with VA had local areas of asynchronous myocardial contraction (AMC). Compared with the control group, VA patients had significantly higher values of end-diastolic volume, end-systolic volume, and lower contractility indices. Negative association was found between total numbers of AMC areas and cardiac contractility indices. Ectopic foci localization, determined based on EPS data, was associated with AMC areas topography based on GBP-SPECT. RFA procedure significantly improved cardiac contractility indices; AMC areas completely disappeared or decreased compared with the preoperative conditions. CONCLUSION: In VA patients, AMC areas were localized mostly in the right ventricle. Comparison of the results of GBP-SPECT and EPS studies showed a relationship between AMC localizations and ectopic foci topography. The fact that AMC areas disappeared after RFA supports the hypothesis stating that the presence of AMC areas is a scintigraphic symptom of ectopic focus.