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Atrial Arrhythmia History in MADIT-RIT Background There are limited data whether history of atrial tachyarrhythmia (AT) modifies the risk of inappropriate ICD therapy, or the efficacy of novel ICD programming to reduce inappropriate ICD therapy events. Methods In MADIT-RIT, we investigated the effects of novel ICD programming with high-rate cut-off VT zone ≥ 200 bpm (arm B), or 60-second delayed therapy in the VT zone 170-199 bpm (arm C), compared to conventional programming VT zone>170 bpm (arm A) on first inappropriate ICD therapy in those with or those without AT prior to enrollment. Results In patients with prior AT (n = 203, 14%) there was a higher risk of inappropriate ICD therapy (HR = 2.10, 95% CI: 1.38-3.20, P < 0.001), and inappropriate ICD shock (HR = 2.56, 95% CI: 1.38-4.74, P = 0.003) compared to those with no prior AT. The effects of innovative programming to reduce inappropriate ICD therapy with either high-rate cut-off or delayed VT therapy were similar in patients with prior AT (arm B vs. A HR = 0.11, P < 0.001, arm C vs. A HR = 0.17, P < 0.001), and also in patients without prior AT before enrollment (arm B vs. A HR = 0.15, P < 0.001, arm C vs. A HR = 0.24, P < 0.001, interaction P-values >0.10 for all). Conclusions Novel ICD programming with a high-rate cut-off or delayed therapy is equally beneficial to reduce inappropriate ICD therapy in patients with or without prior AT, despite the lower risk of inappropriate ICD therapy in patients without prior AT. [ABSTRACT FROM AUTHOR]

ICD Programming in Ischemic and Nonischemic Cardiomyopathy Introduction The MADIT-RIT trial demonstrated reduction of inappropriate and appropriate ICD therapies and mortality by high-rate cut-off and 60-second-delayed VT therapy ICD programming in patients with a primary prophylactic ICD indication. The aim of this analysis was to study effects of MADIT-RIT ICD programming in patients with ischemic and nonischemic cardiomyopathy. Methods and Results First and total occurrences of both inappropriate and appropriate ICD therapies were analyzed by multivariate Cox models in 791 (53%) patients with ischemic and 707 (47%) patients with nonischemic cardiomyopathy. Patients with ischemic and nonischemic cardiomyopathy had similar incidence of first inappropriate (9% and 11%, P = 0.21) and first appropriate ICD therapy (11.6% and 14.1%, P = 0.15). Patients with ischemic cardiomyopathy had higher mortality rate (6.1% vs. 3.3%, P = 0.01). MADIT-RIT high-rate cut-off (arm B) and delayed VT therapy ICD programming (arm C) compared with conventional (arm A) ICD programming were associated with a significant risk reduction of first inappropriate and appropriate ICD therapy in patients with ischemic and nonischemic cardiomyopathy (HR range 0.11-0.34, P < 0.001 for all comparisons). Occurrence of total inappropriate and appropriate ICD therapies was significantly reduced by high-rate cut-off ICD programming and delayed VT therapy ICD programming in both ischemic and nonischemic cardiomyopathy patients. Conclusion High-rate cut-off and delayed VT therapy ICD programming are associated with significant reduction in first and total inappropriate and appropriate ICD therapy in patients with ischemic and nonischemic cardiomyopathy. [ABSTRACT FROM AUTHOR]

Ventricular Tachyarrhythmias and Death Background It is unknown whether circadian variation of ventricular tachyarrhythmias (VTA) affects clinical outcome in heart failure patients. Methods A total of 1,790 patients (males 75%) with heart failure, NYHA class I and II and implantable cardioverter defibrillators (ICD) or cardiac resynchronization (CRT-D) enrolled in the MADIT-CRT study were included. Time of first and all VTAs as detected and treated by the device with appropriate ICD therapy (antitachycardia pacing or shock) was evaluated by hours of the day and weekdays and related to all-cause mortality using Cox regression analyses. Results During a mean follow-up period of 40 months, a total of 3,300 VTA episodes were registered. Of all VTAs recorded, most of them (n = 2977, 90%) occurred in males. Recurrent as well as first VTA episodes were more common in the morning and evening with bimodal peaks from 7:00 to 10:59 (21%) and 18:00-21:59 (23%). VTAs that occurred during morning hours were associated with higher mortality when compared to VTA episodes occurring at other hours (hazard ratios [HR] = 2.07; confidence interval [CI]: 1.135-3.77; P = 0.018) with a significant gender interaction placing females at significantly higher risk of death (HR 6.78; CI 1.55-29.860; P = 0.011) than males (HR 1.79; CI 0.92-3.46; P = 0.086) (interaction P = 0.041) despite an overall lower probability for morning VTA among females (HR 0.32; CI 0.16-0.68; P = 0.003). Conclusions The occurrence of VTAs in heart failure patients shows a circadian variation with highest incidence during morning hours that translates into a significant higher risk of all-cause mortality, with significantly higher risk among females than males. [ABSTRACT FROM AUTHOR]

Recently, research interests are focussed on biomarkers to predict the outcome in patients with coronary artery disease (CAD). We examined whether the levels of N-terminal pro-B-type natriuretic peptide (NT-proBNP) could predict outcome in patients who underwent elective or acute coronary angiography (CAG). A total of 337 patients with suspected CAD who underwent elective or acute CAG were followed up for a mean period of 6.7 years. Primary end points were all-cause mortality (ACM) and the combined end point of ACM, nonfatal myocardial infarction, and revascularization. In all, 53 (16%) patients died and 88 (26%) patients reached the combined end point. Preprocedural NT-proBNP above 32 pmol/L independently predicted ACM (hazard ratio [HR] 3.11; confidence interval [CI]: 1.60-6.07; P = .001) and the combined end point (HR 2.44 [CI: 1.50-3.97]; P < .001). This study indicates that high NT-proBNP is an independent predictor of ACM on long-term follow-up. N-terminal-proBNP is a reliable predictive marker of mortality in the setting of stable or unstable angina. [ABSTRACT FROM PUBLISHER]

Single- versus Dual-Coil ICD Leads Background Current data on efficacy, safety and impact on clinical outcome of single- versus dual-coil implantable cardioverter-defibrillator (ICD) leads are limited and contradictory. Methods Defibrillation threshold (DFT) at implantation and first shock efficacy were compared in patients implanted with single- versus dual-coil ICD leads in MADIT-CRT. The risk for atrial tachyarrhythmias and all-cause mortality were evaluated. Short- (< 30 days after the implantation) and long-term (throughout the entire study duration) complications were assessed. Results Patients with dual-coil ICD leads had significantly lower DFTs compared to patients with single-coil ICD leads (17.6 ± 5.8 J vs 19.4 ± 6.1 J, P < 0.001). First shock efficacy was similar among patients with dual and single-coil ICD leads (89.6% vs 92.3%, P = 1.00). When comparing patients with dual versus single-coil ICD leads, there was no difference in the risk of atrial tachyarrhythmias (HR = 1.57, 95% CI: 0.81-3.02, P = 0.18), or in the risk of all-cause mortality (HR = 1.10, 95% CI: 0.58-2.07, P = 0.77). Patients implanted with single- or dual-coil ICD lead had similar short and long-term complication rates (short-term HR = 0.96, 95% CI: 0.56-1.65, P = 0.88, long-term procedure-related HR = 0.99, 95% CI: 0.62-1.59, P = 1.00, long-term ICD lead related: HR = 1.2, 95% CI: 0.5-2.9, P = 0.68) during the mean follow-up of 3.3 years. Conclusions Patients with single-coil ICD leads have slightly higher DFTs compared to those with dual-coil leads, but the efficacy, safety, and clinical impact on atrial tachyarrhythmias, and mortality is similar. Implantation of single-coil ICD leads may be favorable in most patients. [ABSTRACT FROM AUTHOR]

Inappropriate Therapy in Single Versus Dual Chamber Background The majority of implantable cardioverter defibrillators (ICDs) are dual-chamber devices, but studies on the frequency of inappropriate therapy in dual- versus single-chamber devices have shown conflicting results. The aim of this study is to determine whether implantation of dual-chamber ICD devices decrease the incidence of inappropriate therapy without an unacceptable increase in complications. Methods In the ICD arm of the MADIT-CRT study (N = 704), comparisons of single- versus dual-chamber ICD devices were investigated on the endpoints of inappropriate therapy (antitachycardia pacing [ATP] and shocks) and device- and procedure-related complications by use of multivariate Cox proportional hazard regression analysis (hazard ratio dual:single chamber) adjusting for relevant covariates. Results The frequency of inappropriate therapies in single- and dual-chamber recipients was 41/294 (14%) and 50/410 (12%), respectively. There was no significant difference in overall inappropriate therapy (hazard ratio [HR] = 0.95 [CI: 0.63-1.45], P = 0.95) or inappropriate ATP (HR = 0.98 [CI: 0.61-1.58], P = 0.94), between single- and dual-chamber devices, using single-chamber as a reference (Dual:Single). However, there was a trend toward a decrease in inappropriate shocks (HR = 0.60 [CI: 0.34-1.08], P = 0.09) in the dual-chamber group. The same was evident when only analyzing inappropriate therapy for atrial tachyarrhythmias (HR = 0.88 [CI: 0.56-1.38], P = 0.58). There was no significant difference between the groups in device- or procedure-related complications (HR = 1.54 [CI: 0.82-2.90], P = 0.18). Conclusion No significant difference was found in inappropriate therapy or complications in patients treated with single- versus dual-chamber ICD devices. [ABSTRACT FROM AUTHOR]