Abstract Background Heart Failure (HF) is increasing in prevalence and is a major cause of morbidity and mortality, despite advances in medical and device therapy. Autonomic imbalance, with excess ...sympathetic activation and decreased vagal tone, is an integral component of the pathophysiology of HF. Objectives INOVATE-HF was designed to assess the safety and efficacy of vagal nerve stimulation (VNS) among patients with heart failure and a reduced ejection fraction. Methods INOVATE-HF was a multinational, randomized trial involving 85 centers in patients with chronic HF, NYHA III symptoms and ejection fraction < 40%. Patients were assigned to device implantation to provide VNS (Active) or continued medical therapy (Control) in a 3:2 ratio. The primary efficacy endpoint was the composite of death from any cause or first event for worsening HF. Results There were 707 patients randomized and followed for a mean of 16 months. The primary efficacy outcome occurred in 132 of 436 patients in the VNS group, as compared with 70 of 271 in the control group (30.3% vs. 25.8%; hazard ratio, 1.14; 95% confidence interval CI, 0.86 to 1.53; P = 0.37). During the trial, the estimated annual mortality rates of 9.3% and 7.1%, respectively (p=0.19). Quality of life, New York Heart Association Class and 6 minute walking distance were favorably affected by VNS (p’s < 0.05), but left ventricular end-systolic volume index was not different (P=0.49). Conclusions VNS does not reduce the rate of death or HF events in chronic HF patients. (Clinical Trials.gov number NCT01303718)
Acute studies have suggested that left ventricular pacing (LVP) may have benefits over biventricular pacing (BVP). The adaptive cardiac resynchronization therapy (aCRT) algorithm provides LVP ...synchronized to produce fusion with the intrinsic activation when the intrinsic atrioventricular (AV) interval is normal. The randomized double-blind adaptive cardiac resynchronization therapy trial demonstrated noninferiority of the aCRT algorithm compared to echocardiography-optimized BVP (control).
To examine whether synchronized LVP (sLVP) resulted in better clinical outcomes.
First, stratification by percent sLVP (%sLVP) and multivariate Cox proportional hazards model was used to assess the relationship between %sLVP and clinical outcomes. Second, outcomes were compared between patients in the aCRT arm (n = 318) and control patients (n = 160) stratified by intrinsic AV interval at randomization.
In the aCRT arm, %sLVP ≥50% (n = 142) was independently associated with a decreased risk of death or heart failure hospitalization (hazard ratio 0.49; 95% confidence interval 0.28-0.85; P = .012) compared with %sLVP <50% (n = 172). A greater proportion of patients with %sLVP ≥50% improved in Packer's clinical composite score at 6-month (82% vs. 68%; P = .002) and 12-month (80% vs. 62%; P = .0006) follow-ups compared to controls. In the subgroup with normal AV (n = 241), there was a lower risk of death or heart failure hospitalization (hazard ratio 0.52; 95% confidence interval 0.27-0.98; P = .044) with the aCRT algorithm. A greater proportion of patients in the aCRT arm improved in the clinical composite score at 6-month (81% vs. 69%; P = .041) and 12-month (77% vs. 66%; P = .076) follow-ups compared to controls.
Higher %sLVP was independently associated with superior clinical outcomes. In patients with normal AV conduction, the aCRT algorithm provided mostly sLVP and demonstrated better clinical outcomes compared to echocardiography-optimized BVP.
In patients with sinus rhythm and normal atrioventricular conduction, pacing only the left ventricle with appropriate atrioventricular delays can result in superior left ventricular and right ...ventricular function compared with standard biventricular (BiV) pacing.
To evaluate a novel adaptive cardiac resynchronization therapy ((aCRT) algorithm for CRT pacing that provides automatic ambulatory selection between synchronized left ventricular or BiV pacing with dynamic optimization of atrioventricular and interventricular delays.
Patients (n = 522) indicated for a CRT-defibrillator were randomized to aCRT vs echo-optimized BiV pacing (Echo) in a 2:1 ratio and followed at 1-, 3-, and 6-month postrandomization.
The study met all 3 noninferiority primary objectives: (1) the percentage of aCRT patients who improved in their clinical composite score at 6 months was at least as high in the aCRT arm as in the Echo arm (73.6% vs 72.5%, with a noninferiority margin of 12%; P = .0007); (2) aCRT and echo-optimized settings resulted in similar cardiac performance, as demonstrated by a high concordance correlation coefficient between aortic velocity time integrals at aCRT and Echo settings at randomization (concordance correlation coefficient = 0.93; 95% confidence interval 0.91-0.94) and at 6-month postrandomization (concordance correlation coefficient = 0.90; 95% confidence interval 0.87-0.92); and (3) aCRT did not result in inappropriate device settings. There were no significant differences between the arms with respect to heart failure events or ventricular arrhythmia episodes. Secondary end points showed similar benefit, and right-ventricular pacing was reduced by 44% in the aCRT arm.
The aCRT algorithm is safe and at least as effective as BiV pacing with comprehensive echocardiographic optimization.
Magnetic resonance imaging (MRI) can be safely performed in patients with magnetic resonance (MR)–conditional pacemaker systems but remains relatively contraindicated with non–MR-conditional ...pacemaker systems.
The purpose of this study was to evaluate the safety of MRI without positioning restrictions in patients with an MR-conditional pacemaker and currently a non–MR-conditional Medtronic CapSureFix Novus 5076 lead(s).
The study randomized 266 patients in a 2:1 ratio to the MRI group (177 patients) or to the control group (89 patients). At 9–12 weeks postimplant, the MRI group underwent MRI at 1.5 T. Primary end points were MRI-related complication-free rate and noninferiority of the MRI group compared to the control group with regard to the proportion of patients with an increase of ≤0.5 V in right atrial (RA) and right ventricular (RV) pacing capture thresholds from immediately before MRI to 1-month after MRI.
No MRI-related complications occurred in 156 MRI-scanned patients who were followed through 1-month post-MRI. Differences in the proportion of patients with ≤0.5 V pacing capture threshold changes from pre-MRI to 1-month post-MRI were minimal between the groups for RA (proportions of 100% in both groups; a P value cannot be calculated) and RV leads (proportions of 99.3% in the MRI group and 100% in the control group; noninferiority test, P < .0001). Proportions of patients with acceptable sensing amplitude changes from pre-MRI to 1-month post-MRI were also similar between the 2 groups for RA and RV leads (noninferiority test, P < .0001 and P = .0004, respectively). No arrhythmias occurred during MRI.
MRI scans can be performed safely without positioning restrictions in patients with Medtronic CapSureFix Novus 5076 leads connected to an MR-conditional pacemaker.
Abstract Objectives This study sought to assess the clinical impact of immediate versus delayed invasive intervention in patients with non–ST-segment myocardial infarction (NSTEMI). Background ...Previous studies found conflicting results on the effects of earlier invasive intervention in a heterogeneous population of acute coronary syndromes without ST-segment elevation. Methods We randomized 323 NSTEMI patients to an immediate-intervention group (<2 h after randomization, n = 162) and a delayed-intervention group (2 to 72 h, n = 161).The primary endpoint was the occurrence of death or new myocardial infarction (MI) at 30-day follow-up. Results Median time from randomization to angiography was 1.4 h and 61.0 h in the immediate-intervention group and the delayed-intervention group, respectively (p < 0.001). At 30 days, the primary endpoint was achieved less frequently in patients undergoing immediate intervention (4.3% vs. 13%, hazard ratio: 0.32, 95% confidence interval: 0.13 to 0.74; p = 0.008). At 1 year, this difference persisted (6.8% in the immediate-intervention group vs. 18.8% in delayed-intervention group; hazard ratio: 0.34, 95% confidence interval: 0.17 to 0.67; p = 0.002). The observed results were mainly attributable to the occurrence of new MI in the pre-catheterization period (0 deaths + 0 MIs in the immediate-intervention group vs. 1 death + 10 MIs in the delayed-intervention group). The rate of deaths, new MI, or recurrent ischemia was lower in the immediate-intervention group at both 30 days (6.8% vs. 26.7%; p < 0.001) and 1 year (15.4% vs. 33.1%; p < 0.001). Conclusions Immediate invasive strategy in NSTEMI patients is associated with lower rates of death or new MI compared with the delayed invasive strategy at early and midterm follow-up, mainly due to a decrease in the risk of new MI in the pre-catheterization period. (Immediate Versus Delayed Invasive Intervention for Non-STEMI Patients RIDDLE-NSTEMI; ( NCT02419833 )
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