Rationale and design of the Lead Evaluation for Defibrillation and Reliability study: Safety and efficacy of a novel ICD lead design.

BACKGROUND: Implantable cardioverter defibrillators (ICD) are indicated for primary and secondary prevention of sudden cardiac arrest. Despite enhancements in design and technologies, the ICD lead is the most vulnerable component of the ICD system and failure of ICD leads remains a significant clinical problem. A novel, small-diameter, lumenless, catheter-delivered, defibrillator lead was developed with the aim to improve long-term reliability. METHODS AND RESULTS: The Lead Evaluation for Defibrillation and Reliability (LEADR) study is a multi-center, single-arm, Bayesian, adaptive design, pre-market interventional pivotal clinical study. Up to 60 study sites from around the world will participate in the study. Patients indicated for a de novo ICD will undergo defibrillation testing at implantation and clinical assessments at baseline, implant, pre-hospital discharge, 3 months, 6 months, and every 6 months thereafter until official study closure. Patients may be participating for a minimum of 18 months to approximately 3 years. Fracture-free survival will be evaluated using a Bayesian statistical method that incorporates both virtual patient data (combination of bench testing to failure with in-vivo use condition data) with clinical patients. The clinical subject sample size will be determined using decision rules for number of subject enrollments and follow-up time based upon the observed number of fractures at certain time points in the study. The adaptive study design will therefore result in a minimum of 500 and a maximum of 900 patients enrolled. CONCLUSION: The LEADR Clinical Study was designed to efficiently provide evidence for short- and long-term safety and efficacy of a novel lead design using Bayesian methods including a novel virtual patient approach.

Global LEADR pivotal trial results.

BACKGROUND: Implantable cardioverter-defibrillators last longer, and interest in reliable leads with targeted lead placement is growing. The OmniaSecure™ defibrillation lead is a novel small-diameter, catheter-delivered lead designed for targeted placement, based on the established SelectSecure SureScan MRI Model 3830 lumenless pacing lead platform. OBJECTIVE: This trial assessed safety and efficacy of the OmniaSecure defibrillation lead. METHODS: The worldwide LEADR pivotal clinical trial enrolled patients indicated for de novo implantation of a primary or secondary prevention implantable cardioverter-defibrillator/cardiac resynchronization therapy defibrillator, all of whom received the study lead. The primary efficacy end point was successful defibrillation at implantation per protocol. The primary safety end point was freedom from study lead-related major complications at 6 months. The primary efficacy and safety objectives were met if the lower bound of the 2-sided 95% credible interval was >88% and >90%, respectively. RESULTS: In total, 643 patients successfully received the study lead, and 505 patients have completed 12-month follow-up. The lead was placed in the desired right ventricular location in 99.5% of patients. Defibrillation testing at implantation was completed in 119 patients, with success in 97.5%. The Kaplan-Meier estimated freedom from study lead-related major complications was 97.1% at 6 and 12 months. The trial exceeded the primary efficacy and safety objective thresholds. There were zero study lead fractures and electrical performance was stable throughout the mean follow-up of 12.7 ± 4.8 months (mean ± SD). CONCLUSION: The OmniaSecure lead exceeded prespecified primary end point performance goals for safety and efficacy, demonstrating high defibrillation success and a low occurrence of lead-related major complications with zero lead fractures.

A single institution experience with pacemaker implantation in a pediatric population over 25 years.

BACKGROUND: With the development of new technical devices and software more appropriate for pediatric patients, pacemaker implantations in children and young adults have increased over time. It is necessary to monitor the mid- and long-term consequences. The decision for the implantation of a cardiovertor defibrillator (ICD) in children remains challenging despite technical improvements. OBJECTIVE: To assess the safety of pacemaker implantation in children, to review old and new indications, and to point out changes of management over time. PATIENTS AND METHODS: Between 1984 and 2009, 181 patients required the implantation of a pacemaker or an ICD device at the Heart and Diabetes Centre in Bad Oeynhausen, Germany. Their charts have been reviewed pro- and retrospectively for indications, complications, longevity of the device, and the natural course. RESULTS: Indications have been high-degree atrioventricular block in 65% (postoperative 55%) and sinus node dysfunction in 24% (postoperative 90%), including three patients with vasovagally mediated significant bradycardia. Eleven percent required the implantation of an ICD device secondary to significant ventricular arrhythmias. The indication was class II in one-third of all patients. Complications requiring revision occurred in six patients (3.3%); one of them required removal of the device due to an infection. Ten patients died, but none related to pacemaker implantation. CONCLUSION: Pacemaker implantation even in young pediatric patients is generally safe. No complication led to the death of a patient. The number of class II indications has been increasing. The future aim is to improve pediatric algorithms and to prevent unnecessary pacing.

Heart on a string: a novel approach to managing difficult access to the left pericardiacophrenic vein for phrenic nerve stimulation.

This case highlights the difficulties in pacing lead implantation for transvenous phrenic nerve stimulation to treat central sleep apnea in heart failure. Cannulation of the left pericardiacophrenic vein (PPV) initially failed due to vessel tortuosity. On the basis of sound knowledge of collateral vessels, the inferior phrenic vein (IPV), which drains into the inferior vena cava, was intubated using a guide catheter. A guidewire could be retrogradely advanced via the IPV to the left PPV and brachiocephalic vein. The wire was captured via a snare catheter, such that the heart was held "on a string", thereby providing adequate support for lead placement.

[Transvenous neurostimulation in central sleep apnea associated with heart failure]. / Transvenöse Neurostimulation bei herzinsuffizienzassoziierter zentraler Schlafapnoe.

Sleep-related breathing disorders can be classified as either obstructive (OSA) or central sleep apnea (CSA). Whereas there is substantial knowledge about the pathophysiology and sound recommendations for the diagnosis and treatment of OSA, the origin of CSA is still incompletely understood, patient identification is difficult and the necessity for specific treatment is under debate. CSA often accompanies heart failure and is associated with an adverse prognosis. Optimized heart failure treatment reduces CSA and is thus the cornerstone of CSA treatment. In contrast to OSA, noninvasive ventilation does not lead to prognostic improvement in CSA and ASV ventilation may even lead to an increase in mortality. Transvenous neurostimuation of the phrenic nerve is currently under clinical investigation as a new therapeutic modality for CSA. Early results demonstrate positive effects on sleep parameters and quality of life without any evidence for a negative impact on mortality. However, these results await confirmation in larger studies before this new approach can be advocated for routine clinical use.

[Troubleshooting in Patients with Implanted Pacemaker and ICD]. / Troubleshooting bei Patienten mit Herzschrittmacher und ICD.

Because of the growing number of implanted cardiac pacemakers and defibrillators and the ever-increasing complexity of these devices a fundamental knowledge of device malfunctions is of utmost importance even for the non-cardiology physician. Apart from hardware problems such as device infection, lead fracture or dislocation, basic knowledge of the pacemaker sensing and pacing algorithms is also necessary in order to judge the stimulation behavior in different clinical settings. With this respect, there are specific problems for antibradycardia and resynchronizing pacemakers as well as implantable defibrillators. This article gives an overview of the most common problems with cardiac pacemakers and defibrillators as well as the differential diagnostic and therapeutic management for the physician without specific training in arrhythmology.

Coronary sinus dissection during left ventricular pacing electrode implantation.

Coronary sinus (CS) dissection during biventricular pacing electrode implantation is a complication that rarely develops. A 71-year-old female with recurrent ventricular tachycardia, heart decompensation, and poor left ventricular function because of dilated cardiomyopathy was admitted for the implantation of a cardioverter-defibrillator for biventricular pacing. During the operation, we experienced a CS dissection with hematoma in the left ventricle wall while introducing the guidance catheter into the CS. However, the pacing lead was successfully implanted into the posterolateral vein using the "over-the-wire" technique. The postoperative electrocardiogram showed a decreased QRS; meanwhile, the echocardiography revealed dimensional reduction and functional improvement of the left ventricle.

Coronary vein balloon angioplasty for left ventricular pacemaker lead implantation.

OBJECTIVES: Retrospective analysis of five cases of coronary vein balloon angioplasty performed to allow insertion of left ventricular pacing leads. BACKGROUND: Coronary vein stenoses or an insufficient vessel caliber can preclude transvenous placement of coronary vein leads. METHODS: We compared our total patient population (n = 218), in whom we implanted coronary vein leads, to those five patients who required coronary vein angioplasty to allow lead placement. Standard over-the-wire coronary artery balloon angioplasty catheters were used to dilate the vessel to 2.5 mm (n = 3) or 3.5 mm (n = 2). RESULTS: Transvenous lead placement succeeds in >99% of patients. Four cases of target vein stenoses and one case of a vein of insufficient caliber were successfully treated by balloon angioplasty. There were no complications. CONCLUSIONS: Coronary vein angioplasty is an effective and safe technique to permit transvenous left ventricular pacing lead insertion in cases of target vein stenoses or insufficient target vein caliber.

Successful heart-lung transplantation in a patient with kyphoscoliosis.

The association is well established between congenital heart disease and spinal deformities such as scoliosis or kyphosis, but data are not available for risks and the outcome of heart surgery in patients with spinal deformities. We report a case of successful orthotopic heart lung transplantation in a patient with complex congenital heart disease and severe chest deformity who had undergone previous spinal fusion surgery for progressive right convex thoracic kyphoscoliosis.

Left heart pacing--experience with several types of coronary vein leads.

Our experience with 121 coronary vein (CV) leads in 116 patients shows that CV leads are the leads of choice for pacing the left ventricle (LV). The information gained from pre-operative venous angiography permits individual selection of the most appropriate lead model for each case. The use of steerable electrophysiology catheters facilitates guide catheter cannulation of the coronary sinus (CS) when the anatomy is difficult and reduces the risk of complications. By selecting the CV lead model most suitable for each individual patient, we achieved successful implantation in 99.1% of patients. In this day and age, epicardial electrodes should be restricted to cases with CS anomalies which make CS cannulation impossible, and to LV lead implantation during heart surgery.

[Device related infections. How to identify and how to treat]. / Schrittmacher- und ICD-assoziierte Infektionen. Erkennung und Behandlung.

Because of the enormous increase in pacemaker and implantable cardioverter-defibrillator (ICD) implants, the number of device-related infections has also increased considerably. In fact, this increase has been out of proportion due to the higher patient age at implant, the increased co-morbidity of patients and the higher complexity of the implanted devices. Apart from few exceptions the infection of a pacemaker or ICD requires complete explantation of the whole system with adjunctive antibiotic therapy. The diagnosis of device infection, the indication and different options for therapy are thoroughly discussed in this article according to the current status of knowledge.

[Practical aspects of pacemaker and ICD-lead extractions]. / Extraktionen von Schrittmacherund ICD-Elektroden in der klinischen Praxis.

Special tools for lead removal enables transvenous lead extractions without cardiac exposure. The risk of fatal complications during extraction of long-term implanted leads requires detailed knowledge and trained physicians. In addition to patients' age and gender, individual extraction risk factors are access and time since implantation, lead position, kind and number of leads. Locking stylets to anchor the lead within the lumen are necessary in all extraction procedures while the use of external sheaths is optional. Higher risk of cardiac or central vein perforation during lead mobilisation with external laser sheaths has to be respected, and these tools should be used with strong indication only. In cases of high risk, lead explantation with an open heart procedure should be considered as an alternative.

A silent gigantic solitary fibrous tumor of the pleura: case report.

Solitary fibrous tumor of the pleura is a rare mesenchymal tumor, representing less than 5% of all neoplasms associated with the pleura. A 57-year-old man had general malaise without chest symptoms for 1 month. A chest roentgenogram and computed tomography showed a giant mass in the left thorax. Although the tumor compressed the descending aorta and other mediastinal structures strongly, thereby shifting them to the right side, the patient had no symptoms except malaise. The tumor was successfully resected via two separate thoracotomies. The tumor was measured (20 cm × 19 cm × 15 cm) and weighed (2150 g). The tumor was histologically and immunohistochemically diagnosed as benign. Although SFT is benign, a long follow-up period is essential as even patients with complete resection are at risk of recurrence many years after surgery.

Cardiac resynchronization therapy: long-term alternative to cardiac transplantation?

BACKGROUND: Cardiac transplantation remains the gold standard for treating end-stage heart failure. However, because of donor shortage and posttransplant complications alternative options are needed. METHODS: We investigated the impact of cardiac resynchronization therapy on clinical outcome in 545 patients with left bundle-branch block and interventricular asynchrony, who fulfilled the cardiac criteria for cardiac transplantation listing. Primary end point was heart failure death. Secondary end points were New York Heart Association class, functional (cardiopulmonary exercise tolerance, 6-minute hall walk distance), and morphologic (left ventricular end-diastolic diameter) factors. RESULTS: The average follow-up period was 39.6 months (standard deviation, 26.1 months). In total, 1,784 years of observation were accrued. The percentage of nonresponders (no functional and morphologic improvement during follow-up) was 21.2%. One-year and 3-year freedom from heart failure death was 92.3% and 77.3%, respectively. Functional variables improved, but the left ventricular end-diastolic diameter decreased during the first 6 months of cardiac resynchronization therapy only in patients who survived during follow-up. Under cardiac resynchronization therapy, 42.5% (n = 34) of the cardiac transplantation candidates with atrial fibrillation at baseline returned to sinus rhythm. CONCLUSIONS: Our data suggest that cardiac resynchronization therapy is a reliable long-term therapeutic option for the treatment of end-stage heart failure and intraventricular asynchrony.

Implantation of active fixation leads in coronary veins for left ventricular stimulation: report of five cases.

BACKGROUND: Securing transvenous left ventricular (LV) pacing leads without an active fixation mechanism in proximal coronary vein (CV) segments is usually challenging and frequently impossible. We investigated how active fixation leads can be safely implanted in this location, how to avoid perforating the free wall of the CV, and how to recognize and respond to perforations. MATERIALS AND METHODS: In five patients with no alternative to LV pacing from proximal CV segments, 4 Fr SelectSecure (Medtronic, Minneapolis, MN, USA) leads, which have a fixed helix, were implanted through a modified 6 Fr guide catheter with a pre-shaped tip (Launcher, Medtronic). RESULTS: Active fixation leads were successfully implanted in proximal CVs in five patients. There were no complications. Acute and chronic pacing thresholds were comparable to those of conventional CV leads. The pre-shaped guide catheter tip remains in close proximity to the myocardial aspect of the CV, directing the lead helix toward a safe implantation site. CONCLUSIONS: If only proximal CV pacing sites are available, 4 Fr SelectSecure leads can be safely implanted through a modified Launcher guide catheter, avoiding more invasive implantation techniques. Other than venous stenting or implantation of leads with retractable tines, SelectSecure leads are expected to remain extractable.

Left ventricular pacing through the anterior interventricular vein in a patient with mechanical tricuspid, aortic and mitral valves.

Transvenous endocardial pacemaker implantation is contraindicated in patients after mechanical tricuspid valve replacement. A 76-year-old woman who suffered from bradyarrhythmia was implanted with a left ventricular pacing lead through a transvenous coronary vein after aortic, mitral, and tricuspid valve replacements. There were no complications and the stimulation thresholds were stable. The use of coronary vein leads provides a minimally invasive approach, safety, and effective stimulation for patients with a mechanical tricuspid valve.

Endocardial pacing after Fontan-type procedures.

BACKGROUND: Sinus node dysfunction is a frequent complication of Fontan-type procedure. Epicardial pacing is considered as the standard treatment for these patients. METHODS AND RESULTS: We evaluated an endocardial approach in seven patients using a 4.1 French bipolar lumenless lead (SelectSecure) that is positioned through a steerable guiding catheter. Either a purely transvenous or an open transatrial approach can be used for lead placement. The smallest child weighed 12 kg. Individual anatomy was assessed preimplantation using magnetic resonance imaging and injection of radiographic contrast agent through the guiding catheter. A pullback pressure recording was used to confirm unimpaired blood flow into the pulmonary artery. Five of our seven patients underwent de novo transvenous atrial lead implantation for AAIR pacing. In the remaining two patients, both atrial and ventricular leads were inserted. One patient with an intraatrial tunnel underwent transvenous-lead placement. The remaining patient with an extracardiac conduit received atrial and ventricular leads implanted through a guiding catheter inserted through an atriotomy. The postoperative management included short- or long-term oral anticoagulation. CONCLUSIONS: Transvenous endocardial lead implantation avoids the problem of increasing capture thresholds typically observed with epicardial leads. Due to its high tensile strength and lumenless design, the isodiametric lead is expected to remain extractable for an extended period of time.