Leadless epicardial pacing at the left ventricular apex: an animal study.

AIMS: State-of-the-art pacemaker implantation technique in infants and small children consists of pace/sense electrodes attached to the epicardium and a pulse generator in the abdominal wall with a significant rate of dysfunction during growth, mostly attributable to lead failure. In order to overcome lead-related problems, feasibility of epicardial implantation of a leadless pacemaker at the left ventricular apex in a growing animal model was studied. METHODS AND RESULTS: Ten lambs (median body weight 26.8 kg) underwent epicardial implantation of a Micra transcatheter pacing system (TPS) pacemaker (Medtronic Inc., Minneapolis, USA). Using a subxyphoid access, the Micra was introduced through a short, thick-walled tube to increase tissue contact and to prevent tilting from the epicardial surface. The Micra's proprietary delivery system was firmly pressed against the heart, while the Micra was pushed forward out of the sheath allowing the tines to stick into the left ventricular apical epimyocardium. Pacemakers were programmed to VVI 30/min mode. Pacemaker function and integrity was followed for 4 months after implantation. After implantation, median intrinsic R-wave amplitude was 5 mV [interquartile range (IQR) 2.8-7.5], and median pacing impedance was 2235 Ω (IQR 1725-2500), while the median pacing threshold was 2.13 V (IQR 1.25-2.9) at 0.24 ms. During follow-up, 6/10 animals had a significant increase in pacing threshold with loss of capture at maximum output at 0.24 ms in 2/10 animals. After 4 months, median R-wave amplitude had dropped to 2.25 mV (IQR 1.2-3.6), median pacing impedance had decreased to 595 Ω (IQR 575-645), and median pacing threshold had increased to 3.3 V (IQR 1.8-4.5) at 0.24 ms. Explantation of one device revealed deep penetration of the Micra device into the myocardium. CONCLUSION: Short-term results after epicardial implantation of the Micra TPS at the left ventricular apex in lambs were satisfying. During mid-term follow-up, however, pacing thresholds increased, resulting in loss of capture in 2/10 animals. Penetration of one device into the myocardium was of concern. The concept of epicardial leadless pacing seems very attractive, and the current shape of the Micra TPS makes the device unsuitable for epicardial placement in growing organisms.

The GermAn Laser Lead Extraction RegistrY: GALLERY.

AIMS: The GermAn Laser Lead Extraction RegistrY: GALLERY is a retrospective, national multicentre registry, investigating the safety and efficacy of laser lead extraction procedures in Germany. METHODS AND RESULTS: Twenty-four German centres that are performing laser lead extraction have participated in the registry. All patients, treated with a laser lead extraction procedure between January 2013 and March 2017, were consecutively enrolled. Safety and efficacy of laser lead extraction were investigated. A total number of 2524 consecutive patients with 6117 leads were included into the registry. 5499 leads with a median lead dwell time of 96 (62-141) months were treated. The mean number of treated leads per patient was 2.18 ± 1.02. The clinical procedural success rate was 97.86% and the complete lead removal was observed in 94.85%. Additional extraction tools were used in 6.65% of cases. The rate of procedural failure was 2.14% with lead age ≥10 years being its only predictor. The overall complication rate was 4.32%, including 2.06% major and 2.26% minor complications. Procedure-related mortality was 0.55%. Female sex and the presence of abandoned leads were predictors for procedure-related complications. The all-cause in-hospital mortality was 3.56% with systemic infection being the strongest predictor, followed by age ≥75 years and chronic kidney disease. CONCLUSION: In the GALLERY, a high success- and low procedure-related complication rates have been demonstrated. In multivariate analysis, female sex and the presence of abandoned leads were predictors for procedure-related complications, while the presence of systemic infection, age ≥75 years, and chronic kidney disease were independent predictors for all-cause mortality.

Epicardial implantation of a leadless pacemaker in a lamb model.

BACKGROUND: Pacemaker used in small children typically consist of an abdominally placed generator and epicardially affixed leads, making such a system prone to lead dysfunction during growth. Aim of this study was to investigate the feasibility of epicardial pacing with a leadless pacemaker in a lamb model. ANIMALS AND METHODS: Seventeen lambs underwent epicardial implantation of a Micra transcatheter pacing system (TPS) (Medtronic, Minneapolis, MN, USA) via left-lateral thoracotomy to the left ventricle (LV) surface (n = 11/17) and to the left atrial appendage (n = 6). Ventricular devices were fixated with the tines within the pericardium, whereas the tines of the atrial devices penetrated the myocardium of the left atrial appendage. After 31 weeks, animals were sacrificed and hearts were explanted for histological analysis. RESULTS: Following implantation, median P/R amplitude was 4.25/5.5 mV while median pacing threshold was 1.1/1.9 V at 0.24 ms. After 31 weeks, median P/R amplitude was 3.3/4.2 mV. Median atrial pacing threshold was 0.5/0.24 ms. Eight of 10 ventricular pacemakers had lost capture at standard impulse width even at maximum impulse amplitude. On explantation, firm adhesion of the device to the thoracic wall and dislodgement of the electrode tip was found in those ventricular devices. CONCLUSIONS: Firm fixation of the Micra electrode to the epicardial surface as applied to the atrial devices resulted in excellent electrical properties during midterm follow up. Pericardial fixation as in the ventricular devices was associated with loss of capture. Therefore, it is important to embed the tines in the myocardium and to choose an alternative implantation site allowing for safe fixation of the Micra TPS in a position perpendicular to ventricular epimyocardium.

Viabahn stent graft compared with prosthetic surgical above-knee bypass in treatment of superficial femoral artery disease: Long-term results of a retrospective analysis.

The prosthetic surgical above-knee bypass (pAKB) is a standard therapy in superficial femoral artery (SFA) occlusive disease in absence of suitable vein. Viabahn graft has been established as a promising alternative. Since limited comparative data are available, we conducted a retrospective study to compare long-term outcomes of these 2 therapies in a real-world setting.Records of 52 patients (60 limbs), who were treated by pAKB (29 limbs) or Viabahn (31 limbs) were reviewed. Patients were followed up by clinical assessment, physical examination, and resting ankle brachial index (ABI) after 3, 6, 12 months and yearly thereafter. Long-term data were available for 97% in the Viabahn and 93% for pAKB after 73 ±â€Š3.7 months (mean ±â€Šstandard error [SE]).Long-term primary and secondary patencies in Viabahn group were 40% and 70%, respectively, after 63 ±â€Š2.8 months (mean ±â€ŠSE). Total lesion length was 19 ±â€Š11.06 cm (mean ±â€ŠSE), graft size was 6 ±â€Š0.72 mm (mean ±â€ŠSE). Hospital stay was 4.8 ±â€Š0.72 days (mean ±â€ŠSE). Limb salvage was achieved in 90%. Patients in the pAKB group showed a total lesion length of 24.39 ±â€Š1.97 cm (mean ±â€ŠSE), graft size was 7 ±â€Š0.99 mm (mean ±â€ŠSE). Long-term analysis after 83 ±â€Š6.8 months (mean ±â€ŠSE) revealed a primary patency of 78% with a secondary patency of 94%. Hospital stay was 10.4 ±â€Š1.27 days (mean ±â€ŠSE). Limb salvage was ensured in 97%. Long-term primary patency was lower for Viabahn (P = .044), secondary patency (P = .245), and leg salvage (P = .389) were not significantly different. However, hospital stay was shorter (P = .0002) for Viabahn.Long-term analysis of Viabahn revealed a significantly lower primary patency, a similar secondary patency, limb salvage, and significantly shorter hospital stay when compared with pAKB. Our data suggest that pAKB is still a valuable option in patients suitable for an open operation. However, Viabahn can be used as a less invasive treatment in high risk patients.

Risk and Outcome after Simultaneous Carotid Surgery and Cardiac Surgery: Single Centre Experience.

OBJECTIVE: Carotid artery stenosis in patients undergoing open-heart surgery may increase risk and deteriorate outcome. The aim of the study was the analysis of risks and outcome after simultaneous carotid and cardiac surgery. METHODS: We retrospectively reviewed the medical records of 100 consecutive patients who underwent simultaneous carotid surgery and open-heart surgery during a 5-year period (from 2006 to 2010). Seventy patients were male and 30 female; the mean age was 70.9±7.9 years (median: 71.8 years). Seventy-three patients underwent coronary bypass grafting (CABG), 18 patients combined CABG and valve procedures, 7 patients CABG combined with other procedures, and 3 patients isolated valve surgery. More than half of patients had had bilateral carotid artery pathology (n=51) including contralateral carotid artery occlusion in 12 cases. RESULTS: Carotid artery patch plasty was performed in 71 patients and eversion technique in 29. In 75 cases an intraluminal shunt was used. Thirty-day mortality rate was 7% due to cardiac complications (n=5), metabolic disturbance (n=1), and diffuse cerebral embolism (n=1). There were no carotid surgery-related deaths. Postoperatively, transient cerebral ischemia occurred in one patient and stroke with mild permanent neurological deficit (Rankin level 2) in another patient. CONCLUSION: Simultaneous carotid artery surgery and open-heart surgery have low risk. The underlying cardiac disease influences outcome.

Safety profile of baroreflex activation therapy (NEO) in patients with resistant hypertension.

OBJECTIVE: Unlike safety data of baroreflex activation therapy device (Rheos), only few data of the currently used second device (Barostim neo) are available and little is reported about common side effects. METHODS: We prospectively analyzed patients with resistant hypertension treated with Barostim neo. A standardized interview regarding side effects of the therapy was performed in routine follow-up visits after device implantation in 42 patients to determine adverse events staged into three degrees. RESULTS: Within 6 months of baroreflex activation therapy, the office mean arterial blood pressure decreased from 169 ±â€Š27 to 148 ±â€Š29 mmHg systolic (P < 0.001), respectively, to 145 ±â€Š24 mmHg after 1 year (P < 0.001), whereas the number of prescribed antihypertensive classes decreased from 6.6 ±â€Š1.5 to 5.6 ±â€Š1.8 (P < 0.001). Adverse events were combination of the following field depending on the severity (I° mild: local discomfort, clinical observation only, no intervention indicated; II° moderate: medically significant such as occurrence of hypertensive crisis, syncope, arrhythmias; III° severe: life-threatening events or urgent medical intervention indicated). Adverse events I° were present in almost all patients (97.6%), and occurred mainly within first 6 months after device activation. Device-related events were most frequently and could be resolved by optimization of device parameters. Most procedure-related adverse events were directly related to the incision or anesthetic procedure. Adverse events II° occurred in 28.6% patients treated with Barostim neo, whereas patients' elevated individual risks might be potential triggers. Because of individual diversity of blood pressure response and the occurrence of adverse events, no standardization of parameters of implantable pulse generator could be found. By adapting the pulse generator settings individually, most of adverse events I° resolved without sequel. CONCLUSION: Though there are common side effects, Barostim neo significantly lowers blood pressure in resistant hypertension and provides an adequate safety profile. Regular patient visits are necessary to register side effects.

Supra-aortic interventions for endovascular exclusion of the entire aortic arch.

OBJECTIVE: Our aim was to analyze the outcomes of endovascular exclusion of the entire aortic arch (proximal landing in zone 0, distal landing in zone III or beyond, after Ishimaru) in which complete surgical debranching of the supra-aortic vessels (I), endovascular supra-aortic revascularization (chimney, fenestrated, or branched grafts) with partial surgical debranching (II), or total endovascular supra-aortic revascularization (III) was additionally performed. METHODS: Publications describing endovascular repair of the aortic arch (2000-2016) were systematically searched and reviewed. RESULTS: From a total of 53 relevant studies including 1853 patients, only 1021 patients undergoing 35 different total aortic arch procedures were found eligible for further evaluation and included in group I, II, or III (429, 190, and 402 patients, respectively). Overall early mortality was higher in group I vs groups II and III (P = .001; 1 - ß = 95.6%) but exceeded in group III (18.6%) and group II (14.0%) vs group I (8.0%; P = .044; 1 - ß = 57.4%) for diseases involving zone 0. Mortality was higher in all subgroups treated for zone 0 disease compared with corresponding subgroups treated for zone I to zone III disease. The incidence of cerebral ischemic events was increased in groups I and II vs group III (7.5% and 11% vs 1.7%; P = .0001) and correlated with early mortality (R2 = .20; P = .033). The incidence of type II endoleaks and endovascular reintervention was similar between groups and correlated with each other (R2 = .37; P = .004). Type Ia endoleak occurred more often in groups II and III than in group I (7.1% and 12.1% vs 5.8%; P = .023) and correlated with midterm mortality (R2 = .53; P = .005). Retrograde type A dissection was low in all groups, whereas aneurysm growth was higher in group III (2.6%, 4.2%, 10.7%; P = .002), correlating with midterm mortality (R2 = .311; P = .009). Surgical revision slightly correlated with surgical complications (R2 = .18; P = .044) but not with mortality (R2 = .10; P = .214). CONCLUSIONS: Because early mortality was significantly higher in patients receiving endovascular treatment for proximal aortic disease, endovascular-based approaches proved to be feasible alternatives to hybrid surgical procedures, especially when they were performed for aneurysms located in the distal aortic arch. Whereas cerebral ischemia accompanies both surgical and endovascular involvement of the supra-aortic vessels, endoleaks and aneurysm growth remain hallmarks of endovascular supra-aortic repair. Because surgical revision had no impact on mortality, complete surgical debranching may become the option of choice for patients with good life expectancy suffering from proximal aortic arch disease, whereas total endovascular procedures could be particularly advantageous in patients with short life expectancy and distal aortic arch disease.

Baroreflex activation therapy in patients with prior renal denervation.

BACKGROUND: Both baroreflex activation therapy (BAT) and renal denervation modulate sympathetic activity. The aim of this study was to systematically investigate whether additive modulation of autonomic nervous system by BAT lowers blood pressure (BP) in patients who still suffer from uncontrolled resistant hypertension despite prior renal denervation. METHODS: From 2012 to January 2015, patients treated with BAT for uncontrolled resistant hypertension, who prior received renal denervation were consecutively analyzed in four German centers for hypertension. Analyses of office BP, 24-h ambulatory BP, central hemodynamics, parameters of renal function were performed. RESULTS: A total of 28 patients, who underwent renal denervation at least 5 months before and still suffer from uncontrolled BP, were subsequently treated with BAT. The office SBP decreased from 182 ±â€Š28 to 163 ±â€Š27 mmHg (P < 0.01) with a responder rate of 68% (office SBP reduction ≥10 mmHg) at month 6, whereas the number of prescribed antihypertensive drug classes remained unchanged (6.2 ±â€Š1.5 vs. 6.0 ±â€Š1.7, P = 0.30). Serum creatinine, estimated glomerular filtration rate and cystatin C remained stable (P = 1.00, P = 0.41 and P = 0.22, respectively), whereas albuminuria was significantly reduced by a median of -29% (P = 0.02). Central SBP (-15 ±â€Š24 mmHg, P = 0.047) and end systolic pressure (-14 ±â€Š20 mmHg, P = 0.03) were significantly reduced. CONCLUSION: The present data demonstrate that BAT may exert BP-lowering as well as antiproteinuric effects in patients with prior renal denervation. However, precise evaluation of BAT effects in patients with prior renal denervation will need randomized controlled trials using sham procedures.

Passive-fixation lead failure rates and long-term patient mortality in subjects implanted with Sprint Fidelis electrodes.

AIMS: To evaluate passive-fixation lead failure rates and long-term patient survival in subjects implanted with Sprint Fidelis electrodes. METHODS AND RESULTS: We identified 748 subjects who received a Sprint Fidelis (n = 429; Medtronic models 6948: 94.8%, 6949: 2.6%, 6930: 1.9%, 6931: 0.7%) or a Sprint 'non-Fidelis' implantable cardioverter defibrillator lead (n = 319, Medtronic models 6944: 68.6%, 6947: 17.9%, 6942: 7.8%, 6943: 3.4%, 6945: 2.2%) at our centre between 1998 and 2008. Kaplan-Meier patient survival was lower in the Fidelis group than in the Control cohort (68.4 vs. 77.0% at 5 years, P = 0.0061), but multivariate analyses revealed no significant association between mortality and implanted lead type. Passive-fixation lead failure rate at 5 years was 14.4% (95% confidence interval (CI) [9.2, 19.3]) in the Fidelis (n = 414) group and 1.8% (95% CI [0.0-3.8]) in the Control (n = 241) cohort (P < 0.001 upon multivariate comparison). CONCLUSION: Failure rates of passive-fixation Sprint Fidelis leads are increased and similar to those previously reported for active-fixation Fidelis electrodes. Despite the elevated risk for lead failure and its potential sequelae, the Sprint Fidelis has no obvious impact on long-term mortality.

Is there an alternative to the surgical above-knee bypass in treatment of superficial femoral artery disease? Experiences with Viabahn stent graft.

OBJECTIVE: We conducted a retrospective study to compare short- and mid-term patencies of Viabahn with surgical above-knee prosthetic bypass (pAKB). METHODS: The records of 52 patients with either pAKB (n = 25) or Viabahn (n = 27) were reviewed. The majority had Rutherford clinical grade 3. Patients were followed after 3, 6, and 12 months and yearly thereafter. RESULTS: For Viabahn, the short-term (1-16 months) primary patency rate was 60% with a secondary patency rate of 90%, and mid-term (1-68 months) patencies of 47% and 83.3%, respectively. In pAKB, the short-term results revealed a primary patency rate of 78% with a secondary patency of 91% and mid-term results of 65% and 90%, respectively. No statistical difference was found concerning short-term patencies. Mid-term primary patency was lower for Viabahn (P < .05) and secondary patency proved no significant difference. CONCLUSION: Viabahn revealed similar short-term primary and secondary patencies but lower mid-term primary patency. It provides a good alternative therapy to pAKB.

Randomized Clinical evaluatiON of wireless fluid monitoriNg and rEmote ICD managemenT using OptiVol alert-based predefined management to reduce cardiac decompensation and health care utilization: the CONNECT-OptiVol study.

AIMS: The CONNECT-OptiVol study is designed to investigate whether wireless fluid monitoring using OptiVol alerts as well as implantable cardioverter-defibrillator (ICD) remote monitoring (RM) reduces cardiac decompensations and health care utilization in ICD patients, as compared to standard clinical care. METHODS: Patients undergoing implantation of wireless telemetry-enabled dual chamber (ICD-DR) or cardiac resynchronization therapy/defibrillator (CRT-D) devices with the OptiVol feature are eligible for the study. In a randomized fashion, OptiVol function, its audible alert as well as its remote alert, and other ICD RM alerts are switched ON or OFF. The primary study objective is to estimate an improvement of heart failure status. The primary endpoint is measured as a prolongation of the time to first hospitalization due to worsened heart failure. The secondary objectives are to estimate: a reduction of the time from event to clinical decision, a reduction of the rate of health care utilization, and improved quality of life (QoL) measures (secondary endpoints). The study is designed as a single center pilot study with 180 patients randomized 1:1 to the two study arms. CONCLUSION: The CONNECT-OptiVol study aims to answer whether wireless fluid monitoring integrated into RM may reduce cardiac decompensations and health care utilization in ICD patients. The results can be used to adequately power future studies evaluating the benefit of these features. Study enrollment has been completed, and follow-up is expected to be finished in September 2012.

Treatment of cardiovascular implantable electronic device infection with daptomycin.

We describe a case of 83-year-old man who was admitted to our department for treatment of recurrent device-pocket infections. Our report shows that in a case of high-risk patient with a complicated cardiac implantable electric devices infection involving multidrug-resistent gram-positive pathogen, the application of daptomycin in combination with staged surgical therapy can be efficient and safe.

Acute and long-term feasibility of contralateral transvenous lead placement with subcutaneous, pre-sternal tunnelling in patients with chronically implanted rhythm devices.

AIMS: A growing number of patients with implanted rhythm devices require new or additional leads, e.g. in cases of electrode defect or planned device upgrade. If the ipsilateral subclavian vein is occluded, transvenous electrode placement from the contralateral side with subcutaneous, pre-sternal lead tunnelling (TUN) is one potential option that has been described in anecdotal reports. The aim of this retrospective study was to determine the acute and long-term feasibility of this approach. METHODS AND RESULTS: We identified 18 subjects (67% male, 66±14 years) who underwent TUN at our institution between the years 1995 and 2009. Implantation protocols and patient files were reviewed for peri-operative complications and long-term lead performance. Furthermore, patients were interviewed for symptoms related to the tunnelled lead. Twenty transvenous leads (seven implantable cardioverter defibrillator leads; five left ventricular, four right ventricular, four right atrial pace/sense electrodes) were successfully tunnelled without significant peri-operative complications. The follow-up duration was 29±36 (3-162) months. Electrical parameters remained stable in 95% (19/20) of the tunnelled leads. In one right ventricle pace/sense lead, ventricular oversensing was documented 10 months after TUN, and the lead was replaced because a structural defect could not be excluded. Five patients died without causal relationship to the procedure 4-48 months after TUN. One patient reported discomfort related to the tunnelled lead. CONCLUSION: Contralateral transvenous lead implantation with subcutaneous, pre-sternal TUN appears to be a feasible option in selected patients with an implanted rhythm device and ipsilateral subclavian vein occlusion.

Feasibility of implantable cardioverter defibrillator treatment in five patients with familial Friedreich's ataxia--a case series.

Friedreich's ataxia (FRA) is an autosomal recessive disease of the central nervous system that is associated with familial cardiomyopathy. Cardiac involvement is seen in more than 90% of the patients and is the most common cause of death in these patients. We present a case series and discuss the indications for implantable cardioverter defibrillator (ICD) implantation in FRA with review of the literature. Five pediatric patients who suffer from FRA (four female and one male, mean age 17.4 years) underwent ICD implantation between 2007 and 2008 in the University Hospital of Goettingen. The diagnosis of FRA was established by standard clinical criteria and proven in each case by genotyping at the frataxin locus. The time from diagnosis to ICD implantation was 10.4±1.73 years (range 8-15 years). All patients received transvenous lead systems. There were no intraoperative and postoperative complications. At the latest follow-up, the neuromuscular symptoms exhibited no further progress and no ICD activations were noticed. Only minor repolarization changes were seen on electrocardiogram. All patients had normal echocardiographic findings and no angina has been reported. Coronary angiographies were normal. It is evident that many FRA patients develop ventricular dysfunction. In the absence of a definitive surgical cure an ICD is generally indicated in young patients with hemodynamically significant sustained ventricular tachyarrhythmias for prevention of sudden cardiac death. Our experience implies the safe use of ICD in children with FRA.

Indications for reoperation late after correction of tetralogy of Fallot.

OBJECTIVE: Correction of tetralogy of Fallot has excellent long-term results. The present retrospective study investigates the indications for reoperation late after corrective surgery. METHODS: Data from 914 consecutive cases who underwent correction of tetralogy of Fallot in our department between 1960 and 2002 were retrospectively reviewed and analysed. In 91 patients, a total of 102 reoperations were performed late after repair. RESULTS: The mean time interval between corrective surgery and the first reoperation was 12.8 years. The main indication for reoperation was residual ventricular septal defect in nearly half of the cases, mostly isolated, but also in combination with a right ventricular outflow tract aneurysm or pulmonary stenosis. One-fourth of reoperated patients underwent a procedure on their pulmonary artery or pulmonary valve: replacement of pulmonary valve, replacement of primary implanted pulmonary artery conduits with or without concomitant surgery, and surgery for isolated peripheral pulmonary stenosis. The remaining indications were right ventricular outflow tract aneurysms and others. Aneurysms of the right ventricular outflow tract were seen mostly after the use of autologous - untreated - pericardial patch in 18 of 21 cases. CONCLUSION: The number of reoperations for residual ventricular septal defect decreased during the study period. The primary use of conduits led to an increased number of reoperations for conduit exchange due to degeneration or failure. Use of an untreated autologous pericardial patch for enlargement of the right ventricular outflow tract should be avoided due to increased risk for aneurysm formation.