Andreas Löher

Implantation and follow-up of totally subcutaneous versus conventional implantable cardioverter-defibrillators: A multicenter case-control study

BACKGROUND The approval of an entirely subcutaneous implantable-cardioverter defibrillator (ICD) system (S-ICD) has raised attention about this promising technology. It was developed to overcome lead failure and infection problems of conventional transvenous ICD systems. Nevertheless, lead migration of the initial design and inappropriate shock rates have raised concerns regarding its reliability and safety. OBJECTIVE The purpose of this study was to report the largest multicenter series to date of patients with the new device in comparison with a matched conventional transvenous ICD collective with focus on perioperative complications, conversion of induced ventricular fibrillation (VF), and short-term follow-up. METHODS/RESULTS Sixty-nine patients (50 male and 19 female; mean age 45.7 ± 15.7 years) received an S-ICD in three German centers and were randomly assigned to 69 sex- and age-matched conventional ICD patients. The indication was primary prevention in 41 patients (59.4%) without difference between groups (34 control patients; P = .268). The predominant underlying heart disease was ischemic cardiomyopathy in 11 (15.9%), dilated cardiomyopathy in 25 (36.2%), and hypertrophic cardiomyopathy in 10 (14.5%) in the S-ICD group. Mean implantation time was 70.8 ± 27.9 minutes (P = .398). Conversion rates of induced VF were 89.5% for 65 J (15-J safety margin) and 95.5% including reversed shock polarity (15-J safety margin) in the study group. Termination of induced VF was successful in 90.8% (10-J safety margin, device dependent) of the control patients (P = .815). Procedural complications were similar between the 2 groups. Mean follow-up was 217 ± 138 days. During follow-up, 3 patients with S-ICD were appropriately treated for ventricular arrhythmias. Three inappropriate episodes (5.2%) occurred in 3 S-ICD patients due to T-wave oversensing, whereas atrial fibrillation with rapid conduction was the predominant reason for inappropriate therapy in conventional devices (P = .745). CONCLUSION The novel S-ICD system can be implanted safely with similar perioperative adverse events compared with standard transvenous devices. Our case-control study demonstrates a 10.4% failure of conversion of induced VF with the S-ICD set to standard polarity and 15-J safety margin and comparable inappropriate shock rates during short-term follow-up.

Diastolic filling pattern and left ventricular diameter predict response and prognosis after cardiac resynchronisation therapy

Objective: To investigate predisposing factors for cardiac resynchronisation therapy (CRT) response. Design: Single-centre study. Setting: University hospital in Germany. Patients: 122 consecutive patients with heart failure (mean (SD) age 65 (11) years; ischaemic/non-ischaemic 41%/55%; New York Heart Association (NYHA) class 3.1 (0.3); left ventricular ejection fraction 24.4 (8.1)%; QRS width 170 (32) ms, quality of life (QoL) 43.5 (19.2)) with an indication for CRT and demonstrated left ventricular dyssynchrony by echocardiography including tissue Doppler imaging. Interventions: Besides laboratory testing of clinical variables, results of ECG, echocardiography including tissue Doppler imaging, invasive haemodynamics, measures of QoL and of exercise capacity were obtained before CRT implantation and during follow-up. Main outcome measure: Responders were predefined as patients with improvement by one or more NYHA functional class or reduction of left ventricular end-systolic volume by 10% or more during follow-up. Mean (SD) follow-up was 418 (350) days. Results: Overall, 70.5% of patients responded to CRT. Responders had a significantly improved survival compared with non-responders (96.2% vs 45.5%, log-rank p<0.001). On univariate analysis, left ventricular end-diastolic diameter, left ventricular end-systolic diameter (LVESD), E/A ratio, a restrictive filling pattern, mean pulmonary artery pressure, pulmonary capillary pressure, N-terminal pro-brain natriuretic peptide and Vo2max were significant predictors of outcome. On multivariate analyses, LVESD (p = 0.009; F = 7.83), pulmonary capillary pressure (p = 0.015, F = 6.61) and a restrictive filling pattern (p = 0.026, F = 5.707) remained significant predictors of response. Conclusions: Despite treatment according to present guidelines nearly 30% of patients had no benefit from CRT treatment in a clinical setting. On multivariate analyses, patients with an increased left ventricular end-systolic diameter and concomitant diastolic dysfunction had a significantly worse outcome.

Incidence of Complications in Patients with Implantable Cardioverter/Defibrillator Who Receive Additional Transvenous Pace/Sense Leads

Background: Implantation of an additional pace/sense (P/S) lead is commonly used in patients with implantable cardioverter/defibrillators (ICDs) to overcome P/S defects of integrated defibrillation leads (HV‐P/S leads). No information is available about the clinical outcome and the incidence of complications in these patients.

Two Different Therapeutic Strategies in ICD Lead Defects: Additional Combined LeadVersus Replacement of the Lead

Objectives: Implantation of an additional HV‐P/S lead versus extraction of the defective HV‐P/S lead and implantation of a new one is one possible therapeutic approach in cases of a defective high‐voltage pace/sense lead (HV‐P/S). No information is available on potential differences in clinical outcome in these different approaches.

Impact of malignant hematological disorders on cardiac surgery.

BACKGROUND Patients suffering from malignant hematological disorders may be at increased risk, when undergoing cardiac surgery. We report on our experiences with ten cardiac procedures in nine patients (3 males, 6 females, 19-85 yr old, mean age 61 yr). METHODS AND RESULTS There were two patients with Hodgkins lymphoma and one patient each with Waldenstroms syndrome, multiple myeloma, polycythemia, myelodysplasia, chronic lymphocytic leukemia, non-Hodgkins lymphoma and idiopathic aplastic anemia. Cardiac diseases included coronary artery disease in six, aortic stenosis in two, and mitral insufficiency in one patient. Consecutively, cardiac procedures were coronary artery bypass grafting in six, aortic valve replacement in two, and mitral valve replacement in one patient. No patient died. Postoperatively, one patient suffered from a pericardial tamponade requiring surgical removal and 5 months later from a prosthetic endocarditis necessitating change of the bioprosthesis. One patient developed a superficial wound infection, which was treated conservatively. Four patients received no blood products. Altogether, we transfused 32 packed red blood cells, seven units of fresh frozen plasma and 16 platelet concentrates. Total drainage loss was 883 ml (250-1510 ml). CONCLUSIONS Cardiac surgery in patients suffering from malignant hematological disorders may be performed, but carries an increased morbidity. Therefore, indications for cardiac procedures must be carefully considered.

[Current status and problems of the entirely subcutaneous ICD (S-ICD®)].

ZusammenfassungDie Prävention des plötzlichen Herztods ist eine der wichtigsten Aufgaben der Kardiologie. Transvenöse ICD-Systeme haben ihre Effektivität in zahlreichen randomisierten Studien eindrucksvoll belegt, aber sie haben ihre Grenzen durch häufige Komplikationen im Langzeitverlauf. Das seit wenigen Jahren verfügbare, rein subkutane ICD-System (S-ICD®, Boston Scientific, USA, zuvor Cameron Health, USA) scheint vielversprechend, obwohl prospektive, randomisierte Daten fehlen. Die Implantation des S-ICD® ist einfach, relevante Komplikationen sind wegen der rein subkutanen Lage selten. Die Erkennung und Therapie von lebensbedrohlichen Tachyarrhythmien scheint bislang sicher, obwohl Langzeitdaten noch fehlen und im Fall eines unzureichenden EKG-Screenings inadäquate Therapien ein häufiges Problem darstellen. Der S-ICD® ist wegen der begrenzten Programmiermöglichkeiten sowie der fehlenden Möglichkeit zur Stimulation keine Alternative zum transvenösen System, stellt aber eine interessante Ergänzung der ICD-Therapie dar.AbstractPrevention of sudden cardiac death is one of the most important tasks of cardiology. Transvenous ICD-systems have impressively proven their effectiveness in numerous randomized trials. Transvenous systems have their limitations due to frequent long-term lead complications. Having been available for a few years, the entirely subcutaneous ICD-system (S-ICD®, Boston Scientific, USA, former Cameron Health, USA) seems to be a promising alternative despite the lack of prospective data. The implantation of the S-ICD® can be performed easily; lead complications are rare because of the totally subcutaneous implantation. The detection and therapy of life-threatening tachyarrhythmias seems to be safe, although inappropriate therapies are a common problem in cases of insufficient ECG screening. S-ICD® is no alternative to the transvenous system due to limited programming options and the lack of stimulation, but it is an interesting supplement of ICD therapy.Prevention of sudden cardiac death is one of the most important tasks of cardiology. Transvenous ICD-systems have impressively proven their effectiveness in numerous randomized trials. Transvenous systems have their limitations due to frequent long-term lead complications. Having been available for a few years, the entirely subcutaneous ICD-system (S-ICD®, Boston Scientific, USA, former Cameron Health, USA) seems to be a promising alternative despite the lack of prospective data. The implantation of the SICD® can be performed easily; lead complications are rare because of the totally subcutaneous implantation. The detection and therapy of life-threatening tachyarrhythmias seems to be safe, although inappropriate therapies are a common problem in cases of insufficient ECG screening. S-ICD® is no alternative to the transvenous system due to limited programming options and the lack of stimulation, but it is an interesting supplement of ICD therapy.

Gegenwärtiger Stand und Probleme vollständig subkutaner ICD-Systeme (S-ICD®)

ZusammenfassungDie Prävention des plötzlichen Herztods ist eine der wichtigsten Aufgaben der Kardiologie. Transvenöse ICD-Systeme haben ihre Effektivität in zahlreichen randomisierten Studien eindrucksvoll belegt, aber sie haben ihre Grenzen durch häufige Komplikationen im Langzeitverlauf. Das seit wenigen Jahren verfügbare, rein subkutane ICD-System (S-ICD®, Boston Scientific, USA, zuvor Cameron Health, USA) scheint vielversprechend, obwohl prospektive, randomisierte Daten fehlen. Die Implantation des S-ICD® ist einfach, relevante Komplikationen sind wegen der rein subkutanen Lage selten. Die Erkennung und Therapie von lebensbedrohlichen Tachyarrhythmien scheint bislang sicher, obwohl Langzeitdaten noch fehlen und im Fall eines unzureichenden EKG-Screenings inadäquate Therapien ein häufiges Problem darstellen. Der S-ICD® ist wegen der begrenzten Programmiermöglichkeiten sowie der fehlenden Möglichkeit zur Stimulation keine Alternative zum transvenösen System, stellt aber eine interessante Ergänzung der ICD-Therapie dar.AbstractPrevention of sudden cardiac death is one of the most important tasks of cardiology. Transvenous ICD-systems have impressively proven their effectiveness in numerous randomized trials. Transvenous systems have their limitations due to frequent long-term lead complications. Having been available for a few years, the entirely subcutaneous ICD-system (S-ICD®, Boston Scientific, USA, former Cameron Health, USA) seems to be a promising alternative despite the lack of prospective data. The implantation of the S-ICD® can be performed easily; lead complications are rare because of the totally subcutaneous implantation. The detection and therapy of life-threatening tachyarrhythmias seems to be safe, although inappropriate therapies are a common problem in cases of insufficient ECG screening. S-ICD® is no alternative to the transvenous system due to limited programming options and the lack of stimulation, but it is an interesting supplement of ICD therapy.Prevention of sudden cardiac death is one of the most important tasks of cardiology. Transvenous ICD-systems have impressively proven their effectiveness in numerous randomized trials. Transvenous systems have their limitations due to frequent long-term lead complications. Having been available for a few years, the entirely subcutaneous ICD-system (S-ICD®, Boston Scientific, USA, former Cameron Health, USA) seems to be a promising alternative despite the lack of prospective data. The implantation of the SICD® can be performed easily; lead complications are rare because of the totally subcutaneous implantation. The detection and therapy of life-threatening tachyarrhythmias seems to be safe, although inappropriate therapies are a common problem in cases of insufficient ECG screening. S-ICD® is no alternative to the transvenous system due to limited programming options and the lack of stimulation, but it is an interesting supplement of ICD therapy.

Role of implantable cardioverter defibrillator therapy in patients with acquired long QT syndrome: A long-term follow-up

AIMS The use of implantable cardioverter defibrillators (ICD) in patients with torsade de pointes (TdP) and ventricular fibrillation in the presence of acquired long QT syndrome (aLQTS) is under debate, partly due to the fact that aLQTS is potentially reversible and currently no long-term follow-up data are available. We aimed to evaluate the long-term follow-up of patients with acquired long QT syndrome (aLQTS) who had received an implantable cardioverter defibrillator (ICD) for secondary prevention of sudden cardiac arrest (SCA). METHOD AND RESULTS Over a 10 year period, 43 patients with an ICD after survived cardiac arrest (SCA) due to an aLQTS were included [female n= 27 (63%); mean age 61 ± 16 years]. There was no clinical evidence for congenital LQTS (Schwartz score 1.25 ± 0.8). Structural heart disease was present in 29 patients (47%; ischaemic n= 13; dilated cardiomyopathy n= 9; mean EF 41%± 12). The most common proarrhythmic trigger happened to be antiarrhythmic drugs (n= 34; 79%). Other triggers included contrast agent (n= 1), haloperidol (n= 2), severe hypokalaemia (n= 2), drug abuse/alcohol (n= 2), and mere severe bradycardia (n= 2). Under trigger QTc interval measured 536 ± 58 vs. 438 ± 33 ms without trigger (P< 0.001). During a mean follow-up of 84 ± 55 months, appropriate shocks occurred in 19 patients (44%); inappropriate shocks in 13 patients (30%; only inappropriate n= 3). Appropriate shocks were almost as common in patients without as in those with structural heart disease (35 vs. 48%; P= 0.32). None of the patients were re-exposed to the initial trigger during the follow-up period. Beta-blocker medication did not prevent ICD shocks (12 of 19 vs. 11 of 24 on medication). CONCLUSION Appropriate ICD shocks are a common finding in patients with aLQTS and SCA irrespective of the underlying cause or structural heart disease. Thus, even in the presence of relevant acquired proarrhythmia ICD may be beneficial.

Intraoperative Defibrillation Testing of Subcutaneous Implantable Cardioverter‐Defibrillator Systems—A Simple Issue?

Background The results of the recently published randomized SIMPLE trial question the role of routine intraoperative defibrillation testing. However, testing is still recommended during implantation of the entirely subcutaneous implantable cardioverter‐defibrillator (S‐ICD) system. To address the question of whether defibrillation testing in S‐ICD systems is still necessary, we analyzed the data of a large, standard‐of‐care prospective single‐center S‐ICD registry. Methods and Results In the present study, 102 consecutive patients received an S‐ICD for primary (n=50) or secondary prevention (n=52). Defibrillation testing was performed in all except 4 patients. In 74 (75%; 95% CI 0.66–0.83) of 98 patients, ventricular fibrillation was effectively terminated by the first programmed internal shock. In 24 (25%; 95% CI 0.22–0.44) of 98 patients, the first internal shock was ineffective and further internal or external shock deliveries were required. In these patients, programming to reversed shock polarity (n=14) or repositioning of the sensing lead (n=1) or the pulse generator (n=5) led to successful defibrillation. In 4 patients, a safety margin of <10 J was not attained. Nevertheless, in these 4 patients, ventricular arrhythmias were effectively terminated with an internal 80‐J shock. Conclusions Although it has been shown that defibrillation testing is not necessary in transvenous ICD systems, it seems particular important for S‐ICD systems, because in nearly 25% of the cases the primary intraoperative test was not successful. In most cases, a successful defibrillation could be achieved by changing shock polarity or by optimizing the shock vector caused by the pulse generator or lead repositioning.

Transvenous ICD implantation after artificial tricuspid valve replacement: A new approach placing a transvenous ICD lead in the mid cardiac vein of the coronary sinus

Die konventionelle Implantation eines transvenösen ICD-Systems mit einer rechtsventrikulären ICD-Elektrode ist bei Patienten nach einem Trikuspidalklappenersatz nicht möglich. Ein junger Patient mit der Vorgeschichte eines Thoraxtraumas, Trikuspidalklappenzerreißung, Abriss der rechten Herzkranzarterie und konsekutivem Hinterwandinfarkt wurde initial mit einem Trikuspidalklappenersatz (St Jude Prothese, 33 mm) und einer venösen aortokoronaren Bypassoperation versorgt. Der Patient wurde 4 Jahre später mit einer hämodynamisch nicht tolerierten ventrikulären Tachykardie (VT: CL 250 ms, LAH/LSB-Konfiguration) aufgenommen, die in der elektrophysiologischen Untersuchung reproduzierbar induziert werden konnte. Es erfolgte die Implantation eines ICDs links subpektoral in Kombination mit einer transvenösen ICD-Elektrode. Die transvenöse ICD-Elektrode wurde mittels eines Führungskatheters in einen inferolateralen Seitenast des Koronarsinus platziert und mittels aktiver Schraubfixierung stabilisiert. Die Wahrnehmung und Reizschwelle waren ausreichend. Die Defibrillationsschwelle betrug 25 Joule. In Zusammenfassung stellt die Implantation einer transvenösen ICD-Elektrode in einen Seitenast des Koronarsinus in Kombination mit einem pektoral implantierten ICD-Aggregat eine mögliche Alternative bei Patienten mit fehlendem transvenösen Zugang zum rechten Ventrikel dar. Durch diese Implantationstechnik kann die Implantation einer zusätzlichen subkutanen Fingerelektrode oder eine Thorakotomie vermieden werden. Implantation of a transvenous device in patients with a tricuspid valve replacement or a complex congenital heart disease with no access to the right ventricle represents problems. The lack of access to the right ventricle might preclude transvenous placement of a defibrillation lead at ICD implantation. A young patient (21 years) with a history of severe chest trauma with rupture of the tricuspid valve as well as the right coronary artery and consecutive inferior myocardial infarction was initially treated with tricuspid valve replacement (St Jude Medical artificial prosthesis, 33 mm) and a bypass graft to the right coronary artery. Four years later, the patient was admitted with a hemodynamically not tolerated ventricular tachycardia (VT: CL 250 ms, LBBB, left axis). The VT could be reproduced during electrophysiological testing. An ICD was implanted subpectorally in combination with a transvenous active fixation ICD lead. The transvenous ICD lead was placed via a guiding catheter into a coronary sinus branch (middle cardiac vein). Acceptable pacing and sensing values could be obtained. The defibrillation threshold was 25 J. In conclusion transvenous ICD lead implantation into a side branch of the coronary sinus in combination with a pectorally implanted “active can” ICD device seems to be an alternative approach. This approach may avoid implantation of additional subcutaneous defibrillation leads or even thoracotomy for ICD implantation.