The inwardly rectifying potassium current of the cardiomyocyte (I K1 ) is the main determinant of the resting potential. Ion channels Kir2.1, Kir2.2, and Kir2.3 form tetramers and are the molecular correlate of macroscopic I K1 current. Verapamil is an antiarrhythmic drug used to suppress atrial and ventricular arrhythmias. Its primary mechanism of action is via blocking calcium channels. In addition, it has been demonstrated to block I K1 current and the Kir2.1 subunit. Its effect on other subunits that contribute to I K1 current has not been studied to date. We therefore analyzed the effect of verapamil on the Kir channels 2.1, 2.2, and 2.3 in the Xenopus oocyte expression system. Kir2.1, Kir2.2, and Kir2.3 channels were heterologously expressed in Xenopus oocytes. Respective currents were measured with the voltage clamp technique and the effect of verapamil on the current was measured. At a concentration of 300 µM, verapamil inhibited Kir2.1 channels by 41.36% ± 2.7 of the initial current, Kir2.2 channels by 16.51 ± 3.6%, and Kir2.3 by 69.98 ± 4.2%. As a verapamil effect on kir2.3 was a previously unknown finding, we analyzed this effect further. At wash in with 300 µM verapamil, the maximal effect was seen within 20 min of the infusion. After washing out with control solution, there was only a partial current recovery. The current reduction from verapamil was the same at − 120 mV (73.2 ± 3.7%), − 40 mV (85.5 ± 6.5%), and 0 mV (61.5 ± 10.6%) implying no voltage dependency of the block. Using site directed mutations in putative binding sites, we demonstrated a decrease of effect with pore mutant E291A and absence of verapamil effect for D251A. With mutant I214L, which shows a stronger affinity for PIP 2 binding, we observed a normalized current reduction to 61.9 ± 0.06% of the control current, which was significantly less pronounced compared to wild type channels. Verapamil blocks Kir2.1, Kir2.2, and Kir2.3 subunits. In Kir2.3, blockade is dependent on sites E291 and D251 and interferes with activation of the channel via PIP 2 . Interference with these sites and with PIP 2 binding has also been described for other Kir channels blocking drugs. As Kir2.3 is preferentially expressed in atrium, a selective Kir2.3 blocking agent would constitute an interesting antiarrhythmic concept.
Abstract Aims Remote patient monitoring (RPM) systems offer a promising alternative to conventional In-Clinic check-ups, hereby reducing unnecessary clinic visits. Especially with the rise of the COVID-19 pandemic, this reduction is of paramount importance. Regarding the association between RPM and clinical outcomes, findings of previous studies have been inconsistent. The aim of this study is to elucidate the effect of partly substituting In-Clinic visits by RPM on clinical outcomes in implantable cardioverter-defibrillator (ICD) patients. Methods and results The study included 595 heart failure patients (LVEF ≤35%; NYHA Class II/III) implanted with an ICD compatible with the Boston Scientific LATITUDE™ system. Participants were randomized to RPM plus an annual In-Clinic visit or 3–6 months In-Clinic check-ups alone. The investigated endpoints after 2 years of follow-up included a composite of all-cause mortality and cardiac hospitalization, mortality and cardiac hospitalization as independent endpoints and ICD therapy. The incidence of mortality and hospitalization did not differ significantly as independent, nor as composite endpoint between the RPM and In-Clinic group (all Ps <0.05). The results were similar regarding ICD therapy, except for appropriate ICD therapy (odds ratio 0.50; 95% confidence interval 0.26–0.98; P = 0.04). Exploratory subgroup analyses indicated that the effect of RPM differs between patients with specific characteristics, i.e. ≥60 years and permanent atrial fibrillation (all Ps < 0.05). Conclusion RPM is non-inferior to conventional In-Clinic visits regarding clinical outcomes. Routine In-Clinic follow-up may partly be substituted by RPM without jeopardizing safety and efficiency, and thus reducing unnecessary In-Clinic visits. ClinicalTrials.gov identifier NCT01691586.
INTRODUCTION:Remote patient monitoring (RPM) of heart failure patients has the potential to reduce healthcare resource use and costs, but current evidence has been inconclusive. This study aims assess the impact of RPM of heart failure patients with an implantable cardioverter defibrillator on medical resource use, direct medical costs, quality-adjusted life years (QALYs), and travel time of patients, and to estimate its commercial headroom in the Netherlands and Germany. METHODS:Data from the REMOTE-CIED randomized controlled trial were used to calculate differences in length of hospital stay, outpatient clinic visits, telephone consults, emergency room visits, and travel time between patients on in-clinic follow-up and RPM in the Netherlands, Germany, and France. Incremental cardiac-related healthcare costs and QALYs were calculated and used to calculate the commercial headroom of RPM in the Netherlands and Germany. The impact of imputation, parameter, and case-mix uncertainty on these outcomes was explored using probabilistic analysis. RESULTS:Length of hospitalization, number of unscheduled admissions, and number of outpatient visits were lower in the remote monitoring group in all three countries. Number of hospital admissions was higher, and number of calls was lower in the Netherlands and Germany but not in France. Costs were lower in both the Netherlands (-€1041, 95% confidence interval (CI): -€3308, €1005) and Germany (-€2865, 95% CI: -€7619, €1105), while incremental effectiveness differed: -0.003 (95% CI: -0.114, 0.107) QALY in the Netherlands and +0.086 (95% CI: -0.083, 0.256) in Germany. Commercial headroom was estimated at €881 (95% CI: -€5430, €7208) in the Netherlands and €5005 (95% CI: -€1339, €11,960) in Germany. DISCUSSION:RPM was found to result in reduced medical resource use and travel time. Whether it is cost saving or cost effective strongly depends on the costs of remote monitoring. TRIAL REGISTRATION NUMBER AND TRIAL REGISTER:ClinicalTrials.gov: NCT01691586.
AbstractBackgroundThe inSighT study was designed to determine the prevalence of ischemic changes as recorded by implantable cardioverter–defibrillator (ICD) ST deviations in intracardiac electrocardiograms (EGM) over the 24 h preceding malignant ventricular arrhythmias (VT/VF).MethodsThe study enrolled patients with known coronary artery disease (CAD) or high risk of future development of CAD implanted with an ICD equipped with an ST monitoring feature (Ellipse™/Fortify Assura™, St. Jude Medical). Device session records were collected at each in‐clinic follow‐up. EGM ST levels of the beats over the 15 minutes prior to VT/VF events were compared using a t test with those from a baseline period of 23–24 h prior to the VT/VF event. All events with p < .05 were visually inspected to confirm they were evaluable; additional criteria for exclusion from further analysis included inappropriate therapy, aberrant conduction, and occurrence of VT/VF within 24h prior to the current event.ResultsThe study enrolled 481 ICD patients (64 ± 11 years, 83% male) in 14 countries and followed them for 15±5 months. A total of 165 confirmed VT/VF episodes were observed, of which 71 events (in 56 patients, 34% of all patients with VT/VF) were preceded by significant (p < .05) ST‐segment changes unrelated to known non‐ischemic causes. None of the analyzed demographic and clinical factors proved to be associated with greater odds of presenting with ST‐segment changes prior to VT/VF episode.ConclusionIn this exploratory study, characteristic ST‐segment changes, likely representative of ischemic events, were observed in 34% of all patients with VT/VF episodes.
Introduction: Familial dilated cardiomyopathy (DCM) is clinically variable and has been associated with mutations in more than 50 genes. Rapid improvements in DNA sequencing have led to the identification of diverse rare variants with unknown significance (VUS), which underlines the importance of functional analyses. In this study, by investigating human-induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs), we evaluated the pathogenicity of the p.C335R sodium voltage-gated channel alpha subunit 5 (SCN5a) variant in a large family with familial DCM and conduction disease. Methods: A four-generation family with autosomal dominant familial DCM was investigated. Next-generation sequencing (NGS) was performed in all 16 family members. Clinical deep phenotyping, including endomyocardial biopsy, was performed. Skin biopsies from two patients and one healthy family member were used to generate human-induced pluripotent stem cells (iPSCs), which were then differentiated into cardiomyocytes. Patch-clamp analysis with Xenopus oocytes and iPSC-CMs were performed. Results: A SCN5a variant (c.1003T>C; p.C335R) could be detected in all family members with DCM or conduction disease. A novel truncating TTN variant (p.Ser24998LysfsTer28) could also be identified in two family members with DCM. Family members with the SCN5a variant (p.C335R) showed significantly longer PQ and QRS intervals and lower left ventricular ejection fractions (LV-EF). All four patients who received CRT-D were non-responders. Electrophysiological analysis with Xenopus oocytes showed a loss of function in SCN5a p.C335R. Na+ channel currents were also reduced in iPSC-CMs from DCM patients. Furthermore, iPSC-CM with compound heterozygosity (SCN5a p.C335R and TTNtv) showed significant dysregulation of sarcomere structures, which may be contributed to the severity of the disease and earlier onset of DCM. Conclusion: The SCN5a p.C335R variant is causing a loss of function of peak INa in patients with DCM and cardiac conduction disease. The co-existence of genetic variants in channels and structural genes (e.g., SCN5a p.C335R and TTNtv) increases the severity of the DCM phenotype.
Die Lebensqualität von Patienten mit implantierbarem Kardioverter-Defibrillator (ICD) wird von therapiebedingten Faktoren beeinflusst. Die Studienlage ist jedoch heterogen und validierte krankheitsspezifische Messgrößen der krankheits- oder indikationsspezifischen Lebensqualität (DRQoL) von ICD-Patienten fehlen. Das Ziel der Studie war es, ein erweitertes Verständnis der langfristigen DRQoL von ICD-Patienten zu erlangen. Ein besonderer Fokus lag auf Stressoren und kognitiven Bewältigungsstrategien im Alltag. Die Datenerhebung erfolgte mittels semi-strukturierter leitfadengestützter Interviews. In dieser monozentrischen qualitativen Studie wurden zehn ICD-Patienten mit primär- und sekundärprophylaktischer Indikation eingeschlossen. Drei Fachärzte waren beteiligt. Die Daten wurden unter Berücksichtigung von salutogenetischen Ansätzen (Antonovsky) qualitativ ausgewertet. Der ICD schränkt die Patienten im Alltag mehrheitlich nicht ein. Die Patienten entwickeln Bewältigungsstrategien, um die ICD-Indikation zu verstehen und ihr eine Sinnhaftigkeit zuzuschreiben. Die salutogenetische Betrachtung verdeutlicht, dass der ICD die DRQoL individuell positiv oder negativ durch Kohärenz- und Widerstandsfaktoren beeinflusst. Es wurde eine salutogenetische Konzeptualisierung zur Analyse der DRQoL von ICD-Patienten entwickelt. Anhand dieser können Patienten mit hohem Risiko, geringer Kohärenz und Widerstandsfähigkeit identifiziert werden. Unter Berücksichtigung der individuellen Lebenswelten ist es möglich, eine positive Bewältigung der ICD-Indikation im Versorgungsprozess zu erzielen.
AIMS:Amiodarone and digitalis are frequently used drugs in patients with heart failure. Both have separately been linked to reduced post-transplant survival, but their combined impact on mortality after HTX remains uncertain. This study investigated the effects of combined amiodarone and digitalis use before HTX on post-transplant outcomes.METHODS AND RESULTS:This registry study analysed 600 patients receiving HTX at Heidelberg Heart Center between 1989 and 2016. Patients were stratified by amiodarone and digitalis use before HTX. Analysis included patient characteristics, medication, echocardiographic features, heart rates, permanent pacemaker implantation, atrial fibrillation, and post-transplant survival including causes of death. One hundred eighteen patients received amiodarone before HTX (19.7%), hereof 67 patients with digitalis (56.8%) and 51 patients without digitalis before HTX (43.2%). Patients with and without amiodarone before HTX showed a similar 1 year post-transplant survival (72.0% vs. 78.4%, P = 0.11), but patients with combined amiodarone and digitalis before HTX had a worse 1 year post-transplant survival (64.2%, P = 0.01), along with a higher percentage of death due to transplant failure (P = 0.03). Echocardiographic analysis of these patients showed a higher percentage of an enlarged right ventricle (P = 0.02), left atrium (P = 0.02), left ventricle (P = 0.03), and a higher rate of reduced left ventricular ejection fraction (P = 0.03). Multivariate analysis indicated combined amiodarone and digitalis use before HTX as a significant risk factor for 1 year mortality after HTX (hazard ratio: 1.69; 95% confidence interval: 1.02-2.77; P = 0.04).CONCLUSIONS:Combined pre-transplant amiodarone and digitalis therapy is associated with increased post-transplant mortality.
We established a salutogenic model for the assessment of DRQoL in patients with ICDs. A stable DRQoL on ICD implantation and follow-up could be achieved if patients at high risk (small sense of coherence and reduced resilience) are identified and their individual lifestyles are taken into account.
BACKGROUND:Patient satisfaction with remote patient monitoring (RPM) of implantable cardioverter defibrillators (ICDs) seems to be high, yet knowledge on long-term patient experiences is limited. The European REMOTE-CIED study explored patients' experiences with RPM, examined patient's preferences for ICD follow-up, and identified determinants of patient's preferences in the first 2 years postimplantation. METHODS:European heart failure patients (N = 300; median age = 66 years [interquartile range (IQR) = 59-73], and 22% female) with a first-time ICD received a Boston Scientific LATITUDE RPM system (Marlborough, MA, USA) and had scheduled in-clinic follow-ups once a year. Patients completed questionnaires at 1-2 weeks and also at 3, 6, 12, and 24 months postimplantation and clinical data were obtained from their medical records. Patient evaluation data were analyzed descriptively, and Student's t-tests/Man-Whitney U tests or Chi-square tests/Fisher's exact tests were performed to examine determinants of patient preferences. RESULTS:At 2 years postimplantation, the median patient satisfaction score with the RPM system was 9 out of 10 (IQR = 8-10), despite 53% of the patients experiencing issues (eg, failure to transmit data). Of the 221 patients who reported their follow-up preferences, 43% preferred RPM and 19% preferred in-clinic follow-up. Patients with a preference for RPM were more likely to be higher educated (P = 0.04), employed (P = 0.04), and equipped with a new LATITUDE model (P = 0.04), but less likely to suffer from chronic obstructive pulmonary disease (P = 0.009). CONCLUSION:In general, patients were highly satisfied with RPM, but a subgroup preferred in-clinic follow-up. Therefore, physicians should include patients' concerns and preferences in the decision-making process, to tailor device follow-up to individual patients' needs and preferences.
Background: Permanent pacemaker (PPM) implantation after heart transplantation (HTX) may be required due to severe bradycardia. The aim of this study was to investigate the risk factors, indications, perioperative outcomes and complications of PPM implantation after HTX as well as the underlying effect on post-transplant mortality including causes of death. Methods: This registry study included 621 patients receiving HTX at Heidelberg Heart Center between 1989 and 2018. Patients were stratified by PPM implantation after HTX. Data analysis of risk factors for PPM implantation included donor and recipient demographics, post-transplant medication, mortality, and causes of death. Results: Thirty-six patients (5.8%) received PPM implantation after HTX, 12 (33.3%) with early PPM and 24 (66.7%) with late PPM. Indications for PPM implantation after HTX included sinus node dysfunction (SND) (n=15; 41.7%) and atrioventricular block (AVB) (n=21; 58.3%). Multivariate analysis revealed recipient body mass index (BMI) [hazard ratio (HR): 1.10; confidence interval (CI): 1.01-1.21; P=0.03], donor age (HR: 1.07; CI: 1.03-1.10; P<0.01), and biatrial HTX (HR: 2.63; CI: 1.22-5.68; P=0.01) as significant risk factors for PPM implantation after HTX. Kaplan-Meier estimator displayed a statistically significant inferior 5-year post-transplant survival among patients with early PPM after HTX in comparison to patients with late PPM or no PPM after HTX (P<0.01) along with a higher percentage of death due to infection (P<0.01). Conclusions: Multivariate risk factors for PPM implantation after HTX include recipient BMI, donor age, and biatrial HTX. Early PPM implantation after HTX is associated with increased 5-year post-transplant mortality due to infection.
Abstract Background Post cardiac injury syndrome (PCIS) is an inflammatory process, which occurs in the setting of injury to the pericardium, epicardium or myocardium. It may follow cardiac surgery, myocardial infarction, trauma, intracardiac ablation, percutaneous coronary intervention, and implantation of heart rhythm devices (HRD). In this study we aimed to assess the incidence of PCIS after HRD implantation and its possible risk factors. Material and methods All patients who received HRD implantation at our University Hospital between the years 2000 to 2014 were evaluated (n=4,989 patients) for developing PCIS. Clinical data including age, sex, underlying cardiac disease, type of implanted HRD, location of electrode implantation, clinical symptoms, time of symptom onset of PCIS, therapy, and outcome were extracted and analysed. Results 19 cases of PCIS were identified in altogether 4,989 patients resulting in an incidence of 0.38%. The age in patients with PCIS ranged from 39 to 86 years. Dilated cardiomyopathy (DCM) as underlying cardiac disease and right atrial (RA) lead implantation showed significant association to occurrence of PCIS (p=0.045 in DCM and p<0.001 in RA lead implantation). Dyspnea, chest pain, dry cough and fever were the most frequently reported symptoms in patients with PCIS. Pericardial and pleura effusion, as well as elevated C-reactive protein (CRP), increased erythrocyte sedimentation rate (ESR), and leukocytosis were the most common findings. Conclusion To the best of our knowledge, this is the thus far largest cohort evaluating the incidence of PCIS after HRD implantation. PCIS remains a rare, but potentially lethal complication of heart rhythm device implantation. It should be considered particularly in patients with right atrial lead active fixation and DCM as underlying cardiac disease.
Aims The European REMOTE-CIED study is the first randomized trial primarily designed to evaluate the effect of remote patient monitoring (RPM) on patient-reported outcomes in the first 2 years after implantation of an implantable cardioverter-defibrillator (ICD). Methods and results The sample consisted of 595 European heart failure patients implanted with an ICD compatible with the Boston Scientific LATITUDE (R) RPM system. Patients were randomized to RPM plus a yearly in-clinic ICD check-up vs. 3-6-month in-clinic check-ups alone. At five points during the 2-year follow-up, patients completed questionnaires including the Kansas City Cardiomyopathy Questionnaire and Florida Patient Acceptance Survey (FPAS) to assess their heart failure-specific health status and ICD acceptance, respectively. Information on clinical status was obtained from patients' medical records. Linear regression models were used to compare scores between groups over time. Intention-to-treat and per-protocol analyses showed no significant group differences in patients' health status and ICD acceptance (subscale) scores (all Ps > 0.05). Exploratory subgroup analyses indicated a temporary improvement in device acceptance (FPAS total score) at 6-month follow-up for secondary prophylactic in-clinic patients only (P< 0.001). No other significant subgroup differences were observed. Conclusion Large clinical trials have indicated that RPM can safely and effectively replace most in-clinic check-ups of ICD patients. The REMOTE-CIED trial results show that patient-reported health status and ICD acceptance do not differ between patients on RPM and patients receiving in-clinic check-ups alone in the first 2 years after ICD implantation.
The wearable cardioverter-defibrillator (WCD) was introduced to provide protection from sudden cardiac death (SCD) in patients with transiently elevated risk or during ongoing risk stratification. Benefits and clinical characteristics of routine WCD use remain to be assessed in larger patient populations. This study aims to identify determinants of WCD compliance, therapies, and inappropriate alarms in a real-life cohort. A total of 106 cases (68.9% male) were included between 11/2010 and 04/2016. WCD therapies, automatically recorded arrhythmia episodes, inappropriate WCD alarms, patient compliance, and outcome after WCD prescription were analyzed. Median duration of WCD use was 58.5 days. Average daily wearing time was 22.7 h. Compliance was reduced in patients ≤ 50 years. Three patients received WCD therapies (2.8%). In one case ventricular fibrillation (VF) was appropriately terminated with the first shock. Two patients received inappropriate WCD therapies due to WCD algorithm activation during ventricular pacemaker stimulation. One patient died of asystole while carrying a WCD (0.9%). Additional arrhythmias detected comprised self-terminating sustained ventricular tachycardia (VT; 2.8%), non-sustained VT (2.8%), and supraventricular arrhythmias (5.7%). Inappropriate WCD alarms due to over-/undersensing occurred in 77/106 patients (72.6%), of which 41 (38.7%) experienced ≥ 10 inappropriate WCD alarms during the prescription period. Thirteen patients (12.3%) displayed a mean of > 1 inappropriate alarms/day. WCD use was associated with high compliance and provided protection from VT/VF-related SCD. The majority of patients experienced inappropriate WCD alarms. Alterations in QRS morphology during pacemaker stimulation require consideration in WCD programming to prevent inappropriate alarms.
Left bundle branch block (LBBB) has a predictive value for response to cardiac resynchronization therapy as reported by Zareba et al. (Circulation 123(10):1061–1072, 2011). However, based on ECG criteria, the discrimination between complete LBBB and nonspecific intraventricular conduction delay is challenging. We tested the hypothesis that discrimination can be performed using standard electrophysiological catheters and a simple stimulation protocol.
Increasing numbers of patients with cardiovascular implantable electronic devices (CIEDs) and limited follow-up capacities highlight unmet challenges in clinical electrophysiology. Integrated software (MediConnect®) enabling fully digital processing of device interrogation data has been commercially developed to facilitate follow-up visits. We sought to assess feasibility of fully digital data processing (FDDP) during ambulatory device follow-up in a high-volume tertiary hospital to provide guidance for future users of FDDP software.
The cardiac IK1 current stabilizes the resting membrane potential of cardiomyocytes. Protein kinase A (PKA) induces an inhibition of IK1 current which strongly promotes focal arrhythmogenesis. The molecular mechanisms underlying this regulation have only partially been elucidated yet. Furthermore, the role of A-kinase anchoring proteins (AKAPs) in this regulation has not been examined to date. The objective of this project was to elucidate the molecular mechanisms underlying the inhibition of IK1 by PKA and to identify novel molecular targets for antiarrhythmic therapy downstream β-adrenoreceptors. Patch clamp and voltage clamp experiments were used to record currents and co-immunoprecipitation, and co-localization experiments were performed to show spatial and functional coupling. Activation of PKA inhibited IK1 current in rat cardiomyocytes. This regulation was markedly attenuated by disrupting PKA-binding to AKAPs with the peptide inhibitor AKAP-IS. We observed functional and spatial coupling of the plasma membrane-associated AKAP15 and AKAP79 to Kir2.1 and Kir2.2 channel subunits, but not to Kir2.3 channels. In contrast, AKAPyotiao had no functional effect on the PKA regulation of Kir channels. AKAP15 and AKAP79 co-immunoprecipitated with and co-localized to Kir2.1 and Kir2.2 channel subunits in ventricular cardiomyocytes. In this study, we provide evidence for coupling of cardiac Kir2.1 and Kir2.2 subunits with the plasma membrane-bound AKAPs 15 and 79. Cardiac membrane-associated AKAPs are a functionally essential part of the regulatory cascade determining IK1 current function and may be novel molecular targets for antiarrhythmic therapy downstream from β-adrenoreceptors.
Class IA antiarrhythmic drug quinidine was one of the first clinically used compounds to terminate atrial fibrillation and acts as multichannel inhibitor with well-documented inhibitory effects on several cardiac potassium channels. In the mammalian heart, heteromeric assembly of Kir2.1-2.3 channels underlies IK1 current. Although a low-affinity block of quinidine on Kir2.1 has already been described, a comparative analysis of effects on other Kir2.x channels has not been performed to date. Therefore, we analyzed the effects of quinidine on wild-type and mutant Kir2.x channels in the Xenopus oocyte expression system. Quinidine exerted differential inhibitory effects on Kir2.x channels with the highest affinity toward Kir2.3 subunits. Onset of block was slow and solely reversible in Kir2.2 subunits. Quinidine inhibited Kir2.x currents in a voltage-independent manner. By means of comparative Ala-scanning mutagenesis, we further found that residues E224, F254, D259, and E299 are essential for quinidine block in Kir2.1 subunits. Analogously, quinidine mediated Kir2.3 inhibition by binding corresponding residues E216, D247, D251, and E291. In contrast, Kir2.2 current block merely involved corresponding residue D260. Using channel mutants with altered (phosphatidylinositol 4,5-bisphosphate PIP2) affinities, we were able to demonstrate that high PIP2 affinities (i.e., Kir2.3 I214L) correlate with low quinidine sensitivity. Inversely, mutant channels interacting only weakly with PIP2 (i.e., Kir2.1 K182Q, and L221I) are prone to a higher inhibitory effect. Thus, we conclude that inhibition of Kir2.x channels by quinidine is mediated by joint modes of action involving direct cytoplasmic pore block and an impaired channel stabilization via interference with PIP2.
Background: Studies have shown that remote patient monitoring (RPM) of implantable cardioverter defibrillators (ICDs) is at least comparable to in-clinic follow-up with regard to clinical outcomes and might be cost-effective, yet RPM is not standard clinical practice within Europe. Better insight into the patient perspective on RPM may aid in its acceptance, implementation, and reimbursement. This narrative review (1) summarizes existing evidence on the impact of RPM on patient-reported outcomes and (2) discusses future directions in examining the patient perspective.Methods and Results: Literature review indicated that only five randomized trials on RPM in ICD patients included patient-reported outcomes, with inconclusive results. Observational studies show a trend toward good patient satisfaction and acceptation of RPM. Yet, results should be interpreted with caution due to a number of limitations including a potential selection bias, use of generic/nonvalidated questionnaires, relatively short follow-up durations, and a lack of subgroup identification.Conclusion: Although RPM seems to be safe, effective, timely, and efficient, the patient perspective has received little attention so far. The scarce evidence on patient-reported outcomes in RPM studies seems to be positive, but future trials with a follow-up of 12 months and validated patient-reported outcome measures are needed. The REMOTE-CIED study from our group is the first prospective randomized controlled trial primarily designed to examine the patient perspective on RPM, and is powered to identify characteristics associated with RPM satisfaction and benefit. Results are expected in 2018 and will add valuable information to the current evidence.
Background: Evidence on psychological distress in patients living with an implantable cardioverter defibrillator (ICD) is inconclusive. The current study is the first to examine the prevalence and risk markers of anxiety and/or depression in a large international cohort of European ICD patients with or without cardiac resynchronization therapy (CRT).Method: Heart failure patients (N = 569) from France, Germany, Spain, Switzerland and the Netherlands participating in the REMOTE-CIED study completed a set of questionnaires 1-2 weeks post ICD-implantation, including the 7-item Generalized Anxiety Disorder scale and the 9-item Patient Health Questionnaire to assess anxiety and depressive symptoms, respectively. Patients' clinical data were obtained from their medical records.Results: The prevalence of anxiety was 16% and that of depression 19%, with 25% of patients reporting one or both types of distress. Multivariable logistic regression analysis showed that age < 60 years (odds ratio (OR) = 2.5[95% confidence interval = 1.2-5.0]), having a threatening view of heart failure (OR = 4.7[2.7-8.2]), a high level of ICD-related concerns (OR= 2.9[1.7-5.1]), Type D personality (OR= 2.4[1.3-4.4]), poor patient-reported health status (OR= 2.2[1.3-3.9]) and receiving psychotropicmedication (OR= 3.0[1.5-5.9]) were positively associated with distress, while attending cardiac rehabilitation (OR= 0.3[0.2-0.7]) was negatively associated with distress.Conclusions: A significant subset of European ICD and CRT-defibrillator patients reports anxiety and/or depression in the first weeks post implantation. Patients' psychological characteristics, especially negative perceptions about their illness and treatment, were the strongest associates of distress. Timely identification of these patients is essential as they may benefit from psychological interventions and cardiac rehabilitation in terms of improved quality of life and prognosis. (C) 2017 Elsevier B.V. All rights reserved.
The caged xanthone gambogic acid (GA) is a novel anti-cancer agent which exhibits anti-proliferative, anti-inflammatory and cytotoxic effects in many types of cancer tissues. In a recent phase IIa study, GA exhibits a favourable safety profile. However, limited data are available concerning its interaction with cardiac ion channels. Heteromeric assembly of Kir2.x channels underlies the cardiac inwardly rectifying IK1 current which is responsible for the stabilization of the diastolic resting membrane potential. Inhibition of the cardiac IK1 current may lead to ventricular arrhythmia due to delayed afterdepolarizations. Compared to Kv2.1, hERG and Kir1.1, a slow, delayed inhibition of Kir2.1 channels by GA in a mammalian cell line was reported before but no data exist in literature concerning action of GA on homomeric Kir2.2 and Kir2.3 and heteromeric Kir2.x channels. Therefore, the aim of this study was to provide comparative data on the effect of GA on homomeric and heteromeric Kir2.x channels. Homomeric and heteromeric Kir2.x channels were heterologously expressed in Xenopus oocytes, and the two-microelectrode voltage-clamp technique was used to record Kir2.x currents. To investigate the mechanism of the channel inhibition by GA, alanine-mutated Kir2.x channels with modifications in the channels pore region or at phosphatidylinositol 4,5-bisphosphate (PIP2)-binding sites were employed. GA caused a slow inhibition of homomeric and heteromeric Kir2.x channels at low micromolar concentrations (with IC50 Kir2.1/2.2 < Kir2.2 < Kir2.2/2.3 < Kir2.3 < Kir2.1 < Kir2.1/2.3). The effect did not reach saturation within 60 min and was not reversible upon washout for 30 min. The inhibition showed no strong voltage dependence. We provide evidence for a combination of direct channel pore blockade and a PIP2-dependent mechanism as a molecular basis for the observed effect. We conclude that Kir2.x channel inhibition by GA may be relevant in patients with pre-existing cardiac disorders such as chronic heart failure or certain rhythm disorders and recommend a close cardiac monitoring for those patients when treated with GA.