The incidence of atrial fibrillation detected by implantable loop recorders: a comparison between patients with and without embolic stroke of undetermined source.

Aims: Stroke is the most debilitating outcome of atrial fibrillation (AF). The use of implantable loop recorders increases the detection of AF episodes among patients with embolic stroke of undetermined source. The significance of device-detected AF, or subclinical AF, is unknown. This study aimed to compare the incidence of AF detected by implantable loop recorder in patients with and without embolic stroke of undetermined source. Methods and results: We retrospectively studied all patients without known AF who were referred to our institution for implantable loop recorder implantation following embolic stroke of undetermined source, syncope, or palpitations from March 2009 to November 2019. The primary endpoint was any detection of AF or atrial flutter by implantable loop recorder. Seven hundred and fifty patients were included and followed up for a mean duration of 731 days (SD 443). An implantable loop recorder was implanted following embolic stroke of undetermined source in 323 and for assessment of syncope, palpitations, or another reason in 427 patients. The incidence of AF was significantly (P < 0.001) higher among patients with embolic stroke of undetermined source compared with the non-embolic stroke of undetermined source group; 48.6% vs. 13.8% (for any duration of AF) and 32.2% vs. 12.4% (for AF lasting ≥30 s) both P < 0.001. Kaplan-Meier analysis showed significantly higher incidence of AF for incremental durations of AF up to >5.5 h, but not >24 h. This was driven by longest AF durations of <6 min and between 5.5 h and 24 h, suggesting a bimodal distribution. In a multivariable Cox regression analysis, embolic stroke of undetermined source independently conferred an almost 5-fold increase in the hazard for any duration of AF. Conclusion: The incidence of AF is significantly higher amongst embolic stroke of undetermined source vs. non-embolic stroke of undetermined source patients monitored constantly by an implantable loop recorder. A high number of embolic stroke of undetermined source survivors have short-duration AF episodes. Further work is needed to determine the optimal treatment strategy of these AF episodes in embolic stroke of undetermined source.

Perceived benefits of patient support groups and their format for people with an implantable cardioverter defibrillator.

BACKGROUND: Support groups for people with Implantable Cardioverter Defibrillators (ICDs) are widely used, however, it is not clear what people with ICDs gain from a support group or what format they should take. OBJECTIVES: The aim of the present study is to define the perceived benefit of ICD support groups and develop practical recommendations for group format. METHODS: 14 individuals with ICDs were interviewed using a semi-structured interview guide. Reflexive thematic analysis methods were utilised to code and analyse the transcripts before generating themes. RESULTS: Four themes were defined: confronting mortality, coping through sharing, coping through learning, and providing space. Making connections with other people with ICDs, reassurance, access to information, and advice from health care professionals were important perceived benefits of the support group. CONCLUSION: People with ICDs may have to confront their own mortality and adapt to considerable life changes after implant. The findings from the present study have improved understanding of how support groups are perceived and how ICD indication and group format influence the experience. A blended format of in-person community meetings, online forums, HCP-led education and space for person-person interaction is recommended. Importantly, provision of support should not be time-limited to allow people to access it when it most likely to be of benefit to them.

Location, Location, Location: A Pilot Study to Compare Electrical with Echocardiographic-Guided Targeting of Left Ventricular Lead Placement in Cardiac Resynchronisation Therapy.

Introduction: Cardiac resynchronisation therapy is ineffective in 30-40% of patients with heart failure with reduced ejection fraction. Targeting non-scarred myocardium by selecting the site of latest mechanical activation using echocardiography has been suggested to improve outcomes but at the cost of increased resource utilisation. The interval between the beginning of the QRS complex and the local LV lead electrogram (QLV) might represent an alternative electrical marker. Aims: To determine whether the site of latest myocardial electrical and mechanical activation are concordant. Methods: This was a single-centre, prospective pilot study, enrolling patients between March 2019 and June 2021. Patients underwent speckle-tracking echocardiography (STE) prior to CRT implantation. Intra-procedural QLV measurement and R-wave amplitude were performed in a blinded fashion at all accessible coronary sinus branches. Pearson's correlation coefficient and Cohen's Kappa coefficient were utilised for the comparison of electrical and echocardiographic parameters. Results: A total of 20 subjects had complete data sets. In 15, there was a concordance at the optimal site between the electrically targeted region and the mechanically targeted region; in four, the regions were adjacent (within one segment). There was discordance (≥2 segments away) in only one case between the two methods of targeting. There was a statistically significant increase in procedure time and fluoroscopy duration using the intraprocedural QLV strategy. There was no statistical correlation between the quantitative electrical and echocardiographic data. Conclusions: A QLV-guided approach to targeting LV lead placement appears to be a potential alternative to the established echocardiographic-guided technique. However, it is associated with prolonged fluoroscopy and overall procedure time.

Exploring the Temporal Patterns of Right Ventricular Pacing Burden.

Elevated right ventricular pacing (RVP) burdens are associated with the development of pacing-induced cardiomyopathy. This association is alluded to in the recent European and American pacing guidelines where anticipated pacing burden forms part of the indications for conduction system pacing. Understanding the temporal pattern of RVP burden is important with respect to anticipating future burden and ensuring that the most appropriate pacing modality is selected for patients. To the best of our knowledge, this is the first study to assess how RVP burden changes over time in different pacing indications. A retrospective, single-center, observational study was performed. RVP burdens from pacing checks were extracted and plotted against 6-month time "bins." Graphical plots of RVP burdens for different pacing indications were produced. There was no significant change in the RVP burden across time, independent of the initial pacing indication. Individuals with sinus node disease (SND) and a P-R interval of >250 ms had increased RVP burden. Other than patients with SND and a P-R interval of <250 ms, individuals had pacing burdens higher than those proposed in both the European and American pacing guidelines for conduction system pacing.

Benefits of support groups for patients living with implantable cardioverter defibrillators: a mixed-methods systematic review and meta-analysis.

BACKGROUND: Patients with implantable cardioverter defibrillators (ICD) experience anxiety, depression and reduced quality of life (QoL). OBJECTIVES: This mixed-methods systematic review evaluates whether ICD support groups have a beneficial effect on mental well-being. METHODS: Literature searches were carried out in MEDLINE, Embase, CINAHL, PsycINFO and Web of Science. Eligible studies investigated patient-led support groups for ICD patients aged 18 years or older, using any quantitative or qualitative design. The Mixed-Methods Assessment Tool was used to assess quality. Meta-analysis of measures of mental well-being was conducted. Thematic synthesis was used to generate analytic themes from the qualitative data. The data were integrated and presented using the Pillar Integration Process. RESULTS: Ten studies were included in this review. All studies bar one were non-randomised or had a qualitative design and patients had self-selected to attend a support group. Five contributed to the quantitative data synthesis and seven to the qualitative synthesis. Meta-analysis of anxiety and QoL measures showed no significant impact of support groups on mental well-being, but qualitative data showed that patients perceived benefit from attendance through sharing experiences and acceptance of life with an ICD. DISCUSSION: ICD support group attendance improved the patients' perceived well-being. Attendees value the opportunity to share their experiences which helps to accept their new life with an ICD. Future research could consider outcomes such as patient acceptance and the role of healthcare professionals at support groups.

Managing anticoagulation in patients receiving implantable cardiac devices.

A substantial proportion of patients who undergo cardiac device implantation receive oral anticoagulation to prevent thromboembolism or antiplatelets to prevent thrombotic events. Anticoagulation and antiplatelets increase the risk of hemorrhagic complications, while discontinuation may increase thromboembolic risk and thrombotic events. With the introduction of non-vitamin K antagonist oral anticoagulant agents and the newer antiplatelet agents such as prasugrel or ticagrelor, the perioperative management of patients has become more challenging. In this article, we review the recent trials and meta-analysis and describe the available evidence, as well as the current recommendations in order to inform best practice. We also reinforce the importance of further trials in this complex and rapidly evolving area.

An open-label study to assess the feasibility and tolerability of rilmenidine for the treatment of Huntington's disease.

Preclinical data have shown that rilmenidine can regulate autophagy in models of Huntington's disease (HD), providing a potential route to alter the disease course in patients. Consequently, a 2-year open-label study examining the tolerability and feasibility of rilmenidine in mild-moderate HD was undertaken. 18 non-demented patients with mild to moderate HD took daily doses of 1 mg Rilmenidine for 6 months and 2 mg for a further 18 months followed by a 3-month washout period. The primary outcome was the number of withdrawals and serious adverse events. Secondary outcomes included safety parameters and changes in disease-specific variables, such as motor, cognitive and functional performance, structural MRI and serum metabolomic analysis. 12 patients completed the study; reasons for withdrawal included problems tolerating study procedures (MRI, and venepuncture), depression requiring hospital admission and logistical reasons. Three serious adverse events were recorded, including hospitalisation for depression, but none were thought to be drug-related. Changes in secondary outcomes were analysed as the annual rate of change in the study group. The overall change was comparable to changes seen in recent large observational studies in HD patients, though direct statistical comparisons to these studies were not made. Chronic oral administration of rilmenidine is feasible and well-tolerated and future, larger, placebo-controlled, studies in HD are warranted. TRIAL REGISTRATION: EudraCT number 2009-018119-14.

Development of a multiparametric score to predict left ventricular remodelling and prognosis after cardiac resynchronization therapy.

AIMS: Optimal delivery of CRT requires appropriate patient selection and device implantation. Echocardiographic predictors of CRT response individually appear to enhance patient selection, but do not fully reflect the complex underlying myocardial dysfunction. We hypothesized that a multiparametric approach would offer greater predictive value and sought to derive a score incorporating baseline characteristics including: dyssynchrony, LV function, and LV lead position. METHODS AND RESULTS: Data were analysed from 294 patients undergoing CRT between June 2008 and December 2012. All patients were in sinus rhythm with QRS >120 ms, NYHA class II-IV, and LVEF <35%. Detailed clinical assessment including echocardiography was completed at baseline and 6 months after CRT. Response was defined as a ≥15% reduction in LV end-systolic volume. Dyssynchrony (interventricular delay and radial strain delay), global longitudinal strain, and LV lead position were independent predictors of LV remodelling and were used to derive a predictive score which correlated with reduction in LV volume (r = - 0.5, P < 0.001) and was higher with QRS >150 ms and non-ischaemic aetiology. A cut-off score <0.6 offered the highest specificity and positive predictive value (100%) to determine non-response. A score >3.28 offered high specificity (specificity 86%, sensitivity 70%) to predict response. Survival proportion at longer term follow-up was low (21%) in the group with predictive score <0.6. CONCLUSION: A multiparametric strategy, which defines anticipated probability of response to CRT, offers potential to predict non-responders with poor long-term survival following CRT. The value of this approach in avoiding unnecessary device implantation with potential for harm requires validation in large multicentre studies.

Prognostic benefit of optimum left ventricular lead position in cardiac resynchronization therapy: follow-up of the TARGET Study Cohort (Targeted Left Ventricular Lead Placement to guide Cardiac Resynchronization Therapy).

OBJECTIVES: This study was conducted to assess the impact of left ventricular (LV) lead position on longer-term survival after cardiac resynchronization therapy (CRT). BACKGROUND: An optimal LV lead position in CRT is associated with improved clinical outcome. A strategy of speckle-tracking echocardiography can be used to guide the implanter to the site of latest activation and away from segments of low strain amplitude (scar). Long-term, prospective survival data according to LV lead position in CRT are limited. METHODS: Data from a follow-up registry of 250 consecutive patients receiving CRT between June 2008 and July 2010 were studied. The study population comprised patients recruited to the derivation group and the subsequent TARGET (Targeted Left Ventricular Lead Placement to guide Cardiac Resynchronization Therapy) randomized, controlled trial. Final LV lead position was described, in relation to the pacing site determined by pre-procedure speckle-tracking echocardiography, as optimal (concordant/adjacent) or suboptimal (remote). All-cause mortality was recorded at follow-up. RESULTS: An optimal LV lead position (n = 202) conferred LV remodeling response superior to that of a suboptimal lead position (change in LV end-systolic volume: -24 ± 15% vs. -12 ± 17% [p < 0.001]; change in ejection fraction: +7 ± 8% vs. +4 ± 7% [p = 0.02]). During long-term follow-up (median: 39 months; range: <1 to 61 months), an optimal LV lead position was associated with improved survival (log-rank p = 0.003). A suboptimal LV lead placement independently predicted all-cause mortality (hazard ratio: 1.8; p = 0.024). CONCLUSIONS: An optimal LV lead position at the site of latest mechanical activation, avoiding low strain amplitude (scar), was associated with superior CRT response and improved survival that persisted during follow-up.

Safety of the colonoscope magnetic imaging device (ScopeGuide) in patients with implantable cardiac devices.

BACKGROUND AND STUDY AIMS: Use of the colonoscope magnetic imaging device (ScopeGuide, Olympus Medical Systems, Tokyo, Japan) is currently contraindicated by the manufacturer for patients with implantable cardiac devices, a group of patients that is increasing annually along with the number of colonoscopies performed in the era of colorectal cancer screening. This is the first study to examine the safety of ScopeGuide in patients with permanent pacemakers, implantable cardioverter defibrillators, and cardiac resynchronization therapy. PATIENTS AND METHODS: Nonimplanted cardiac devices were exposed to the electromagnetic field of ScopeGuide ex vivo and assessed for evidence of interference or change in device settings. Following this, consecutive patients attending device check clinics were prospectively recruited and exposed to the ScopeGuide electromagnetic field. After an initial device check, patients underwent continuous external cardiac monitoring and device interrogation while a colonoscope was placed on the abdomen over clothing and connected to ScopeGuide to simulate colonoscopy. Patients were monitored for 2 minutes to assess for any interference. ScopeGuide was then disconnected and devices were checked for any change in settings. RESULTS: A total of 230 patients were invited to participate and 100 were recruited to the study. There was no evidence of interference on device leads or change in programming following exposure to the electromagnetic field generated by ScopeGuide. CONCLUSION: ScopeGuide does not appear to cause interference or change in settings and is therefore likely to be safe for use in patients with implantable cardiac devices.

Incidence of atrial fibrillation detected by implantable loop recorders in unexplained stroke.

OBJECTIVES: The usefulness of the implantable loop recorder (ILR) with improved atrial fibrillation (AF) detection capability (Reveal XT) and the factors associated with AF in the setting of unexplained stroke were investigated. METHODS: A cohort study is reported of 51 patients in whom ILRs were implanted for the investigation of ischemic stroke for which no cause had been found (cryptogenic) following appropriate vascular and cardiac imaging and at least 24 hours of cardiac rhythm monitoring. RESULTS: The patients were aged from 17 to 73 (median 52) years. Of the 30 patients with a shunt investigation, 22 had a patent foramen ovale (73.3%; 95% confidence interval [CI] 56.5%-90.1%). AF was identified in 13 (25.5%; 95% CI 13.1%-37.9%) cases. AF was associated with increasing age (p = 0.018), interatrial conduction block (p = 0.02), left atrial volume (p = 0.025), and the occurrence of atrial premature contractions on preceding external monitoring (p = 0.004). The median (range) of monitoring prior to AF detection was 48 (0-154) days. CONCLUSION: In patients with unexplained stroke, AF was detected by ILR in 25.5%. Predictors of AF were identified, which may help to target investigations. ILRs may have a central role in the future in the investigation of patients with unexplained stroke.

Radial strain delay based on segmental timing and strain amplitude predicts left ventricular reverse remodeling and survival after cardiac resynchronization therapy.

BACKGROUND: Dyssynchrony assessment based on the timing of regional contraction is inherently independent of underlying myocardial contractility. We tested the hypothesis that patient selection for cardiac resynchronization therapy (CRT) would be enhanced using a parameter derived from the net radial strain delay (RSD) for the 12 basal and mid-left ventricular segments (calculated radial strain delay RSD [RSDc]), based on not only timing but also amplitude of segmental strain. METHODS AND RESULTS: Echocardiographic data were analyzed in 240 patients with symptomatic heart failure undergoing CRT (New York Heart Association class III/IV; QRS >120 milliseconds; ejection fraction, 23±7%). RSDc was calculated as the sum of difference between peak radial strain and radial strain at aortic valve closure before CRT implantation. CRT response was defined as >15% reduction in left ventricular end-systolic volume at 6 months. In a derivation group (n=102), RSDc was higher in responders compared with nonresponders (74±39% versus 29±15%; P<0.001) and related to the change in left ventricular end-systolic volume (r=-0.53; P<0.001). RSDc >40% predicted remodeling (sensitivity, 87%; specificity, 88%). In the validation group (n=108), RSDc similarly predicted response (sensitivity, 89%; specificity, 84%). Survival at long-term follow-up was greater in patients with RSDc >40% (P<0.0001). CONCLUSIONS: RSDc, based on both the timing and the amplitude of segmental strain, has a strong predictive value for CRT remodeling response and long-term survival.