Why does CRT work better in women?

Introduction

It has been recently postulated that cardiac resynchronization therapy (CRT) might have a higher efficacy in women, with a greater reverse cardiac remodeling in this population. The reasons for these differences are not yet completely understood. We aimed to detect sex differences in the degree of ventricular asynchrony (VA) and mitral regurgitation (MR) in patients undergoing CRT implantation.

Methods

We analyzed baseline characteristics of a prospective international clinical trial that compared CRT response rate in a HF population with a comparable distribution of men and women (BIOWOMEN). A total of 408 patients were analyzed. The degree of mitral regurgitation and intra and inter-ventricular asynchrony was assessed by independent echocardiographers in a core lab. Inter-ventricular asynchrony was defined as an interventricular mechanical delay greater than 40ms and intra-ventricular asynchrony as differences greater than 50ms among regional pre-ejection periods. Multivariable logistic regression was performed using commercial data analysis software.

Results

As expected, ventricular asynchrony was dependent on QRS duration and the presence of LBBB (p<0.01). Baseline QRS duration was significantly shorter in women than men (155.85±19.0 in women vs 160.4±21.6, p=0.02). However, for a similar QRS duration, there were no differences in asynchrony parameters between the two groups (p=0.43; Figure 1). Female sex was associated with a significantly higher proportion of mitral regurgitation for a given QRS duration, which was independent of the etiology (p=0.05).

Conclusions

In our analysis, for a given QRS duration there was not a higher degree of asynchrony in women with HF. However, female sex was associated with a significantly higher proportion of mitral regurgitation for a given QRS duration irrespective of baseline HF etiology. Further investigations are needed to establish a possible link between these findings and better CRT outcomes in women.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): BIOTRONIK SE & Co. KG

Single versus dual antiplatelet therapy following transcatheter left atrial appendage closure

Funding Acknowledgements

Type of funding sources: None.

Background

Left atrial appendage occlusion (LAAO) had emerged as an alternative to anticoagulation in patients with non-valvular atrial fibrillation and a contraindication to long-term oral anticoagulants (OAC). LAAO implantation aims to reduce the risk of both systemic thromboembolism and the bleeding events associated with prolonged OAC. Post-procedural antithrombotic regimen varies among patients and may include antiaggregant (dual or single agents) or anticoagulation therapy in minority patients. The current study aims to compare the effectiveness and safety of post-procedural antithrombotic treatment with either dual antiplatelet therapy (DAPT) or single antiplatelet therapy (SAPT) in a real-world cohort.

Methods

The cohort consisted of 205 consecutive patients who had undergone LAAO at Sheba medical center between the years 2010-2020. We prospectively evaluated baseline characteristics and periprocedural clinical, laboratory, and imaging data. All patients were followed by scheduled in-clinic visits. After excluding patients prescribed OAC following the procedure or deceased in the index procedure, the study cohort was divided into two groups according to the antithrombotic regimen following the LAAO: SAPT (35 patients) versus DAPT (151 patients). A propensity analysis via the stabilized inverse-probability-of-treatment weighting (IPTW) was applied.

Results

The leading etiologies for transcatheter LAAO were previous gastrointestinal bleeding (41%) and previous intracranial bleeding (32%). The median CHADSVASC score is 5 [IQR:4-6]. Patients discharged with SAPT following LAAO were older (78±8 yrs vs.75±8 yrs), accompanied by an evident trend over the years of discharging more patients with SAPT instead of DAPT (Figure 1). No statistically significant differences were observed in other baseline characteristics, including gender, hypertension, diabetes mellitus, malignancy, chronic renal or heart failure. During two years of clinical follow-up, no differences in major adverse cardiovascular events were observed between the two groups (20% vs.19% for SAPT and DAPT, respectively). After applying an IPTW propensity analysis adjusting for several clinical and procedural relevant parameters, a K-M survival curve demonstrates no survival benefits of dual over single antiplatelet therapy (Figure 2).

Conclusions

Among patients undergoing LAAO, post-procedural DAPT provides no survival benefits over single antiplatelet therapy.

Intraoperative defibrillation testing during replacements of implantable cardioverter-defibrillators: The Simpler trial

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): Maurice Kahn Foundation via the Mayo- Sheba Collaboration Fund.

Background

The need for intraoperative defibrillation testing (DFT) during implant and/or replacement of implantable cardioverter-defibrillators (ICDs) has been a matter of debate for many years. This debate was put to rest by the Simple and the Nordic ICD trials, and the practice of testing during new implantations has practically been nearly abandoned.

Nevertheless, induction of VF for testing purposes (VFT) may still have an important role in selective populations at risk for defibrillation failure, who were not included in the SIMPLE and Nordic trials. One such population includes those who undergo device replacements. Old registries demonstrated an increased incidence of significant findings in VFT during replacements. In the present study, we sought to test this observation.

Objectives

Evaluate frequency of significant findings and the safety of VFT in subjects undergoing device replacement.

Methods

A prospective observational multi-center study of VFT included consecutive patients undergoing ICD generator replacement in 5 centers in Israel, Europe, and the US. All centers followed the same VFT protocol. The primary outcome was defined as failure to terminate induced VF with a single shock at 10 Joules below the maximal capacity of the device. Secondary outcomes included complications of VFT. Patients were followed-up at 1 month and 6 months post-procedure. Data collection included documentation of any peri-operative complications and clinical endpoints (occurrence of appropriate shock, inappropriate shocks, lead failure, need for re-intervention, and infection).

Results

A total of 92 patients were eligible, and consented for the study, of which 84 underwent DFT during battery replacement. The median age was 68 years and 79.8% were male subjects. Induction of VF was successful in all 84 patients as well as VFT with a successful conversion on first attempt. During follow up one patient had two appropriate ICD shock events. In four patients, the ICD programming was changed. None suffered an inappropriate shock. There was no evidence of lead malfunction. A total of two deaths occurred, none of which were related to the device.

Conclusion

The present study found VFT was not associated with complications in patients undergoing ICD/CRTD generator replacement but produced no clinically important information.

Occluded vein as a predictor for complications in non-infectious transvenous lead extraction

Funding Acknowledgements

Type of funding sources: None.

Background

Cardiovascular implantable electronic device (CIED) use is steadily increasing, with subsequent need to solve lead failure issues and device upgrades with an occluded vein. Transvenous lead extraction (TLE) has inherent risks that must be carefully weighed. Currently there is lack of conclusive data regarding many non-infectious indications.

Methods

A retrospective study on indications and outcomes of TLE for non-infectious reasons at our medical center, between the years 2011 to 2020 was performed. Occluded vein (OV) presence was compared for characteristics, extraction methods and periprocedural complications and outcomes.

Results

A total of 88 patients underwent TLE for non-infectious reasons. The majority were referred due to lead malfunction (70.5%) and CIED upgrade with an OV (25%), while 4 patients had other TLE indication (intractable pain, heart transplant, severe Tricuspid regurgitation, and irradiation). fourteen patients referred due to lead malfunction had an OV observed during venography.

The OV group (36 patients) were significantly older (65.7±14.1 vs 53.8±15.9 respectively, p=0.001) and had more comorbidities. EF was significantly lower for the OV group (27.5% vs 57.5%, p=0.001) as was longer lead dwell time (3226±2324 vs 2191±1355 days, respectively, p=0.012).

Major complications were exclusive for the OV group (16.7% vs none, p=0.02), and most minor complications occurred in the OV group as well (38.9% vs 4.1% respectively, p<0.001). Laser sheath and Mechanical tools for TLE were frequently used for OV as compared to the non-occluded group (94.4% vs 73.5% respectively, p=0.012). Procedure success was higher in the non-occluded group compared to the OV group (98% vs 83.3%, respectively, p=0.047). Despite these results, peri-procedural mortality was similar between groups.

Conclusions

Among TLE for non-infectious reasons, vein occlusion appears as a major predictor for complex TLE tools use, complications, and procedural success. Venography should be routinely performed prior to non-infectious TLE to identify high-risk patients.

Permanent pacemaker implantation post transcatheter aortic valve replacement- the role of pacing burden

Introduction

Previous studies have provided inconsistent results regarding the clinical impact of new permanent pacemaker (PPM) post TAVR. Our aim is to evaluate whether new PPM post TAVR is associated with higher 1-year mortality and/or heart failure hospitalizations and whether pacing burden is related to adverse outcomes.

Results

Overall, 1245 patients underwent TAVR between the years 2008–2019 and were included in our analysis with a median follow up of 2.3 years (IQR 1–4). 191 (15%) had a new PPM implantation during index admission. Compared to patients without PPM those implanted had significantly higher 1-year mortality rate (18% vs 11%, p-0.007) as well has higher combined outcome of mortality and HF hospitalizations. There was no difference in pacing burden between survivors and non survivors in all models examined: first and last clinic visit, maximal pacing during the first-year post implantation and the difference in pacing trend between visits. Older age, peripheral artery disease (PAD) and previous myocardial infarction (MI) were independently associated with mortality or combined outcome of mortality and HF hospitalizations.

Conclusion

New pacemaker implantation post TAVR is associated with higher 1-year mortality and HF hospitalization, however pacing burden isn't associated with adverse clinical course.

Funding Acknowledgement

Type of funding sources: None.

Leadless pacemaker implant in patients requiring CIED extraction: outcomes based upon timing of extraction

Background

Previous results from global Micra Transcatheter Pacemaker clinical trials have demonstrated leadless pacing as a safe and attractive option for patients with prior cardiac implantable electronic device (CIED) infection and extraction. Whether outcomes differ based upon the timing of prior device extraction has not been studied.

Purpose

To describe characteristics and outcomes of patients undergoing CIED extraction during or prior to Micra implantation.

Methods

Patients who underwent CIED explant and Micra implantation were identified from the Micra Post-Approval Registry and Micra Acute Performance studies. Baseline characteristics were summarized. A Fine-Gray competing risk model was used to compare risk for major complication through 24 months.

Results

Of the 2739 patients included in the studies, 99 (3.6%) patients had CIED extraction the day of Micra implantation (same day) and 127 (4.6%) patients had CIED extraction within 30 days prior to Micra implantation (prior). Although infection was the primary reason for CIED extraction in both groups, a larger proportion of prior patients underwent extraction for this reason (87.4% vs. 42.4%). In contrast, more same day patients underwent CIED extraction for physician/elective reasons (16.2% vs. 3.1%). Same day patients prior device history included pacemaker (42 dual chamber and 30 single chamber), ICD (1 single chamber and 4 dual chamber), CRT (7 CRT-ICD and 13 CRT-P) while prior patients device history included pacemaker (29 single chamber, 80 dual chamber), ICD (3 dual chamber), CRT (5 CRT-ICD and 7 CRT-P). Overall, patients with extraction were aged 72.8±14.3 years, predominantly male (65.9%), and medical history was similar between groups, with the exception to CHF, which was higher for the same day group (18.2% vs 6.3%, P=0.021). The implant success rate was 98.0% for same day patients and 100% for prior patients. Median procedure duration was not significantly different between the groups (26.0 minutes and 25.0 minutes for same day and prior, respectively). Average follow-up duration was 16.5±13.8 months (range 0–53.4) for same day patients and 18.2±15.2 months (range 0–58.3) for subsequent patients. The rate of acute major complications (<30 days) was 5.1% for same day and 3.2% for prior. Through 24 months, the rate of major complications was 6.4% for same day and 6.0% for prior (HR: 1.19, 95% CI: 0.40 – 3.50, P=0.76, Figure). The rate of major complications related to infection was low and did not differ by group (1.01% vs. 1.57%, P=1.00)

Conclusion

The Micra leadless pacemaker was implanted with a high success rate following CIED extraction. Outcomes following CIED extraction appear similar, whether the extraction is performed during or prior to Micra implant.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Medtronic, Inc. Risk of major complications

Predictors and outcomes of TLE via femoral vein bailout

Background

Transvenous Lead Extraction (TLE) is usually performed via a superior approach. Predictors and outcomes of TLE via femoral vein bailout are ill defined.

Methods

A single tertiary center cohort of 426 consecutive patients who underwent TLE between May 2010 and February 2020 were analyzed. Venography was routinely performed before system upgrade to identify occluded veins. Patients were divided into 2 groups on the basis of the need for femoral bailout extraction. Predictors for TLE requiring femoral bailout and outcomes were analysed.

Results

A total of 928 leads were extracted and femoral bailout approach was needed in 49 patients (11.5%). A higher proportion of RV leads required femoral bailout approach [51/499 (10.2%)]. Femoral bailout was more common among younger patients, longer lead dwell time, more pocket entries, higher number of extracted leads, presence of abandoned leads [14/49 (28.6%)], and among patients with occluded veins [10/22 (45.5%)]. The presence of abandoned leads, vascular occlusion and age remained a significant predictor for femoral bailout in multivariate analysis. Femoral bailout TLE resulted in a relatively higher rate of major complications [5/49 (10.2%) vs 9/377 (2.4%); p=0.02) but had no related intra-procedural mortality (0/3) and no additional 30 day mortality [2/49 (4.1%) vs 33/377 (8.8%); p=0.4].

Conclusion

TLE of abandoned leads, occluded veins and younger age were found to be predictors of femoral bailout requirement. Despite higher rates of major complications in femoral TLE bailout this did not result in increased mortality. Venography before TLE should be considered for procedure planning.

Funding Acknowledgement

Type of funding sources: None.

Novel insights on Andersen-Tawil syndrome type 1

Background

Andersen-Tawil Syndrome type 1 (ATS1) in a rare arrhythmogenic disease caused by loss-of-function mutations in the KCNJ2 gene and characterized by ventricular arrhythmias, dysmorphic features and episodes of periodic paralysis. Although the prognosis of ATS1 patients is typically considered benign, definitive outcome data are lacking.

Purpose

We aimed to: 1) define the risk of life-threatening arrhythmic events (LAEs); 2) identify risk factors for such events; 3) assess the efficacy of anti-arrhythmic drugs in preventing LAEs.

Methods

We included 118 ATS1 patients from 57 families with confirmed pathogenic or likely pathogenic KCNJ2 mutations. Clinical and genetical data were acquired by investigators from 23 centers in 9 countries.

Results

Baseline characteristics of the population are presented in the Table. Over a follow-up of 6.2 years, 17/118 (14%) patients experienced a first LAE, with a 5-year cumulative probability of 7.9% (Figure). Cox multivariable analysis demonstrated that a previous history of syncope (HR 4.5, p=0.02), the documentation of sustained VT (HR 9.3, p=0.001) and the administration of amiodarone (HR 268, p<0.001) were associated with an increased risk of LAE. The baseline rate of LAE was not reduced by beta-blockers alone (1.37 per 100 py; p=1), or in combination with class Ic antiarrhythmic drugs (1.46 per 100 py, p=1).

Conclusions

Our data demonstrate that the clinical course of patients with ATS1 is characterized by a high rate of LAE. A history of unexplained syncope, and documentation of sustained ventricular tachycardia are independently associated with a higher risk of LAE. Amiodarone is proarrhythmic and should be avoided in ATS1 patients.

ATS1: Diagnosis, Outcome, Risk Factors

Funding Acknowledgement

Type of funding source: Public grant(s) – EU funding. Main funding source(s): ERN Guard-Heart European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart

Is chest CT sufficient for follow-up of primary mediastinal B-cell lymphoma in remission?

OBJECTIVE

We aimed to evaluate whether chest CT alone is sufficient for follow-up assessment of patients with primary mediastinal B-cell lymphoma that is in remission.

MATERIALS AND METHODS

A retrospective review of medical records and CT examinations of patients who received a diagnosis of primary mediastinal B-cell lymphoma between January 1989 and January 2000 was performed. The first-year follow-up comprised examinations at 3-month intervals of the neck, chest, abdomen, and pelvis, with the examination modality alternating between CT and gallium scintigraphy. Patients who achieved complete remission underwent the same CT protocol twice the following year and then once a year during sequential follow-up.

RESULTS

Fifty-three patients with primary mediastinal B-cell lymphoma at presentation--31 females and 22 males, ranging in age from 17 to 61 years (average age at diagnosis, 34 years)--were studied. The follow-up time ranged from 6 to 143 months (average follow-up time, 42.4 months). Although 11 of the patients had only a partial remission, 42 patients (79%) achieved complete remission, with one patient lost to follow-up and thus excluded from study. Recurrence was diagnosed in six of these 42 patients. All six had mediastinal recurrence with additional involvement of the lungs, chest wall, pericardium, and pleura. One patient also had bone marrow involvement at recurrence.

CONCLUSION

Recurrence of primary mediastinal B-cell lymphoma in patients who achieve complete remission appears to be confined to the chest. Consequently, chest CT alone is sufficient for routine follow-up of these patients.