Prognostic significance of mean transmitral pressure gradient in degenerative non-rheumatic mitral valve: insights from a vast echocardiographic database

Background

The incidence and prevalence of senile, non-rheumatic mitral valve disease are increasing and there is a renewed interest in new transcatheter structural cardiac interventions intended to treat that valvular disorder. While the severity of rheumatic mitral valve disease can be accurately assessed by echocardiography using various parameters, including mean transmitral pressure gradient, these methods have been questioned for quantifying senile mitral valve disorder and their prognostic significance is still unknown.

Aims

The current study aims to document the natural history of patients with elevated senile mean transmitral pressure gradient (MG) and assess its prognostic significance.

Methods

A vast institutional echocardiography database was retrospectively analyzed from 2009 to 2020 for all patients aged over 60 years with a detailed echocardiography report with valid measurement of transmitral gradients. Patients with rheumatic valvular disease or who underwent surgical or transcatheter valvular replacement/repair were excluded. All-cause mortality was set to be the primary outcome, and survival models utilizing univariable and adjusted multivariable analysis for various clinical and echocardiographic variables were applied.

Results

A total of 5524 patients consisted of the final cohort. They were stratified by the MG into three groups: MG <3 (2914 patients, 53%), 3≤MG<6 (2079 patients, 37.6%) and MG ≥6 mmHg (531 patients,9.6%). The mean age of the total cohort was 77.2±7.9 years; 60.5% were female, 33.3% with diabetes mellitus, 15.1% with chronic kidney disease, and 14.1% with ischemic heart disease. An Adjusted Cox proportional hazard regression model demonstrated that MG is independently associated with all-cause mortality (adjusted HR 1.04 per 1 mmHg increase, 95% CI 1.02–1.05, p<0.001). Moreover, an elevated MG was associated with a rise in all-cause mortality (HR of 1.15 and 1.4 for patients with 3≤MG<6 and MG ≥6 mmHg, respectively (Fig. 1).

Conclusion

The elevated mean transmitral gradient in senile non-rheumatic valves is an independent predictor for all-cause mortality. Interventions and prospective trials intended to mitigate that risk should be needed.

Funding Acknowledgement

Type of funding sources: None.

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.

Failed shocks in hypertrophic cardiomyopathy patients: prevalence, predictors and outcome

Funding Acknowledgements

Type of funding sources: None.

Introduction

An implantable cardioverter-defibrillator (ICD) is used in selected high-risk hypertrophic cardiomyopathy (HCM) patients in order to prevent sudden arrhythmic death. The unique features of this population raise concerns regarding the reliability of successful defibrillation.

Purpose

To describe the rate and discover potential predictors of failed shocks in HCM patients.

Methods

We retrospectively evaluated all HCM patients with an ICD from a single tertiary medical center. Clinical, electrocardiographic and echocardiographic data were collected and compared among patients with and without failed shocks.

Results

A total of 99 patients (77% male, 45±17 years old) were analyzed. Over a median follow up of 6.3 years (IQR 2.6-10.7), 20 patients developed sustained ventricular arrhythmia (VTA). Of those, 18 patients received appropriate shocks from their ICD. VTA was associated with younger age at diagnosis, history of syncope and thicker maximal LV width. Six patients experienced at least one failed shock. The likelihood of failed shocks was similar when single or dual coil electrodes were used (dual coils in 67% of patients with failed shocks and 50% in those without), and the only predictor was increased wall thickness [OR 1.2 (1.07-1.38) per 1 mm]. All-cause mortality was low and similar in patients with an without failed shocks (0% vs 8%, P=0.5)

Conclusions

Failed shocks are a rare entity in HCM patients. Increased maximal LV width was the only predictor of those events. Our findings support avoiding defibrillation threshold testing routinely, but may indicate its need in patients with extreme LV wall thickening (≥23 mm).

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.

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.

Atrial fibrillation in the young: clinical characteristics, predictors of new onset and outcomes

Funding Acknowledgements

Type of funding sources: None.

Introduction

Atrial fibrillation (AF) onset in the young (≤45 years) is uncommon and not well studied.

Purpose

Identifying the determinants of AF in this population in order to help direct timely diagnosis, appropriate follow up and management.

Methods

We retrospectively evaluated all patients aged ≤45, admitted to the internal and cardiology wards between January 2009 and December 2019 at a large tertiary center. Clinical, electrocardiographic and echocardiographic data were collected and compared among patients with and without AF at baseline. A subgroup of patients with no AF at baseline and a subsequent hospital visit were followed for development of new onset AF (NOAF).

Results

A total of 16,432 patients (55.5% male, 33 ±8.3 years old) were analyzed. At baseline, patients with AF (n = 366) tended to be older, more often male, and had a higher proportion of comorbidities and ECG conduction disorders, compared with the patients without AF (n = 16,066). Male sex, increased age, obesity, heart failure (HF) and the presence of left or right bundle branch block (LBBB and RBBB, respectively) were all strongly and independently associated with young-onset AF. A total of 10,691 patients were followed for a median of 41.5 (16.6-78.6) months, during which 85 patients developed NOAF (equivalent to 0.5%/year). Increased age, hypertension, HF, RBBB and LBBB were independent predictors of NOAF. CHARGE-AF score outperformed CHA2DS2-VASc score in NOAF prediction [AUC of ROC 0.75 (0.7-0.8) vs. 0.56 (0.48-0.65)].

Conclusions

The annual risk of NOAF among young adults admitted to the hospital is noteworthy. NOAF may be predicted by clinical risk factors and the CHARGE-AF score. Characteristic No AF (N = 16066) AF (N = 366) Total (N = 16432) P value Age- yr. 33.06 ± 8.3 36.8 ± 7.3 33.1 ±8.3 <0.0001 Male gender 8914 (55.5) 240 (65.6) 9154 (55.7) <0.0001 BMI- kg/m2 25.5 ± 5.75 27.48 ± 6.36 25.2 ± 5.8 <0.0001 HTN 2679 (16.7) 73 (19.9) 2752 (16.7) 0.098 CHF 124 (0.8) 13 (3.6) 137 (0.8) <0.0001 PR interval > 200ms 117 (1.3) 15 (9.1) 132 (1.5) <0.0001 QRS interval > 120ms 220 (2.4) 25 (8.4) 245 (2.6) <0.001 LBBB 29 (0.2) 6 (1.6) 35 (0.2) <0.0001 LVEF < 40 323 (10.1) 35 (16.9) 358 (10.5) 0.002 CHA2DS2-VASc 0.75 ±0.75 0.73 ±0.84 0.74 ±0.76 0.647 CHARGE AF 6.3 ±1.1 6.8 ±0.9 6.32 ±1.06 <0.001

Induction of oral tolerance towards hepatitis B envelope antigens in a murine model

BACKGROUND

Hepatitis B virus (HBV) is a non-cytopathic virus, and the hepatocellular injury that occurs as a consequence of HBV infection is mediated by the host antiviral immune response. Subjects with natural tolerance to HBV have minimal or no liver injury despite chronic viremia. We have shown that immune tolerance towards viruses can be induced by oral administration of viral proteins.

AIMS

To test whether oral induction of tolerance can be induced towards HBV antigens, and whether oral tolerance induction downregulates preexisting anti-HBV immune response.

METHODS

Oral tolerance was induced via feeding of five low oral doses of HBV proteins (HBsAg+preS1+preS2, BioHepB). This was followed by two inoculations with the BioHepB vaccine. Humoral immune tolerance was evaluated by measuring serum levels of anti-HBs antibody titers at monthly intervals. To determine if oral tolerance induction downregulates pre-existing anti-HBs immunity, mice were inoculated twice with the BioHepB vaccine, followed by feeding of BioHepB-HBV proteins.

RESULTS

Feeding of HBV proteins markedly inhibited production of anti-HBs antibodies in naive mice. Anti-HBs titers were 45 versus 135 mIU/ml, in tolerized versus non-tolerized controls (P<0.005). Moreover, oral tolerance induction effectively down-regulated pre-existing immunity and reduced the anti-HBs titers in previously immunized mice to 112 versus 223 mIU/ml, in tolerized compared with non-tolerized controls (P<0.01).

CONCLUSIONS

Induction of oral tolerance towards HBV proteins downregulates the antiviral humoral immune response in naive mice, and in the presence of preexisting anti-HBV immunity. This approach should be further investigated as a method for alleviation of antiviral-mediated liver injury in chronic HBV hepatitis.

Induction of oral tolerance in splenocyte recipients toward pretransplant antigens ameliorates chronic graft versus host disease in a murine model

Chronic graft versus host disease (cGVHD) is a major complication that can develop after bone marrow transplantation. It involves an immune-mediated attack by transplanted donor lymphocytes, and often results in inflammatory damage of host target organs. Immune hyporesponsiveness induced by oral antigen administration has been recently shown to prevent the development of cGVHD in a murine model. The aim of this study was to evaluate whether tolerance induction in bone marrow transplant (BMT) recipients after transplantation, toward their pretransplant antigens, can alleviate preexisting cGVHD in a mouse model. cGVHD was generated by infusing 2.5 x 10(7) splenocytes from B10.D2 donor mice, to sublethally irradiated (6 Gy) BALB/c recipient mice, which differ by minor histocompatibility antigens. Transplantation resulted in cGVHD, with characteristic scleroderma-like cutaneous fibrosis, increased skin collagen content, decreased body weight, and hepatic and small bowel inflammation. Oral tolerance was induced by feeding recipient BALB/c mice with proteins extracted from BALB/c splenocytes for 11 days after B10.D2 splenocyte transplantation. Tolerance induction was evidenced by a significant reduction in mixed lymphocyte response of effector splenocytes from tolerant BALB/c mice transplanted with B10.D2 splenocytes against BALB/c target splenocytes. Oral tolerance decreased skin collagen deposits. Reduction of collagen alpha1(I) gene expression and skin collagen were shown by in situ hybridization and histochemistry, respectively. Liver and bowel biopsy specimens revealed less inflammation. Serum IL-10 levels were higher in tolerant mice than in controls, whereas IFNgamma was significantly reduced. Oral tolerance of BMT recipients toward their pretransplant antigens after splenocyte transplantation down-regulated the immune attack by transplanted cells, thus ameliorating cGVHD.