P780 Left ventricular torsion in severe valvular disease

Introduction

Left Ventricular (LV) torsion is an important component of LV performance. With the development of speckle tracking echocardiography, it became possible and feasible to measure rotation and twisting with a high degree of accuracy. No standard normal values are defined for peak torsion, although mean values around 10° are found in normal subjects with a slight increase with age.

Purpose

In this study we aimed to evaluate torsion in the different types of severe valvular disease.

Methods

We conducted a retrospective, observational study including patients with severe valvular disease with suitable images for torsion analysis. We included 61 patients (21 with severe aortic stenosis (AS), 20 with severe aortic regurgitation (AR) and 20 with severe mitral regurgitation (MR). Circumferential basal and apical strain was performed, and peak torsion was calculated. Results were compared between groups and were related with echocardiographic parameters, including left ventricle ejection fraction (LVEF).

Results

Mean age was 70.3 ± 13.6 years with a male preponderance (66%). Mean LVEF was within normal range in the aortic valve disease group; no significant difference was found in LVEF between AS and AR patients (57 ± 7.7% vs 55 ± 9.7%, p = 0.57). In comparison with the aortic disease group, MR patients had a reduced LVEF (48 ± 17.3% vs 56 ± 8.7%, p = 0.05). Mean peak torsion was 8.9 ± 5.1° in AS, 12.6 ± 4.9° in AR and 7.9 ± 3.2° in MR (p = 0.004). Comparing with aortic valve disease patients, MR patients had a reduced mean peak torsion (7.9 ± 3.2° vs 10.7 ± 5.3°, p = 0.03). In relation with patients with AS, those with AR had a higher peak torsion (12.6 ± 4.9° vs 8.9 ± 5.1°, p = 0.024) and a higher left ventricle end-diastolic volume (87.3 ± 29.1 mL.m-² vs 64.5 ± 24.9 mL.m-², p = 0.011). Circumferential apical strain showed a negative correlation with peak torsion (r²=0.203, p = 0.006) and with LVEF (r²=0.290, p < 0.001). Peak torsion did not demonstrate any significant correlation neither LVEF nor circumferential basal strain.

Conclusion

LV function and peak torsion are more associated with apical than basal circumferential movement. Aortic valve disease is responsible for LV torsion variations in patients with normal ejection fraction, showing an increase in AR and a reduction in AS. In MR patients a reduced LVEF could entails a decrease in peak torsion.

P1541 Left ventricular global longitudinal strain can predict the risk of ventricular arrhythmias in hypertrophic cardiomyopathy patients with preserved left ventricle function

Introduction

Hypertrophic cardiomyopathy (HCM) is characterized by a heterogeneous clinical expression with increased risk of sudden cardiac death (SCD) from ventricular arrhythmias (VAs).Several studies have shown that patients with malignant arrhythmias have increased electrical dispersion and in homogeneity of intraventricular conduction. Strain by echocardiography is an excellent tool for assessing regional and global left ventricular (LV) function and mechanical dispersion reflects heterogeneous myocardial contraction. We aimed to explore the value of strain parameters in prediction of VAs in HCM with LV preserved systolic function.

Methods

Retrospective observational study including all patients with HCM and ICD implanted in setting of primary prevention in our centre. Patients with LVEF < 40% or coronary artery disease were excluded. LV GLS was defined as the average of peak longitudinal strains from a 16 LV segments model, obtained from three apical views. Time to peak strain was defined as the time from onset Q/R wave on ECG to peak negative longitudinal strain during the entire cardiac cycle. Mechanical dispersion was defined as the standard deviation of time to peak negative strain in 16 LV segments. Patients with VA (group1) and patients without VA (group2) were compared.

Results

The study population included 48 patients, 63.3% of male gender. A family history of HCM was present in 64 pts (43%). All patients were under anti arrhythmic therapy (BB in 95.6%, other anti-arrhythmic in 28.2%). VAs (sustained and non sustained) were documented in 27 (55%) patients. The study groups did not differ regarding to mean age (54 ± 12 vs 56 ± 12 years, p = 0.67), male gender (54% vs 56%, p = 0.87) and BB therapy (91% vs 96%,p = 0.07). Mean LVEF was 58% in group 1 and 61% in group 1, p = 0.56; a LVOT gradient >30mmHg was present in 52% of group 1 pts and 45% of group 2 pts, p = 0.06. Mean wall thickness was 22mm vs 18 mm, p = 0.03, respectively.

GLS was significantly lower in group 1 (- 13.9 ±3.4 vs -16.1 ±3.5, p = 0.02), mechanic dispersion was significantly higher in group 1(81 ± 14 vs 60 ± 12ms, respectively, p = 0.01. Using a multivariate logistic regression model including variables included in SCD HCM risk score proposed by ESC mechanical dispersion (OR: 1.54 (1.03–8.7), p = 0,03) was a strong and independent risk predictor of VA. Using optimal cut-off values from ROC analyses, patients with mechanical dispersion >67 ms (AUC = 0.82, p= 0.02) had more VAs.

Conclusions

Mechanical dispersion and GLS may help to identify HCM patients with high risk of VAs and SCD.

Abstract P1541 Figure 1

P5694Outcomes of patients with arrhythmogenic right ventricular cardiomyopathy after ventricular tachycardia ablation without an implantable cardioverter-defibrillator: a multicenter international study

Background

In arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D), implantable cardioverter-defibrillators (ICD) after an episode of sustained monomorphic ventricular tachycardia (MVT) are currently recommended in most situations. However, radiofrequency catheter ablation (RCA) is effective in reducing recurrent VT and whether MVT is a surrogate of sudden cardiac death is debated when other risk factors are lacking.

Purpose

To report the outcomes of patients with ARVC/D who underwent RCA of well-tolerated MVT without a back-up ICD.

Methods

Patients with a definite ARVC/D diagnosis according to the 2010 Task Force revised criteria who underwent RCA of well-tolerated MVT at 9 tertiary centers across 5 countries, without an ICD prior to RCA and in the 3 following months were retrospectively included. Patients presenting with syncope or electrical storm, and patients with left ventricular ejection fraction <50% were excluded. Similar patients implanted with an ICD prior or without RCA in the same period served as controls.

Results

Sixty-five patients [median age 46.1 years, range (19.5–73.8), 75% males] underwent RCA of MVT between 2003 and 2016. Familial history of ARVC/D was found in 11% of patients. Epsilon-waves were present in 19% and T-waves inversion beyond V2 in 43%. A right ventricular (RV) ejection fraction ≤40% or fractional area change ≤33% was found in 14 (25%) patients. Median left ventricular ejection fraction was 61% (50–70). Clinical presentation was palpitations in 81% of patients and near-syncope in 14%. Prior to RCA, patients were on beta-blockers alone in 18%, class I drugs in 37% and amiodarone in 9%, while 15% of patients were free any antiarrhythmic medication. Only 1 patient (2%) had >1 clinical VT morphology. Median VT rate was 180 (110–270). An epicardial approach was used in 31% patients. The clinical VT was inducible in 84% of patients. The median number of targeted RV site was 1 (1–3) (RV outflow tract in 72%). Full acute success defined inability to induce any VT was achieved in 72% of patients. During a median follow-up time of 49 month (1.4–162), there was no death or aborted cardiac arrest. Survival without VT recurrence was estimated at 82%, 71% and 60%, 12-, 36- and 60-months after RCA. No VT recurrence was observed among patient who had undergone an epicardial ablation. Among patients with VT recurrence, 6 (35%) did not receive an ICD, and 14 (70%) underwent redo RCA. An ICD was implanted in 10 patients, including 5 for VT recurrence. Fifty-eight patients constituted the control group, and 64% had appropriate ICD interventions during follow-up.

Conclusions

Despite a significant rate of VT recurrence, selected patients with ARVC/D who underwent RCA for stable MVT without an ICD did not experience any arrhythmic death. Further prospective studies are mandatory to precise the respective places of ICD and RCA in the management of ARVC/D patients with well-tolerated MVT.

Acknowledgement/Funding

None

P6564Prediction of the progression from paroxysmal to persistent or permanent atrial fibrillation using different scores. Is AF progression mainly atrial aging?

Methods

All patients with AF seen over a period of 10 years were identified in a database and followed up for AF progression and mortality. Predictors of outcomes were identified using Cox regression model. The values of HATCH, CHA2DS2-VASc, ALARMEc, APPLE, MB-LATER scores and CHARLSON comorbidity index were evaluated with C statistics for prediction of AF progression.

Results

Among 8962 patients (71±14 years), 4991, 476 and 3495 had paroxysmal, persistent AF, and permanent AF, respectively. During a follow-up of 927±1084 days, 404 paroxysmal AF patients progressed to persistent or permanent AF (yearly rate of 3.0%). Progression was associated with a trend toward increased cardiovascular mortality. Independent predictors of AF progression were heart failure (hazard ratio (HR) 2.07; 95% CI 1.50–2.85, p<0.0001), valvular disease (HR=1.87, 95% CI=1.35–2.58, p=0.0002) and the use of digoxin (HR=2.39, 95% CI=1.75–3.29, p<0.001). Conversely, a history of stroke was associated with a lower rate of progression (HR=0.50, 95% CI=0.28–0.88, p=0.02). Overall, most of the score, particularly the HATCH score, were modest predictors of progression (table). The best score was actually the CHARLSON comorbidity index. The predictive values of all scores were better on patients not treated with antiarrhythmic agent.

C-statistics for AF progression All patients (n=4,991) p value* HATCH 0.576 (0.562–0.590) <0.0001 CHA2DS2-VASc 0.532 (0.503–0.560) <0.0001 ALARMEc 0.634 (0.607–0.660) 0.03 APPLE 0.631 (0.605–0.658) 0.03 MB-LATER 0.612 (0.587–0.638) 0.001 CHARLSON 0.667 (0.640–0.693) – *DeLong test vs CHARLSON comorbidity index.

Conclusion

Most of scores have a modest predictive value to identify the risk of evolution to permanent AF. Among them, the CHARLSON comorbidity index had the best predictive value and outperformed other tools. This suggests that AF progression may actually reflect global aging both at the individual and local atrial level.

5205Electrocardiographic predictors of appropriate implantable cardioverter defibrillator therapies in patients with tetralogy of Fallot

Background

The electrocardiogram (ECG) is widely available and may contribute to a better risk stratification for sudden cardiac death in patients with tetralogy of Fallot. QRS duration has been consistently associated with outcomes, with a lack of specificity for sudden mortality and a relatively low predictive value. New markers such as QRS fragmentation and vectocardiographic parameters have been recently suggested.

Purpose

To identify ECG predictors of appropriate therapies in patients with tetralogy of Fallot and implantable cardioverter defibrillator (ICD).

Methods

The DAI-T4F study is a large ongoing national French registry including all patients with tetralogy of Fallot and ICD (NCT03837574). Information have been collected prospectively since 2010 with annual update. Baseline patient characteristics and clinical events during the follow-up were analyzed with central adjudication. Cox proportional hazard models were used to identify factors associated with appropriate ICD therapies.

Results

A total of 134 patients (median age 41.7 years, 70.7% males) were enrolled. During a median (IQR) follow-up of 6.1 (2.7–10.2) years, 59 (44.0%) patients received at least one appropriate ICD therapy, giving annual incidence of 5.5% and 7.1% in primary and secondary prevention, respectively (p=0.058). Overall, QRSd ≥180ms (p=0.073), QRS fragmentation (p=0.052), and QRS vector magnitude (vm, p=0.327) were not significantly associated with appropriate ICD therapies, whereas QRS fragmentation in right leads (HR=1.7, 95% CI: 1.1–2.9, p=0.039) and the association of QRSd ≥180ms and overall QRS fragmentation (HR=1.9, 95% CI: 1.1–3.4, p=0.036) were associated with an increased risk of appropriates ICD therapies. In patients with ICD for primary prevention (47 patients, 35.1%), 53.8% had QRS fragmentation, 48.6% had decreased QRS vm, and 41.0% had QRSd ≥180ms. In this group, while non-sustained ventricular tachycardia (NSVT) considered isolated was not associated with ventricular events during follow-up (p=0.069), respective combinations with QRSd ≥180 ms (HR=7.2, 95% CI: 1.6–32.7, p=0.011), QRS fragmentation (HR=3.8, 95% CI: 1.2–12.4, p=0.025), or decreased QRS vm (HR=3.6, 95% CI: 1.1–12.1, p=0.042) were all associated with a higher incidence of appropriate ICD therapies. Positive predictive value and negative predictive value were 0.33 and 0.85, 0.58 and 0.74, and 0.36 and 0.84 in patients with NSVT and QRS ≥180ms, NSVT and QRS fragmentation, and NSVT and decreased QRS vm, respectively.

Conclusions

Our findings highlight that cumulative risk score derived from ECG may contribute to improve risk stratification in patients with tetralogy of Fallot, in particular QRS fragmentation and QRS vm in association with QRS duration and other traditional risk factors.

Functional and Phenotypic Characterization of Tumor-Infiltrating Leukocyte Subsets and Their Contribution to the Pathogenesis of Hepatocellular Carcinoma and Cholangiocarcinoma

Hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA) represent the most common primary liver malignancies whose outcome is influenced by the immune response. In the present study, we evaluated the tumor-infiltrating leukocyte (TIL) populations in 21 HCC patients and 8 CCA patients by flow cytometry immediately after the surgical procedure. Moreover, CD4⁺ T cells, CD8⁺ T cells, monocytes, and macrophages were purified by cell sorting for further analysis of gene expression by quantitative reverse-transcription polymerase chain reaction. Regarding tumor-infiltrating macrophages, we observed a significantly higher expression of markers associated with M2 phenotype and a higher expression of PD-L1 in patients with HCC in comparison to CCA. In addition, for HCC patients, we found a significant increase in the expression of CD200R in macrophages from tumors that were in grade G3-G4 as compared to tumors in grade G1-G2. Besides, a significantly higher frequency of tumor-infiltrating lymphocytes, CD8⁺CD56⁺ T cells, and natural killer cells was detected in HCC biopsies in comparison to CCA. In summary, this study has revealed functional and phenotypic differences in TIL cell subpopulations between CCA and HCC, as well as among different histopathological grades and tumor aggressiveness degrees, and it has provided evidence to better understand the tumor immune microenvironment of CCA and HCC.

Influence of Ischemia Time in Injury of Deep Peribiliary Glands of the Bile Ducts Graft: A Prospective Study

The deep peribiliary glands (DPBG) are a niche of progenitor cells in the wall of the biliary duct (BD) and are the second line of multiplication when severe lesion of the epithelium occurs. Previous studies have identified DPBG injury as a cause of post-liver transplant (LT) biliary stenosis; this complication is a major cause of post-LT morbidity. The incidence of biliary stenosis in our center is high (38.1%). This study evaluates the lesion of DPBG in response to ischemia. Graft BD was collected in adult LT between August 2016-July 2017, from donation after brain death. Samples of 45 grafts were collected at 2 moments: BD1-during graft preparation and BD2-before biliary anastomosis. Histological analysis of the samples was performed and then classified according to degree of lesion (0, ≤50%, and >50%). A comparison was made between the degree of lesion and graft ischemia, graft histology, donor, and procurement variables. The DPBG lesion was more frequent in BD2 (20.9% vs 7%, P = .079). BD2 lesions with DPBG lesions had higher medians and means at all times of ischemia. The difference was greater in the warm ischemia time (0: 43.3 ± 12.53 minutes vs ≤50%: 52.4 ± 14.38 minutes, P = .068). The group of BD1 with DPBG lesion presented superior median cold ischemia time (CIT). In the analysis of the remaining variables there were also no statistically significant differences. We concluded that during the period of CIT there is already lesion of the DPBG, which increases after reperfusion of the graft, in greater association with longer warm ischemia time.

Osseointegration of zirconia and titanium implants in a rabbit tibiae model evaluated by microtomography, histomorphometry and fluorochrome labeling analyses

OBJECTIVES

This study compares the osseointegration of machined-zirconia implants containing yttria (M-Y-TZP) with machined (M-Ti) and resorbable blast media (RBM-Ti) titanium implants.

MATERIAL AND METHODS

M-Y-TZP, M-Ti and RBM-Ti implants were randomly placed in rabbit tibiae. Fluorochrome bone labels (tetracycline, alizarin and calcein) were administered at different time periods. After 8 weeks, osseointegration was evaluated in terms of bone-to-implant contact (BIC), new bone area (nBA), remaining cortical bone area (rBA) and temporal quantification of fluorochromes, using micro-CT and histomorphometric analyses.

RESULTS

RBM-Ti implants showed higher resorption of the remaining cortical bone and bone formation (rBA = 36.9% and nBA = 38.8%) than M-Y-TZP implants (rBA = 48% and nBA = 26.5%). The BIC values showed no differences among the groups in the cortical region (mean = 52.2%) but in the medullary region, they were 0.45-fold higher in the RBM-Ti group (51.2%) than in the M-Y-TZP group (35.2%). In all groups, high incorporation of tetracycline was observed (2nd to 4th weeks), followed by alizarin (4th to 6th weeks) and calcein (6th to 8th weeks). In the cortical region, incorporation of tetracycline was similar between RBM-Ti (49.8%) and M-Y-TZP (35.9%) implants, but higher than M-Ti (28.2%) implants. Subsequently, alizarin and calcein were 1.1-fold higher in RBM-Ti implants than in the other implants. In the medullary region, no significant differences were observed for all fluorochromes.

CONCLUSION

All implants favored bone formation and consequently promoted primary stability. Bone formation around the threads was faster in RBM-Ti and M-Y-TZP implants than in M-Ti implants, but limited bone remodeling with M-Y-TZP implants over time can have significant effects on secondary stability, suggesting caution for its use as an alternative substitute for titanium implants.