Implantable cardioverter defibrillator use in arrhythmogenic right ventricular cardiomyopathy in North America and Europe

BACKGROUND AND AIMS

Implantable cardioverter-defibrillators (ICDs) are critical for preventing sudden cardiac death (SCD) in arrhythmogenic right ventricular cardiomyopathy (ARVC). This study aims to identify cross-continental differences in utilization of primary prevention ICDs and survival free from sustained ventricular arrhythmia (VA) in ARVC.

METHODS

This was a retrospective analysis of ARVC patients without prior VA enrolled in clinical registries from 11 countries throughout Europe and North America. Patients were classified according to whether they received treatment in North America or Europe and were further stratified by baseline predicted VA risk into low- (<10%/5 years), intermediate- (10%-25%/5 years), and high-risk (>25%/5 years) groups. Differences in ICD implantation and survival free from sustained VA events (including appropriate ICD therapy) were assessed.

RESULTS

One thousand ninety-eight patients were followed for a median of 5.1 years; 554 (50.5%) received a primary prevention ICD, and 286 (26.0%) experienced a first VA event. After adjusting for baseline risk factors, North Americans were more than three times as likely to receive ICDs {hazard ratio (HR) 3.1 [95% confidence interval (CI) 2.5, 3.8]} but had only mildly increased risk for incident sustained VA [HR 1.4 (95% CI 1.1, 1.8)]. North Americans without ICDs were at higher risk for incident sustained VA [HR 2.1 (95% CI 1.3, 3.4)] than Europeans.

CONCLUSIONS

North American ARVC patients were substantially more likely than Europeans to receive primary prevention ICDs across all arrhythmic risk strata. A lower rate of ICD implantation in Europe was not associated with a higher rate of VA events in those without ICDs.

Safety of ventricular arrhythmia radiofrequency ablation with half-normal saline irrigation

AIMS

Failure of radiofrequency (RF) ablation of ventricular arrhythmias is often due to inadequate lesion size. Irrigated RF ablation with half-normal saline (HNS) has the potential to increase lesion size and reduce sodium delivery to the patient if the same volume of RF irrigant were used for normal saline (NS) and HNS but could increase risks related to steam pops and lesion size. This study aims to assess periprocedural complications and acute ablation outcome of ventricular arrhythmias ablation with HNS.

METHODS AND RESULTS

Prospective assessment of outcomes was performed in 1024 endocardial and/or epicardial RF ablation procedures in 935 consecutive patients (median age 64 years, 71.2% men, 73.4% cardiomyopathy, 47.2% sustained ventricular tachycardia). Half-normal saline was selected at the discretion of the treating physician. Radiofrequency ablation power was generally titrated to a ≤15 Ω impedance fall with intracardiac echocardiography monitoring. Half-normal saline was used in 900 (87.9%) and NS in 124 (12.1%) procedures. Any adverse event within 30 days occurred in 13.0% of patients treated with HNS RF ablation including 4 (0.4%) strokes/transient ischaemic attacks and 34 (3.8%) pericardial effusions requiring treatment (mostly related to epicardial access). Two steam pops with perforation required surgical repair (0.2%). Patients who received NS irrigation had less severe disease and arrhythmias. In multivariable models, adverse events and acute success of the procedure were not related to the type of irrigation.

CONCLUSION

Half-normal saline irrigation RF ablation with power guided by impedance fall and intracardiac echocardiography has an acceptable rate of complications and acute ablation success while administering half of the saline load expected for NS irrigation.

Stroke and Bleeding Risks of Endocardial Ablation for Ventricular Arrhythmias

BACKGROUND

Risks of radiofrequency catheter ablation for ventricular arrhythmias include emboli and bleeding complications but data on antithrombotic regimens are limited and guidelines do not specify a systematic approach.

OBJECTIVES

This study sought to assess embolic and bleeding complications in relation to pre-periprocedure and post-periprocedure antithrombotic regimens.

METHODS

Prospective assessment for complications was performed for 663 endocardial radiofrequency catheter ablation procedures in 616 consecutive patients (median age 64 years [Q1-Q3: 54-73 years], 70.3% men, 71.6% with cardiomyopathy, 44.5% with sustained ventricular tachycardia).

RESULTS

There were 2 strokes (0.3%; 95% CI: 0.0%-0.8%), 1 transient ischemic attack (0.15%), and 2 pulmonary emboli (0.3%). There were 39 bleeding complications (5.9%) including 11 pericardial effusions (1.7%), and 28 related to vascular access (4.2%). Consistent with the prevalence of coronary artery disease (47.5%), atrial fibrillation (30.0%), and prior stroke (10.6%), preprocedure, 464 patients (70.0%) were taking antithrombotic agents including 220 (33.2%) taking aspirin alone (ASA), and 163 (24.6%) taking warfarin or a direct acting oral anticoagulant (DOAC). Preprocedure non-ASA antiplatelet use (OR: 2.846; P = 0.011) and DOAC use (OR: 2.585; P = 0.032) were associated with risk of bleeding complications. Following ablation, 49.8% of patients were treated with ASA 325 mg/d and 30.3% received DOACs or warfarin. New DOAC or warfarin administration was initiated in only 6.6% of patients. Overall, 39.7% of patients continued the same preprocedure antithrombotic regimen.

CONCLUSIONS

Stroke is a rare complication of radiofrequency catheter ablation for ventricular arrhythmia using ASA 325 mg/d as a minimal postprocedure regimen with more potent regimens for selected patients.

Catheter Ablation for Ventricular Tachycardia in Patients With Desmoplakin Cardiomyopathy

BACKGROUND

Desmoplakin (DSP) pathogenic/likely pathogenic (P/LP) variants are associated with malignant phenotypes of arrhythmogenic cardiomyopathy (DSP-ACM). Reports of outcomes after ventricular tachycardia (VT) ablation in DSP-ACM are scarce.

OBJECTIVES

In this study, the authors sought to report on long-term outcomes of VT ablation in DSP-ACM.

METHODS

Patients with P/LP DSP variants at 9 institutions undergoing VT ablation were included. Demographic, clinical, and instrumental data as well as all ventricular arrhythmia (VA) events were collected. Sustained VAs after the index procedure were the primary outcome. A per-patient before and after ablation comparison of rates of VA episodes per year was performed as well.

RESULTS

Twenty-four DSP-ACM patients (39.3 ± 12.1 years of age, 62.5% male, median 6,116 [Q1-Q3: 3,362-7,760] premature ventricular complexes [PVCs] per 24 hours, median 4 [Q1-Q3: 2-11] previous VA episodes per patient at ablation) were included. Index procedure was most commonly endocardial/epicardial (19/24) The endocardium of the right ventricle (RV), the left ventricle (LV), or both ventricles were mapped in 8 (33.3%), 9 (37.5%), and 7 (29.2%) cases, respectively. Low voltage potentials were found in 10 of 15 patients in the RV and 11 of 16 in the LV. Endocardial ablation was performed in 18 patients (75.0%). Epicardial mapping in 19 patients (79.2%) identified low voltage potentials in 17, and 16 received epicardial ablation. Over the following 2.9 years (Q1-Q3: 1.8-5.5 years), 13 patients (54.2%) experienced VA recurrences. A significant reduction in per-patient event/year before and after ablation was observed (1.4 [Q1-Q3: 0.5-2.4] to 0.1 [Q1-Q3: 0.0-0.4]; P = 0.009). 2 patients needed heart transplantation, and 4 died (3 of heart failure and 1 noncardiac death).

CONCLUSIONS

VT ablation in DSP-ACM is effective in reducing the VA burden of the disease, but recurrences are common. Most VT circuits are epicardial, with both LV and RV low voltage abnormalities. Heart failure complicates clinical course and is an important cause of mortality.

Minimizing Shivering During Targeted Normothermia: Comparison Between Novel Transnasal and Surface Temperature-Modulating Devices

BACKGROUND

Shivering is a common adverse effect of achieving and maintaining normothermia in neurocritical care patients. We compared the burden of shivering and shivering-related interventions between a novel transnasal temperature-modulating device (tnTMD) and surface cooling temperature-modulating devices (sTMDs) during the first 24 h of targeted normothermia in mechanically ventilated febrile neurocritical care patients.

METHODS

This is a case-control study controlling for factors that impact shiver burden: age, sex, body surface area. All patients underwent transnasal cooling (CoolStat, KeyTech, Inc.) as part of an ongoing multicenter clinical trial (NCT03360656). Patients undergoing treatment with sTMDs were selected from consecutively treated patients during the same time period. Data collected included the following: core body temperature (every 2 h), bedside shivering assessment scale (BSAS) score (every 2 h), and administration of antishivering medication for a BSAS score > 1. Time to normothermia (≤ 37.5 °C), as well as temperature burden > 37.5 °C (°C × h), were compared between groups using Student's t-test for mean differences. The proportion of patients requiring interventions, as well as the number of interventions per patient, was compared using the χ2 test. Significance was determined based on a p value < 0.05.

RESULTS

There were 10 tnTMD patients and 30 sTMD patients included in the analysis (mean age: 62 ± 4, 30% women, body surface area = 1.97 ± 0.25). There were no differences between groups in temperature at cooling initiation (tnTMD: 38.5 ± 0.2 °C vs. sTMD: 38.7 ± 0.5 °C, p = 0.3), time to ≤ 37.5 °C (tnTMD: 1.8 ± 1.5 h vs. sTMD: 2.9 ± 1.4 h, p = 0.1), or temperature burden > 37.5 (tnTMD: - 0.4 ± 1.13 °C × h vs. sTMD median [IQR]: - 0.57 ± 0.58 °C × h, p = 0.67). The number of tnTMD patients who received pharmacologic shivering interventions was lower than the number of controls (20 vs. 67%, p = 0.01). tnTMD patients also had fewer shivering interventions per patient (0 [range: 0-3] vs. 4 [range: 0-23], p < 0.001).

CONCLUSIONS

A transnasal cooling approach achieved similar time to normothermia and temperature burden with less shivering than surface cooling. This approach may be a feasible option to consider for mechanically ventilated febrile neurocritical care patients.

Rapid, selective and homogeneous brain cooling with transnasal flow of ambient air for pediatric resuscitation

Neurologic outcome from out-of-hospital pediatric cardiac arrest remains poor. Although therapeutic hypothermia has been attempted in this patient population, a beneficial effect has yet to be demonstrated, possibly because of the delay in achieving target temperature. To minimize this delay, we developed a simple technique of transnasal cooling. Air at ambient temperature is passed through standard nasal cannula with an open mouth to produce evaporative cooling of the nasal passages. We evaluated efficacy of brain cooling with different airflows in different size piglets. Brain temperature decreased by 3°C within 25 minutes with nasal airflow rates of 16, 32, and 16 L/min in 1.8-, 4-, and 15-kg piglets, respectively, whereas rectal temperature lagged brain temperature. No substantial spatial temperature gradients were seen along the neuroaxis, suggesting that heat transfer is via blood convection. The evaporative cooling did not reduce nasal turbinate blood flow or sagittal sinus oxygenation. The rapid and selective brain cooling indicates a high humidifying capacity of the nasal turbinates is present early in life. Because of its simplicity, portability, and low cost, transnasal cooling potentially could be deployed in the field for early initiation of brain cooling prior to maintenance with standard surface cooling after pediatric cardiac arrest.

Outcomes Comparison of Robot-Assisted and Video-Assisted Thoracoscopic Cardiac Sympathetic Denervation

OBJECTIVE

Cardiac sympathetic denervation (CSD) is a surgical antiadrenergic procedure that can reduce sustained ventricular tachyarrhythmia (VT). Video-assisted thoracoscopic surgery (VATS) is currently the standard approach used in CSD, and the practicality for robot-assisted thoracoscopic surgery (RATS) has yet to be investigated.

METHODS

We conducted a single-center retrospective study of all adult patients (N = 67) who underwent CSD from 2015 to 2021. We compared short-term outcomes of those treated with RATS versus VATS thoracic sympathectomy. For patients with VT, we examined the effectiveness of a RATS approach in reducing implantable cardioverter defibrillator (ICD) shock burden.

RESULTS

A total of 34 patients underwent RATS cardiac denervation, and 33 underwent VATS cardiac denervation. Those undergoing RATS denervation had a significantly shorter procedure duration with a median of 129 min (P = 0.008). Patients receiving the VATS approach were significantly more complicated by pneumothorax (P = 0.004) and overall complications (P = 0.01) when compared with the RATS approach. At 1 year after surgery, both groups had significant reductions in ICD shocks compared with before surgery, both decreasing from a median of 4 to 0 shocks (P < 0.001). In addition, at 1 year after surgery, the percentage of patients with persistent ICD shocks and the median of ICD shocks were similar between the groups.

CONCLUSIONS

The RATS approach to cardiac denervation has similar 1-year follow-up outcomes in reducing recurrent VT as the VATS approach. However, patients undergoing RATS denervation experienced better perioperative outcomes. This shows promise for robotic CSD to be an effective and safe therapeutic option for patients with malignant arrhythmias.

Determinants of acute irreversible electroporation lesion characteristics after pulsed field ablation: the role of voltage, contact, and adipose interference

AIMS

Pulsed field ablation (PFA) is a non-thermal ablative approach in which cardiomyocyte death is obtained through irreversible electroporation (IRE). Data correlating the biophysical characteristics of IRE and lesion characteristics are limited. The aim of this study was to assess the effect of different procedural parameters [voltage, number of cycles (NoCs), and contact] on lesion characteristics in a vegetal and animal model for IRE.

METHODS AND RESULTS

Two hundred and four Russet potatoes were used. Pulsed field ablation lesions were delivered on 3 cm cored potato specimens using a multi-electrode circular catheter with its dedicated IRE generator. Different voltage (from 300 to 1200 V) and NoC (from 1 to 5×) protocols were used. The impact of 0.5 and 1 mm catheter-to-specimen distances was tested. A swine animal model was then used to validate the results observed in the vegetable model. The association between voltage, the NoCs, distance, and lesion depth was assessed through linear regression. An almost perfect linear association between lesion depth and voltage was observed (R2 = 0.95; P < 0.001). A similarly linear relationship was observed between the NoCs and the lesion depth (R2 = 0.73; P < 0.001). Compared with controls at full contact, a significant dampening on lesion depth was observed at 0.5 mm distance (1000 V 2×: 2.11 ± 0.12 vs. 0.36 ± 0.04, P < 0.001; 2.63 ± 0.10 vs. 0.43 ± 0.08, P < 0.001). No lesions were observed at 1.0 mm distance.

CONCLUSION

In a vegetal and animal model for IRE assessment, PFA lesion characteristics were found to be strongly dependent on voltage settings and the NoCs, with a quasi-linear relationship. The lack of catheter contact was associated with a dampening in lesion depth.

Sex and Race Differences in Cardiac Sarcoidosis Presentation, Treatment and Outcomes

BACKGROUND

Although sex- and race-based patterns have been described in the extracardiac organ involvement of sarcoidosis, cardiac sarcoidosis (CS)-specific studies are lacking.

METHODS

We studied CS presentation, treatment and outcomes based on sex and race in a tertiary-center cohort. Multivariable adjusted Cox proportional hazards and survival analyses were performed for primary composite outcomes (left ventricular assist device, heart transplantation, all-cause death) and for secondary outcomes (ventricular arrhythmia and all-cause death.

RESULTS

We identified 252 patients with CS (108 female, 109 Black). At presentation with CS, females vs males (P = 0.001) and Black vs White individuals (P = 0.001) more commonly had symptomatic heart failure (HF), with HF most common in Black females (ANOVA P < 0.001). Treatment differences included more corticosteroid use (90% vs 79%; P = 0.020), higher 1-year prednisone dosage (13 vs 10 mg; P = 0.003) and less frequent early steroid-sparing agent use in males (29% vs 40%; P = 0.05). Black participants more frequently received a steroid-sparing agent (75% vs 60%; P = 0.023). Composite outcome-free survival did not differ by sex or race. Male sex had an adjusted hazard ratio of 2.34 (95% CI 1.13, 4.80; P = 0.021) for ventricular arrhythmia.

CONCLUSION

CS course may differ by sex and race and may contribute to distinct clinical CS phenotypes.

Association of Sinus Wavefront Activation and Ventricular Extrastimuli Mapping With Ventricular Tachycardia Re-Entrant Circuits

BACKGROUND

Substrate-based ablation targets areas of delayed and fractionated electrograms during sinus rhythm, which are sensitive for identifying the ventricular tachycardia (VT) isthmus but is influenced by the activation wavefront direction and decremental pacing.

OBJECTIVES

The aim of this study was to correlate the areas of latest activation during varying wavefront activation mapping and decremental pacing mapping with sites critical to the VT isthmus.

METHODS

Three high-density electroanatomical substrate maps were created in patients presenting for ablation of monomorphic VT: 1) native sinus rhythm; 2) right ventricular (RV) apical pacing; and 3) an RV apical S2 map following the S1 drive train at 20 ms above the ventricular effective refractory period. Areas corresponding to the latest activation were compared with the VT isthmus identified by conventional mapping.

RESULTS

Twenty patients with structural heart disease with a mean age of 55.6 ± 16.9 years were included. The majority of the cohort consisted of patients with ischemic heart disease (50%) and arrhythmogenic RV cardiomyopathy (35%). Epicardial ablation was performed in 45% of patients. The concordance of the site of latest activation in sinus rhythm with the VT isthmus was 75%. The location of the latest activation during RV apical pacing corresponded with the VT isthmus in 85% of cases. However, in 95% of cases, the site of the latest activation following the S2 stimulus colocalized to the VT isthmus.

CONCLUSIONS

In a mix of underlying myocardial substrates, regions of conduction slowing during decremental pacing colocalize with the VT isthmus more frequently than sinus rhythm activation mapping and may have a role in substrate-based ablation where VT induction is undesirable.

Subcutaneous and Transvenous Defibrillators in Arrhythmogenic Right Ventricular Cardiomyopathy: A Comparison of Clinical and Quality-of-Life Outcomes

BACKGROUND

There is limited evidence guiding the selection between subcutaneous and transvenous implantable cardioverter-defibrillators (ICDs) in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) at risk for sudden death.

OBJECTIVES

This study aimed to compare clinical and quality-of-life outcomes between transvenous and subcutaneous ICDs among patients with ARVC.

METHODS

Patients with a subcutaneous ICD (n = 57) were matched to patients with a transvenous ICD (n = 88) based on sex, proband status, primary prevention or secondary prevention, monomorphic ventricular tachycardia before implantation, and year of implantation. Appropriate therapy for ventricular arrhythmia, inappropriate shocks, and complications were compared. Quality-of-life surveys were conducted annually.

RESULTS

The matched cohort (median age of 35 years, 43% men, 78% proband, and 37% secondary prevention device) were prospectively followed for 5.1 ± 2.5 years. No significant difference was observed in the rate of appropriate ICD shocks. The subcutaneous group had more inappropriate shocks (23% vs 10%) and fewer procedure-related complications (4% vs 14%) than the transvenous group (P < 0.05). The association between ICD type and the composite of inappropriate shock and complication was not statistically significant (subcutaneous vs transvenous adjusted HR: 1.43; 95% CI: 0.72-2.84). A subcutaneous ICD was associated with more body image concerns and range of motion than a transvenous ICD (P < 0.05).

CONCLUSIONS

In patients with ARVC receiving an ICD, the risk of inappropriate shocks from a subcutaneous ICD should be balanced against the significant vascular complication risk from a transvenous ICD. Patients with a subcutaneous ICD had more concerns for body image and range of motion.

Quality assessment of cardiac magnetic resonance myocardial scar imaging prior to ventricular arrhythmia ablation

High-resolution scar characterization using late gadolinium enhancement cardiac magnetic resonance imaging (LGE-CMR) is useful for guiding ventricular arrhythmia (VA) treatment. However, imaging study quality may be degraded by breath-holding difficulties, arrhythmias, and implantable cardioverter-defibrillators (ICDs). We evaluated the effect of image quality on left ventricle (LV) base to apex scar interpretation in pre-VA ablation LGE-CMR. 43 consecutive patients referred for VA ablation underwent gradient-recalled-echo LGE-CMR. In ICD patients (n = 24), wide-bandwidth inversion-recovery suppressed ICD artifacts. In non-ICD patients, single-shot steady-state free-precession LGE-CMR could also be performed to reduce respiratory motion/arrhythmia artifacts. Study quality was assessed for adequate/limited scar interpretation due to cardiac/respiratory motion artifacts, ICD-related artifacts, and image contrast. 28% of non-ICD patients had studies where image quality limited scar interpretation in at least one image compared to 71% of ICD patient studies (p = 0.012). A median of five image slices had limited quality per ICD patient study, compared to 0 images per non-ICD patient study. Poorer quality in ICD patients was largely due to motion-related artifacts (54% ICD vs 6% non-ICD studies, p = 0.001) as well as ICD-related image artifacts (25% of studies). In VA ablation patients with ICDs, conventional CMR protocols frequently have image slices with limited scar interpretation, which can limit whole-heart scar assessment. Motion artifacts contribute to suboptimal image quality, particularly in ICD patients. Improved methods for motion and ICD artifact suppression may better delineate high-resolution LGE scar features of interest for guiding VA ablation.

Catheter Ablation of Ventricular Tachycardia in Arrhythmogenic Right Ventricular Cardiomyopathy

Arrhythmogenic right ventricular cardiomyopathy is an inherited desmosomal myopathy characterized by progressive fibrofatty replacement of the myocardium, right ventricular enlargement, and malignant ventricular arrhythmias. Ventricular tachycardias is one of the most common initial presentation of ARVC. This manuscript addresses invasive VT ablation options for the managmenet of VT in patients with ARVC.

Programmed Ventricular Stimulation as an Additional Primary Prevention Risk Stratification Tool in Arrhythmogenic Right Ventricular Cardiomyopathy: A Multinational Study

BACKGROUND

A novel risk calculator based on clinical characteristics and noninvasive tests that predicts the onset of clinical sustained ventricular arrhythmias (VA) in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) has been proposed and validated by recent studies. It remains unknown whether programmed ventricular stimulation (PVS) provides additional prognostic value.

METHODS

All patients with a definite ARVC diagnosis, no history of sustained VAs at diagnosis, and PVS performed at baseline were extracted from 6 international ARVC registries. The calculator-predicted risk for sustained VA (sustained or implantable cardioverter defibrillator treated ventricular tachycardia [VT] or fibrillation, [aborted] sudden cardiac arrest) was assessed in all patients. Independent and combined performance of the risk calculator and PVS on sustained VA were assessed during a 5-year follow-up period.

RESULTS

Two hundred eighty-eight patients (41.0±14.5 years, 55.9% male, right ventricular ejection fraction 42.5±11.1%) were enrolled. At PVS, 137 (47.6%) patients had inducible ventricular tachycardia. During a median of 5.31 [2.89-10.17] years of follow-up, 83 (60.6%) patients with a positive PVS and 37 (24.5%) with a negative PVS experienced sustained VA (P<0.001). Inducible ventricular tachycardia predicted clinical sustained VA during the 5-year follow-up and remained an independent predictor after accounting for the calculator-predicted risk (HR, 2.52 [1.58-4.02]; P<0.001). Compared with ARVC risk calculator predictions in isolation (C-statistic 0.72), addition of PVS inducibility showed improved prediction of VA events (C-statistic 0.75; log-likelihood ratio for nested models, P<0.001). PVS inducibility had a 76% [67-84] sensitivity and 68% [61-74] specificity, corresponding to log-likelihood ratios of 2.3 and 0.36 for inducible (likelihood ratio+) and noninducible (likelihood ratio-) patients, respectively. In patients with a ARVC risk calculator-predicted risk of clinical VA events <25% during 5 years (ie, low/intermediate subgroup), PVS had a 92.6% negative predictive value.

CONCLUSIONS

PVS significantly improved risk stratification above and beyond the calculator-predicted risk of VA in a primary prevention cohort of patients with ARVC, mainly for patients considered to be at low and intermediate risk by the clinical risk calculator.

Longitudinal Prediction of Ventricular Arrhythmic Risk in Patients With Arrhythmogenic Right Ventricular Cardiomyopathy

BACKGROUND

The arrhythmogenic right ventricular cardiomyopathy (ARVC) risk calculator stratifies risk for incident sustained ventricular arrhythmias (VA) at the time of ARVC diagnosis. However, included risk factors change over time, and how well the ARVC risk calculator performs at follow-up is unknown.

METHODS

This was a retrospective analysis of patients with definite ARVC and without prior sustained VA. Risk factors for VA including age, nonsustained ventricular tachycardia, premature ventricular complex burden, T-wave inversions on electrocardiogram, cardiac syncope, right ventricular function, therapeutic medication use, and exercise intensity were assessed at the time of 2010 Task Force Criteria based ARVC diagnosis and upon repeat evaluations. Changes in these risk factors were analyzed over 5-year follow-up. The 5-year risk of VA was predicted longitudinally using (1) the baseline ARVC risk calculator prediction, (2) the ARVC risk prediction calculated using updated risk factors, and (3) time-varying Cox regression. Discrimination and calibration were assessed in comparison to observed VA event rates.

RESULTS

Four hundred eight patients with ARVC experiencing 132 primary VA events were included. Matched comparison of risk factors at baseline versus at 5 years of follow-up revealed decreased burdens of premature ventricular complexes (-1200/day) and nonsustained ventricular tachycardia (-14%). Presence of significant right ventricular dysfunction and number of T-wave inversions on electrocardiogram were unchanged. Observed risk for VA decreased by 13% by 5 years follow-up. The baseline ARVC risk calculator's ability to predict 5-year VA risk worsened during follow-up (C statistics, 0.83 at diagnosis versus 0.68 at 5 years). Both the updated ARVC risk calculator (C statistics of 0.77) and time-varying Cox regression model (C statistics, 0.77) had strong discrimination. The updated ARVC risk calculator overestimated 5-year VA risk by an average of +6%.

CONCLUSIONS

Risk factors for VA in ARVC are dynamic, and overall risk for incident sustained VA decreases during follow-up. Up-to-date risk factor assessment improves VA risk stratification.

Effect of Corticosteroids on Left Ventricular Function in Patients With Cardiac Sarcoidosis

Cardiac sarcoidosis (CS) is an important cause of cardiomyopathy. The trajectory of left ventricular ejection fraction (LVEF) in patients with CS undergoing treatment remains unclear. Patients with CS who were treated with corticosteroids and who underwent transthoracic echocardiography were studied. Baseline characteristics, treatment, echocardiographic data (including baseline to follow-up change in LVEF), and outcomes were retrospectively evaluated. Among 100 patients, 55 had baseline reduced LVEF (<50%), and 45 had preserved LVEF (≥50%). At follow-up, 82% of patients demonstrated stable or improved LVEF. Change in LVEF was significantly higher in the baseline reduced than in the preserved LVEF group (5% [interquartile range 0 to 15] vs 0% [interquartile range -10% to 5%], p = 0.001). There was no difference in corticosteroid exposure or use of heart failure guideline-directed medical therapy between patients who did experience improvement in LVEF and those who did not experience improvement in LVEF. On multivariable analysis, baseline reduced LVEF (Odds ratio 54.89, 95% confidence interval 3.84 to 785.09, p = 0.003) and complete heart block (Odds ratio 28.88, 95% confidence interval 2.17 to 383.74, p = 0.011) at presentation were significantly associated with reduced LVEF after treatment. In conclusion, most patients with CS treated with corticosteroids maintain or improve LV systolic function. Cardiac characteristics at presentation impact prognosis in CS, despite treatment.

Arrhythmogenic Right Ventricular Cardiomyopathy Prevalence and Arrhythmic Outcomes in At-Risk Family Members: A Systematic Review and Meta-Analysis

Background:

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a complex cardiomyopathy with autosomal dominant inheritance and age-related incomplete penetrance, characterized by a high risk of sudden cardiac death. Recent professional consensus guidelines recommend clinical cardiac lifelong serial screening for at-risk family members refined only by age, but family genotype might influence necessary screening. Although numerous studies report prevalence of disease and arrhythmia in family members and explore predictors of penetrance and arrhythmic risk, a systematic review consolidating this evidence is lacking.

Methods:

We searched Medline (PubMed), Embase, The Cochrane Library, and Web of Science for studies that reported prevalence of (1) diagnosis of ARVC per 2010 Task Force Criteria and/or (2) sustained ventricular arrhythmias (VA) in at least 10 family members of definite patients with ARVC.

Results:

We identified 41 studies, including 36 that reported diagnosis by Task Force Criteria and 22 VA. Meta-analysis of 1359 family members, from 13 unique cohorts showed an average prevalence estimate of 25% for diagnosis as per Task Force Criteria (95% CI, 0.15–0.35, I 2 = 96.44%). Overall prevalence of VA among gene-positive family members was 18% (95% CI, 0.13–0.23, I 2 =33.25%) in 7 independent studies (n=597). Family genotype was a significant risk factor for diagnosis of both ARVC (odds ratio, 6.91 [95% CI, 1.27–37.70]; P =0.0005) and VA (odds ratio, 13.62 [95% CI, 0.91–204.13]; P =0.06). Male gender was not associated with disease prevalence (odds ratio, 1.18 [95% CI, 0.72–1.95]; P =0.42) or VA (odds ratio, 0.81 [95% CI, 0.51–1.29]; P =0.91).

Conclusions:

The prevalence of ARVC and VA in at-risk family members differs significantly based on family genotype. Although recent recommendations provide a guideline based only on age, we propose screening every 1 to 2 years for gene-positive family members and every 3 to 5 years for first-degree relatives of gene-elusive cases, as long as they are asymptomatic and not athletes.

A new prediction model for ventricular arrhythmias in arrhythmogenic right ventricular cardiomyopathy

AIMS

Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVC) is characterized by ventricular arrhythmias (VAs) and sudden cardiac death (SCD). We aimed to develop a model for individualized prediction of incident VA/SCD in ARVC patients.

METHODS AND RESULTS

Five hundred and twenty-eight patients with a definite diagnosis and no history of sustained VAs/SCD at baseline, aged 38.2 ± 15.5 years, 44.7% male, were enrolled from five registries in North America and Europe. Over 4.83 (interquartile range 2.44-9.33) years of follow-up, 146 (27.7%) experienced sustained VA, defined as SCD, aborted SCD, sustained ventricular tachycardia, or appropriate implantable cardioverter-defibrillator (ICD) therapy. A prediction model estimating annual VA risk was developed using Cox regression with internal validation. Eight potential predictors were pre-specified: age, sex, cardiac syncope in the prior 6 months, non-sustained ventricular tachycardia, number of premature ventricular complexes in 24 h, number of leads with T-wave inversion, and right and left ventricular ejection fractions (LVEFs). All except LVEF were retained in the final model. The model accurately distinguished patients with and without events, with an optimism-corrected C-index of 0.77 [95% confidence interval (CI) 0.73-0.81] and minimal over-optimism [calibration slope of 0.93 (95% CI 0.92-0.95)]. By decision curve analysis, the clinical benefit of the model was superior to a current consensus-based ICD placement algorithm with a 20.3% reduction of ICD placements with the same proportion of protected patients (P < 0.001).

CONCLUSION

Using the largest cohort of patients with ARVC and no prior VA, a prediction model using readily available clinical parameters was devised to estimate VA risk and guide decisions regarding primary prevention ICDs (www.arvcrisk.com).

Association of Premature Ventricular Contraction Burden on Serial Holter Monitoring With Arrhythmic Risk in Patients With Arrhythmogenic Right Ventricular Cardiomyopathy

IMPORTANCE

A high burden of premature ventricular contractions (PVCs) at disease diagnosis has been associated with an overall higher risk of ventricular arrhythmias in arrhythmogenic right ventricular cardiomyopathy (ARVC). Data regarding dynamic modification of PVC burden at follow-up with Holter monitoring and its impact on arrhythmic risk in ARVC are scarce.

OBJECTIVE

To describe changes in the PVC burden and to assess whether serial Holter monitoring is dynamically associated with sustained ventricular arrhythmias during follow-up in patients with ARVC.

DESIGN, SETTINGS, AND PARTICIPANTS

In this cohort study, patients with a definite ARVC diagnosis, available Holter monitoring results at disease diagnosis, and at least 2 additional results of Holter monitoring during follow-up were enrolled from 6 ARVC registries in North America and Europe. Data were collected from June 1 to September 15, 2021.

MAIN OUTCOMES AND MEASURES

The association between prespecified variables retrieved at each Holter monitoring follow-up (ie, overall PVC burden; presence of sudden PVC spikes, defined as absolute increase in PVC burden ≥5000 per 24 hours or a relative ≥75% increase, with an absolute increase of ≥1000 PVCs; presence of nonsustained ventricular tachycardia [NSVT]; and use of β-blockers and class III antiarrhythmic drugs) and sustained ventricular arrhythmias occurring within 12 months after that Holter examination was assessed using a mixed logistical model.

RESULTS

In 169 enrolled patients with ARVC (mean [SD] age, 36.3 [15.0] years; 95 men [56.2%]), a total of 723 Holter examinations (median, 4 [IQR, 4-5] per patient) were performed during a median follow-up of 54 (IQR, 42-63) months and detected 75 PVC spikes and 67 sustained ventricular arrhythmias. The PVC burden decreased significantly from the first to the second Holter examination (mean, 2906 [95% CI, 1581-4231] PVCs per 24 hours; P < .001). A model including 24-hour PVC burden (odds ratio [OR] 1.50 [95% CI, 1.10-2.03]; P = .01), PVC spikes (OR, 6.20 [95 CI, 2.74-13.99]; P < .001), and NSVT (OR, 2.29 [95% CI, 1.10-4.51]; P = .03) at each follow-up Holter examination was associated with sustained ventricular arrhythmia occurrence in the following 12 months.

CONCLUSIONS AND RELEVANCE

These findings suggest that in patients with ARVC, changes in parameters derived from each Holter examination performed during follow-up are associated with the risk of sustained ventricular arrhythmias within 12 months of disease diagnosis.

Reduced Motion External Defibrillation (RMD): Reduced Subject Motion with Equivalent Defibrillation Efficiency validated in Swine

BACKGROUND

External defibrillators are used for arrhythmia cardioversion and for defibrillating during cardiac arrest. During defibrillation, short-duration Biphasic pulses cause intense motion due to rapid chest-wall muscle contraction. A reduced-motion external defibrillator (RMD) was constructed by integrating a commercial defibrillator with a Tetanizing-waveform generator. A long-duration low-amplitude Tetanizing-waveform slowly stimulated the chest musculature prior to the Biphasic pulse, reducing muscle contraction during the shock.

OBJECTIVE

Evaluate RMD defibrillation in swine for subject-motion during defibrillation pulses and for defibrillation effectiveness. RMD defibrillation can reduce the duration of arrhythmia ablation-therapy or simplify cardioversion procedures.

METHODS

The Tetanizing unit delivered a triangular 1-kHz pulse of 0.25-2.0sec duration and 10-100Volt peak amplitude, subsequently triggering the conventional defibrillator to output standard 1-200J energy Biphasic pulses at the next R-wave. Forward-limb motion was evaluated by measuring Peak Acceleration and Limb Work during RMD (Tetanizing+Biphasic) or Biphasic-pulse-only waveforms at 10^-3sec sampling-rate. Seven swine were arrested electrically and subsequently defibrillated. Biphasic-pulse-only and RMD defibrillations were repeated 25-35 times/swine, varying Tetanizing parameters and the Biphasic-pulse energy. Defibrillation thresholds (DFTs) were established by measuring the minimum energy required to restore sinus-rhythm with Biphasic-pulse-only or RMD defibrillations.

RESULTS

Two forward-limb acceleration-peaks occurred during both the Tetanizing-waveform and Biphasic-pulse, indicating rapid and slower nociceptic (pain-sensation) nerve-fiber activation. Optimal RMD Tetanizing-parameters (25-35V, 0.25-0.75sec duration), relative to Biphasic-pulse-only defibrillations, resulted in 74+10% smaller Peak Accelerations and 85+10% reduced Limb Work. DFT energies were identical, comparing RMD to Biphasic-pulse-only defibrillations.

CONCLUSION

Relative to conventional defibrillations, RMD defibrillations maintain rhythm-restoration efficiency with drastically reduced subject-motion.

Prognostic value of strain by feature-tracking cardiac magnetic resonance in arrhythmogenic right ventricular cardiomyopathy

AIMS

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is characterized by ventricular dysfunction and ventricular arrhythmias (VA). Adequate arrhythmic risk assessment is important to prevent sudden cardiac death. We aimed to study the incremental value of strain by feature-tracking cardiac magnetic resonance imaging (FT-CMR) in predicting sustained VA in ARVC patients.

METHODS AND RESULTS

CMR images of 132 ARVC patients (43% male, 40.6 ± 16.0 years) without prior VA were analysed for global and regional right and left ventricular (RV, LV) strain. Primary outcome was sustained VA during follow-up. We performed multivariable regression assessing strain, in combination with (i) RV ejection fraction (EF); (ii) LVEF; and (iii) the ARVC risk calculator. False discovery rate adjusted P-values were given to correct for multiple comparisons and c-statistics were calculated for each model. During 4.3 (2.0-7.9) years of follow-up, 19% of patients experienced sustained VA. Compared to patients without VA, those with VA had significantly reduced RV longitudinal (P ≤ 0.03) and LV circumferential (P ≤ 0.04) strain. In addition, patients with VA had significantly reduced biventricular EF (P ≤ 0.02). After correcting for RVEF, LVEF, and the ARVC risk calculator separately in multivariable analysis, both RV and LV strain lost their significance [hazard ratio 1.03-1.18, P > 0.05]. Likewise, while strain improved the c-statistic in combination with RVEF, LVEF, and the ARVC risk calculator separately, this did not reach statistical significance (P ≥ 0.18).

CONCLUSION

Both RV longitudinal and LV circumferential strain are reduced in ARVC patients with sustained VA during follow-up. However, strain does not have incremental value over RVEF, LVEF, and the ARVC VA risk calculator.

Heart transplantation outcomes in arrhythmogenic right ventricular cardiomyopathy: a contemporary national analysis

Aims

Heart failure is an increasingly recognized later stage manifestation of arrhythmogenic right ventricular cardiomyopathy (ARVC) that can require heart transplantation (HT) to appropriately treat. We aimed to study contemporary ARVC HT outcomes in a national registry.

Methods and results

The United Network for Organ Sharing registry was queried for HT recipients from 1/1994 through 2/2020. ARVC patients were compared with non‐ARVC dilated, restrictive, and hypertrophic cardiomyopathy HT patients (HT for ischaemic and valvular disease was excluded from analysis). Post‐HT survival was assessed using Kaplan–Meier estimates. A total of 189 of 252 (75%) waitlisted ARVC patients (median age 48 years, 65% male) underwent HT, representing 0.3% of the total 65 559 HT during the study time period. Annual frequency of HT for ARVC increased significantly over time. ARVC patients had less diabetes (5% vs. 17%, P < 0.001), less cigarette use (15% vs. 23%, P < 0.001), lower pulmonary artery and pulmonary capillary wedge pressures, and lower cardiac output than the 33 659 non‐ARVC patients (P < 0.001). Ventricular assist device use was significantly lower in ARVC patients (8% vs. 32%, P < 0.001); 1 and 5 year post‐HT survival was 97% and 93% for ARVC vs. 95% and 82% for non‐ARVC HT recipients (P < 0.001). On adjusted multivariable Cox regression, ARVC had decreased risk of post‐HT death compared with non‐ARVC aetiologies (hazard ratio 0.48, 95% confidence interval 0.28–0.82, P = 0.008). Patients with ARVC also had lower risk of death or graft failure than non‐ARVC patients (hazard ratio 0.51, 95% confidence interval 0.32–0.81, P = 0.004).

Conclusions

In the largest series of HT in ARVC, we found that HT is increasingly performed in ARVC, with higher survival compared with other cardiomyopathy aetiologies. The right ventricular predominant pathophysiology may require unique considerations for heart failure management, including HT.

Multimodality Imaging in Arrhythmogenic Right Ventricular Cardiomyopathy

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a rare, heritable myocardial disease associated with the development of ventricular arrhythmias, heart failure, and sudden cardiac death in early adulthood. Multimodality imaging is a central component in the diagnosis and evaluation of ARVC. Diagnostic criteria established by an international task force in 2010 include noninvasive parameters from echocardiography and cardiac magnetic resonance imaging. These criteria identify right ventricular structural abnormalities, chamber and outflow tract dilation, and reduced right ventricular function as features of ARVC. Echocardiography is a widely available and cost-effective technique, and it is often selected for initial evaluation. Beyond fulfillment of diagnostic criteria, features such as abnormal tricuspid annular plane excursion, increased right ventricular basal diameter, and abnormal strain patterns have been described. 3-dimensional echocardiography may also expand opportunities for structural and functional assessment of ARVC. Cardiac magnetic resonance has the ability to assess morphological and functional cardiac features of ARVC and is also a core modality in evaluation, however, tissue characterization of the right ventricle is limited by spatial resolution and low specificity for detection of pathological changes. Nonetheless, the ability of cardiac magnetic resonance to identify left ventricular involvement, offer high negative predictive value, and provide a reproducible structural evaluation of the right ventricle enhance the ability and scope of the modality. In this review, the prognostic significance of multimodality imaging is outlined, including the supplemental value of multidetector computed tomography and nuclear imaging. Strengths and weaknesses of imaging techniques, as well as future direction of multimodality assessment, are also described.

Heart transplantation strategies in arrhythmogenic right ventricular cardiomyopathy: a tertiary ARVC centre experience

Aims

Methods and results

Conclusions

Assessment of an ECG-Based System for Localizing Ventricular Arrhythmias in Patients With Structural Heart Disease

Background

We have previously developed an intraprocedural automatic arrhythmia‐origin localization (AAOL) system to identify idiopathic ventricular arrhythmia origins in real time using a 3‐lead ECG. The objective was to assess the localization accuracy of ventricular tachycardia (VT) exit and premature ventricular contraction (PVC) origin sites in patients with structural heart disease using the AAOL system.

Methods and Results

In retrospective and prospective case series studies, a total of 42 patients who underwent VT/PVC ablation in the setting of structural heart disease were recruited at 2 different centers. The AAOL system combines 120‐ms QRS integrals of 3 leads (III, V2, V6) with pace mapping to predict VT exit/PVC origin site and projects that site onto the patient‐specific electroanatomic mapping surface. VT exit/PVC origin sites were clinically identified by activation mapping and/or pace mapping. The localization error of the VT exit/PVC origin site was assessed by the distance between the clinically identified site and the estimated site. In the retrospective study of 19 patients with structural heart disease, the AAOL system achieved a mean localization accuracy of 6.5±2.6 mm for 25 induced VTs. In the prospective study with 23 patients, mean localization accuracy was 5.9±2.6 mm for 26 VT exit and PVC origin sites. There was no difference in mean localization error in epicardial sites compared with endocardial sites using the AAOL system (6.0 versus 5.8 mm, P=0.895).

Conclusions

The AAOL system achieved accurate localization of VT exit/PVC origin sites in patients with structural heart disease; its performance is superior to current systems, and thus, it promises to have potential clinical utility.

Clinical characteristics and risk stratification of desmoplakin cardiomyopathy

Aims

Desmoplakin (DSP) cardiomyopathy is an increasingly recognized form of arrhythmogenic cardiomyopathy. With a genotype-specific approach, we characterized the diagnosis, natural history, and risk for ventricular arrhythmia and heart failure in DSP cardiomyopathy.

Methods and results

We followed 91 individuals [45 probands, 34% male, median age 27.5 years (interquartile interval 20.0–43.9)] with pathogenic or likely pathogenic DSP variants for a median of 4.3 years. Regarding the ventricular involvement, left predominance was most common (n = 22, 28%) followed by bi-ventricular in 12 (15%) and right predominance in 5 (6%). Myocardial injury (chest pain, elevated troponin, normal coronary angiogram) occurred in 20 (22%) individuals. Incidence rates of sustained ventricular arrhythmia and heart failure (ventricular dysfunction ± symptoms) were 5.9 [95% confidence interval (CI): 3.9–9.1] and 6.7 (95% CI: 4.5–9.8) per 100 person-years, respectively. In univariate regression, myocardial injury was associated with sustained ventricular arrhythmia [hazard ratio (HR) 2.53, 95% CI: 1.05–6.11] and heart failure (HR 7.53, 95% CI: 3.10–18.26). After adjustment, left ventricular ejection fraction <35% and right ventricular dysfunction were prognostic for sustained ventricular arrhythmia while proband status and myocardial injury were prognostic for heart failure (all P < 0.05). The sensitivity of the arrhythmogenic right ventricular cardiomyopathy Task Force Criteria in diagnosing left dominant disease was 0.73; 5/22 (23%) of patients with sustained ventricular arrhythmias did not meet these criteria.

Conclusion

DSP cardiomyopathy affects both ventricles and carries high risk for ventricular arrhythmia and heart failure. Myocardial injury is associated with worse disease outcomes. Both diagnosis and risk stratification of DSP cardiomyopathy need refinement.

Cardiac Sarcoidosis With Prominent Epsilon Waves: A Perfect Phenocopy of ARVC

Cardiac sarcoidosis (CS) overlaps in clinical presentation with arrhythmogenic right ventricular cardiomyopathy and shares phenotypic classification, including the presence of epsilon waves. The presence of conduction disease is seen exclusively in CS, as an important phenotypic difference. We present a case of ventricular tachycardia and epsilon waves due to CS, without conduction disease. (Level of Difficulty: Intermediate.).

Characterization of the Electrophysiologic Remodeling of Patients With Ischemic Cardiomyopathy by Clinical Measurements and Computer Simulations Coupled With Machine Learning

Rationale

Patients with ischemic cardiomyopathy (ICMP) are at high risk for malignant arrhythmias, largely due to electrophysiological remodeling of the non-infarcted myocardium. The electrophysiological properties of the non-infarcted myocardium of patients with ICMP remain largely unknown.

Objectives

To assess the pro-arrhythmic behavior of non-infarcted myocardium in ICMP patients and couple computational simulations with machine learning to establish a methodology for the development of disease-specific action potential models based on clinically measured action potential duration restitution (APDR) data.

Methods and Results

We enrolled 22 patients undergoing left-sided ablation (10 ICMP) and compared APDRs between ICMP and structurally normal left ventricles (SNLVs). APDRs were clinically assessed with a decremental pacing protocol. Using genetic algorithms (GAs), we constructed populations of action potential models that incorporate the cohort-specific APDRs. The variability in the populations of ICMP and SNLV models was captured by clustering models based on their similarity using unsupervised machine learning. The pro-arrhythmic potential of ICMP and SNLV models was assessed in cell- and tissue-level simulations. Clinical measurements established that ICMP patients have a steeper APDR slope compared to SNLV (by 38%, p < 0.01). In cell-level simulations, APD alternans were induced in ICMP models at a longer cycle length compared to SNLV models (385–400 vs 355 ms). In tissue-level simulations, ICMP models were more susceptible for sustained functional re-entry compared to SNLV models.

Conclusion

Myocardial remodeling in ICMP patients is manifested as a steeper APDR compared to SNLV, which underlies the greater arrhythmogenic propensity in these patients, as demonstrated by cell- and tissue-level simulations using action potential models developed by GAs from clinical measurements. The methodology presented here captures the uncertainty inherent to GAs model development and provides a blueprint for use in future studies aimed at evaluating electrophysiological remodeling resulting from other cardiac diseases.

Diagnosing arrhythmogenic right ventricular cardiomyopathy by 2010 Task Force Criteria: clinical performance and simplified practical implementation

Aims

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is diagnosed by a complex set of clinical tests as per 2010 Task Force Criteria (TFC). Avoiding misdiagnosis is crucial to prevent sudden cardiac death as well as unnecessary implantable cardioverter-defibrillator implantations. This study aims to validate the overall performance of the TFC in a real-world cohort of patients referred for ARVC evaluation.

Methods and results

We included patients consecutively referred to our centres for ARVC evaluation. Patients were diagnosed by consensus of three independent clinical experts. Using this as a reference standard, diagnostic performance was measured for each individual criterion as well as the overall TFC classification. Of 407 evaluated patients (age 38 ± 17 years, 51% male), the expert panel diagnosed 66 (16%) with ARVC. The clinically observed TFC was false negative in 7/66 (11%) patients and false positive in 10/69 (14%) patients. Idiopathic outflow tract ventricular tachycardia was the most common alternative diagnosis. While the TFC performed well overall (sensitivity and specificity 92%), signal-averaged electrocardiogram (SAECG, P = 0.43), and several family history criteria (P ≥ 0.17) failed to discriminate. Eliminating these criteria reduced false positives without increasing false negatives (net reclassification improvement 4.3%, P = 0.019). Furthermore, all ARVC patients met at least one electrocardiogram (ECG) or arrhythmia criterion (sensitivity 100%).

Conclusion

The TFC perform well but are complex and can lead to misdiagnosis. Simplification by eliminating SAECG and several family history criteria improves diagnostic accuracy. Arrhythmogenic right ventricular cardiomyopathy can be ruled out using ECG and arrhythmia criteria alone, hence these tests may serve as a first-line screening strategy among at-risk individuals.

Left ventricular fibro-fatty replacement in arrhythmogenic right ventricular dysplasia/cardiomyopathy: prevalence, patterns, and association with arrhythmias

BACKGROUND

Left ventricular (LV) fibrofatty infiltration in arrhythmogenic right ventricular (RV) dysplasia/cardiomyopathy (ARVD/C) has been reported, however, detailed cardiovascular magnetic resonance (CMR) characteristics and association with outcomes are uncertain. We aim to describe LV findings on CMR in ARVD/C patients and their relationship with arrhythmic outcomes.

METHODS

CMR of 73 subjects with ARVD/C according to the 2010 Task Force Criteria (TFC) were analyzed for LV involvement, defined as ≥ 1 of the following features: LV wall motion abnormality, LV late gadolinium enhancement (LGE), LV fat infiltration, or LV ejection fraction (LVEF) < 50%. Ventricular volumes and function, regional wall motion abnormalities, and the presence of ventricular fat or fibrosis were recorded. Findings on CMR were correlated with arrhythmic outcomes.

RESULTS

Of the 73 subjects, 50.7% had CMR evidence for LV involvement. Proband status and advanced RV dysfunction were independently associated with LV abnormalities. The most common pattern of LV involvement was focal fatty infiltration in the sub-epicardium of the apicolateral LV with a "bite-like" pattern. LGE in the LV was found in the same distribution and most often had a linear appearance. LV involvement was more common with non-PKP2 genetic mutation variants, regardless of proband status. Only RV structural disease on CMR (HR 3.47, 95% CI 1.13-10.70) and prior arrhythmia (HR 2.85, 95% CI 1.33-6.10) were independently associated with arrhythmic events.

CONCLUSION

Among patients with 2010 TFC for ARVD/C, CMR evidence for LV abnormalities are seen in half of patients and typically manifest as fibrofatty infiltration in the subepicardium of the apicolateral wall and are not associated with arrhythmic outcomes.

Clinical outcomes of catheter ablation of ventricular tachycardia in patients with arrhythmogenic right ventricular cardiomyopathy: Insights from the Johns Hopkins ARVC Program

BACKGROUND

Previous studies of radiofrequency catheter ablation (RFA) of ventricular tachycardia (VT) in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC), relying on limited numbers of procedures, have not reported VT-free survival in parallel for single and multiple procedures (ie, after the last procedure). Data regarding the impact of RFA on VT burden are scarce.

OBJECTIVE

The purpose of this study was to provide new insights on clinical outcomes based on a large series of VT ablation procedures from the current era in ARVC patients.

METHODS

We evaluated consecutive patients with definite ARVC who underwent RFA procedures between 2009 and 2019 at our center. We assessed VT-free survival, for single and multiple procedures, and changes in VT burden and antiarrhythmic drugs (AADs) after RFA.

RESULTS

Among 116 patients, there were 166 RFA procedures, 106 (63.9%) of which involved epicardial ablation. Cumulative freedom from VT after a single procedure was 68.6% and 49.8% at 1 and 5 years, respectively. Cumulative VT-free survival after multiple procedures was 81.8% and 69.6% at 1 and 5 years, respectively. VT burden per RFA was reduced after vs before ablation (mean 0.7 vs 10.0 events/year; P <.001). Furthermore, VT burden per patient was reduced after last ablation vs before first ablation (mean 0.5 vs 10.9 events/year; P <.001). Use of AADs decreased after ablation (22.2% vs 51.9%; P <.001).

CONCLUSION

In ARVC patients, RFA provided good VT-free survival after a single procedure, with multiple procedures required for more sustained freedom from VT recurrence. Marked reduction in VT burden permitted discontinuation of AADs.