Recurrences of Atrial Fibrillation Despite Durable Pulmonary Vein Isolation: The PARTY-PVI Study.

BACKGROUND: Recurrences of atrial fibrillation (AF) after pulmonary vein isolation (PVI) are mainly due to pulmonary vein reconnection. However, a growing number of patients have AF recurrences despite durable PVI. The optimal ablative strategy for these patients is unknown. We analyzed the impact of current ablation strategies in a large multicenter study. METHODS: Patients undergoing a redo ablation for AF and presenting durable PVI were included. The freedom from atrial arrhythmia after pulmonary vein-based, linear-based, electrogram-based, and trigger-based ablation strategies were compared. RESULTS: Between 2010 and 2020, 367 patients (67% men, 63±10 years, 44% paroxysmal) underwent a redo ablation for AF recurrences despite durable PVI at 39 centers. After durable PVI was confirmed, linear-based ablation was performed in 219 (60%) patients, electrogram-based ablation in 168 (45%) patients, trigger-based ablation in 101 (27%) patients, and pulmonary vein-based ablation in 56 (15%) patients. Seven patients (2%) did not undergo any additional ablation during the redo procedure. After 22±19 months of follow-up, 122 (33%) and 159 (43%) patients had a recurrence of atrial arrhythmia at 12 and 24 months, respectively. No significant difference in arrhythmia-free survival was observed between the different ablation strategies. Left atrial dilatation was the only independent factor associated with arrhythmia-free survival (HR, 1.59 [95% CI, 1.13-2.23]; P=0.006). CONCLUSIONS: In patients with recurrent AF despite durable PVI, no ablation strategy used alone or in combination during the redo procedure appears to be superior in improving arrhythmia-free survival. Left atrial size is a significant predictor of ablation outcome in this population.

Transseptal versus retrograde approach for ablation of left-sided accessory pathways: impact on radiation exposure.

Management of left-sided accessory pathways (APs) is based on catheter ablation through an antegrade or retrograde approach. Both are safe and effective but are associated with exposure to x-rays; however, recipients of ablation are generally young. We sought to evaluate the impact of the approach chosen on dose-area product (DAP). A total of 95 patients who underwent radiofrequency ablation of a left-sided AP between January 2011 and January 2020 were included. The primary endpoint was the radiation dose received by the patient. Secondary endpoints were procedural success and complication and recurrence rates. The mean age of the study population was 34.3 ± 16.6 years. The antegrade transseptal approach was used in 63.5% of cases. By multivariate analysis, the antegrade transseptal approach was associated with a 53% reduction in DAP (p< 0.001). The radiation dose received was also significantly associated with body mass index and total fluoroscopy time (p< 0.001). There was no significant difference in other secondary endpoints between approaches. The use of an antegrade transseptal approach is associated with a significant reduction in DAP compared with the retrograde approach, and procedural success and complication and recurrence rates are similar.

Cardiovascular outcomes after cardiac resynchronization therapy in cardiac amyloidosis.

AIMS: Cardiac resynchronization therapy (CRT) is highly effective in dilated cardiomyopathy (DCM) patients with impaired left ventricular ejection fraction (LVEF) and left bundle block branch. In cardiac amyloidosis (CA) patients, left ventricular dysfunction and conduction defects are common, but the potential of CRT to improve cardiac remodelling and survival in this particular setting remains undefined. We investigated cardiovascular outcomes in CA patients after CRT implantation in terms of CRT echocardiographic response and major cardiovascular events (MACEs). METHODS AND RESULTS: Our retrospective study included 47 CA patients implanted with CRT devices from January 2012 to February 2020, in nine French university hospitals (77 ± 6 years old, baseline LVEF 30 ± 8%) compared with propensity-matched (1:1 for age, LVEF at implantation, and CRT indication) DCM patients with a CRT device. CA patients had lower rates of CRT response (absolute delta LVEF ≥ 10%) compared with DCM patients (36% vs. 70%, P = 0.002). After multivariate Cox analysis, CA was independently associated with MACE (hospitalization for heart failure/cardiovascular death) [hazard ratio (HR) 3.73, 95% confidence interval (CI) 1.85-7.54, P < 0.001], along with the absence of CRT response (HR 3.01, 95% CI 1.56-5.79, P = 0.001). The presence of echocardiographic CRT response (absolute delta LVEF ≥ 10%) was the only predictive factor of MACE-free survival in CA patients (HR 0.36, 95% CI 0.15-0.86, P = 0.002). CONCLUSION: Compared with a matched cohort of DCM patients, CA patients had a lower rate of CRT response and consequently a worse cardiovascular prognosis after CRT implantation. However, CRT could be beneficial even in CA patients given that CRT response was associated with better cardiac outcomes in this population.

Impact of Obesity on Overall Radiation Exposure for Patients Who Underwent Radiofrequency Ablation of Atrial Fibrillation.

Patients who underwent radiofrequency ablation of atrial fibrillation are exposed to X-rays not only during the procedure but also during the preprocedural computed tomography. No study has investigated the cumulative effective dose received by patients who underwent atrial fibrillation ablation and identified factors influencing this dose. We aimed to evaluate the overall exposure to ionizing radiation in patients who underwent radiofrequency ablation of atrial fibrillation. The secondary objective was to estimate the impact of obesity on this exposure. All patients who underwent a first attempt of radiofrequency ablation of atrial fibrillation in our center over a 21 months period were included. Dosimetric indicators from preprocedural computed tomography and the ablation procedure were collected and converted into an effective dose. A total of 144 radiofrequency ablation of atrial fibrillation were included. The mean cumulative effective dose was 11.4 mSv, and 82% of the dose was from the computed tomography. Obese patients received a dose that was 75% higher than normal-weight patients, and this increase remained significant by multivariate analysis. In conclusion, overall exposure to ionizing radiation for patients who underwent radiofrequency ablation of atrial fibrillation seems acceptable, and the majority of the overall effective dose comes from the computed tomography. Obese patients are exposed to a 75% higher dose than normal-weight patients.

Physicians' exposure to radiation during electrophysiology procedures.

PURPOSE: Cardiologists are among the health professionals that are most exposed to ionizing radiation, but there is no study comparing the level of exposure of physicians during different electrophysiology procedures. We aimed to measure and compare cardiologists' exposure to radiation during different electrophysiology procedures. METHODS: The study population comprised all electrophysiology procedures performed over a 6-month period in a large referral centre. The endpoint was operator radiation exposure, assessed using a personal electronic dosimeter located on the operator's left arm. RESULTS: In total, 150 electrophysiology procedures were analyzed. Compared with electrophysiology studies (reference category), physician radiation exposure was 3-fold greater during ablation of atrial fibrillation, 9-fold greater during ablation of atrioventricular nodal reentrant tachycardia (AVNRT)/atrioventricular reentrant tachycardia (AVNT), and 10-fold greater during ablation of atrial flutter (p < 0.001). Physician exposure was mainly related to X-ray time (R2 = 0.28). CONCLUSIONS: Our study showed significant differences in cardiologists' exposure to ionizing radiation depending on the type of electrophysiology procedure. Atrial flutter and AVNRT/AVNT ablations are the procedures in which operators are most exposed to ionizing radiation.

Impact of cardiac resynchronisation therapy on cardiologists' exposure to radiation during implantation of pacemakers and implantable cardioverter-defibrillators.

Cardiologists are among the health professionals that are most exposed to ionizing radiation, but there is no recent study quantifying overexposure of physicians during cardiac resynchronisation therapy (CRT) procedures compared to 'classical' implantation of pacemakers (PMs) or implantable cardioverter-defibrillators (ICDs). We aimed to measure and compare operator exposure to radiation during implantation of PM and ICD with or without CRT. The study population comprised all PMs and ICDs implanted in a large referral centre over a six months period. The endpoint was operator radiation exposure, assessed using a personal electronic dosimeter located on operator's chest. In total, 169 PM/ICD implantations were analysed, 19 of which included CRT. Compared with 'classical' implantation, cardiologist radiation exposure was 9-fold greater during CRT procedures (p < 0.001). Physician exposure was related to dose-area product (R2 = 0.21 during 'classical' implantations and R2 = 0.57 during CRT procedures). Our study shows that cardiologists' exposure to radiation during CRT implantation was 9-fold greater than during procedures without CRT.

Enterovirus but not Parvovirus B19 is associated with idiopathic dilated cardiomyopathy and endomyocardial CD3, CD68, or HLA-DR expression.

We assessed Enterovirus (EV) &Parvovirus B19 (PVB19) genomes and CD3, CD68&HLA-DR detection in dilated cardiomyopathies (DCM). EV&PVB19 genomes and CD3, CD68&HLA-DR were detected by PCR and immunohistochemistry assays in 115 endomyocardial biopsies obtained in 13 idiopathic DCM (iDCM) and 10 explained DCM (eDCM) patients. Results were compared with those of 47 atrial surgical samples (47 surgery controls) and 22 autoptic cardiac samples (11 healthy heart controls) (2008-2014, Reims, France). EV was detected in 23.1% of iDCM patients but not in eDCM and controls (P = 0.003) (viral load 803 copies/µg). PVB19 was detected in 76.9%, 80.0%, 63.6% and 78.2% of iDCM, eDCM, healthy heart and surgery controls (P = 0.99) with a mean viral load of 413, 346, 1,428, and 71 copies/µg. CD3, CD68 or HLA-DR were detected in 100 and 50% of EV and PVB19 "mono-infected" iDCM patients. EV was exclusively detected in iDCM cases in association with CD3, CD68, or HLA-DR indicating that EV could be an etiological cause in a subset of iDCM cases. By contrast the equal frequent detection of PVB19 in iDCM cases and controls without association with CD3, CD68, or HLA-DR suggested that PVB19 could be a bystander in many DCM cases. J. Med. Virol. 89:55-63, 2017. © 2016 Wiley Periodicals, Inc.

Quantitative genomic and antigenomic enterovirus RNA detection in explanted heart tissue samples from patients with end-stage idiopathic dilated cardiomyopathy.

Standardized one-step real-time RT-PCR assay detected enterovirus RNA in cardiac biopsy samples from 4 of 20 patients suffering from idiopathic dilated cardiomyopathy (IDCM). The median viral load was 287 copies per microgram of total extracted nucleic acids, with positive- to negative-strand RNA ratios ranging from 2 to 20. These results demonstrate enterovirus persistence in the heart of IDCM patients, characterized by low viral loads and low positive- to negative-RNA ratios.

A fatal case of Human Herpesvirus 6 chronic myocarditis in an immunocompetent adult.

BACKGROUND: Human Herpesvirus 6 (HHV-6) is an important cause of fulminant or acute viral myocarditis in immunocompromised or immunocompetent patients. However the physiopathological mechanisms of HHV-6 related acute myocarditis and the involvement of subsequent HHV-6 reactivation phases in the development of chronic cardiomyopathies remain to be assessed. OBJECTIVES: To describe a case of fatal HHV-6 chronic myocarditis in an immunocompetent adult. STUDY DESIGN: Case report and detailed histological and viral diagnoses by combination of histology/immunohistochemistry and polymerase chain reaction techniques on cardiac tissues. RESULTS: Histopathological analysis of ventricular tissues showed large interstitial and scarring fibrotic areas with a moderate mononuclear cell infiltrate compatible with histological aspect of chronic myocarditis. Detection of both HHV-6 by real-time PCR and viral glycoproteins in mononuclear and endothelial cells by immunohistochemistry evidenced an ongoing cardiac HHV-6 replication with viral late protein synthesis activity. CONCLUSIONS: This case report indicates that HHV-6 can establish a chronic active myocarditis leading to heart failure in immunocompetent subjects.