[Rythmology activity in France and consequences of new thresholds approvals]. / État de l'activité de rythmologie interventionnelle en France et conséquences des réformes des seuils sur les autorisations d'activité.

BACKGROUND: Interventional rhythmology activity (electrophysiology and pacing) has progressed in France during the last decade. The objective of this article is to assess the distribution of this activity depending on the type of centre (public, university or non-university, private). As the French government issued a new regulation regarding rhythmology activity in 2022, the impact of this regulation on activity distribution has been evaluated. METHODOLOGY: All French data activity can be evaluated after accessing to a national database called PMSI [Programme de Médicalisation des Systèmes d'Information]. Based on data collected in year 2021, the level of activity of the different centres, and the impact of the new criteria of the French regulation regarding rhythmology activity have been analysed. RESULTS: About 200,000 arrhythmias interventions have been done in France in 2021 in 382 centres. According to the new criteria of the French regulation, 66% responded to level A (diagnostic electrophysiology, single- and dual-chamber pacing), 68% for level B (A+ right atrial ablation, implantable automatic defibrillator, cardiac resynchronisation therapy) and 70% for level C (B + left atrial and ventricular ablation). 1/4 of the centres do not meet criteria for level A activity, and 1/5 of them for levels B and C CONCLUSIONS: This work showed that immediat and systematic application of new threshold could be threatening for 1/4 of A center and 1/5 of B or C center. The priority will be to reinforce existing centres before allowing new centres to perform arrhythmias management activity in France.

Comparison between tafamidis and liver transplantation as first-line therapy for hereditary transthyretin amyloidosis.

BACKGROUND: By stabilizing transthyretin, tafamidis delays progression of amyloidosis due to transthyretin variant (ATTRv) and replaced liver transplantation (LT) as the first-line therapy. No study compared these two therapeutic strategies. METHODS: In a monocentric retrospective cohort analysis, patients with ATTRv amyloidosis treated with either tafamidis or LT were compared using a propensity score and a competing risk analysis for three endpoints: all-cause mortality, cardiac worsening (heart failure or cardiovascular death) and neurological worsening (worsening in PolyNeuropathy Disability score). RESULTS: 345 patients treated with tafamidis (n = 129) or LT (n = 216) were analyzed, and 144 patients were matched (72 patients in each group, median age 54 years, 60% carrying the V30M mutation, 81% of stage I, 69% with cardiac involvement, median follow-up: 68 months). Patients treated with tafamidis had longer survival than LT patients (HR: 0.35; p = .032). Conversely, they also presented a 3.0-fold higher risk of cardiac worsening and a 7.1-fold higher risk of neurological worsening (p = .0071 and p < .0001 respectively). CONCLUSIONS: ATTRv amyloidosis patients treated with tafamidis would present a better survival but also a faster deterioration of their cardiac and neurological statuses as compared with LT. Further studies are needed to clarify the therapeutic strategy in ATTRv amyloidosis.

[Where are done electrophysiology procedures in France and what is the expected evolution ?] / Où se fait l'activité de rythmologie interventionnelle en France et quelle est son évolution ?

INTRODUCTION: Interventional rhythmology activity (electrophysiology and pacing) has progressed in France during the last decade. The objective of this article was to assess the distribution of this activity depending on the type of centre (public, university or non-university, private). As the French government issued a new regulation regarding rhythmology activity in 2022, the impact of this regulation on activity distribution has been evaluated. METHODOLOGY: All French data activity can be evaluated after accessing to a national database called PMSI [Programme de médicalisation des systèmes d'information]. Based on data collected in year 2019, the level of activity of the different centres, and the impact of the new criteria of the French regulation regarding rhythmology activity have been analysed. RESULTS: About 180,000 arrhythmias interventions have been done in France in 2019 in 377 centres. According to the new criteria of the French regulation, only 76% responded to level A (diagnostic electrophysiology, single- and dual-chamber pacing), 52% for level B (A+ right atrial ablation, implantable automatic defibrillator, cardiac resynchronisation therapy) and 54% for level C (B + left atrial and ventricular ablation). CONCLUSIONS: This work showed that approximately a quarter of the centres do not meet criteria for level A activity, and approximately half of them for levels B and C. The priority will be to reinforce existing centres before allowing new centres to perform arrhythmias management activity in France.

Evaluation of an Ambulatory ECG Analysis Platform Using Deep Neural Networks in Routine Clinical Practice.

Background Holter analysis requires significant clinical resources to achieve a high-quality diagnosis. This study sought to assess whether an artificial intelligence (AI)-based Holter analysis platform using deep neural networks is noninferior to a conventional one used in clinical routine in detecting a major rhythm abnormality. Methods and Results A total of 1000 Holter (24-hour) recordings were collected from 3 tertiary hospitals. Recordings were independently analyzed by cardiologists for the AI-based platform and by electrophysiologists as part of clinical practice for the conventional platform. For each Holter, diagnostic performance was evaluated and compared through the analysis of the presence or absence of 5 predefined cardiac abnormalities: pauses, ventricular tachycardia, atrial fibrillation/flutter/tachycardia, high-grade atrioventricular block, and high burden of premature ventricular complex (>10%). Analysis duration was monitored. The deep neural network-based platform was noninferior to the conventional one in its ability to detect a major rhythm abnormality. There were no statistically significant differences between AI-based and classical platforms regarding the sensitivity and specificity to detect the predefined abnormalities except for atrial fibrillation and ventricular tachycardia (atrial fibrillation, 0.98 versus 0.91 and 0.98 versus 1.00; pause, 0.95 versus 1.00 and 1.00 versus 1. 00; premature ventricular contractions, 0.96 versus 0.87 and 1.00 versus 1.00; ventricular tachycardia, 0.97 versus 0.68 and 0.99 versus 1.00; atrioventricular block, 0.93 versus 0.57 and 0.99 versus 1.00). The AI-based analysis was >25% faster than the conventional one (4.4 versus 6.0 minutes; P<0.001). Conclusions These preliminary findings suggest that an AI-based strategy for the analysis of Holter recordings is faster and at least as accurate as a conventional analysis by electrophysiologists.

A novel risk model for predicting potentially life-threatening arrhythmias in non-ischemic dilated cardiomyopathy (DCM-SVA risk).

BACKGROUND: Non-ischemic dilated cardiomyopathy (DCM) can be complicated by sustained ventricular arrhythmias (SVA) and sudden cardiac death (SCD). By now, left-ventricular ejection fraction (LV-EF) is the main guideline criterion for primary prophylactic ICD implantation, potentially leading either to overtreatment or failed detection of patients at risk without severely impaired LV-EF. The aim of the European multi-center study DETECTIN-HF was to establish a clinical risk calculator for individualized risk stratification of DCM patients. METHODS: 1393 patients (68% male, mean age 50.7 ± 14.3y) from four European countries were included. The outcome was occurrence of first potentially life-threatening ventricular arrhythmia. The model was developed using Cox proportional hazards, and internally validated using cross validation. The model included seven independent and easily accessible clinical parameters sex, history of non-sustained ventricular tachycardia, history of syncope, family history of cardiomyopathy, QRS duration, LV-EF, and history of atrial fibrillation. The model was also expanded to account for presence of LGE as the eight8h parameter for cases with available cMRI and scar information. RESULTS: During a mean follow-up period of 57.0 months, 193 (13.8%) patients experienced an arrhythmic event. The calibration slope of the developed model was 00.97 (95% CI 0.90-1.03) and the C-index was 0.72 (95% CI 0.71-0.73). Compared to current guidelines, the model was able to protect the same number of patients (5-year risk ≥8.5%) with 15% fewer ICD implantations. CONCLUSIONS: This DCM-SVA risk model could improve decision making in primary prevention of SCD in non-ischemic DCM using easily accessible clinical information and will likely reduce overtreatment.

The IC-D score for predicting prophylactic cardioverter-defibrillator implantation following acute myocardial infarction.

BACKGROUND: A reduced left ventricular ejection fraction (LVEF) ≤35% ≥6 weeks following an acute myocardial infarction (MI) may indicate prophylactic implantation of a cardioverter-defibrillator (ICD). We sought to find predictors of absence of significant left ventricular (LV) remodeling post-MI. METHODS: All consecutive patients hospitalized for acute MI with an LVEF ≤35% at discharge in our institution from 2010 were retrospectively included. Patients were assigned to two groups according to the persistence of an LVEF ≤35% (ICD+) or a recovery >35% (ICD-). Logistic regression was performed to build a predictive score, which was then externally validated. RESULTS: Among a total of 1533 consecutive MI patients, 150 met inclusion criteria, 53 (35%) in the ICD+ group and 97 in the ICD group. After multivariable analyses, an LVEF ≤25% at discharge (adjusted OR 6.23 [2.47 to 17.0], p < .0001) and a CPK peak at the MI acute phase >4600 UI/L (adjusted OR 9.99 [4.27 to 25.3], p < .0001) both independently predicted non-recovery at 6 weeks. The IC-D (Increased Cpk-LV Dysfunction) score predicted persistent LVEF ≤35% with areas under curve of 0.83 and 0.73, in the study population and in a multicenter validation cohort of 150 patients, respectively (p < .0001). CONCLUSIONS: The association of a severely reduced LVEF and a major release of myocardial necrosis biomarkers at the acute phase of MI predict unfavorable remodeling, and prophylactic ICD implantation.

Interrelationships between interventricular electrical delays in cardiac resynchronization therapy.

INTRODUCTION: In cardiac resynchronization therapy, pacing the left ventricle (LV) at sites of prolonged electrical delay is associated with better outcomes. We sought to characterize the interrelationships between intrinsic, right-ventricular (RV)-paced, and LV-paced interventricular delays. METHODS AND RESULTS: The following electrical timings were measured at implantation for all electrodes of the LV quadripolar leads: QLV, interventricular delay in intrinsic rhythm (RVs-LVs), in RV-paced rhythm (RVp-LVs), and in LV-paced rhythm (LVp-RVs). We included 32 patients (78% men, age 72 years, LV ejection fraction 29%, left bundle branch block 84%). QLV and RVs-LVs were correlated (R2 = .72, p < .0001), as were RVs-LVs and RVp-LVs (R2 = .27, p = .002) and RVp-LVs and LVp-RVs (R2 = .60, p < .001). Direction of activation along the four LV lead electrodes was concordant between RVs-LVs and RVp-LVs in only 17 (53%) patients. The latest-activated electrodes in RVs-LVs and RVp-LVs were concordant in 26 (81%) patients, adjacent in 3 (9%) patients, and remote in 3 (9%) patients. Biventricular-paced QRS duration varied by more than 10 ms between the two electrodes in half of the patients with dissimilar latest electrodes. Among the seven echocardiographic nonresponders at 6 months, the programmed electrode was remote from the latest electrode in RVs-LVs in five patients and in RVp-LVs in three patients. CONCLUSION: Intrinsic and RV-paced interventricular electrical delays are correlated, but there is substantial heterogeneity between patients. The latest-activated electrode may be different between RVs-LVs and RVp-LVs, and this might have important implications in selecting the optimal LV vector.

Unexpected and undesired side-effects of pacing algorithms during exercise.

While the implantable pacemaker has initially been developed to treat symptomatic bradycardia, we demand of modern devices that they also function properly during exercise. In recent years, device manufacturers have implemented multiple proprietary algorithms which aim to improve pacemaker function by avoiding unnecessary right ventricular pacing, optimizing atrial refractory periods and diagnosing pacemaker mediated tachycardia. When activated, these algorithms may save the associated EGM into the device memory which enables later analysis by remote monitoring or device interrogation. In addition, the performance of an exercise-test while analyzing the EGM, enables the verification of proper algorithm function, the evaluation of residual symptoms and the optimization of specific parameters that vary as a function of heart rate. In this manuscript, we demonstrate how pacemaker algorithms may induce dropped P-waves during exercise in pacemaker dependent patients and loss of biventricular pacing in CRT patients.

Combination of the best pacing configuration and atrioventricular and interventricular delays optimization in cardiac resynchronization therapy.

BACKGROUND: Cardiac resynchronization therapy optimization can be pursued by left ventricular pacing vector selection and atrioventricular (AV) and interventricular (VV) delays optimization. The combination of these methods and its comparison with multipoint pacing (MPP) is scarcely studied. METHODS: Using noninvasive cardiac output (CO) measurement, the best of five left ventricular pacing vectors was determined, then AV and VV delays optimization was applied on top of the best vector. Response to the optimization protocol was defined as a >5% CO increase compared to the standard biventricular configuration. RESULTS: Twenty-two patients (18 men, age 71 ± 9 years) were included. Standard biventricular configuration increased CO compared to baseline (4.65 ± 1.55 L/min vs 4.27 ± 1.53 L/min, respectively, P = 0.02). The best quadripolar configuration increased CO to 4.85 ± 1.67 L/min (P = 0.03 compared to the standard biventricular configuration). AV then VV delay optimization both provided additional benefit (final CO 5.56 ± 2.03 L/min, P = 0.001 compared to the best quadripolar configuration). Fifteen (68%) patients responded to the optimization protocol. Anatomical MPP (based on maximal anatomical separation between electrodes) and electrical MPP (based on maximal electrical activation difference between electrodes) were evaluated in 16 patients and yielded a CO similar to that of the optimization procedure. CONCLUSIONS: The combination of choosing the best quadripolar pacing configuration and optimizing atrioventricular and interventricular delays resulted in an improvement of cardiac output compared to standard biventricular stimulation in 68% of patients. The final cardiac output was comparable to multipoint pacing.

Frequency of Recovery from Complete Atrioventricular Block After Cardiac Surgery.

Best timing for permanent pacemaker implantation to treat complete atrioventricular block (AVB) after cardiac surgery is unclear, as late pacemaker dependency was found low in recent observational studies. This study aimed to identify factors associated with spontaneous recovery from AVB. In a prospective and observational cohort, all patients who underwent cardiothoracic surgery during a 14-month-period were included (n = 1,200). Risk factors of postoperative AVB were assessed by logistic regression. Among patients who developed AVB, variables associated with recovery from AVB were assessed by Cox and logistic regression. Overall incidence of postoperative AVB was 6.0%. Risk factors of AVB were age (OR 1.03 [1.00 to 1.06], p = 0.023); female gender (OR 2.06 [1.24 to 3.41], p = 0.005), active endocarditis (OR 3.31 [1.33 to 8.26], p = 0.01), and aortic valve replacement (OR 3.17 [1.92 to 5.25], p <0.001). Among aortic valve replacement, sutureless aortic valve replacement was associated with more AVB (26.7% vs 8.1%, p <0.01). Recovery from AVB occurred in 30 patients (41.7%) in a median period of 3 days [interquartile range = 1;5]. Among patients who would recover from AVB, 90% of patients did so before day 7. None of the studied variable was independently associated with recovery from AVB. In conclusion, identified risk factors of postoperative AVB after cardiac surgery were age, female gender, endocarditis, and aortic valve replacement. Because most patients who would recover did so before day 7, this study validates modern guidelines suggesting permanent pacemaker implantation on day 7.