Advantages and disadvantages of drug challenge during electrophysiological study in patients with new left bundle branch block after transaortic valve implantation.

AIMS: Electrophysiological study (EPS) is recommended in case of new-onset persistent left bundle branch block (NOP-LBBB) after transaortic valve implantation (TAVI) to identify patients at high risk of delayed atrioventricular block (D-AVB). We evaluated the added value of drug challenge, after normal baseline EPS, to predict D-AVB in such patients. METHODS: We conducted a comparative single-centre study of two successive periods, during which we used baseline EPS alone (first period) or drug challenge in case of normal baseline EPS (second period), for patients with NOP-LBBB after TAVI. The primary endpoint was a composite of pacemaker use, documented D-AVB, cardiac syncope, sudden death, or delayed pacemaker implantation. RESULTS: Among 736 patients with TAVI implantation between January 2016 and September 2019, 64 with NOP-LBBB were included. During the first period, 4/22 (18.2%) presented with a positive baseline EPS. After a mean (standard deviation [SD]) of 15.6 (8.3) months, 7/22 (31.8%) reached the primary endpoint. During the second period, 19/42 (45.2%) presented with a positive EPS. After a mean (SD) of 12.8 (3.5) months, 8/42 (19.0%) reached the primary endpoint. There was a tendency to increased sensitivity (42.9-87.5%; P = 0.12) and negative predictive value (77.8-95.7%; P = 0.15) of the EPS, respectively during the first to the second period. However, the specificity decreased (93.3-64.7%; P = 0.04). CONCLUSION: Diagnostic yield improved with drug challenge in case of normal baseline EPS. However, the decrease in specificity led to a high rate of unnecessary pacemaker implantation.

Smartwatch Electrocardiogram and Artificial Intelligence for Assessing Cardiac-Rhythm Safety of Drug Therapy in the COVID-19 Pandemic. The QT-logs study.

BACKGROUND: QTc interval monitoring, for the prevention of drug-induced arrhythmias is necessary, especially in the context of coronavirus disease 2019 (COVID-19). For the provision of widespread use, surrogates for 12­lead ECG QTc assessment may be useful. This prospective observational study compared QTc duration assessed by artificial intelligence (AI-QTc) (Cardiologs®, Paris, France) on smartwatch single­lead electrocardiograms (SW-ECGs) with those measured on 12­lead ECGs, in patients with early stage COVID-19 treated with a hydroxychloroquine-azithromycin regimen. METHODS: Consecutive patients with COVID-19 who needed hydroxychloroquine-azithromycin therapy, received a smartwatch (Withings Move ECG®, Withings, France). At baseline, day-6 and day-10, a 12­lead ECG was recorded, and a SW-ECG was transmitted thereafter. Throughout the drug regimen, a SW-ECG was transmitted every morning at rest. Agreement between manual QTc measurement on a 12­lead ECG and AI-QTc on the corresponding SW-ECG was assessed by the Bland-Altman method. RESULTS: 85 patients (30 men, mean age 38.3 ± 12.2 years) were included in the study. Fair agreement between manual and AI-QTc values was observed, particularly at day-10, where the delay between the 12­lead ECG and the SW-ECG was the shortest (-2.6 ± 64.7 min): 407 ± 26 ms on the 12­lead ECG vs 407 ± 22 ms on SW-ECG, bias -1 ms, limits of agreement -46 ms to +45 ms; the difference between the two measures was <50 ms in 98.2% of patients. CONCLUSION: In real-world epidemic conditions, AI-QTc duration measured by SW-ECG is in fair agreement with manual measurements on 12­lead ECGs. Following further validation, AI-assisted SW-ECGs may be suitable for QTc interval monitoring. REGISTRATION: ClinicalTrial.govNCT04371744.

Right ventricular and tricuspid valve function in patients chronically implanted with leadless pacemakers.

Aims: Leadless cardiac pacing has recently been proposed as alternative to conventional right ventricular (RV) pacing. With this approach, devices are directly screwed or fixed with tines in the RV wall, but the possible consequences on RV and tricuspid valve (TV) structure and function remain unknown. We thus conducted a study to evaluate this potential impact in chronically implanted patients. Methods and results: Repeated echocardiographic studies were performed prior to implantation, at discharge, and 2 months thereafter on all consecutive patients implanted with a leadless pacemaker at our centre between October 2014 and end-December 2015. Whenever possible, patients were evaluated in non-paced rhythm. Anatomical and functional parameters of RV, TV, and left cardiac structures were assessed. Overall, 23 patients (12 females, aged 85.2 ± 6.3 years) were included, with 14 implanted using Nanostim™ (Saint Jude Medical) and 9 with Micra™ (Medtronic). Indications for pacing were paroxysmal atrio-ventricular block in 12 patients, intermittent sinus bradycardia in 5, unexplained syncope in 3, and atrial fibrillation with slow ventricular rate in the remaining 3. The pacing percentage was 34 ± 42% at the last visit. Most devices were implanted in the septo-apical or mid-septal region. There were no significant changes in echocardiographic parameters observed. One patient developed significantly increased TV regurgitation, without abnormal leaflet motion or TV annulus size changes, suggesting it to be due to RV pressure changes. Conclusion: In patients chronically implanted with leadless pacemakers, there were no significant changes in heart structure and function observed, especially concerning the RV and TV.

Outcomes and costs associated with two different lead-extraction approaches: a single-centre study.

AIMS: We sought to compare outcomes and costs of a stepwise approach to transvenous lead extraction (TLE) involving laser-assisted sheaths or mechanical polypropylene sheaths, with/without crossover. METHODS AND RESULTS: We prospectively included patients who underwent TLE (between August 2013 and December 2014) as part of a stepwise approach involving simple traction, lead snaring, and sheath-assisted dissection; all of these patients underwent a first-line polypropylene-sheath-extraction approach (Group A). The comparison group (Group B) was consecutive patients who had undergone TLE before August 2013, during which laser-assisted sheath extraction was the first-line approach. The number of patients in Group B was adjusted to match the number who eventually needed sheaths in Group A. Procedural data, outcomes, and costs were compared between groups (comparison of approaches) and in patients who needed sheath-assisted extraction (comparison of techniques). Overall, 521 leads were extracted (131 patients in Group A, 104 in Group B). Radiological and clinical success rates were similar; crossover from polypropylene to laser sheaths was needed in 10 patients in Group A (vs. none in Group B). Radiological (P< 0.001) and clinical (P= 0.01) success rates were higher and were achieved with a lower radiation exposure (P= 0.03) with laser sheaths in patients (60 in each group) who needed sheath-assisted extraction. Complication rates were similar in both groups (P= 0.66) but two deaths occurred in Group B. The laser approach had higher material cost (P= 0.002). CONCLUSIONS: Although laser-assisted TLE was more effective than polypropylene sheath-assisted TLE, the latter was associated with fewer complications and was more cost-effective.