AUTHOR=Bisignani Giovanni , De Bonis Silvana , Pierre Bertrand , Lau Dennis H. , Hofer Daniel , Sanfins Victor Manuel , Hain Andreas , Cabanas Pilar , Martens Eimo , Berruezo Antonio , Eschalier Romain , Milliez Paul , Lüsebrink Ulrich , Mansourati Jacques , Papaioannou Georgios , Giacopelli Daniele , Gargaro Alessio , Ploux Sylvain 

TITLE=Insertable cardiac monitor with a long sensing vector: Impact of obesity on sensing quality and safety

JOURNAL=Frontiers in Cardiovascular Medicine

VOLUME=Volume 10 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/cardiovascular-medicine/articles/10.3389/fcvm.2023.1148052

DOI=10.3389/fcvm.2023.1148052

ISSN=2297-055X

ABSTRACT=Background: Fat layers in obese patients can impair R-wave detection and diagnostic performance of a subcutaneous insertable cardiac monitor (ICM). We compared safety and ICM sensing quality between obese patients (body mass index [BMI] ≥30 kg/m2) and normal-weight controls (BMI <30 kg/m2) in terms of R-wave amplitude and time in noise mode (noise burden) detected by a long-sensing-vector ICM.
Materials and methods: Patients from two multicentre, non-randomized clinical registries are included in the present analysis on January 31, 2022 (data freeze), if the follow-up period was at least 90 days after ICM insertion, including daily remote monitoring. The R-wave amplitudes and daily noise burden averaged intraindividually for days 61-90 and days 1-90, respectively, were compared between obese patients (n=104) and unmatched (n=268) and a nearest-neighbour propensity score (PS) matched (n=69) normal-weight controls.
Results: The average R-wave amplitude was significantly lower in obese (median 0.46 mV) than in normal-weight unmatched (0.70 mV, p<0.0001) or PS-matched (0.60 mV, p=0.003) patients. The median noise burden was 1.0% in obese patients, which was not significantly higher than in unmatched (0.7%; p=0.056) or PS-matched (0.8%; p=0.133) controls. The rate of adverse device effects during the first 90 days did not differ significantly between groups.
Conclusion: Although increased BMI was associated with reduced signal amplitude, also in obese patients the median R-wave amplitude was >0.3 mV, a value which is generally accepted as the minimum level for adequate R-wave detection. The noise burden and adverse event rates did not differ significantly between obese and normal-weight patients.