First in-man study of miniaturised implantable cardiac monitor shows positive results


First in-man multicentre study of the miniaturised implantable cardiac monitor Reveal Linq (Medtronic) suggests the device is safe and provides adequate sensing capabilities to detect arrhythmias.

Results of the non-randomised, prospective, multicentre trial, recently published in HeartRhythm, by Helmut Pürerfellner (Elisabethinen University Teaching Hospital, Linz, Austria) and others, show positive results for Reveal Linq regarding easy implantation, quality of electrocardiograms obtained, remote monitoring as assessed by daily transmissions, absence of major complications and no significant device migration after one-month follow-up.

According to Pürerfellner et al, the utility and cost-effectiveness of implantable cardiac monitors in the evaluation of syncope and investigation of patients with infrequent but recurrent palpitations has proven such that recent guidelines have advocated early use of these devices. Moreover, the researchers note, “there is growing interest in the use of such monitoring in arrhythmia detection following cryptogenic stroke and after ablation of atrial fibrillation.”

Reveal Linq is a novel implantable cardiac monitor that uses wireless telemetry for remote monitoring; it is 87% smaller than its predecessor (Reveal XT) and features the addition of a new p-wave filter to further refine the performance of the atrial fibrillation algorithm detector. “These improvements aim to simplify the implant procedure, increase patient acceptance and enhance the device atrial fibrillation detection capabilities,” the authors write.

In the study, 30 patients (mean age 55±15 years, 63% female) were inserted with the device at eight centres in Austria, The Netherlands, Australia and Slovakia. Patients were followed-up for one month after the procedure. The primary indications for device implant were syncope (n=19), suspected atrial fibrillation (n=2), atrial fibrillation ablation monitoring (n=2), atrial fibrillation management (n=3), palpitations (n=3), and cryptogenic stroke (n=1).

The authors reported that all procedures were undertaken with local anaesthesia and all patients underwent a successful implant with minimal to no incision bleeding in 93.3% of the cases. However, during one month of follow-up there were ten adverse events reported in nine patients, four related to the procedure (two due to implant site pain and two for wound infection).

The main objective of the study was to assess the percentage of successful transmissions by the system during the first 30 days after implant for what Pürerfellner et al reported a success rate of 79.5% from the device to Medtronic’s CareLink remote monitoring network. Most of the failures in transmission, the researchers note, were due to errors in some of the data received or because the patient was out of range from the CareLink home monitor.

Pürerfellner et al also note that a patient survey showed 76.7% of the patients were “Very satisfied” and 20% were “Satisfied” with the Reveal Linq device and 96.7% rated the MyCareLink home monitor as “Very easy to use”.

Regarding detection of arrhythmias, the researchers reported, the device stored and transmitted 217 episodes in 10 patients during the first month of follow-up for all 30 patients. The episodes detected were atrial fibrillation (111), asystole (95), bradycardia (4), fast ventricular tachycardia (1) and ventricular tachycardia (6).

The authors conclude that the first in-man experience with Reveal Linq shows the device is “functional and safe in patients indicated for insertable cardiac monitor implantation.” They add, “Device miniaturisation in combination with technological advances may further enhance its use in daily cardiac care as well as in clinical research.” They highlight that compared to previous generation of implantable monitors, “Reveal Linq supports improvements in various dimensions: ease of implant, electrogram quality and remote monitoring.”

Pürerfellner told Cardiac Rhythm News that “the new device is now ready for more widespread use in various clinical scenarios (cryptogenic stroke, atrial fibrillation ablation) to enhance atrial fibrillation detection and to further improve this arrhythmia’s management.” A real-world study, recently presented at the International Stroke Conference in Nashville, showed that Reveal Linq detected atrial fibrillation in cryptogenic stroke patients in everyday practice at an even greater rate than that found in a recent, rigorously-conducted clinical trial (CRYSTAL-AF).

Medtronic sponsored entirely this study.