Matrix study

Ability to remotely monitor atrial high-rate episodes using a single-chamber implantable cardioverter-defibrillator with a floating atrial sensing dipole

Hindricks G, Bollmann A et al., EUROPACE 2023

Largest Trial on DX Technology in Single-Chamber ICD Patients

The 2020 ESC Guidelines for Diagnosis and Management of Atrial Fibrillation (AF)2  recommend remote monitoring (RM) of device-detected atrial high rate episodes (AHRE) and propose options for managing AHRE along pre-specified strata (6min…<1h, 1h…<24h, ≥24h)3 . DX Technology is unique in that it offers true atrial sensing in single-chamber ICD systems. This analysis aimed to assess the DX-ICD system’s capability to follow this recommendation, and to evaluate findings on AHRE detection and progression regarding their clinical implications based on real-life MATRIX registry data. MATRIX is the largest trial involving DX-ICD systems to date, enrolling 2,054 patients in 119 centers worldwide. 

The study found that the DX-ICD system demonstrates a high detection accuracy for AHRE throughout 2 years of follow-up. Combined with the high transmission rate of BIOTRONIK Home Monitoring (HM), this allows reliable, guideline-recommended screening for subclinical AF and monitoring of AHRE duration progression.

Furthermore, the clinical relevance of new-onset AHRE detection and burden monitoring was underlined by MATRIX results, as new-onset AHRE was not rare, and progression shown to be common in these patients. In fact, the majority of patients with new-onset AHRE (69.5%) presented with AHRE of longer duration (i.e., 1 hour or more) during follow-up. More importantly, 80% of patients with new-onset AHRE had a substantial risk of thromboembolic events (i.e. a high CHA2DS2-VASc score) - and in most of these cases (69.5%), patients were not on oral anticoagulation (OAC) at baseline.  

Read more about the study design, key results, and clinical relevance below. 

Study Design

  • International, multicenter registry including 119 sites in 24 countries
  • 2,054 DX-ICD patients with standard single-chamber ICD indication enrolled
  • Follow-up 24 months, according to the centers’ routine follow-up scheme (i.e., in a real-life setting)
  • BIOTRONIK (Home Monitoring recommended)

Two objectives:

  • To evaluate the ability of a DX-ICD system to remotely monitor AHRE and progression of arrhythmia duration (i.e., to implement the guideline-recommended remote monitoring of subclinical AF), and
  • To analyze the clinical implications of findings on AHRE detection and progression.

Key Result 1
Highly Accurate AHRE Detection

Adjudication of Device-Detected AHRE Shows High Positive Predictive Value

Analyzing the detection accuracy of DX-ICD systems for different AHRE durations, the first occurring AHRE per duration stratum was adjudicated, revealing a positive predictive value (PPV) of >99.7% for AHRE durations ≥1h.

Investigators Value the System’s Atrial Signal Detection Quality

Key Result 2
Reliable Monitoring

DX-ICD systems including Home Monitoring (HM) delivered a high real-life transmission performance: In patients with active HM (n=1,841), the median daily transmission rate (i.e., % of days with transmissions) was 92.5%.  

Capability to Implement Guideline-Recommended Subclinical AF Monitoring

The system's high transmission rate, combined with its high AHRE detection accuracy, allows for reliable, guideline -recommended remote monitoring of subclinical AF.


Key Result 3
New-Onset AHRE Not Rare, Progression and High Stroke Risk Common

New-Onset AHRE Is Not Rare
In patients with no AF history (n = 1,451), new-onset AHRE occurred in 119 patients (8.2%) during the 2 years of follow-up.

Progression Is Common 
Progression to a stratum of longer duration was rather frequent (31.1%)

Episode Duration Often Exceeded 1h  
By end of follow-up, AHRE duration reached or exceeded 1h in approx. 7 out of 10 patients (82/119, 69%) with new onset AHRE. 


Many New-Onset AHRE Patients Were at High Risk of Thromboembolic Events
79.8% of patients with new-onset AHRE had a high CHA2DS2-VASc stroke risk (95/119).

Most of these were not on OAC therapy at baseline (66/95, 69.5%).

Clinical Relevance

  • MATRIX is largest clinical evaluation of DX Technology to date
  • In this unselected, real-life setting, the findings confirm that DX Technology, combined with Home Monitoring, allows for reliable, guideline-recommended remote monitoring of subclinical AF
  • The clinical relevance of AHRE monitoring is underlined by the fact that patients with new-onset AHRE often experience AHRE progression and are at substantial risk of thromboembolic events, while most of them are not on OAC.

Study Objective To explore the impact of enhanced features and capabilities of the BIOTRONIK DX system on detection and management of AF in an unselected real-life setting.
Clinical Sites
  • 119 sites in 24 countries 
Sample Size
  • 2054 patients enrolled
Main Inclusion Criteria
  • Indication for implantation of a single-chamber ICD (primary or secondary prevention) 
  • Implanted with a BIOTRONIK DX-ICD system within 90 days prior to enrollment
Main Exclusion Criteria
  • Age < 18 years
  • Female patients who are pregnant or breastfeeding or planning a pregnancy during the course of the study
  • Known active malignant disease or recovered from malignant disease •    within 2 years prior to enrollment
  • Simultaneous participation in another study
  • Life expectancy < 2 years
  • BIOTRONIK Lumax 540 VR-T DX ICD with Linoxsmart S DX or successor single-chamber DX system
  • Mean follow-up was 677 ± 173 days (median 727, IQR 685-759).
Study Duration
  • Jan 2013 – Jun 2018
Reference no.
  • NCT01774357
Principal Investigators
  • Gerhard Hindricks, Chief Integration Officer at Deutsches Herzzentrum der Charité, Germany
  • Andreas Bollmann, Heart Center Leipzig at the University of Leipzig and Helios Health Institute, Germany



i AHRE lasting ≥ 6 minutes were included in the analysis. 
"Active": at least 1 HM transmission was received during the 24 months of follow-up.
iii transmission rate = % of days with transmissions