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More than a decade of peer-reviewed evidence.

A continuous clinical research program validating Cardio Explorer®.

Validated across the cardiovascular risk spectrum

Cardio Explorer® was developed, refined, and validated through retrospective diagnostic accuracy studies spanning algorithm development, model lock, and intended-use validation. A prospective implementation study is now evaluating clinical adoption, usability, and impact on patient management in routine care.

Obstructive CAD

Anatomical endpoint
University Hospital Basel

Basel I

Initial algorithm development and internal validation

First feasibility cohort: machine-learned pattern recognition trained on patients referred for invasive coronary angiography.

LURIC Study

LURIC

Algorithm refinement and lock in a high-risk population

Locked model evaluated on independent validation sets within a high cardiovascular-risk cohort.

Maastricht University

Maastricht

Pivotal evaluation in the intended-use population

Validated in the intended-use population: low-to-intermediate-risk outpatients referred for CAD workup.

iGES

AOK Niedersachsen

Prospective implementation in primary care

Multicentre controlled study evaluating Cardio Explorer® acceptance, usability, and impact on diagnostic pathways in general practice.

Myocardial ischemia

Functional endpoint
University Hospital Basel

Basel II

Validation of the algorithm for ischemia prediction

Prospective single-centre cohort validating the memetic pattern-based algorithm (MPA) against Rubidium-82 PET myocardial perfusion imaging.

Publication

Original research · Open access

Artificial intelligence to improve ischemia prediction in Rubidium Positron Emission Tomography — a validation study

Frey SM, Bakula A, Tsirkin A, et al. EPMA J. 2023;14:631–643.

doi:10.1007/s13167-023-00341-5

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Study design

Design
Prospective single-centre cohort; validation of the memetic pattern-based algorithm (MPA) for ischemia prediction
Population
Consecutive patients referred for Rubidium-82 PET myocardial perfusion imaging (ischemia work-up for suspected/known CAD)
Sample size
2,417 validation
Setting
Tertiary centre, University Hospital Basel, Switzerland (Jul 2018 – Feb 2022)
Reference standard
Rubidium-82 PET myocardial perfusion imaging (rest / pharmacologic stress with adenosine or regadenoson)
Ischemia definition
Summed difference score (SDS) ≥ 2

Consistent diagnostic performance across populations

Performance of the current CE-marked algorithm (Cardio Explorer® v1.5) in three validation cohorts: how well it discriminates, how safely it rules out obstructive CAD, and how reliably it rules it in at the thresholds used in the clinical pathway.

Area under the ROC curve

Bar chart. AUC by cohort: Basel I 0.835, LURIC 0.875, Maastricht 0.878.

Source: Exploris Health clinical performance data for Cardio Explorer® v1.5. AUC and the 15% threshold values are documented in the Instructions for Use v1.5, Table 1.

Scientific evidence behind Cardio Explorer®

Organised by evidence type to show the breadth and maturity of the science behind the Memetic Pattern Algorithm and the Cardio Explorer® platform: from the original 2014 methodology paper to current ESC-level comparative evaluations. Within each category, sorted newest to oldest.

Peer-reviewed publications

5 entries

Independent and collaborative research published in peer-reviewed journals.

  • Coronary Heart Disease — A German Paradox

    Remppis A, et al. Herzschrittmachertherapie + Elektrophysiologie. 2025.

    Peer-reviewed analysis of Cardio Explorer® performance versus guideline-based approaches, with a description of the underlying AI architecture.

    Authors
    Remppis A, et al.
    DOI
    10.1007/s00399-025-01094-6
    Abstract

    Despite extensive guideline coverage and broad access to cardiovascular diagnostics, Germany continues to observe substantial rates of missed and late-diagnosed coronary artery disease — the so-called German paradox. This article reviews the structural drivers of that gap and introduces Cardio Explorer® as a clinically deployable AI decision-support tool that combines clinical, laboratory, and demographic variables into a single probabilistic estimate of obstructive CAD. The paper details the Memetic Pattern Algorithm architecture, summarises validation across the Basel, LURIC and Maastricht cohorts, and discusses integration into ambulatory cardiology pathways.

  • Artificial intelligence to improve ischemia prediction in Rubidium Positron Emission Tomography — a validation study

    Frey SM, Bakula A, Tsirkin A, et al. EPMA Journal. 2023.

    Peer-reviewed validation in 2,417 consecutive patients referred for Rubidium-82 PET: the memetic pattern-based algorithm predicted ischemia more accurately than ESC and ACC pre-test probability models.

    Authors
    Frey SM, Bakula A, Tsirkin A, et al.
    DOI
    10.1007/s13167-023-00341-5
    Abstract

    Consecutive patients (n = 2,417) referred for Rubidium-82 positron emission tomography were evaluated. Pre-test probability (PTP) was calculated using the ESC 2013/2019 and ACC 2012/2021 guidelines, and a memetic pattern-based algorithm (MPA) was applied incorporating symptoms, vitals, ECG and biomarkers; ischemia was defined as a summed difference score ≥ 2. Ischemia was present in 37.1%. The MPA model was the most accurate predictor of ischemia (AUC 0.758 vs. 0.585–0.673 for the guideline models, p < 0.001). At the < 5% threshold, its sensitivity and negative predictive value to rule out ischemia were 99.1% and 96.4%. The model allocated patients more evenly across PTP categories, reduced the proportion in the intermediate (15–85%) range by 29–51%, and was the only tool to correctly predict ischemia prevalence in the very low PTP category.

  • Use of artificial intelligence to assess the risk of coronary artery disease without additional (non-invasive) testing: validation in a low-risk to intermediate-risk outpatient clinic cohort

    Eurlings C, et al. BMJ Open. 2022.

    Maastricht validation of the Cardio Explorer® AI model in a low-prevalence outpatient cohort. Reported AUC 0.87.

    Abstract

    Objective: To evaluate the diagnostic performance of an artificial intelligence (AI) model — Cardio Explorer® — to assess the probability of obstructive coronary artery disease (CAD) in a low- to intermediate-risk outpatient population, using only clinical and laboratory variables already available at the point of care. Design: Retrospective diagnostic accuracy study using prospectively collected charts from an outpatient cardiology clinic at Maastricht University Medical Centre (MUMC+). Reference standard combined invasive coronary angiography, coronary CT angiography, and ≥3 years event-free follow-up. Results: The algorithm achieved an AUC of 0.87 (95% CI 0.84–0.91) with high sensitivity and a strong negative predictive value, supporting its use as a non-invasive rule-out tool in the intended-use population.

  • A New Non-Invasive Diagnostic Tool in Coronary Artery Disease: Artificial Intelligence as an Essential Element of Predictive, Preventive, and Personalized Medicine

    Zellweger MJ, et al. EPMA Journal. 2018.

    Core Cardio Explorer® validation paper framing the algorithm within predictive, preventive, and personalized medicine (PPPM).

    Authors
    Zellweger MJ, et al.
    DOI
    10.1007/s13167-018-0142-x
    Abstract

    This paper situates Cardio Explorer® within the framework of Predictive, Preventive and Personalized Medicine (PPPM). It describes how a Memetic Pattern Algorithm trained and validated across independent European cohorts can support individualised CAD risk estimation without exposing patients to additional radiation, contrast, or stress testing. The article details the inputs, outputs, intended clinical use and the regulatory positioning of the tool, and outlines how AI-based pre-test probability can be integrated into shared decision-making for downstream imaging or invasive evaluation.

  • A New Memetic Pattern Based Algorithm to Diagnose / Exclude Coronary Artery Disease

    Zellweger MJ, Brinkert M, Bucher U, Tsirkin A, Ruff P, Pfisterer ME. International Journal of Cardiology. 2014.

    Foundational peer-reviewed publication introducing the Memetic Pattern Algorithm (MPA) for CAD diagnosis.

    Authors
    Zellweger MJ, Brinkert M, Bucher U, Tsirkin A, Ruff P, Pfisterer ME.
    DOI
    10.1016/j.ijcard.2014.03.184
    Abstract

    This foundational paper introduces a memetic pattern based algorithm (MPA) for the non-invasive diagnosis and exclusion of coronary artery disease. Using clinical, demographic, and laboratory inputs, the algorithm reconstructs patient-specific risk patterns and benchmarks them against a reference library of phenotypes with known coronary status. Initial evaluation in a Basel high-prevalence cohort referred for invasive coronary angiography demonstrated the feasibility of using machine-learned pattern recognition as a triage step prior to invasive testing, establishing the methodological foundation for the Cardio Explorer® platform.

Conference abstracts

1 entry

Presentations and abstracts from international cardiology congresses.

  • Comparison of a Novel Scientific Model of the Memetic Pattern Based MPA v3 and the ESC 2024 RF-CL Algorithm

    Büsser AJ, et al. European Heart Journal — Digital Health. 2026.

    ESC AI Congress abstract benchmarking MPA v3 against the ESC 2024 risk-factor weighted clinical likelihood model.

    Authors
    Büsser AJ, et al.
    Abstract

    This ESC AI Congress abstract compares the third-generation Memetic Pattern Algorithm (MPA v3) — the engine behind Cardio Explorer® — to the ESC 2024 RF-CL (Risk Factor weighted Clinical Likelihood) algorithm for the estimation of obstructive coronary artery disease. Using a contemporary outpatient cohort, the analysis evaluates discrimination, calibration, and net reclassification across pre-test probability strata, with a particular focus on the low-to-intermediate risk band where guideline pathways most often produce ambiguous recommendations. MPA v3 demonstrates improved discrimination and a more favourable rule-out profile than RF-CL while preserving sensitivity, supporting its role as a non-invasive triage tool prior to advanced imaging.

Clinical trial registrations

1 entry

Registered prospective studies evaluating Cardio Explorer® in clinical practice.

  • Cardio Explorer® Risk Assessment Trial

    ISRCTN Registry. Ongoing.

    Prospective clinical implementation study evaluating Cardio Explorer® in routine outpatient cardiology practice.

    Abstract

    Registered clinical study describing the prospective implementation of the Cardio Explorer® AI algorithm in routine outpatient cardiology practice. The protocol assesses real-world diagnostic performance, downstream resource utilisation, and impact on clinical decision-making versus standard guideline-based pathways.