AK+ Guard™ Pilot Study in Chronic Kidney Disease: Outpatient Diagnostic Accuracy and Remote Monitoring

Diagnostic Accuracy, Usability, Patient Compliance, and System Reliability of the AK+ Guard™ ECG Application for Hyperkalemia Prediction in Ambulatory Chronic Kidney Disease Patients (Outpatient and Remote Monitoring Arms)

The goal of this observational pilot study is to evaluate the investigational AK+ Guard™ software as a medical device (SaMD) for detection of moderate to severe hyperkalemia (serum potassium (K+) ≥ 6.5 mmol/L) in adults with chronic kidney disease (CKD).

Study objectives are:

• Arm 2A (Outpatient Diagnostic Accuracy): To generate a preliminary, real-world signal of the diagnostic performance of AK+ Guard™ when used in an ambulatory CKD cohort for identifying clinically significant hyperkalemia episodes (serum K+ ≥ 6.5 mmol/L) at the time of an outpatient laboratory draw.
• Arm 2B (Remote Patient Monitoring): To assess participant compliance, usability, and end-to-end system reliability of AK+ Guard™ when deployed for daily remote monitoring of CKD patients outside the clinical environment for up to four weeks.

The AK+ Guard™ application is an investigational Software as a Medical Device (SaMD) developed by AccurKardia, Inc. (New York, USA). It is designed to aid in the diagnosis of moderate to severe hyperkalemia (serum potassium ≥ 6.5 mmol/L) in adults using artificial intelligence analysis of Lead I electrocardiogram (ECG) data. The software is intended as a clinical decision support tool for adults at risk of hyperkalemia, including but not limited to those with end-stage renal disease (ESRD), chronic kidney disease (CKD) on renin-angiotensin-aldosterone system inhibitors, heart failure, adrenal disorders, and patients taking aldosterone synthase inhibitors. The AK+ Guard™ application analyzes only Lead I ECG signals, which may be obtained from standard 12-lead ECGs, clinical-grade ECG devices with Lead I capability, or consumer wearable devices (e.g., Apple Watch).

This pilot study is designed to generate preliminary real-world evidence on both the diagnostic performance of the application and its usability in daily life. The study includes two arms:

Arm 2A - Outpatient Diagnostic Accuracy:

• Estimate sensitivity, specificity, PPV, and NPV of AK+ Guard™ in ambulatory CKD stages III-IV
• Evaluate interoperability across selected Lead I ECG capture devices (Apple Watch, HeartBeam, and 12 lead reference)
• Characterize system reliability metrics (upload success, algorithm runtime) in the outpatient setting

Arm 2B - Remote Patient Monitoring

• Quantify participant compliance, data completeness, and attrition during four week remote monitoring
• Evaluate user experience using System Usability Scale (SUS) score, Net Promoter Score (NPS), and semi structured feedback
• Capture technical performance metrics in a real world, unsupervised context

Inclusion Criteria:

(Arm 2A - Outpatient Diagnostic Accuracy)

• Age 22 years or older
• CKD stages III-IV managed at Central Jersey Kidney Care outpatient clinic
• Scheduled outpatient serum potassium laboratory test
• On RAASi therapy or documented hyperkalemia (K+ ≥ 5.5 mmol/L) within the past 12 months
• Able to provide written informed consent

(Arm 2B - Remote Patient Monitoring)

• Completion of Arm 2A visit
• Owns an iPhone compatible with the study application

Exclusion Criteria (Both arms):

• Age 21 years or younger
• Pacemaker or implantable cardioverter defibrillator
• Pre existing Left Bundle Branch Block (LBBB), Right Bundle Branch Block (RBBB), Intraventricular Conduction Delay (IVCD), or clinically significant hypocalcemia
• Potassium lowering treatment administered before Lead I ECG acquisition
• Trauma, acute events, or active interventions altering potassium homeostasis
• Physical limitation precluding ECG acquisition