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

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