POTCAST Trial
POTCAST Trial
Presented at ESC 2025 – Madrid & published in NEJM at the same time.
Source: Medical News | August 29, 2025
1. Trial Design
• POTCAST trial: 1200 patients with cardiovascular disease + ICD at high risk for ventricular arrhythmias.
• Randomized to raise potassium (diet, supplements, MRAs) vs standard care.
• Goal: increase plasma potassium to high-normal (4.5–5.0 mmol/L).
• Baseline potassium: 4.0 mmol/L.
2. Main Results
• Intervention raised potassium by +0.3 mmol/L.
• 24% lower risk of composite endpoint (VT, ICD shocks/pacing, HF/arrhythmia hospitalization, or death).
• Driven mainly by 25% reduction in ventricular tachycardia (122 vs 92 cases).
• Benefit consistent across subgroups.
3. Safety
• Slight rise in creatinine (+4 µmol/L).
• Hospitalizations: 17 intervention vs 12 control (not significant).
• No excess hyperkalemia-related adverse events in patients with preserved kidney function.
4. Clinical Significance
• First RCT to show that actively raising potassium reduces arrhythmias in ICD patients.
• Comparable benefit to antiarrhythmic drugs, but with cheap, simple therapy.
• Experts highlight importance of keeping potassium “as high as possible within the safe range.”
5. Broader Implications
• Supports prior observational evidence: higher potassium → better CV outcomes + lower blood pressure.
• Could extend to other CV patients, but US experts warn:
• Trial excluded renal dysfunction.
• Denmark’s organized healthcare system may not reflect US practice.
• In the US, may be most suitable for patients closely monitored in advanced HF/ICD clinics.
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👉 Conclusion:
POTCAST provides high-level evidence that modestly increasing potassium to the high-normal range can significantly reduce ventricular arrhythmias and ICD shocks — a low-cost, safe strategy for many ICD patients, though careful monitoring is essential, especially outside trial settings.
