Potassium Control Could Be Key for HFpEF Management, Study Suggests
China: For patients with heart failure with preserved ejection fraction (HFpEF), maintaining potassium levels in the optimal range could significantly influence long-term cardiovascular outcomes. A new analysis published in BMJ Open Heart introduces an important metric—time in target range (TTR)—that emphasizes not just achieving, but sustaining optimal serum potassium (sK) levels.
Potassium imbalance is a well-known risk factor in heart failure, often linked to arrhythmias and mortality. Traditionally, clinicians have relied on single-point measurements or average sK values, which fail to reflect fluctuations over time. This study highlights TTR as a potentially superior measure for risk prediction and management in HFpEF patients.
Researchers, led by Wenlong Xu from the Sixth Affiliated Hospital of South China University of Technology in China, analyzed data from 3,141 patients enrolled in the TOPCAT trial. All participants had HFpEF and underwent at least five serum potassium measurements over a median of 3.9 years. The target sK range was defined as 4.3–4.9 mmol/L, and TTR represented the percentage of time a patient’s potassium stayed within this window.
Key findings include:
- Patients who spent more time in the 4.3–4.9 mmol/L range had a 29% lower risk of cardiovascular events (HR 0.71).
- Both 4.3–4.6 mmol/L and 4.6–4.9 mmol/L ranges provided protective benefits.
- 4.0–4.3 or 4.9–5.2 mmol/L showed no advantage and even potential harm.
- The association remained significant after adjusting for mean potassium levels and variability across all subgroups.
These results emphasize the importance of consistency over time, rather than single lab values, in managing electrolyte balance in HFpEF. “The message is clear—maintaining potassium within the optimal range most of the time reduces cardiovascular risk,” the authors noted. The study suggests that TTR could become a valuable metric in routine heart failure management, guiding both monitoring strategies and treatment adjustments.
The analysis, based on the TOPCAT trial, involved mostly white participants from the U.S., Russia, and Georgia, limiting its generalizability. Additionally, unmeasured factors such as kidney function and medication use could influence results. The researchers call for validation in diverse, real-world populations and exploration of TTR in patients with reduced ejection fraction.
"For HFpEF patients, keeping potassium between 4.3–4.9 mmol/L most of the time may significantly cut cardiovascular risk, reinforcing the need for continuous monitoring and personalized care," the authors concluded.
Reference:
Wenlong Xu, Zhiwen Xiao, Yating Tang, Yingxuan Li, Xingqiao Chen, Fengling He, Haoxiang Huang, Chuling Li, Yu Liu, Jiajun Zhou, Yuegang Wang, Jianping Bin, Yanmei Chen - Association of serum potassium time in target range with cardiovascular outcomes in patients with HFpEF: Open Heart 2025;12:e003439.
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