Blood potassium disorders are a common phenomenon in patients with HF, which may be related to complications of HF (such as decreased potassium intake, renal insufficiency) and medical treatment of HF (such as diuretics, ACEi/ ARB) [9]. It is showed that abnormal changes in sK can cause myocardial cell membrane potential instability, increase the risk of malignant arrhythmia, and result in a high mortality rate [10].~Current guidelines in China recommend ACEi/ARBs, β receptor blockers, MRAs, and diuretics for treating HF patients . However, β receptor blockers, ACEi/ARB and MRA can also cause hyperkalemia , which often leads to dose reduction or even discontinuation of the medicines, it affects the patients to benefit from these treatment.~At present, there are few studies to describe the clinical outcomes of HF patients with different sK levels in China. Utilizing the CN-HF database, this study is aimed to describe the sK levels of hospitalized HF patients and its impact to the clinical outcomes of patients.
China National Heart Failure Registration Study (CN-HF) is a nationwide, hospital-based, multicentre, prospective registry study sponsored by Ministry of Science and Technology of the People's Republic of China. It is aimed to understand the etiology, clinical features and treatments of in-hospital HF patients in China [3].~At present, there are few studies to describe the clinical outcomes of HF patients with different sK levels in China. Utilizing the CN-HF database, this study is aimed to describe the sK levels of hospitalized HF patients and its impact to the clinical outcomes of patients.