The following is a summary of “Relationship between serum potassium levels and cardiac arrhythmias in left ventricular assist device (LVAD) recipients: a comprehensive analysis and prognostic evaluation,” published in the August 2024 issue of Cardiology by Lombardi et al.

Researchers conducted a retrospective study examining the association between serum potassium (K⁺) levels and the development of new heart rhythm problems in patients using left ventricular assist devices (LVAD).

They utilized the INTERMACS registry, focusing on adult patients with K⁺ measurements taken 1 month after LVAD implantation. The K⁺ levels were examined both as a continuous and categorical variable (quartiles of baseline K⁺ distribution). The primary outcome was the incidence of new arrhythmia events, including sustained (ventricular [VA] or supraventricular arrhythmia [SVA]) and non-sustained (atrial fibrillation/flutter [AF]) events. All-cause mortality was assessed as a secondary outcome. Time-dependent Cox regression models and natural splines were applied to explore the relationship between K⁺ levels and the outcomes.

The results showed 10,570 patients, the lowest quartile of longitudinal K⁺ was linked to a higher risk of arrhythmic events (HR 1.28, 95% CI 1.08–1.53, P=0.005), and the highest quartile also showed increased risk (HR 1.24, 95% CI 1.02–1.49, P=0.027). A similar U-shaped relationship was observed for sustained ventricular arrhythmias (SVAs) and atrial fibrillation/flutter (AF). Both the highest and lowest quartiles of longitudinal K⁺ were significantly associated with an increased HR of death, reflecting a U-shaped pattern.

Investigators concluded that both low and high blood potassium levels were linked to an increased risk of heart rhythm problems in patients using left ventricular assist devices, with these problems being associated with poorer patient survival.

Source: link.springer.com/article/10.1007/s00392-024-02531-1