The relationship between serum potassium levels and cardiac arrhythmias in left ventricular assist device (LVAD) recipients: a comprehensive analysis and prognostic evaluation.

BACKGROUND

This study aimed to comprehensively analyze the relationship between serum potassium (K) levels and the risk of de novo cardiac arrhythmias in left ventricular assist device (LVAD) recipients.

METHODS

We performed a retrospective study using the INTERMACS registry. Data was collected on adult patients with available K measurements taken 1-month post-LVAD implantation. K levels were the main exposure of interest and were analyzed as a continuous and categorical variable (quartiles of baseline K distribution). The main outcome of interest was the occurrence of de novo arrhythmia events, either sustained (ventricular [VA] or supraventricular arrhythmia [SVA]) or not sustained (atrial fibrillation/flutter [AF]). All-cause mortality was evaluated as the secondary outcome. Multivariable adjusted time-dependent Cox regression models and natural splines were used to describe the relationship between the exposure and outcomes of interest.

RESULTS

10,570 patients met our inclusion criteria. A significant and consistent relationship was observed between the lowest quartile of longitudinal K and the risk of arrhythmic events (HR 1.28, 95% CI 1.08, 1.53, p = 0.005) as well as in the highest K quartile (HR 1.24, 95% CI 1.02, 1.49, p = 0.027). A similar relationship was confirmed in the stratified analysis of arrhythmia types for SVAs and AF. The data were reflected in a U shaped relationship. Similarly, the highest and lowest quartiles of longitudinal K were independently associated with a significant increase in the HR of death, which was reflected by a U shaped relationship.

CONCLUSIONS

Our study reveals a significant U shaped relationship between low and high K + levels and cardiac arrhythmias in LVAD patients, particularly SVAs and AF. Both high and low K + levels negatively impacted patient survival.