Prognostic impact of potassium levels in patients with ventricular tachyarrhythmias

Background The study sought to assess the prognostic impact of potassium levels (K) in patients with ventricular tachyarrhythmias. Methods A large retrospective registry was used including all consecutive patients presenting with ventricular tachyarrhythmias on admission from 2002 to 2016. Patients...
Ausführliche Beschreibung

Background The study sought to assess the prognostic impact of potassium levels (K) in patients with ventricular tachyarrhythmias. Methods A large retrospective registry was used including all consecutive patients presenting with ventricular tachyarrhythmias on admission from 2002 to 2016. Patients with hypokalemia (i.e., K < 3.3 mmol/L), normokalemia (i.e., K 3.3–4.5 mmol/L), and hyperkalemia (i.e., K > 4.5 mmol/L) were compared applying multi-variable Cox regression models and propensity-score matching for evaluation of the primary endpoint of all-cause mortality at 3 years. Secondary endpoints were early cardiac death at 24 h, in-hospital death, death at 30 days, as well as the composite endpoint of early cardiac death at 24 h, recurrences of ventricular tachyarrhythmias, and appropriate ICD therapies at 3 years. Results In 1990 consecutive patients with ventricular tachyarrhythmias, 63% of the patients presented with normokalemia, 30% with hyperkalemia, and 7% with hypokalemia. After propensity matching, both hypokalemic (HR = 1.545; 95% CI 0.970–2.459; p = 0.067) and hyperkalemic patients (HR = 1.371; 95% CI 1.094–1.718; p = 0.006) were associated with the primary endpoint of all-cause mortality at 3 years compared to normokalemic patients. Hyperkalemia was associated with even worse prognosis directly compared to hypokalemia (HR = 1.496; 95% CI 1.002–2.233; p = 0.049). In contrast, potassium measurements were not associated with the composite endpoint at 3 years. Conclusion In patients presenting with ventricular tachyarrhythmias, normokalemia was associated with best short- and long-term survival, whereas hyperkalemia and hypokalemia were associated with increased mortality at 30 days and at 3 years. Graphic abstract Ausführliche Beschreibung