Background
Potassium disturbances per se increase the risk of
ventricular fibrillation (VF). Whether
potassium disturbances in the acute phase of
ST-segment-elevation myocardial infarction (
STEMI) are associated with VF before primary
percutaneous coronary intervention (PPCI) is uncertain. Methods and Results All consecutive
STEMI patients were identified in the Eastern Danish Heart Registry from 1999 to 2016. Comorbidities and medication use were assessed from Danish nationwide registries.
Potassium levels were collected immediately before PPCI start. Multivariate logistic models were performed to determine the association between
potassium and VF. The main analysis included 8624
STEMI patients of whom 822 (9.5%) had VF before PPCI. Compared with 6693 (77.6%) patients with normokalemia (3.5-5.0 mmol/L), 1797 (20.8%) patients with
hypokalemia (<3.5 mmol/L) were often women with fewer comorbidities, whereas 134 (1.6%) patients with
hyperkalemia (>5.0 mmol/L) were older with more comorbidities. After adjustment, patients with
hypokalemia and
hyperkalemia had a higher risk of VF before PPCI (odds ratio 1.90, 95% CI 1.57-2.30, P<0.001) and (odds ratio 3.36, 95% CI 1.95-5.77, P<0.001) compared with normokalemia, respectively. Since the association may reflect a post-
resuscitation phenomenon, a sensitivity analysis was performed including 7929
STEMI patients without VF before PPCI of whom 127 (1.6%) had VF during PPCI. Compared with normokalemia, patients with
hypokalemia had a significant association with VF during PPCI (odds ratio 1.68, 95% CI 1.01-2.77, P=0.045) after adjustment. Conclusions
Hypokalemia and
hyperkalemia are associated with increased risk of VF before PPCI during
STEMI. For
hypokalemia, the association may be independent of the measurement of
potassium before or after VF.