In acute coronary syndrome ( ACS ), potassium imbalance at admission has been associated with in-hospital arrhythmias, cardiac arrest, and mortality.
However, several important presentation characteristics and subtype of ACS have not been considered.
Consecutive patients ( n = 32,955 ) admitted with suspected ACS between 2006 and 2011, registered in the Swedish Web-System for Enhancement and Development of Evidence-Based care in Heart Disease Evaluated According to Recommended Therapies ( SWEDEHEART ) and the Stockholm CREAtinine Measurements ( SCREAM ) project were included.
Associations between admission plasma potassium categories ( reference 3.5 less than 4.0 mmol/L ) and in-hospital outcomes including mortality, cardiac arrest, new-onset atrial fibrillation, and second- or third-degree atrioventricular block were assessed with logistic regression models.
U-shaped associations between admission potassium, mortality and cardiac arrest were observed. However, in fully adjusted models, only hyperkalemia ( 5.0 - less than 5.5 [ odds ratio, OR 1.83; 95% CI, 1.34-2.49 ] and greater than or equal to 5.5 mmol/L [ OR 2.27; 95% CI, 1.57-3.27 ] ) was associated with mortality, while only hypokalemia ( 3.0 - less than 3.5 [ OR 1.63; 95% CI, 1.21-2.19 ] and less than 3.0 mmol/L [ OR 2.72; 95% CI, 1.56-4.74 ] ) was associated with cardiac arrest.
Potassium less than 3.0 mmol/L ( OR 1.93; 95% CI, 1.00-3.76 ) was associated with new-onset atrial fibrillation.
After multivariable adjustment, no association was observed between potassium and second- or third-degree atrioventricular block.
Results were not modified by main diagnosis ( ACS subtype or non-ACS diagnosis ) or eGFR ( estimated glomerular filtration rate ).
In conclusion, hyperkalemia at admission is associated with in-hospital mortality and hypokalemia with cardiac arrest and new-onset atrial fibrillation in patients admitted with suspected acute coronary syndrome. ( Xagena )
Faxén J et al, Int J Cardiol 2018; Epub ahead of print