Death Risk Influenced by Post PCI-Hydration Choice

Using a sodium bicarbonate (NaHCO₃) solution instead of saline for hydration during and for four hours after coronary angiography might reduce the risk of death, according to a new study.

Researchers at the University of Vermont (Burlington, USA) compared NaHCO3 and saline for the prevention of a composite of death, renal replacement therapy, or progressive kidney failure over six months in 391 patients who had an estimated glomerular filtration rate of 44 mL/min/1.73 m² and who were undergoing any type of percutaneous coronary intervention (PCI). Both treatments were given in a bolus of 5 mL/kg over 1 hour before the procedure, followed by 1.5 mL/kg/hour during and for 4 hours after the angiogram; 80% underwent coronary angiography and the rest underwent peripheral angiography.

The results of the study, which was halted prematurely because of futility on the primary endpoint, showed that the rate of all-cause death through six months was significantly lower when NaHCO₃ was used during coronary angiography (3.2% versus 10.8% for saline), with no such difference for peripheral angiography. According to the researchers, the potential mechanism remains unclear, and the results are still only hypothesis generating. The study was presented at the Transcatheter Cardiovascular Therapeutics (TCT) annual meeting, held during October 2013 in San Francisco (CA, USA).

“Many people, including myself, have argued that the mortality difference in trials to prevent acute kidney injury results from protecting the kidney. And here there's a clear dissociation between the effects on the kidney and the mortality,” said lead author and study presenter Richard Solomon, MD. “There was no difference between the two hydration strategies in the occurrence of contrast-induced nephropathy, suggesting a nonrenal mechanism for cardioprotection.”

Animal studies have demonstrated a beneficial effect of pre- and post-hydration with sodium bicarbonate with regard to contrast-induced nephropathy. The result is thought to be due to a decrease in free radical formation rising from an increase in urinary pH.

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