Sodium thiosulfate (STS) was found to be well-tolerated and safe in combination with vasodilatory and blood pressure-lowering drugs in patients with acute coronary syndrome (ACS) undergoing coronary angiography, according to a pilot study published in the Journal of Interventional Cardiology.

Researchers sought to evaluate the safety and tolerability of the hydrogen sulfide (H2S) donor STS in patients with ACS. A total of 18 patients (mean age, 62.2±10.0 years; 66.7% men) who were undergoing coronary angiography and received STS intravenously immediately after arrival at the catheterization laboratory according to a “3 + 3 dose-escalation design” with fixed dosing endpoint (0, 2.5, 5, 10, 12.5, and 15 g) were enrolled.

The first STS dose was combined with verapamil and nitroglycerin; the second dose was administered 6 hours later. The study’s primary endpoint was dose-limiting toxicity, which was defined as significant hemodynamic instability or death up to 24 hours after intervention or before discharge from the coronary care unit.


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A total of 16 participants received 2 dosages of STS and 2 patients received 1 dosage. No patient reached the primary endpoint or had a serious adverse event. Significant but clinically well-tolerated reduction in systolic blood pressure was observed in all participants 1 hour after the initial STS administration in combination with verapamil/nitroglycerin (average reduction, 16.8 mmHg; 95% CI, 8.1-25.5; P =.0008). No significant decline in systolic blood pressure occurred after the second dose, and mild nausea was observed in 1 patient.

 “This is the first study in which the H2S donor STS was administered in patients presenting with an ACS,” noted the study authors. “We demonstrated that STS is well-tolerated and appears to be safe in combination with concomitant administration of vasodilatory and blood pressure-lowering drugs in [patients with] ACS undergoing coronary angiography via the transradial approach.”

Study limitations include the small sample size, relatively short follow-up, and inclusion of clinically stable patients with ACS with mostly small infarction.

“Our findings and encouraging preclinical data provide the basis for further clinical assessment on safety and efficacy of STS administration in patients with acute coronary syndromes,” concluded the investigators.

Reference

de Koning M-S LY, Assa S, Maagdenberg CG, et al. Safety and tolerability of sodium thiosulfate in patients with an acute coronary syndrome undergoing coronary angiography: A dose-escalation safety pilot study (SAFE-ACS) [published online September 24, 2020]. J Interv Cardiol. doi: 10.1155/2020/6014915