Evaluation of the safety and efficacy of TY-51924 in patients with ST elevated acute myocardial infarction – Early phase II first in patient pilot study

Pharmacologic Prevention of Myocardial Ischemia-Reperfusion Injury in Patients With Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention

ABSTRACT

Establishing efficient perfusion into the myocardium is the main purpose in patients with acute coronary syndrome, but the process of reperfusion is not without risk and can damage the myocardium paradoxically. Unfortunately, there is no effective treatment for reperfusion injury, and efforts to find an efficient preventive approach are still ongoing. In the past 3 decades, there have been many successful animal studies on how to prevent reperfusion injury; nonetheless, translation to the clinical setting has almost always proven disappointing. In this article, we review clinical studies on the prevention of reperfusion injury in patients with acute coronary syndrome undergoing primary percutaneous coronary intervention in a pharmacologic-based approach. We categorize all the agents that are evaluated for the prevention of myocardial reperfusion injury based on their mechanisms of action into 5 groups: drugs that can reduce oxidative stress, drugs that can affect cellular metabolism, rheological agents that target microvascular obstruction, anti-inflammatory agents, and agents with mixed mechanisms of action. Then, review all the clinical studies of these agents in the setting of primary percutaneous coronary intervention. Finally, we will discuss the possible reasons for the failure in translation of studies into practice and propose potential solutions to overcome this problem.

Randomized controlled trial of TY-51924, a novel hydrophilic NHE inhibitor, in acute myocardial infarction

BACKGROUND

In patients with ST-elevation acute myocardial infarction (STEMI), reperfusion therapy limits infarct size, but can directly evoke myocardial reperfusion injury. Activation of the Na(+)/H(+) exchanger (NHE) plays an important role in reperfusion injury. TY-51924, a novel NHE inhibitor, significantly reduced infarct size in animal studies and was well tolerated in early-phase clinical trials. This study aim was to evaluate the efficacy and safety of TY-51924 in patients with STEMI.

METHODS

In this multicenter, randomized, double-blind, placebo-controlled Phase II trial, 105 patients with first anterior STEMI undergoing primary percutaneous coronary intervention (pPCI) were randomly assigned to receive an intravenous infusion of either TY-51924 or placebo. Primary endpoints were myocardial salvage index (MSI) as determined by single photon emission computed tomography (SPECT) 3-5 days after pPCI and safety up to 7 days.

RESULTS

Baseline characteristics were similar in the two groups. MSI 3-5 days after pPCI (0.200 vs. 0.290, p=0.56), 3 months after pPCI (0.470 vs. 0.500, p=0.76), and the incidences of side effects did not differ between the two groups as a whole. However, on post hoc analysis of 52 patients with a large area at risk (AAR) (≥38%) and no antegrade coronary flow, MSI by SPECT at 3 months after pPCI was significantly higher in TY-51924 group (0.450 vs. 0.320, p=0.03). TY-51924 did not adversely influence hemodynamics.

CONCLUSIONS

TY-51924 did not improve MSI or increase side effects as a whole. However, TY-51924 is potentially cardioprotective in the presence of a large AAR and no antegrade coronary flow.