Synchrotron Imaging Reveals Hexarelin's Heart-Protective Effects Post-Myocardial Infarction

Cardiovascular diseases, particularly myocardial infarction (MI) (heart attack) and subsequent heart failure, remain leading causes of mortality worldwide. After an MI, the heart undergoes detrimental remodeling, leading to scar tissue formation and impaired function. Growth hormone secretagogues (GHS) like Hexarelin have shown cardioprotective properties, but the precise microstructural mechanisms by which they improve cardiac function and remodeling are not fully understood. This study aimed to elucidate the detailed actions of Hexarelin on cardiac microvasculature and tissue architecture using advanced synchrotron radiation imaging techniques.

Treatment with Hexarelin significantly preserved cardiac function and attenuated adverse remodeling post-MI. Echocardiography revealed that Hexarelin-treated rats exhibited a 15% absolute increase in left ventricular ejection fraction (LVEF) (from 35% in MI controls to 50% in Hexarelin group, p<0.01) and a 33% relative improvement in fractional shortening compared to untreated MI controls. Synchrotron imaging confirmed a substantial reduction in fibrotic tissue, with a 40% relative decrease in collagen deposition in the infarct border zone (p<0.001). Furthermore, microvascular density, a key indicator of angiogenesis (new blood vessel formation), was increased by 2.5-fold in the Hexarelin-treated hearts (p<0.01). This enhanced vascularization likely contributed to improved tissue perfusion and survival. The most significant finding was that Hexarelin treatment led to a 43% relative improvement in left ventricular ejection fraction, demonstrating robust preservation of pumping capacity after a heart attack.