Defibrotide Prevents Fatal Heart Rhythm Loss After Coronary Occlusion in Cats

Niada and colleagues, writing in Thrombosis Research in 1986, tested whether a polydeoxyribonucleotide drug called defibrotide could protect against sudden cardiac death caused by blocked blood flow to the heart.

Defibrotide is described in the paper as a natural polydeoxyribonucleotide drawn from mammalian lung tissue, already known for helping dissolve clots and resisting blood clotting processes, though without acting as a conventional blood thinner. In this animal study, researchers tied off a coronary artery in cats to trigger acute heart muscle starvation of oxygen, a procedure that caused fatal abnormal heart rhythm (ventricular fibrillation) and death in 17 of 20 untreated cats. When cats instead received defibrotide, given as an initial injection followed by a continuous infusion, 19 of 20 survived to the end of the experiment. Treated animals also showed less damage by several measures: blood and heart-muscle enzyme levels, heart rhythm tracings, and blood flow measurements all looked closer to normal.

The authors note defibrotide appeared to help the vessel walls release a clot-dissolving, vessel-relaxing compound and preserved energy stores in heart tissue, but they state plainly that exactly how this translates into protection against fatal arrhythmia remains unclear. The study was done in anesthetized cats only, used one drug dose and timing, and cannot show whether these effects occur in humans or apply to skin or wound-related uses.