Early renal sympathetic denervation after myocardial infarction in pigs reduced ventricular tachycardia inducibility (0% vs. 60%) and was associated with smaller, more vascularized scars.
RCT (n=10)
Randomized
Does early renal sympathetic denervation improve cardiac function and reduce arrhythmic susceptibility in a porcine model of myocardial infarction?
Early renal denervation after myocardial infarction in a porcine model reduces scar size and ventricular tachycardia inducibility, suggesting a protective effect on post-infarction remodeling.
Absolute Event Rate: 0% vs 60%
Abstract Background Activation of the sympathetic nervous system after myocardial infarction (MI) is associated with adverse cardiac remodelling, ventricular dysfunction, heart failure, and arrhythmias. Catheter-based renal sympathetic denervation (RSD) reduces systemic sympathetic activity through renal nerve ablation and currently is only indicated for patients with pharmacologically uncontrolled arterial hypertension. Purpose This study aimed to evaluate the effect of early RSD on cardiac function, arrhythmic substrate, and myocardial scar characteristics in a porcine MI model. Methods Ten pigs with MI were randomized to a Control group or an RSD-treated group (n=5 per group). RSD was performed immediately after MI induction by radiofrequency ablation. Cardiac function was assessed by magnetic resonance imaging at days 2 and 29 post-MI. On day 30, an electrophysiological study with programmed electrical stimulation and high-density mapping was performed to evaluate electrophysiological properties and ventricular tachycardia (VT) inducibility. Myocardial samples from infarcted and remote regions were collected for histological and immunohistochemical analysis of fibrosis and vascularization, as well as RNA-seq evaluation. Results At day 2 post-MI, the RSD group showed improved left ventricular ejection fraction (LVEF) without differences in scar size compared to controls. By day 29, LVEF was similar between groups, but total and dense scar mass was significantly smaller in RSD-treated animals. At 30 days, the RSD group tended to have fewer deceleration zones and exhibited markedly reduced VT inducibility (0% vs. 60% in controls). Analyses of myocardial infarcted tissue showed no differences in type I or III collagen content, whereas vascular density within the scar was higher in the RSD group. RNA-seq of infarcted tissue identified 143 differentially expressed genes between groups, revealing broad down-regulation of inflammatory pathways, including those related to lymphocyte activation and migration in the RSD group. Conclusions Early RSD after MI down-regulates inflammatory and lymphocyte-related pathways, which is associated with a smaller and more vascularized scar, and reduced arrhythmic susceptibility, suggesting a protective effect on post-infarction remodelling.
Falguera et al. (Fri,) conducted a rct in Myocardial infarction (n=10). Renal sympathetic denervation (RSD) vs. Control was evaluated on Ventricular tachycardia (VT) inducibility. Early renal sympathetic denervation after myocardial infarction in pigs reduced ventricular tachycardia inducibility (0% vs. 60%) and was associated with smaller, more vascularized scars.