Plasma IL-18 and IL-18BP are altered differently in reverse remodeling following aortic valve replacement

Patients with aortic stenosis (AS) develop left ventricular remodeling characterized by changes in extracellular matrix (ECM) and cardiomyocyte-hypertrophy. Aortic valve replacement (AVR) reverses this process (reverse remodeling). We examined plasma levels of interleukin-18 (IL-18) and its binding protein (IL-18BP) before and after AVR for AS since these mediators have been shown experimentally to exert effects on myocardial remodeling.

Plasma levels of IL-18 and IL-18BP were analyzed in 22 patients with AS undergoing AVR, preoperatively, two days, six and 12 months postoperatively. Echocardiography and functional testing were performed.

IL-18BP was significantly increased by 28% and 15% at two days and six months after AVR, compared to preoperative values. In contrast, IL-18 showed a later peak (increased by 24% at 12 months postoperatively) when IL-18BP was normalized. IL-18 correlated positively with deceleration time (R = 0.44) at this time-point which might indicate an association with diastolic function.

We report for the first time that plasma IL-18 and IL-18BP are differentially regulated after AVR for AS with an early increase in IL-18BP postoperatively followed by a later peak in IL-18 at 12 months. Given the known effects of these mediators on myocardial remodeling and function, they might play a role in the reverse and remodeling process associated with AVR.