Impact of Prosthesis-Patient Mismatch After Transcatheter Aortic Valve Replacement on Changes in Cardiac Sympathetic Nervous Function.

Abstract

The impact of prosthesis-patient mismatch (PPM) after transcatheter aortic valve replacement (TAVR) on changes in cardiac sympathetic nervous (CSN) function remains unclear. Using 123I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy, we investigated the impact of PPM after TAVR on CSN activity.We enrolled 44 of 117 patients with severe aortic stenosis who underwent TAVR for analysis in the present study. We conducted 123I-MIBG scintigraphy at baseline and at about 9 months after TAVR. Differences between baseline and post-TAVR 123I-MIBG parameters were compared between cases with and without PPM.There were 17 and 27 patients with and without PPM, respectively. Those without PPM exhibited significantly decreased left ventricular mass index (122 ± 36 g/m2 versus 108 ± 30 g/m2, P < 0.001) following TAVR, whereas those with PPM did not (117 ± 21 g/m2 versus 110 ± 17 g/m2, P = 0.09). Significant improvements in delayed heart-to-mediastinum (H/M) ratio (2.8 ± 0.4 versus 3.0 ± 0.4, P = 0.004) and washout rate (WR) (33% ± 10% versus 24% ± 12%, P < 0.001) were observed after TAVR in patients without PPM but not in those with PPM. Multivariable linear regression analysis revealed PPM to be a negative predictor of improvements in delayed H/M ratio and WR.Delayed H/M ratio and WR improve significantly after TAVR in the absence of PPM, whereas these improvements are not observed in patients with PPM. Hence, the presence of PPM is a negative predictor of improvements in delayed H/M ratio and WR in patients undergoing TAVR.