Clinical significance and correlation of microRNA-21 expression in patients undergoing transcatheter aortic valve replacement

Transcatheter aortic valve replacement (TAVR) is an increasingly common procedure for treating severe aortic stenosis. Although cardiac biomarker elevation post-TAVR is common, its correlation with outcomes remains controversial. MicroRNAs (miRNAs) have emerged as potential biomarkers in cardiovascular diseases. This study aimed to assess the prognostic significance of various miRNAs on outcomes after TAVR to stratify high-risk patients for adverse outcomes. Consecutive patients undergoing transfemoral TAVR were prospectively enrolled. Blood samples were collected at baseline and 6 h postprocedure. MiRNA levels, including miR-21, miR-1, and miR-210, were quantified using polymerase chain reaction (PCR). The relative quantification (RQ) was analyzed by the ΔΔCt method. The primary outcome was major adverse cardiovascular or cerebrovascular events (MACCE). Receiver-operating characteristic curve analysis was performed to assess the correlation between miRNAs and MACCE. Seventy-six patients were included in the study, with a mean age of 80.8 yr. Nearly a quarter of patients experienced MACCE. RQ analysis of miR-21 showed moderate-prognostic accuracy for predicting freedom from MACCE (<i>R</i> = 0.61). An RQ of miR-21 cutoff value of 0.709 yielded a sensitivity of 71% and specificity of 56%. Patients experiencing a significant decrease in miR-21 levels (RQ < 0.709) had significantly higher MACCE rates and 30-day mortality compared with those with a nonsignificant change in miR-21 levels (40% vs. 16%, <i>P</i> = 0.025 and 12% vs. 0%, <i>P</i> = 0.033, respectively). A significant decrease in miR-21 levels at 6 h post-TAVR is associated with poor patient outcomes. MiR-21 may serve as a potential biomarker for risk stratification and personalized post-TAVR management.<b>NEW & NOTEWORTHY</b> A significant drop in circulating microRNA-21 levels 6 h after transcatheter aortic valve replacement (TAVR) was associated with a fourfold increased risk of major adverse cardiovascular or cerebrovascular events (MACCE). This prospective study identifies microRNA-21 as a promising early biomarker for risk stratification and prognosis after TAVR, offering potential for more personalized postprocedural care.