Prognostic value of angiographic microvascular resistance for atrial fibrillation and clinical outcomes in patients undergoing transcatheter aortic valve replacement

Background Atrial fibrillation (AF) has complex interplay with aortic stenosis (AS), and has been identified as a predictor of adverse clinical outcomes for transcatheter aortic valve replacement (TAVR) patients[1,2]. Angiographic microvascular resistance (AMR), a marker of coronary microvascular dysfunction (CMD), may link AS-related cardiac remodeling and AF. Purpose To evaluate the association between AMR and the presence of pre-existing AF in TAVR patients and to determine the impact of these factors on clinical outcomes of patients after TAVR. Methods A total of 1118 patients with severe AS who underwent TAVR at a single center from November 2012 to May 2025 were screened for inclusion in this retrospective study, and 742 patients who met all criteria were included. AMR was calculated using a quantitative flow ratio (QFR)-based approach from coronary angiography[3]. AF was diagnosed through electrocardiogram according to current guidelines. The primary endpoint was major adverse cardiovascular events (MACE), a composite of all-cause mortality, heart failure readmission, and acute myocardial infarction. Results AF was present in 111 (15.0%) patients. Patients with AF had significantly higher AMR levels than those without (248 ± 74 vs 226 ± 68, P=0.004). Multivariable logistic regression demonstrated that AMR was a significant independent predictor of AF after adjustment for age, body mass index, hyperlipidemia, previous heart failure, log-transformed NT-proBNP, left atrial diameter and left ventricular ejection fraction (OR: 1.054; 95% CI: 1.022–1.086; P < 0.001). Restricted cubic spline analysis revealed a significant linear association between AMR and the risk of AF (P for overall < 0.001, P for non-linearity = 0.567). Subgroup analyses confirmed the consistency of the association between elevated AMR and the presence of AF across various clinical strata. During a follow-up of 1440 days, a total of 206 patients (27.8%) experienced MACE. Kaplan–Meier analysis demonstrated significant differences in MACE-free survival among the four groups stratified by AF status and AMR levels (log-rank P < 0.001). Patients with AF and elevated AMR had the lowest MACE-free survival, followed by those with AF and lower AMR levels. Multivariable Cox regression analysis confirmed that the coexistence of AF and high AMR remained a robust predictor of MACE (adjusted HR: 2.16; 95% CI: 1.33–3.50; P = 0.0018). Conclusions AMR is an independent predictor of pre-existing AF for TAVR patients. The coexistence of AF and CMD was associated with adverse prognosis in TAVR patients. As a marker of advanced cardiac remodeling, microcirculatory assessment should be incorporated into risk stratification to help refine individualized management.