BACKGROUND: The anatomic and physiological changes associated with severe aortic stenosis may influence the functional evaluation of coronary stenoses. In this study, we aimed to assess changes in functional resting and hyperemic indices before and immediately after transcatheter aortic valve implantation (TAVI) and their relationship with microvascular resistance. METHODS: In this pooled analysis of 3 prospective observational studies, fractional flow reserve (FFR), resting full-cycle ratio (RFR), and resting distal coronary pressure to aortic pressure ratio (Pd/Pa) were measured in patients with severe aortic stenosis before and after TAVI in the left anterior descending artery. Coronary microcirculation was also assessed using thermodilution-based methods, with microvascular resistance reserve (cutoff ≤3) used to identify coronary microvascular dysfunction. RESULTS: A total of 126 patients were included. Baseline Pd/Pa, RFR, and FFR measurements were 0.93±0.04, 0.90±0.07, and 0.89±0.07, respectively. Immediately post-TAVI, a small but significant decrease was observed for both RFR and FFR (RFR, 0.88±0.08; FFR, 0.88±0.08; P <0.05 for all). Coronary flow reserve and microvascular resistance reserve also remained unchanged. Applying the established cutoff values, 16 (12.7%) vessels had a positive FFR, while a higher proportion of vessels were positive for Pd/Pa and RFR (35.7% and 43.7%, respectively; P <0.001). The concordance between pre- and post-TAVI FFR was higher (92.8%) compared with Pd/Pa (75.4%) and RFR (73.8%) ( P <0.001 for both). The rate of disagreement between resting and hyperemic indices remained unchanged, regardless of the presence of coronary microvascular dysfunction. CONCLUSIONS: TAVI is associated with a small but significant reduction in FFR and RFR immediately post-procedure. Overall, the agreement between pre- and post-TAVI values of FFR was higher compared with resting indices.

Mitral stenosis (MS) poses significant challenges in diagnosis and management due to its varied etiologies, such as rheumatic mitral stenosis (RMS) and degenerative mitral stenosis (DMS). While rheumatic fever-induced RMS has declined in prevalence, DMS is rising with aging populations and comorbidities. Starting from a complex clinical case of DMS, the aim of this paper is to review the literature on mitral stenosis by analyzing the available tools and the differences in terms of diagnosis and treatment for rheumatic and degenerative stenosis. Emerging transcatheter techniques, such as transcatheter mitral valve replacement (TMVR) and lithotripsy-facilitated percutaneous mitral commissurotomy (PMC), represent promising alternatives for DMS patients deemed unfit for surgery. In particular, intravascular lithotripsy (IVL) has shown potential in facilitating percutaneous interventions by fracturing calcific deposits and enabling subsequent interventions. However, larger prospective studies are warranted to validate these findings and establish IVL’s role in DMS management. To further enhance this technique, research could focus on investigating the long-term outcomes and durability of mitral lithotripsy, as well as exploring its potential in combination with PMC or TMVR.

Underexpansion of a self-expanding transcatheter aortic valve (TAVI) is a critical issue that can negatively impact long-term outcomes, including paravalvular leak, valve thrombosis, and increased mortality. This paper provides a comprehensive review of the pathophysiology and consequences of such complications, including three primary mechanisms: (1) infolding, (2) incorrect site of crossing and (3) true underexpansion. It also discusses strategies to address these challenges, including pre-procedural planning and procedural techniques to ensure proper valve deployment and expansion. Mitigating these issues is essential to improving both immediate and long-term outcomes in TAVI patients.

Ischemia with no obstructive coronary artery disease (INOCA) is not an uncommon diagnosis in patients presenting with chest pain who undergo clinically indicated coronary angiography. However, the symptoms reported by patients with INOCA may be heterogeneous, leading to misdiagnosis and undertreatment. Herein we report 3 clinical cases of INOCA misdiagnosis and describe how the cases were reinvestigated following the appropriate diagnostic pathway. (Level of Difficulty: Advanced.)