Lots of interesting abstracts and cases were submitted for TCTAP 2025. Below are the accepted ones after a thorough review by our official reviewers. Don’t miss the opportunity to expand your knowledge and interact with authors as well as virtual participants by sharing your opinion in the comment section!
TCTAP A-051
Exploring the Relationship Between Invasive Indices of Microvascular Function in Patients With Severe Aortic Stenosis
By Harsh Thakkar, Michael Michail, Andrea Comella, James Cameron, Brian Ko, Adam Brown
Presenter
Adam Brown
Authors
Harsh Thakkar1, Michael Michail1, Andrea Comella1, James Cameron1, Brian Ko1, Adam Brown1
Affiliation
Victorian Heart Hospital, Australia1
View Study Report
TCTAP A-051
FFR
Exploring the Relationship Between Invasive Indices of Microvascular Function in Patients With Severe Aortic Stenosis
Harsh Thakkar1, Michael Michail1, Andrea Comella1, James Cameron1, Brian Ko1, Adam Brown1
Victorian Heart Hospital, Australia1
Background
Coronary microvascular dysfunction is common in patients with severe aortic stenosis (AS). Microcirculatory resistance reserve (MRR) is a novel index of microvascular function independent of LV mass, that was validated in patients without AS. This study explores the relationship between MRR and the index of microcirculatory resistance (IMR) in patients with severe AS. These invasive measures are then compared with LV systolic and diastolic parameters.
Methods
Patients with severe AS undergoing angiography prior to valve intervention were prospectively recruited. Only patients with <50% visual diameter stenosis in the left anterior descending artery (LAD) were included. Patients with prior history of myocardial infarction or percutaneous or surgical revascularisation, atrial fibrillation, chronic kidney disease and LV systolic function ≤35% were excluded. Coronary microvascular function was assessed in the LAD using Pressure Wire X and bolus thermodilution. MRR was calculated as (CFR/FFR) x Pressure aortic (Pa) rest/Pa hyperaemia. Diastolic function was defined according to ASE 2016 guidelines.
Results
26 patients were included, with average age 77.9±10.5yrs and 50% male. Mean AVA was 0.82±0.25mm2, MG 45±9.5mmHG and DI 0.23±0.04. The average FFR, RFR, CFR, IMR and MRR were 0.88±0.05, 0.89±0.06, 2.14±0.7, 18.1±9.8 and 2.9±1.25. Abnormal CFR was present in 77%, abnormal IMR in 27% and abnormal MRR (≤3) in 69%. There was a very strong relationship between CFR and MRR (r=0.92, p<0.001), but no significant relationship between IMR and MRR or CFR (both p>0.05). MRR was related to ejection fraction (r=0.41, p=0.03) and measures of diastolic function, including E/e’ (r=-0.39, p=0.04) and LA volume indexed (r=-0.4, p=0.04). IMR did not demonstrate a relationship with LV function (p>0.05 for all).
Conclusion
In patients with severe AS, there is no discernible relationship between MRR and IMR. However, MRR correlates with measures of LV systolic and diastolic function. Our data suggests that the relationship between MRR and IMR in patients with severe AS warrants further investigation to ensure operators understand the clinical relevance of invasive microcirculatory assessment.