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Updated: May 11, 2026
12:17
Full-root Aortic Valve Replacement by Stentless Aortic Xenografts in Patients with Small Aortic Roots
Published on: May 21, 2017
Functional changes in coronary microcirculation after valve replacement in patients with aortic stenosis
Kim Rajappan1, Ornella E Rimoldi, Paolo G Camici
1Academic Cardiology Unit, St Mary's Hospital, London, UK.
Circulation
|June 11, 2003
Summary
Aortic stenosis (AS) patients show improved coronary microcirculation after aortic valve replacement (AVR). Reduced compression and better diastolic perfusion time (DPT), not just left ventricular mass (LVM) regression, drive these beneficial changes.
Area of Science:
- Cardiovascular Medicine
- Cardiac Surgery
- Medical Imaging
Background:
- Coronary microcirculatory dysfunction in aortic stenosis (AS) is linked to extravascular compression and reduced diastolic perfusion time (DPT).
- The impact of aortic valve replacement (AVR) on these microcirculatory alterations is not fully understood.
- This study investigates changes in transmural perfusion and coronary vasodilator reserve (CVR) post-AVR.
Purpose of the Study:
- To quantify changes in transmural perfusion and CVR after AVR in AS patients.
- To assess the roles of left ventricular mass (LVM) regression, aortic valve area (AVA) changes, and DPT in post-AVR microcirculatory function.
- To determine the primary mechanisms driving improved coronary microcirculation post-AVR.
Main Methods:
- Twenty-two AS patients underwent assessment before and 1 year after AVR.
- Echocardiography, cardiovascular magnetic resonance, and positron emission tomography were used.
- Measurements included AVA, LVM, resting and hyperemic myocardial blood flow (MBF), and CVR.
Main Results:
- Significant LVM regression occurred in all patients post-AVR (129±30 to 94±24 g/m²).
- Resting MBF decreased, while CVR increased post-AVR, with notable individual variability.
- Increased hyperemic MBF and CVR correlated with AVA increase; DPT changes were linked to CVR improvements.
Conclusions:
- Post-AVR improvements in coronary microcirculation are not solely dependent on LVM regression.
- Reduced extravascular compression and increased DPT are key mechanisms enhancing myocardial blood flow and CVR after AVR.
- These findings highlight the importance of addressing microcirculatory factors in AS management.
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