Microvascular Function in Patients Undergoing Transcatheter Aortic Valve Implant (TAVI) for Severe Symptomatic Aortic Stenosis: Association With Myocardial Fibrosis

Severe symptomatic aortic stenosis is commonly encountered in clinical practice, affecting close to 5% of individuals older than 65 years of age, and carries a dismal prognosis if left untreated.(1,2) Chronically increased left ventricular afterload triggers a compensatory myocardial response, ultimately leading to ventricular hypertrophy, aimed at reducing chronically increased wall tension an restore cardiac performance.(3) Hypertrophy ultimately results in maladaptive changes and ultimately leads to heart failure and eventually increased risk of cardiac mortality. Myocardial fibrosis and altered myocardial perfusion appear to play a role in progressive cardiac decompensation.

Inclusion criteria

• All patients referred to IRCCS Ospedale San Raffaele who are candidates to receive a TAVI implant for severe, symptomatic aortic stenosis under current appropriateness criteria and clinical practice guidelines will be considered eligible to take part in the study

Exclusion criteria

• Age <18 years
• Inability to express informed consent to take part in the present study.
• Pregnancy or lactation
• Pre-existing known disease determining a prognosis quo ad vitam shorter than the follow up of the present study
• Significant chronic kidney disease (estimated glomerular filtration rate <30 ml/min)
• Known significant epicardial coronary artery stenosis
• Known contraindication to adenosine administration:
• Known allergic reactions
• Second or third degree atrioventricular block before the procedure (in absence of a functional permanent pacemaker)
• Long QT syndrome
• Unstable angina
• Severe hypotension
• Acutely decompensated heart failure
• Chronic obstructive pulmonary disease with bronchospasm
• Concomitant use of dypiridamole