Evaluation of Cerebral Thromboembolism After Transcatheter Aortic Valve Replacement (EARTH TAVR): A Serial Magnetic Resonance Imaging Evaluation as Substudy of the GALILEO Trial

Temporary decrease in microvascular tissue saturation after transcatheter aortic valve implantation

BACKGROUND

Data on the effect of transcatheter aortic valve implantation (TAVI) on peripheral microcirculation are limited.

OBJECTIVE

The aim of this study is to evaluate peripheral microvascular tissue saturation (StO2) before and after TAVI in relation to central and peripheral hemodynamics, cardiac and renal function.

METHODS

In this single-center prospective study, patients with severe aortic stenosis (sAS) scheduled for TAVI or cardiac catheterization (control) were assessed before and up to five days after the procedure. Cardiac function including cardiac output (CO) was assessed by echocardiography. Brachial (bBP) and central blood pressure (cBP), ankle brachial index (ABI), and parameters of arterial stiffness, including augmentation pressure (AP) and augmentation index adjusted for heart rate (AIx@HR75) were measured to assess hemodynamic changes. StO2 was measured in all extremities using a near-infrared spectroscopy (NIRS) camera. Renal function was measured by creatinine levels.

RESULTS

26 patients underwent TAVI and 11 patients served as control. Cardiac output was significantly increased, whereas hemodynamic parameters and peripheral StO2 were significantly decreased after TAVI. At follow-up, StO2 returned to baseline values. Changes in StO2 were negatively related to creatinine levels.

CONCLUSION

Transcatheter aortic valve implantation causes a temporary decrease in microvascular tissue saturation that is associated with renal function.

Antithrombotic therapy after transcatheter aortic valve implantation

INTRODUCTION

Transcatheter aortic valve implantation (TAVI) is a treatment option for patients with symptomatic severe aortic stenosis across the entire spectrum of surgical risk. TAVI conveys some risk for thrombotic complications, requiring antithrombotic drugs for their prevention. Bleeding events represent the major drawback of antithrombotic therapy, which should be carefully tailored over the individual patient's risk profile.

AREAS COVERED

This review aimed at exploring the rationale for the adoption of a tailored antithrombotic therapy after successful TAVI, with a description and analysis of common complications and their impact on therapy selection. In addition, we aimed at reviewing and discussing current knowledge in this area, with a main focus on the high-quality evidence supporting latest guideline recommendations. Finally, ongoing studies and future directions on antithrombotic therapy after TAVI were outlined.

EXPERT OPINION

Initial experience with antithrombotic therapy after TAVI was derived from percutaneous coronary intervention practice. Accruing evidence in the field led to the current monotherapy paradigm, which prioritizes oral anticoagulant and single antiplatelet therapy in patients with or without an established indication for long-term anticoagulation, respectively. Future studies will investigate the role of alternative antithrombotic strategies to improve clinical outcomes of TAVI patients by minimizing both thrombotic and bleeding complications.