NIRS cerebral oxygenation monitoring during transcutaneous aortic valve implant (TAVI)

Abstract

Introduction: Most recent attention in interventional cardiology is directed towards treatment of valvular heart disease. In high risk pts, transcutaneous aortic valve implantation (TAVI) offers a therapeutic solution. Near Infrared Spectroscopy (NIRS) has been introduced as a useful non-invasive cerebral monitoring technique assessing cerebral oxygenation. During TAVI procedure, transient cardiac standstill by rapid ventricular pacing (RVP) is induced to minimize cardiac motion. In most cases, this hemodynamic deficit is well tolerated, due to the brief duration of RVP. But as far as today no data are available on cerebral oxygenation during these critical periods of RVP.

Methods: We report on 10 consecutive pts (>75yrs, major comorbidities) suffering from severe aortic stenosis. Bilateral ForeSight sensors were applied after induction of anesthesia. We studied the changes in cerebral oxygenation (SctO2 monitoring) occurred during these RVP periods.

Results: In all pts, procedure was technically successful. Mean SctO2 before RVP was 67% (59-71%) with immediate decrease during RVP to m54% (37-70%). In 7 pts, RVP resulted in SctO2 decreases below 55% (m44%; range 37-52%), lasting for m20 min (14sec-87 min). Systolic blood pressure before RVP was m135mmHg (95-165mmHg) and decreased to m74mmHg (112-42mmHg) during RVP. In 6 pts, RVP resulted in systolic blood pressure below 90mmHg, immediately countered by vasoactive drugs. In 2 pts, extensive hypotension persisted despite vasoactive support and CPR had to be initiated. In 1 pt, SctO2 values remained below 55% for 87 min and pt was declared brain dead 48 h later.

Conclusion: Transcutaneous cardiac interventions, with transient cardiac standstill, can induce longlasting inadequacy of cerebral perfusion, despite immediate restoration of normal hemodynamics. Future strategies should focus on optimalizing cerebral oxygenation before RVP.