NIRS cerebral oxygenation monitoring during transcutaneous aortic valve implantation

Abstract

Introduction: Most recent attention in interventional cardiology is now directed towards the treatment of valvular heart disease. In high risk pts, transcutaneous aortic valve implantation (TAVI) could offer a therapeutic solution. In the past years, Near Infrared Spectroscopy (NIRS) has been introduced as a useful non‐invasive cerebral monitoring technique assessing cerebral oxygenation. As far as today, no reports have been published on the use of any NIRS technology during TAVI procedures. During valve prosthesis implantation, a transient partial cardiac standstill by rapid ventricular pacing (RVP) is induced to minimize cardiac motion and pulsatile transaortic flow. 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.Patients and methods: We report on 10 consecutive pts (all > 75yrs, with major comorbidities) suffering from severe aortic stenosis. Bilateral ForeSight sensors were applied after induction of anesthesia. In posthoc analysis, we were especially interested if any change in cerebral oxygenation (SctO2 monitoring) occurred during these RVP periods.Results: In all pts, procedure was technically successfully performed. Mean SctO2 before RVP was 67% (59‐71%) and immediately decreased during RVP to m54% (37‐70%); this implies a mean decrease in SctO2 of 13% (1‐25%). In 7 pts, RVP resulted in SctO2 decreases below 55% (m44%; range 37‐52%). These decreases below 55% lasted for m20min (14sec‐87min). Systolic blood pressure before RVP was m135mmHg (95‐165mmHg) and decreased to m74mmHg (112‐42mmHg) during RVP. In 6 pts, RVP resulted in a decrease in systolic blood pressure below 90mmHg, that was immediately countered by vasoactive drugs (adrenaline). In 2 pts, extensive hypotension persisted despite vasoactive support and CPR had to be initiated. In 1 pt, SctO2 values remained below 55% for 87min and pt was declared brain dead 48h later.Conclusion: Transcutaneous cardiac interventions, especially those with transient partial cardiac standstill, can induce longlasting intraprocedural inadequacy of cerebral perfusion, despite immediate restoration of normal blood pressure. Future strategies should therefore be focused on optimalizing cerebral oxygenation before RVP.