Dynamics of cerebral oxygenation during rapid ventricular pacing and its impact on outcome in transfemoral transcatheter aortic valve implantation

Background Cerebral O-2 saturation (ScO2) reflects cerebral perfusion and can be measured noninvasively by near-infrared spectroscopy (NIRS). Objectives In this pilot study, we describe the dynamics of ScO2 during TAVI in nonventilated patients and its impact on procedural outcome. Methods and Results We measured ScO2 of both frontal lobes continuously by NIRS in 50 consecutive analgo-sedated patients undergoing transfemoral TAVI (female 58%, mean age 80.8 years). Compared to baseline ScO2 dropped significantly during RVP (59.3% vs. 53.9%, p < .01). Five minutes after RVP ScO2 values normalized (post RVP 62.6% vs. 53.9% during RVP, p < .01; pre 61.6% vs. post RVP 62.6%, p = .53). Patients with an intraprocedural pathological ScO2 decline of >20% (n = 13) had higher EuroSCORE II (3.42% vs. 5.7%, p = .020) and experienced more often delirium (24% vs. 62%, p = .015) and stroke (0% vs. 23%, p < .01) after TAVI. Multivariable logistic regression revealed higher age and large ScO2 drops as independent risk factors for delirium. Conclusions During RVP ScO2 significantly declined compared to baseline. A ScO2 decline of >20% is associated with a higher incidence of delirium and stroke and a valid cut-off value to screen for these complications. NIRS measurement during TAVI procedure may be an easy to implement diagnostic tool to detect patients at high risks for cerebrovascular complications and delirium.

Automated summary

In nonventilated patients undergoing TAVI, a significant drop in ScO2 during rapid ventricular pacing (RVP) was observed, with a decline of >20% being associated with an increased risk of delirium and stroke. Monitoring ScO2 levels during the procedure could be a valuable diagnostic tool to identify patients at high risk for cerebrovascular complications and delirium.