Prediction of the development of delirium after transcatheter aortic valve implantation using preoperative brain perfusion SPECT

Abstract

Objectives: Delirium is an important prognostic factor in postoperative patients undergoing cardiovascular surgery and intervention, including transcatheter aortic valve implantation (TAVI). However, delirium after transcatheter aortic valve implantation (DAT) is difficult to predict and its pathophysiology is still unclear. We aimed to investigate whether preoperative cerebral blood flow (CBF) is associated with DAT and, if so, whether CBF measurement is useful for predicting DAT.

Methods: We evaluated CBF in 50 consecutive patients before TAVI (84.7±4.5 yrs., 36 females) using 99mTc ethyl cysteinate dimer single-photon emission computed tomography. Preoperative CBF of the DAT group (N = 12) was compared with that of the non-DAT group (N = 38) using whole brain voxel-wise analysis with SPM12 and region of interest-based analysis with the easy-Z score imaging system. Multivariable logistic regression analysis with the presence of DAT was used to create its prediction model.

Results: The whole brain analysis showed that preoperative CBF in the insula was lower in the DAT than in the non-DAT group (P<0.05, family-wise error correction). Decrease extent ratio in the insula of the DAT group (17.6±11.5%) was also greater relative to that of the non-DAT group (7.0±11.3%) in the region of interest-based analysis (P = 0.007). A model that included preoperative CBF in the insula and conventional indicators (frailty index, short physical performance battery and mini-mental state examination) showed the best predictive power for DAT (AUC 0.882).

Conclusions: These results suggest that preoperative CBF in the insula is associated with DAT and may be useful for its prediction.

Fig 1. Flow chart of patient enrollment in the present study.

Abbreviations: AS, aortic stenosis; DAT, delirium after TAVI; NYHA, New York Heart Association; SPECT, single-photon emission computed tomography; TAVI, transcatheter aortic valve implantation.

Fig 2. Lower insular perfusion in the DAT group compared with the non-DAT group.

Results of the whole brain voxel-wise analysis shown in the sagittal (A), axial (B), and the coronal slices (C) (red areas, P<0.05 with family-wise error corrections; yellow areas, P<0.001 without corrections for multiple comparisons). In the region of interest-based analysis, decrease extent ratios were higher in the DAT group (N = 12) than in the non-DAT group (N = 38) (D). Abbreviations: DAT, delirium after transcatheter aortic valve implantation.

Fig 3. Results of multivariable logistic regression analyses with an addition of CBF in the insula to classical indicators.

Abbreviations: AUC, area under curve; CBF, cerebral blood flow; Ins, insular; MMSE, mini mental state examination; SPPB, short physical performance battery.

Fig 4. Multifactorial nature of DAT and possible involvement of preoperative CBF in the insula.

Significant (P>0.10) factors that contribute the onset of DAT in the present study are emphasized as red-front. Abbreviations: CBF, cerebral blood flow; DAT, delirium after transcatheter aortic valve implantation.