Postoperative delirium in 47 379 individuals undergoing transcatheter aortic valve replacement: a systematic review and meta-analysis

OBJECTIVE: The study aims to discuss the assessment methods used for the incidence of in-hospital postoperative delirium (IHPOD) in transcatheter aortic valve replacement (TAVR) patients and explore possible strategies for preventing and reducing postoperative complications in the geriatric population. METHODOLOGY: An electronic search of PubMed, Embase, BioMedCentral, Google Scholar, and the Cochrane Central Register of Controlled Trials was conducted up to August 2021, to identify studies on the IHPOD following TAVR in patients above 70 years. The primary objective of the study was to determine the incidence of delirium following TAVR and procedures like transfemoral (TF) and non-TF approaches. The secondary objectives were to determine the incidence of stroke and incidence according to the confusion assessment method (CAM) diagnostic tool. The authors only included studies published in English and excluded patients with comorbidities and studies with inaccessible full-text. RESULTS: Among the selected 42 studies with 47 379 patients, the incidence of IHPOD following TAVR was 10.5% (95% CI: 9.2–11.9%, I(2)=95.82%, P<0.001). Incidence based on CAM was 15.6% (95% CI: 10.5–20.7%, I(2)=95.36%, P<0.001). The incidence of IHPOD after TF-TAVR was 9.3% (95% CI: 7.6–11.0%, I(2)=94.52%, P<0.001), and after non-TF TAVI was 25.3% (95% CI: 15.4–35.1%, I(2)=92.45%, P<0.001). The incidence of stroke was 3.7% (95% CI: 2.9–4.5%, I(2)=89.76%, P<0.001). Meta-regression analyses between mean age (P=0.146), logistic EuroSCORE (P=0.099), or percentage of participants treated using the TF approach (P=0.276) were nonsignificant while stroke (P=0.010) was significant. When considering these variables, the residual heterogeneity remained high indicating that other variables influence the heterogeneity. CONCLUSION: IHPOD following TAVR was observed in 10.5% of individuals and in 15.6% using CAM. Its incidence was found to be three times higher after non-TF TAVR (25.3%) compared to TF TAVR (9.3%). Stroke showed an incidence of 3.7% after TAVR and was found to be significantly associated with the risk of developing delirium following TAVR. Further studies are needed to evaluate possible causes and risk factors responsible for delirium and to assess the role of anesthesia and cerebral embolic protection in preventing delirium after TAVR.