Relative band power in assessing temporary neurological dysfunction post- type A aortic dissection surgery: a prospective study

Abstract

Temporary neurological dysfunction (TND), a common complication following surgical repair of Type A Aortic Dissection (TAAD), is closely associated with increased mortality and long-term cognitive impairment. Currently, effective treatment options for TND remain elusive. Therefore, we sought to investigate the potential of postoperative relative band power (RBP) in predicting the occurrence of postoperative TND, with the aim of identifying high-risk patients prior to the onset of TND. We conducted a prospective observational study between February and December 2022, involving 165 patients who underwent surgical repair for TAAD at our institution. Bedside Quantitative electroencephalography (QEEG) was utilized to monitor the post-operative brain electrical activity of each participant, recording changes in RBP (RBP Delta, RBP Theta, RBP Beta and RBP Alpha), and analyzing their correlation with TND. Univariate and multivariate analyses were employed to identify independent risk factors for TND. Subsequently, line graphs were generated to estimate the incidence of TND. The primary outcome of interest was the development of TND, while secondary outcomes included intensive care unit (ICU) admission and length of hospital stay. A total of 165 patients were included in the study, among whom 68 (41.2%) experienced TND. To further investigate the independent risk factors for postoperative TND, we conducted both univariate and multivariate logistic regression analyses on all variables. In the univariate regression analysis, we identified age (Odds Ratio [OR], 1.025; 95% CI, 1.002-1.049), age ≥ 60 years (OR, 2.588; 95% CI, 1.250-5.475), hemopericardium (OR, 2.767; 95% CI, 1.150-7.009), cardiopulmonary bypass (CPB) (OR, 1.007; 95% CI, 1.001-1.014), RBP Delta (OR, 1.047; 95% CI, 1.020-1.077), RBP Alpha (OR, 0.853; 95% CI, 0.794-0.907), and Beta (OR, 0.755; 95% CI, 0.649-0.855) as independent risk factors for postoperative TND. Further multivariate regression analyses, we discovered that CPB time ≥ 180 min (OR, 1.021; 95% CI, 1.011-1.032), RBP Delta (OR, 1.168; 95% CI, 1.105-1.245), and RBP Theta (OR, 1.227; 95% CI, 1.135-1.342) emerged as independent risk factors. TND patients had significantly longer ICU stays (p < 0.001), and hospital stays (p = 0.002). We obtained the simplest predictive model for TND, consisting of three variables (CPB time ≥ 180 min, RBP Delta, RBP Theta, upon which we constructed column charts. The areas under the receiver operating characteristic (AUROC) were 0.821 (0.755, 0.887). Our study demonstrates that postoperative RBP monitoring can detect changes in brain function in patients with TAAD during the perioperative period, providing clinicians with an effective predictive method that can help improve postoperative TND in TAAD patients. These findings have important implications for improving clinical care in this population.Trial registration ChiCTR2200055980. Registered 30th Jan. 2022. This trial was registered before the first participant was enrolled.

Keywords: Aortic Dissection; Cardiopulmonary bypass; Delayed recovery; Delirium; Relative band power; Temporary neurological dysfunction.

Figure 1

Consolidated standards of reporting trials diagram demonstrating selection of patients undergoing TAAD surgery repair. RBP relative band power.

Figure 2

QEEG collects the raw EEG signal from the scalp, analyzes it by fast Fourier transform (FFT), and displays the spectrum and power spectrum of the EEG sequence signal in the form of a trend spectrum. FD frequency domain, TD time domain.

Figure 3

AUROC curve analysis of the Model for TND Post-RBP Delta and Theta; AUROC = 0.800 which is equal to a c-statistic.

Figure 4

Internal calibration curves for Model. The Model perfectly accurate model would produce a graph where the observed and predicted probabilities match exactly, and follow the 45-degree line (dotted line) downwards. The apparent calibration curve (red line) represents the calibration of the model in the development dataset, while the bias-corrected calibration curve (green line) is the calibration result after correcting for optimism using 1000 bootstrap resamples. The brier is 0.170 and the model has good calibration.

Figure 5

Diagnostic nomogram of Model for predicting TND after surgery for TAAD.

Figure 6

(A) The DCA shows the clinical net benefit of Model for TND. (B) The clinical impact curve of predictive Model for TND.