The German Registry of Acute Aortic Dissection Type A (GERAADA) score uses very basic and easily retrievable parameters and was specifically designed for predicting the 30-day mortality rate in patients undergoing surgery for acute aortic dissection.Czerny et al. stressed that the GERAADA score should not be viewed as an absolute decision-making tool for accepting or rejecting treatment. Instead, it should be considered a valuable instrument for predicting postoperative outcomes using easily accessible and fundamental parameters5. Given the elevated mortality rate associated with type A aortic dissection, this predictive scoring system can be a valuable asset for surgeons.
The overall mortality rate in our study stands at 19.06%, while the GERAADA score predicted a mortality of 18.18%.No significant difference was found between the mortality group and the predicted group with an Area Under Curve of 0.599 (95% CI 0.558, 0.622) (Fig. 1).In their study, M. Ma et al. found that the GERAADA score and EuroSCORE II predicted 30-day mortality rates of 14.7% and 3.1%, respectively, while the observed rate was 12.5%7. On a similar note, K. Sugiyama et al. calculated an overall 30-day mortality for their study cohort using the GERAADA score as 14.3%(8.1–77.6%),whereas the actual mortality rate was 6%8.GERAADA has the particularity to be focused on aortic dissection and take in consideration some aspect of complications of ATAAD like malperfusion.
Malperfusion is recognized to occur in a significant portion of ATAAD cases, affecting approximately 20–30% of patients9. Consequently, the mortality rate for individuals experiencing this complication varies significantly, falling within the range of 17–44%10. It is crucial to emphasize that aortic dissection complicated by malperfusion is intimately associated with heightened mortality rates. This risk is amplified as the extent of organ involvement increases, making the management of multiple organ malperfusion an especially formidable challenge. Our study further supports this connection by revealing a noteworthy correlation between multiple organ malperfusion and in-hospital mortality. This finding is consistent with the research conducted by Kawahito and colleagues11. Numerous studies have examined mortality risk factors, and many of them have identified independent risk factors, as reflected in our study. Recent research conducted by Khan et al a range of independent risk factors associated with prolonged ICU stays have been identified. These factors encompass age, preoperative D-dimer levels, CPB time, the use of deep hypothermic circulatory arrest, the occurrence of postoperative stroke, postoperative acute respiratory failure, and postoperative acute renal failure91213. Our study corroborates these recent research findings, highlighting that the duration of ICU stay, lung infections, and respiratory failure identified as risk factors for in-hospital mortality1415. This association can primarily be attributed to postoperative interventions within the ICU, such as ECMO, IABP, CPR, tracheotomy, and the prolonged use of mechanical ventilation, all of which have been identified in our study as contributing factors to hospital mortality.
In our actual mortality group, a notable increase in mortality is observed, particularly reaching 35.71% in cases categorized as other malperfusion, where multiple organ malperfusion is present. This contrasts with the lower prediction of 17.38% (± 1.80). Luehr et al., in their literature, reported a similar trend with more deaths in the study group, particularly in the prediction score for coronary malperfusion, where the actual mortality was 29.6% compared to the predicted 30% (± 19.4)6 and for other malperfusion the reported 19.9% (± 19.4) for GERAADA prediction score vs 24%for the study group. No deaths were observed in patients with hemiparesis or those experiencing peripheral malperfusion, contrary to the predictions. This underscores the effectiveness of prompt aortic and organ reperfusion16. Patients with hemiparesis and peripheral malperfusion experienced significant post-surgery recovery, with their symptoms greatly alleviated.
The GERAADA prediction score in our study, with an Area Under Curve (AUC) of 0.599 (95% CI: 0.558–0.622) as depicted in Fig. 1, does not represent a robust model for predicting mortality in ATAAD patients.Similar to the findings of I.Zivkovi whose study concluded that EuroSCORE II demonstrates superior discriminative power for predicting operative mortality in ATAAD surgery compared to the GERAADA score. Both scoring systems demonstrate good calibration ability.In a recent assessment of popular online prediction models, Ma et al. discovered that the EuroSCORE II displayed superior predictive accuracy for surgical mortality in ATAAD patients, with the observed 30-day mortality rate validating the GERAADA score's excellent calibration7.
Furthermore, S. Lilyanna et al. propose that the optimal utilization of the new GERAADA score should not be for patient selection or decision-making but rather for quality control and performance comparison between different hospitals, facilitating retrospective evaluation and improved resource management.
Some recent studies have proposed more effective models tailored to ATAAD patients1718. H. Lin et al. introduced a straightforward nomogram based on six predictors, including left ventricular end-diastolic diameter < 45mm, estimated glomerular filtration rate < 50 ml/min/1.73 m², persistent abdominal pain, radiological celiac trunk malperfusion, concomitant coronary artery bypass grafting, and cardiopulmonary bypass time > 4 hours, to predict 30-day mortality. Meanwhile, T. Guo et al. in their literature presented a highly effective machine learning model with an AUC of 0.927 (95% CI: 0.860–0.968) 1920.
These results indicate a potential avenue for improving the predictive precision of the GERAADA score, designed for aortic dissection, by integrating intraoperative factors, given the continual advancements in surgical techniques. This enhancement gains significance, especially in the backdrop of ongoing progress in surgical methods and postoperative ICU care.K.Sugiyama suggest to add parameters such as the time from onset to arrival, family background, and hemodialysis for further accuracy.
Study limitation
This study has certain limitations that should be acknowledged. It is a retrospective, single-center investigation that incorporates various surgical approaches and involves multiple surgeons. Furthermore, the criteria and diagnosis of malperfusion may deviate from those established by the GERAADA score.