Acute aortic syndrome type A is a pathology with high morbidity and mortality due to the natural history of the disease, the frequent delays in diagnosis, and the complexity of its treatment. Emergency surgery is the treatment of choice, though hospital mortality in major series is around 17-25%. Various studies have shown significant improvement in outcomes by concentrating experience in high-volume centers with specialized multidisciplinary teams. The Aorta Code was implemented in 2019 within a cardiovascular network comprising 5 hospitals in the Community of Madrid, with Hospital Clínico San Carlos as the reference center, covering a population of 1.3 million people. It was based on three key aspects: early diagnosis, immediate transfer to the reference center, and treatment by an expert multidisciplinary team.

To increase diagnosed cases and ensure as early a diagnosis as possible, a simple diagnostic algorithm was designed, and initial training sessions were held in Emergency Services, which were repeated every six months. Regarding the protocol, once a diagnosis was established, the Hospital Emergency Services communicated with the Extrahospital Emergency Service (SUMMA 112) who activated the Aorta Code and performed the immediate transfer of the patient to the Acute Cardiovascular Care Unit of the reference center. An experienced multidisciplinary team was created there, composed of 3 Cardiologists, 2 Cardiac Surgeons, 2 Vascular Surgeons, and 3 Anesthesiologists, providing 24/7 coverage throughout the year. Upon admission, the team jointly evaluates the patient and decides the timing and type of procedure to be performed. Protocols for preoperative medical and anesthetic management were defined, and surgical techniques standardized according to anatomical and clinical features.

With the recent publication of this program’s results, the purpose of today’s study was to retrospectively compare all patients with type A acute aortic syndrome before the implementation of the Aorta Code (2005-2018) and after its implementation (2019-2023). Baseline characteristics, intraoperative details, and 30-day morbidity and mortality were analyzed.

Between January 2005 and February 2023, a total of 172 patients were operated on (102 in the pre-Aorta Code period and 70 post-Aorta Code implementation). During the Aorta Code period, there was an increase in the number of patients operated on per year (from 7.3 to 16.8), with an increase in the number of patients transferred from other hospitals. The median time to diagnosis (6.5 hours vs. 4.2 hours), transfer to the center (4 hours vs. 2.2 hours), and transfer to the operating room (2.7 hours vs. 1.8 hours) was significantly shorter (p < 0.05). Regarding surgical technique, aortic valve preservation and total arch replacement were more frequent after the Aorta Code was established, with shorter times for cardiopulmonary bypass and ischemia. There was also a significant decrease in the incidence of prolonged mechanical ventilation (53.9% vs. 36.9%), stroke (17.7% vs. 7.1%), and 30-day mortality (27.5% vs. 7.1%; p = 0.001).

The study concluded that the Aorta Code can be successfully implemented using a standardized protocol within a hospital network. This increases the number of cases operated per year, shortens the times to diagnosis, transfer, and arrival at the operating room, and significantly reduces 30-day mortality.

COMMENTARY:

The goal of implementing the Aorta Code was to improve outcomes in acute aortic syndrome by optimizing resource use and reducing variability in healthcare delivery. An organizational and process change was implemented by establishing simplified and standardized diagnosis and treatment protocols, continuous medical education through training sessions at the involved centers, early transfer to the reference center, and optimal medical and surgical management by an experienced multidisciplinary team.

Some key aspects of the program’s success include:

1. Having a coordinated transportation system through a single phone call to reduce pre-surgical times.
2. Having a multidisciplinary team managed by professionals from different specialties allowing 24-hour coverage every day of the week.
3. Diagnosing patients with acute aortic syndrome requires a high index of suspicion and can often be confused with other entities. Although treatment is centralized at H. Clínico San Carlos, it is crucial that other involved hospitals recognize it and activate the code promptly. The diagnostic algorithm implemented is based on three fundamental steps: initial clinical suspicion, basic evaluation with complementary tests, and confirmation or exclusion of the pathology through diagnostic imaging. The average time to diagnosis according to the International Registry of Aortic Dissection (IRAD) was 4.3h, whereas after the implementation of the Aorta Code, the average time of diagnosis was reduced from 6.5 hours to 4.2 hours, thus meeting international standards.
4. Once the diagnosis is made, medical management until intervention is crucial to reduce the risk of complications and keep the patient stable. Among the measures aimed at this are strict control of blood pressure and heart rate, as well as pain management.
5. Close collaboration between the Cardiac Surgery and Vascular Surgery teams allows for joint planning of procedures to define the most appropriate surgical strategy based on the clinical and anatomical profile of the patient, reducing the risk of developing certain complications, including malperfusion syndrome.
6. Regarding surgical technique, after the implementation of the Aorta Code, surgery was of greater complexity and quality, with a higher number of complete arch replacements (20.6% vs. 40.0%) and most performed using the frozen elephant trunk technique. Various studies demonstrate the association between experienced surgical teams and improved outcomes in type A acute aortic syndrome. In the pre-Aorta Code era, interventions were performed by 8 different surgeons, while after the implementation of the Aorta Code, 94% of the interventions were performed by two surgeons members of the multidisciplinary team.
7. Finally, the implementation of a standardized protocol for patient management during the intervention, with strict intraoperative monitoring, and adequate myocardial and cerebral protection during cardiopulmonary bypass is important. Considering all the previously mentioned measures, the Aorta Code has had a significant impact on the short-term morbidity and mortality of patients operated on for type A acute aortic syndrome. The effect of these measures on long-term terms of reintervention and survival currently requires further follow-up.

REFERENCE:

Maroto L, Ferrera C, Cobiella J, Carnero M, Beltrao R, Martínez I, et al. Impovement of Early Outcomes in Type A Acute Aortic Syndrome After an Aorta Code Implementation. Ann Thorac Surg. 2024; 117(4):770-778. doi: 10.1016/j.athoracsur.2023.07.010