Aortic Dissection Type A

The goal of this clinical trial is to learn if a technique called remote ischemic preconditioning (RIPC) helps protect organs during emergency surgery for acute type A aortic dissection (ATAAD). The main questions it aims to answer are: Does RIPC reduce the risk of major complications after surgery, such as heart, brain, or kidney problems? Is RIPC safe to use during emergency ATAAD surgery? Researchers will compare the RIPC group to a control group (who will receive a placebo) to see if RIPC can reduce complications after surgery. Participants will: Receive either RIPC or a sham intervention during their surgery. Be monitored for up to 30 days after surgery for complications. Have follow-up visits at 3 months, 1 year, and then yearly for up to 5 years to track their recovery.

The goal of this prospective multicenter observational study is to learn whether an artificial intelligence model based on electrocardiograms (ECGs) can help diagnose acute type A aortic dissection (TAAD) in adults who come to the emergency department with chest pain or related symptoms. The main question it aims to answer is: Can the AI-ECG model accurately distinguish TAAD from other causes of chest pain in a real-world emergency setting? Researchers will compare the AI model's ECG-based predictions with the final diagnosis confirmed by computed tomographic angiography (CTA), which is the reference standard. Participants will undergo routine emergency ECG testing and subsequent diagnostic evaluation as part of standard care. Clinical and ECG data will be collected from five tertiary hospitals, and the model's diagnostic performance will be assessed across centers.

Acute Type A aortic dissection (ATAAD) and its complications are life-threatening conditions that cause more than 1400 hospital admissions and 300 deaths every year in Hong Kong and cause 172,927 deaths globally in 2019. There is an increasing trend in recent years. Given the hyperacute presentation and complexity of the clinical manifestation with various mal-perfusion syndromes, the mortality of ATAAD remained high in all international reported registries and published series. Conventional Hemiarch (HAR) replacement has been the gold standard procedure for ATAAD in most of cardiac surgical centers around the world because of the relative simplicity of the procedure. However, around 50-70% of patients were reported to develop distal anastomosis new entry after hemiarch procedure and for those with entry tear over aortic arch and distal mal-perfusion, hemiarch alone might not be able to solve the downstream problem. On the other hand, total arch replacement and frozen elephant trunk procedure (TARFET) is more complex, technically demanding procedure that could potentially cover/resect the arch entry tear and exclude tear over proximal descending thoracic aorta and, hence, solve the distal mal-perfusion syndrome. To date, there is no randomized control trial to answer whether HAR or TARFET procedure is superior in patients with ATAAD and entry tear is over the aortic arch or proximal descending thoracic aorta. We plan to conduct a multi-center trial to recruit consecutive patients with ATAAD with entry tear beyond ascending aorta and randomized them, after informed consent, into either the conventional hemiarch replacement group (HAR) or total arch replacement and frozen elephant trunk (TARFET). The participating centers will collect pre- operative, intra-operative and post-operative clinical parameters for two groups of patients via REDCap system. Written informed consent, specifically allowing the use of clinical records for this randomized study, will be obtained from every patient prior to data collection. The primary outcome is the 30-day mortality of the ATAAD patients with surgically treated by HAR versus TARFET approach. The secondary outcomes are the major adverse cardiovascular and cerebral events, post-op renal replacement therapy, re-exploration for bleeding and re-intervention within 30-days. This study will be the world's first multi-center randomized control trial in ATAAD to compare the 30-day mortality of patients treated with HAR and TARFET. It could be a guideline-changing study for the treatment of ATAAD and its impact on the surgical approach to patients suffering from ATAAD.

The goal of this clinical trial is to determine if autologous platelet rich plasma (PRP) can reduce the need for blood transfusions in patients undergoing open surgery for Type A aortic dissection. It will also evaluate the potential organ-protective effects of autologous PRP. The main questions it aims to answer are: 1. Does PRP reduce the amount of allogeneic red blood cell transfusions for participants? 2. Does PRP administration provide protective effects on organs (heart, liver, lungs, kidneys, brain) in participants? Researchers will compare the administration of autologous PRP with no PRP infusion to assess whether PRP can reduce blood transfusions and provide organ-protective effects in patients undergoing open surgery for Type A aortic dissection. Participants will: 1. Receive autologous PRP infusion during surgery 2. Undergo multiple checkups and tests before and after surgery 3. Be recorded for allogeneic red blood cell usage within 24 hours perioperatively and all allogeneic blood products usage during the entire hospitalization 4. Be assessed for organ function (heart, liver, lungs, kidneys, brain) and symptom-related outcomes through clinical evaluations