The emergency call for an elderly patient with an acute type A aortic syndrome (AAAS) at the hospital’s door always generates uncertainty regarding the optimal therapeutic approach. On one hand, avoiding a high mortality rate justifies the futility of a substantial surgical effort from the team. However, multiple studies highlight that surgical intervention in selected patients, even octogenarians, may offer survival benefits in the short and mid-term.

The presentation of AAAS as noncommunicating acute type A aortic dissection (a common term in Asian literature for what we know as ascending aortic intramural hematoma, IMH-A) in elderly patients further supports the potential utility of surgical intervention, as these patients, except for cases of pericardial effusion/tamponade, typically show fewer complications than those with other types of AAAS. Japanese studies have advocated for conservative management in elderly or high-risk patients with favorable survival outcomes.

This study analyzed short- and mid-term outcomes in 66 patients over 75 years with IMH-A treated at a Japanese center from October 2011 to December 2020: 30 initially assigned to optimal medical management and 36 treated surgically. The surgical intervention performed in most cases involved isolated replacement of the ascending aorta. Three patients (10%) in the medical group showed IMH-A progression to type A aortic dissection, with two undergoing surgery. The groups did not significantly differ in in-hospital or intensive care unit mortality rates or length of stay. During follow-up, four-year survival rates were 78.3% and 71.4% in the surgical and conservative groups, respectively (p = 0.154). Seven patients in the medical group experienced late aorta-related events, compared to none in the surgical group (p = 0.003), leading to a significantly higher rate of interventions for new aortic events in the conservative management group. However, both groups showed no significant differences in all-cause and aorta-related mortality during the first four years.

The authors concluded that surgical outcomes for IMH-A in elderly patients were favorable. However, this did not translate into significant differences in survival compared to conservative management in either short- or mid-term, when considering all-cause and aortic-related mortality.

COMMENTARY:

The results align with other published findings cited below, supporting this alternative perspective on addressing this aortic pathology. The guidelines from the Japanese Circulation Society (JCS) and the work of Kaji et al., a reference on conservative management of IMH-type AAS, suggest considering IMH as a distinct entity within AAS. IMH is classified into two types: type 1, resulting from bleeding within the tunica media due to rupture of the nourishing vasa vasorum; and type 2, linked to degenerative changes in the aortic wall, such as atherosclerosis, which serve as an entry point for bleeding into the tunica media (e.g., IMH associated with plaque fissure/ulceration).

The “Japanese approach” to IMH leverages these distinct IMH characteristics: a less affected aortic wall and, therefore, a reduced rupture risk (compared to dissection or penetrating ulcer), along with reduced progression toward the aortic root or supra-aortic trunks, which lowers risks of malperfusion or aortic insufficiency (relative to dissection). Moreover, type 2 IMH often occurs in older patients with greater atheromatous burden and more comorbidities. This profile suggests that selecting patients for conservative management can yield good outcomes. The Achilles heel of this strategy lies in identifying patients at risk for disease progression, which could transform to aortic dissection due to communication between the IMH and aortic lumen through media-intimal rupture. Poor prognostic indicators include IMH thickness >11 mm, an aortic diameter >48–50 mm, and the presence of ulcer-like precursor lesions on CT, appearing as small discontinuities in the media-intimal layer. Although conservative management is not routinely practiced in our setting except in patients unfit for surgery, nor is it advocated in our clinical guidelines, we might reconsider IMH-A in stable patients as a non-emergency. Akin to an acute coronary syndrome once stabilized: optimal medical treatment, close monitoring including CT scans, and urgent intervention in the following days with a fresh surgical team after optimizing the patient’s clinical condition (suspension of antiplatelet/anticoagulant therapy, adequate blood pressure control), etc. This may be a means of improving outcomes, particularly in comorbid or elderly patients where emergent intervention may entail increased morbidity and mortality due to inadequate preparation.

REFERENCE:

Nakamae K, Oshitomi T, Uesugi H, Ideta I, Takaji K, Sassa T, Murata H, Hirota M. Noncommunicating acute type A aortic dissection in elderly patients: Surgery versus medical management. Eur J Cardiothorac Surg. 2022 Nov 3;62(6). doi: 10.1093/ejcts/ezac484.

Kaji S, Akasaka T, Horibata Y, Nishigami K, Shono H, Katayama M, Yamamuro A, Morioka S, Morita I, Tanemoto K, Honda T, Yoshida K. Long-term prognosis of patients with type a aortic intramural hematoma. Circulation. 2002 Sep 24;106(12 Suppl 1). Doi: 10.1161/01.cir.0000032897.55215.