Comparative insights into type non-A non-B vs type B acute aortic syndromes and their blood pressure management: a monocentric, retrospective, 11-year study

Abstract Background Acute aortic syndromes (AAS) are classified either as type A, if the ascending aorta is involved, or as type B, if only the descending aorta is; AAS affecting the aortic arch, alone or in combination with the descending aorta, have recently been classified as type non-A-non-B (NANB). Few and discordant data are available about the differences between type B and type NANB AAS, especially in terms of presentation, management and prognosis. Little evidence also exists about the effects of blood pressure (BP) management, peaks and variability on in-hospital outcomes in such context. In particular, the largest international AAS registry suggests a comparable course and prognosis, while a recent meta-analysis indicates a poorer clinical outcome with higher rate of complications, need of invasive treatment and mortality in the case of type NANB AAS. Methods We conducted a monocentric, observational, analytical, retrospective registry study including all patients ≥ 18 years old admitted to our tertiary referral hospital with a diagnosis of type B or type NANB AAS from January 2011 to December 2021. Epidemiological, clinical, operative and outcome data were analyzed by comparing type B and type NANB AAS patients. We also focused on systolic and diastolic BP, in terms of both peak values as well as BP variability (BPV); BPV was defined as the difference between the peak and the through value on a certain day. Blood pressure variables were analyzed in relationship with mortality and the failure of an initial conservative management. Results 274 type B and 44 type NANB AAS patients were enrolled. The only significant differences between the two groups were a higher rate of pre-operative complications in type NANB patients (p=0.002) resulting in a higher rate of invasive management (p=0.005), particularly as failure of an initial conservative strategy (p=0.018). However, comparable rates of post-operative complications and in-hospital mortality (overall 7%) were observed. In the overall population, lower limb ischemia, ST segment depression, and post-operative visceral ischemia were associated with higher in-hospital mortality. Peri-aortic effusion was independently associated with failure of conservative management, whereas diagnosis of intramural hematoma (as opposed to other subtypes of AAS) appeared to be protective. Among all BP variables (including anti-hypertensive treatment intensity and daily systolic or diastolic BP peaks and variability), only peak systolic BP on day 5 was found to be non-independently associated with a higher risk of in-hospital mortality and failure of an initially conservative strategy. Conclusions In our study type NANB AAS were more often complicated and treated invasively than type B AAS, while having the same rates of post-operative complications and overall mortality. BP peaks had only a minor effect on outcomes, while BPV and BP management intensity did not have any significant impact.OutcomesBlood Pressure