Admission systolic blood pressure is a significant predictor of in-hospital mortality in patients with acute type A aortic dissection (ATAAD). While previous studies have focussed on recording the highest blood pressure value from both arms, this study aimed to evaluate the associations between blood pressure in bilateral arms and in-hospital mortality.

Data were analysed from 262 patients with ATAAD treated at a single centre. The relationship between bilateral arm blood pressure upon admission and in-hospital mortality was assessed in a logistic regression model. To comprehensively evaluate potential non-linear relationships, the association between admission bilateral systolic blood pressure (SBP) and the risk of in-hospital mortality was analysed using restricted cubic splines on a continuous scale.

Mean age was 53.6±12.5 years and 194 (74.0%) were male. Baseline and operative data showed that ages, body mass index, smoking, left-arm SBP, left-arm diastolic blood pressure (DBP), right-arm SBP, right-arm DBP, syncope, cerebral/cardiac ischaemia, retrograde brain perfusion, Bentall procedure, coronary artery bypass grafting, and aortic valve replacement significantly differed among the left-arm SBP tertiles. In-hospital mortality was 17.6% (46 of 262). Restricted cubic splines demonstrated that the relationship between presenting left-arm SBP and in-hospital mortality followed a U-shaped curve, whereas non-linearity was not detected in the right arm.

This study found a U-shaped association between admission left-arm SBP and in-hospital mortality in ATAAD surgery patients, whereas a non-linearity relationship was not detected for right-arm SBP. Low left-arm SBP independently correlated with increased in-hospital mortality, underscoring the significance of bilateral blood pressure differences in ATAAD prognosis.