[Exercise systolic blood pressure variability and long-term prognosis in patients with acute coronary syndrome].

Objective: To investigate the association between exercise systolic blood pressure variability (eSBPV) and the risk of major adverse cardiovascular events (MACE) in patients with acute coronary syndrome (ACS) following percutaneous coronary intervention (PCI), and to evaluate its value in risk stratification. Methods: This retrospective cohort study enrolled patients with ACS who underwent PCI and subsequently completed a standardized symptom-limited cycle ergometer cardiopulmonary exercise test at the Second Affiliated Hospital of Harbin Medical University, Guangdong Provincial People's Hospital, and Hegang People's Hospital between January 2018 and December 2023. The primary endpoint was the occurrence of MACE during follow-up. Cox proportional hazards regression was used to evaluate the association between eSBPV and MACE risk, and restricted cubic spline analysis was performed to examine whether this association departed from linearity. Patients were dichotomized into low-eSBPV (≤15.1%) and high-eSBPV (>15.1%) groups based on the median eSBPV value. Kaplan-Meier curves were constructed to compare cumulative event-free survival between groups, with differences assessed using the log-rank test. Hazard ratios were estimated using Cox regression models. Subgroup analyses and interaction tests were performed according to hypertension history and hypertensive response to exercise status. Results: A total of 3 549 post-PCI ACS patients were included, with a median age of 57.0 (50.0, 63.0) years; 2 879 (81.1%) were men. Over a median follow-up of 24.0 (18.0, 36.0) months, 207 MACE events (5.8%) occurred. After adjustment for confounders, each 1% increment in eSBPV was associated with a reduction in MACE risk (HR=0.969, 95%CI: 0.947-0.992, P=0.009). Restricted cubic spline analysis demonstrated a linear inverse association between eSBPV and MACE risk (overall P=0.001, nonlinear P=0.254). Kaplan-Meier analysis showed that the high-eSBPV group had a significantly better cumulative event-free survival than the low-eSBPV group (log-rank P=0.001). Cox regression analysis further indicated that the low-eSBPV group had a higher MACE risk compared with the high-eSBPV group (HR=1.558, 95%CI: 1.181-2.054, P=0.002). Subgroup analyses revealed that the inverse association between eSBPV and MACE risk was generally consistent across different hypertension and hypertensive response to exercise statuses, with no significant interaction in the combined stratification analysis (interaction P=0.412). Conclusions: eSBPV is linearly and inversely associated with long-term MACE risk in post-PCI ACS patients and can effectively distinguish different risk levels. As a functional assessment parameter, it provides a potential novel prognostic marker for risk stratification in post-PCI ACS patients.