Temporal Relationship Between Arterial Stiffness and Systolic Blood Pressure Under Intensive or Standard Control: A Post Hoc Analysis of the STEP Trial

BACKGROUND: Whether or not the temporal relationship between arterial stiffness and systolic blood pressure (SBP) is affected by how strictly SBP is controlled (intensive, 110-<130 mmHg; standard, 130-<150 mmHg) has been unclear. METHODS: The temporal relationship between brachial-ankle pulse wave velocity (baPWV) and SBP was assessed using a cross-lagged panel model in the 5369 participants in the STEP trial (Strategy of Blood Pressure Intervention in the Elderly Hypertensive Patients) for whom baseline and follow-up baPWV data were complete. RESULTS: Patients with arterial stiffening (baPWV >= 1800 cm/s) at baseline were significantly less likely to achieve their target SBP than those without arterial stiffening in the intensive and standard treatment groups (65.17% versus 76.91% and 97.33% versus 98.96%, respectively, both P<0.05). The standardized regression coefficient from baseline baPWV to followup SBP was 0.05 (95% CI, 0.02-0.08; P<0.001) and that from baseline SBP to follow-up baPWV was insignificant from zero (beta=-0.007 [95% CI, -0.03 to 0.02]; P=0.62) after adjustment for confounders. CONCLUSION: Arterial stiffening consistently preceded SBP in the intensive and standard groups, and it led to difficulty in reaching target SBP, particularly in the intensive treatment group. Besides, assignment to intensive treatment group was associated with an attenuation of the age-related increase in baPWV at 3-year follow-up.