CENTRAL BLOOD PRESSURE AND AUGMENTATION INDEX DECREASE ARE DEPENDENT ON AORTIC PULSE WAVE VELOCITY IMPROVEMENT: THE EXPLOR STUDY: PP.10.406

Abstract

Antihypertensive drugs have different effects on peripheral and central blood pressure (BP). In the EXPLOR trial, we have demonstrated that angiotensin-receptor blockers (ARBs) lower central BP more efficiently than atenolol, when amlodipine is given in association. In this analysis we investigated the interrelationship between decrease in central pressure and augmentation index and changes in pulse wave velocity. Methods: Central systolic BP (cSBP) was measured with applanation tonometry (Sphygmocor ®) after 28 weeks active treatment by the single pill combination valsartan-amlodipine (VA, 80/5 mg then 160/10 mg) or an atenolol-amlodipine combination (AA, 50/5 mg then 100/10 mg) in a prospective, randomized, parallel groups, PROBE design, multicentric trial. Data quality was controlled by a Core-Lab, blinded for center, visit and treatment allocation. VA or AA were were uptitrated from W8 to W24. We analyzed changes in central systolic pressure (cSBP), augmentation index (AIx), and carotid-to-femoral pulse wave velocity (PWV) between W24 and baseline. Results are expressed as slope (β), standardized slope (βs), % explained variance (%EV) and p values. Results: Data were adjusted on age, sex, treatment, changes in HR and baseline values. Change in cSBP was significantly associated with change in PWV (β: 2.4, βs: 0.35, EV%: 12%, p < 10–6). Similarly, change Aix was significantly associated with change in PWV (β: 0.27, βs: 0.12, EV%: 1.5%, p < 0.01). Changes in PWV were strongly dependent on changes in HR, cSBP or AIx. Correlation with change in cSBP was stronger than those with brachial SBP (EV% 8% and 0.9%, respectively). Interestingly, changes in cSBP and AIx remained significantly larger with valsartan-amlodipine, compared to atenolol-amlodipine when changes in PWV were accounted for. Conclusion: Changes in central systolic blood pressure and augmentation index are dependent on changes in aortic PWV. The differential effect of valsartan over atenolol on central SBP and augmentation index remained significant, even when adjusted on PWV.