Background: Both diastolic dysfunction and increased vascular stiffness represent important measures of target-organ damage in hypertension. Whether intensive blood pressure (BP) control can further improve these measures remains unknown.
Methods: EXCEED is a prospective, randomized open-label blinded endpoint trial (PROBE) design, aiming to test the hypothesis that more aggressive BP lowering would result in greater improvement in diastolic function among patients with stage II hypertension, evidence of diastolic dysfunction and preserved systolic function (EF > or = 50%). Patients were randomized to one of two treatment strategies, targeting systolic blood pressure (SBP) <140 mmHg or <130 mmHg using a combination of amlodipine/valsartan with additional antihypertensive medications as needed to achieve the prescribed targets. Diastolic function was assessed using Doppler tissue imaging of early diastolic velocity of lateral mitral annulus (E'), while vascular stiffness was assessed using radial augmentation index (RAI) derived from radial artery tonometry. The study primary endpoint will be the change in lateral E' velocity between baseline and 24 weeks.
Results: Two hundred and twenty eight patients (50% female) with mean age of (59.6+/-9.7) years and mean BP of (162+/-14/92+/-13 mmHg) were randomized equally to either treatment strategies. Left ventricular hypertrophy was present among <4% of the enrolled patients. Inspite diastolic function was impaired, baseline lateral E' velocity (7.6+/-1.2 cm/s) was not related to baseline SBP while baseline RAI was weakly related (r = 0.2, p <0.01) to SBP even after adjustment to age, gender and heart rate.
Conclusion: EXCEED will determine whether intensive BP lowering will further improve diastolic dysfunction and vascular stiffness among patients with uncontrolled hypertension.