Abstract 4426: Device-Based Reduction in Blood Pressure is Associated with Increased Diameter of the Left Ventricular Outflow Tract: Results from European and United States Trials of the Rheos® Hypertension System
Aortic root diameter is believed to be abnormal in hypertension. Recent studies suggest that therapies which increase the diameter of the proximal aorta and left ventricular outflow tract (LVOT) may lower pulse pressure (PP) and thus may benefically impact cardiovascular risk. Rheos Hypertension (HT) Therapy has been shown to lower blood pressure (BP) but its effects on the LVOT have not previously been reported. Stage II hypertensives (systolic BP ≥160 mmHg) taking ≥3 anti-HTN drugs (≥1 diuretic) were implanted with the Rheos HT System in US and European feasibility studies. Baseline data were acquired before implant. The Rheos HT System was activated 1 month after implant. Follow-up occurred after 3 and 12 months of therapy. Brachial BP was measured in-office by an oscillometric device. Echocardiograms were reviewed at a blinded core lab. LVOT diameter was measured 1 cm from the aortic valve annulus at mid-systole. Changes at follow-up versus baseline were analyzed with paired t-tests for all subjects with echocardiograms available at baseline and follow-up. 32 subjects (23 Europe/9 US, 17 M/15 F, Age 52.1±10.4 yr, BMI 33.3±7.3 kg/m2) were implanted at 8 centers. Rheos HT Therapy reduced BP, including PP, increased LVOT diameter and reduced left ventricular mass index (LVMI). No unanticipated adverse events occurred. Chronic Rheos HT Therapy in hypertension patients increases LVOT diameter while reducing BP, PP and LVMI. Benefits are in addition to those achieved with intensive drug therapy. The present results add supporting evidence that Rheos HT Therapy may reduce long-term health risks and warrants further prospective evaluation.