Abstract 19263: Vasodilator Use and Wave Intensity Patterns in Hypertension

Abstract

Background: Blood pressure is the result of interactions between the heart and the arteries. Although the effects of vasoactive blood pressure-lowering drugs on arteries has been widely investigated, their in vivo effects on ventricular-arterial interactions are not well understood. Hypothesis: We aimed to assess the relationship between antihypertensive drug use and ventricular arterial interactions assessed via wave intensity analysis (WIA), which quantifies the energy contained in waves generated by the heart and/or reflected from the periphery (figure). Methods: We studied 152 subjects with treated hypertension. We measured central pressure using carotid arterial tonometry. Ascending aortic flow was quantified with through-plane phase-contrast MRI. We performed WIA and assessed the relationship between specific classes of blood pressure lowering drug use and WIA patterns. Results: In models that adjusted for age, gender, body size, race, presence of diabetes and glomerular filtration rate, angiotensin receptor blocker (ARB) use was associated with a greater likelihood of a mid-systolic expansion (i.e., suction) wave (Hazard Ratio=31.1; P=0.005), whereas beta-blocker use was associated with a lower likelihood of such wave (HR=0.16; P=0.02). ARB use was also independently associated with a lower energy in the late systolic forward suction wave (Beta=-0.18; standardized beta=-0.24; P=0.007). This association persisted after adjustment for the forward compression wave (beta=-0.13; standardized beta=-0.16; P=0.008). No associations between WIA patterns and calcium channel blocker use, diuretic use, ACE inhibitor use or long-anting nitrate use were found. Conclusions: Wave intensity analysis is a useful tool to assess the effects of vasodilators on ventricular-arterial interactions. ARB use is selectively associated with systolic suction waves (from blood inertia), which may in turn unload the heart in mid and late systole.