Abstract 2995: Impact of Atenolol versus Losartan-Based Treatment on Aortic Root Dilatation in Hypertension: The LIFE Study
Background: Medical therapy of patients with aortic dilatation or dissection is based on beta-blocker (BB) therapy, reflecting clinical observations at a time when few classes of antihypertensive medication were available and evidence of acute reduction of left ventricular (LV) contractility by BBs. However, there is no documentation of either long-term persistence of reduced LV contractility or slowed increase of aortic root diameter (ARD) in a large prospectively studied population. Recent data from a murine model of the Marfan syndrome suggests that losartan may prevent increase of ARD.
Methods: We compared the impact of BB therapy based on atenolol to losartan-based antihypertensive treatment on a measure of LV contractile performance (LV velocity of circumferential fiber shortening [VCF]) in 945 participants in the echocardiography substudy of Losartan Intervention For Endpoint reduction in hypertension (LIFE) study and on increase of ARD in the subset with dilated aortic roots (ARD ≥ 4.5 cm) at baseline and after 5 years follow-up.
Results: In the entire population, VCF at enrolment was similar in both BB- and losartan-treated patients (106 ± 21 and 108 ± 24 c/sec, p = NS) but was 5–7% lower with BB treatment compared to losartan treatment on annual echocardiograms after 1 to 5 years of treatment (0.0005 < p < 0.02). Baseline ARD was ≥ 4.5 cm in 17 patients (2%). There was no difference between treatment arms in ARD at 1- to 5-year re-evaluations (all p ≥ 0.08). However, in the subset with ARD ≥ 4.5 cm, mean ARD was modestly lower on BB therapy (4.5 ± 0.1 vs. 4.8 ± 0.2 cm, p = 0.014).
Conclusion: Serial echocardiographic evaluation of a large population of hypertensive patients documented long-term reduction of VCF, a measure of LV contractile performance, with BB treatment. In the subgroup of hypertensive patients with ARD ≥ 4.5 cm, a group at increased risk of aortic dissection, conventional BB therapy based on atenolol resulted in slightly less increase of ARD over 5 years than losartan-based therapy.