Left ventricular structure in different types of chronic pressure overload
Institute of Medicine, University of Bergen and Department of Heart Diseases, Haukeland University Hospital, N-5021 Bergen, Norway
* Corresponding author. Tel: +47 55 97 21 70; fax: +47 55 97 58 90. E-mail address: gerdtsev{at}online.no
Aims: Hypertension and aortic stenosis (AS) are different forms of chronic pressure overload that lead to changes in left ventricular (LV) geometry. This article explores the relationship between LV geometry and outcomes, as well as the distribution of LV geometric patterns in patients with hypertension and those with asymptomatic AS with or without concomitant hypertension.
Methods and results: Studies describing the distribution of LV geometry, or the relationship between LV geometry and outcome, in patients with hypertension and/or AS were reviewed. Abnormal LV geometry increases the risk of major cardiovascular events and mortality in patients with untreated hypertension, with concentric hypertrophy conferring the greatest risk, followed by eccentric hypertrophy and then concentric remodelling. Abnormal LV geometry during antihypertensive drug therapy also increases cardiovascular risk compared with normal geometry. In asymptomatic AS, the relationship between LV geometry and outcome remains to be clarified. A pooled analysis of data from two major clinical studies, Losartan Intervention for Endpoint Reduction in Hypertension (LIFE) and Simvastatin and Ezetimibe in Aortic Stenosis (SEAS), showed that the prevalence of abnormal LV geometry increases with increasing chronic pressure overload—from 35% in normotensive patients with asymptomatic mild-to-moderate AS to 80% in patients with hypertension and electrocardiographic evidence of LV hypertrophy (LVH). In patients with asymptomatic AS, concentric LV geometry is most common, whereas eccentric hypertrophy is the most common LV geometric abnormality in patients with hypertension and LVH.
Conclusion: Abnormal LV geometry has been independently associated with adverse outcomes in hypertension. Patients with asymptomatic mild-to-moderate AS often have abnormal LV geometry irrespective of the presence of concomitant hypertension, and, accordingly, may be at higher cardiovascular risk than expected on the basis of their AS alone. In the future, ongoing clinical trials involving AS patients, such as the Simvastatin and Ezetimibe in Aortic Stenosis (SEAS) study, may help to provide further information concerning relationships between abnormal LV geometry and clinical outcomes among individuals with asymptomatic AS.
Key Words: Left ventricular geometry • Left ventricular hypertrophy • Aortic stenosis • Hypertension