Predicting outcome in asymptomatic aortic stenosis: should we measure the severity of obstruction or its physiological consequences?

Abstract

This editorial refers to ‘Left ventricular systolic and diastolic function assessed by tissue Doppler imaging and outcome in asymptomatic aortic stenosis’, by R.A.H. Stewart et al. doi:10.1093/eurheartj/ehq159 ‘Information is not knowledge’.Albert Einstein In patients with severe aortic stenosis, it is well recognized that when symptoms develop, death will ensue unless the obstruction is relieved. Development of cardiac symptoms of angina, syncope, or heart failure indicate that a critical severity of obstruction has occurred and mark a change in the natural history of aortic stenosis. However, symptoms may be subtle, especially in the elderly patient who may have co-morbidities, including arthritis, lung disease, neurological disease, and frailty, that limit exercise capacity. Even if symptoms are realized, these may not be reported by the patient. Moreover, even in the truly asymptomatic patient, it is recognized that aortic stenosis is associated with a small risk of sudden death, which has been estimated at 1% per year.1 Because of difficulties in determining exactly when the symptomatic stage of aortic stenosis has developed, and because of the risk of sudden death, many efforts have been made to predict outcomes in aortic stenosis accurately. Multiple investigators have tried to characterize the clinical, electrocardiographic, haemodynamic, imaging, and biomarker features which identify the patient at risk of adverse outcome. Echocardiography has become the mainstay of diagnostic assessment in patients with aortic stenosis. Initial efforts to predict events in aortic stenosis have focused on quantifying the severity of obstruction. More recently, the physiological consequences of the obstruction, namely the effects on left ventricular (LV) mass and systolic and diastolic function, have gained attention ( Figure 1 ). The recent, carefully conducted, multicentre study by Stewart et al. 2 was intended to combine these interests and to explore the role of tissue Doppler measures of LV systolic and diastolic function …