Studies are urgently needed that evalu- ate the value of newer measures of LV size, function, and myocardial structure in predicting outcomes after valve intervention, especially in patients with chronic severe AR. However, LV enlargement and dysfunction are late consequences of valve dysfunction; as more durable approaches to restoring normal valve function are developed, the benefit risk balance for intervention will shift to earlier in the disease. Studies examining the role of earlier markers of myocardial dysfunction, such as strain and strain-rate imaging, diastolic dysfunction, circulating blood markers, and other novel approaches to defining the optimal timing of intervention, also are needed. Few studies have included adequate numbers of older adults to make specific recommendations for this group of patients, for whom particular concerns, such as cognitive function, frailty, and mobility challenges, may change the decision algorithms. In addition, wom- en and minorities often are underrepresented in clinical trials. Directed efforts are needed to ensure all patient groups are included with numbers adequate to perform separate data analysis. Given the relatively low risk associated with inter- vention in otherwise healthy patients and the improved options for valve repair or replacement, RCTs of inter- vention for severe asymptomatic VHD will be important and are in progress for some conditions, such as severe AS. Other specific conditions where clinical equipoise exists are asymptomatic severe AR with normal LV sys- tolic function, severe primary MR with normal LV func- tion and a high likelihood of valve repair, and the role of intervention for TR. Data from large, carefully designed registries are also needed for defining and improving quality of care. Long-term follow-up will be needed to ensure the lifetime risks of a prosthetic valve or valve repair are balanced against any benefits attributable to 16.4. 