TY - JOUR T1 - The Authors' reply JF - Heart JO - Heart SP - 1991 LP - 1991 DO - 10.1136/heartjnl-2011-301002 VL - 97 IS - 23 AU - Alex Pitcher AU - Deborah Ashby AU - Paul Elliott AU - Steffen E Petersen Y1 - 2011/12/01 UR - http://heart.bmj.com/content/97/23/1991.2.abstract N2 - The Authors' reply We are grateful to Dr Eitel and colleagues for their interest1 in our recent review.2 This paper was intended primarily to emphasise the principles of application of this powerful and expanding set of techniques to clinical trials and to provide a few examples of (generally) well-established biomarkers, rather than to provide an exhaustive list of all established and emerging techniques of potential utility. We welcome the attention that they bring to several emerging biomarkers, which show considerable promise as reliable surrogate markers … ER -