Surrogate markers in clinical trials--challenges and opportunities

Atherosclerosis. 2009 Sep;206(1):8-16. doi: 10.1016/j.atherosclerosis.2008.12.009. Epub 2008 Dec 14.

Abstract

Surrogate markers have recently come under scrutiny since a few of the considered most reliable intermediate endpoints (LDL-c, HDL-c and HbA(1c)) have failed to predict clinical benefit following pharmacological intervention in the causal pathway. However, it follows that comprehending the pathophysiological complexity of atherosclerotic vascular disease, no single surrogate is likely to be omniscient in the translation of benefit or harm of a certain therapy. Especially surrogates that are assessed in the circulation merely reflect a part of the complex multipathway disease. Such markers do not have the ability to monitor potential side effects of interventions or assess the activation of unknown pro-atherogenic pathways. Contrary to such soluble endpoints, vascular imaging data can provide information on atherosclerosis as a continuous variable, since the disease process of the vascular wall itself is assessed. Understanding this continuity from the earliest stages through to the vascular complications is essential, as the arterial wall reflects the net effect of either known or yet to be discovered hereditary as well as environmental factors. In this review we will focus on challenges and pitfalls using plasma biomarkers as surrogate endpoints for the assessment of cardiovascular drug efficacy. Subsequently, we will focus on vascular imaging modalities as tools to investigate atherosclerosis.

Publication types

  • Review

MeSH terms

  • Atherosclerosis / blood*
  • Atherosclerosis / diagnostic imaging
  • Biomarkers*
  • Brachial Artery / diagnostic imaging
  • Cardiovascular Agents / therapeutic use*
  • Carotid Arteries / diagnostic imaging
  • Cholesterol, HDL / blood
  • Cholesterol, LDL / blood
  • Clinical Trials as Topic / methods*
  • Coronary Vessels / diagnostic imaging
  • Glycated Hemoglobin / analysis
  • Humans
  • Magnetic Resonance Imaging
  • Regional Blood Flow
  • Research Design
  • Tunica Intima / diagnostic imaging
  • Ultrasonography
  • Vasodilation / physiology

Substances

  • Biomarkers
  • Cardiovascular Agents
  • Cholesterol, HDL
  • Cholesterol, LDL
  • Glycated Hemoglobin A
  • hemoglobin A1c protein, human