SEARCH was a large UK, randomized controlled trial of more intensive cholesterol-lowering with simvastatin 80mg daily versus a standard dose of simvastatin 20mg daily and of homocysteine-lowering with folic acid and vitamin B12 versus matching placebo. Between 1998 and 2001, 12,064 patients who had survived a heart attack were randomized in 88 hospital-based clinics around the UK. These patients were followed up for an average of about 7 years in the study clinics while they continued on their randomized treatment and follow-up is on-going for mortality and cancer via centralised electronic health records. 

SEARCH has shown that:

  • The additional reduction in LDL-cholesterol with allocation to simvastatin 80mg daily versus 20mg daily reduced LDL-cholesterol by 0.35 mmol/L and major vascular events (MVEs i.e. heart attacks, strokes or coronary or non-coronary revascularisation) by 6% (95% CI 12% to +1%). This reduction was in line with expectations and contributed to the CTT meta-analysis showing that more intensive LDL-cholesterol lowering produces additional benefits.
  • Supplementation with folic acid plus vitamin B12 significantly reduced homocysteine levels  and is safe, but does not reduce the risk of major vascular events or cancer
  • Simvastatin 80mg daily was associated with an increased risk of myopathy (muscle symptoms with raised blood creatine kinase) with 53 vs 2 cases respectively among those allocated 80mg vs 20mg simvastatin daily  
  • In a nested genetic case-control a genetic marker in the SLCO1B1 gene was shown to increase the risk of statin-induced myopathy

The SEARCH database continues to provide valuable information on other risk factors for myopathy. Data from SEARCH contributes to the CTT meta-analyses and the B Vitamin Treatment Trialists’ Collaboration (BVTTC) analyses. On-going investigations include looking at the long-term effects (over 10 years) of homocysteine-lowering on vascular and non-vascular deaths and cancers using data from electronic health records

The SEARCH trial was funded by Merck who also provided the packaged simvastatin and the packaged folic acid plus vitamin B12 combination tablet and matching placebos. The long-term follow-up is funded by core grants to CTSU from the Medical Research Council, British Heart Foundation and Cancer Research UK.

Further information:

Our team

  • Jane Armitage
    Jane Armitage

    Professor of Clinical Trials and Epidemiology, and Honorary Consultant in Public Health Medicine

  • Louise Bowman
    Louise Bowman

    Associate Professor of Clinical Trials and Epidemiology & Honorary Consultant Physician (Lipidology)

  • Richard Bulbulia
    Richard Bulbulia

    Research Fellow, Clinical Trial Service Unit, University of Oxford

  • Rory Collins
    Rory Collins

    Head of Nuffield Department of Population Health and BHF Professor of Medicine and Epidemiology

  • Richard Haynes
    Richard Haynes

    Associate Professor

  • Sarah Parish
    Sarah Parish

    Professor of Medical Statistics and Epidemiology


Unrestricted grant from Merck, Sharp and Dohne (see Unit's funding policy here)

Selected publications

Related research themes