The burden of valvular heart disease (VHD) is rising rapidly as life expectancy increases. The prevalence in the USA alone is 13% in those aged over 75 years,1 while the global prevalence of rheumatic heart disease is estimated at 15.6-19.6 million.2 Despite this, the treatment of VHD still lacks an adequate research base. None of the 64 recommendations in the 2012 European Society of Cardiology (ESC) VHD guidelines3 had Level A evidence and only 14% had Level B evidence. This compares with 28% at Level A and 42% at Level B among the 270 recommendations in the 2010 ESC myocardial revascularisation guidelines.4 Therefore, there is an urgent need to stimulate the investigation. In this article, we identify deficits in our knowledge which may be amenable to research and make a call for national and international collaborative efforts to address this evidence gap.