[1] Univ Groningen, Univ Med Ctr Groningen, Dept Cardiol, NL-9700 RB Groningen, Netherlands
[2] Univ Groningen, Univ Med Ctr Groningen, Dept Nephrol, NL-9700 RB Groningen, Netherlands
[3] Univ Groningen, Univ Med Ctr Groningen, Dept Epidemiol, NL-9700 RB Groningen, Netherlands
[4] Univ Hull, Acad Dept Cardiol, Castle Hill Hosp, Cottingham, England