[1] Univ Heart Ctr Zurich, Dept Cardiol, Ramistr 100, CH-8091 Zurich, Switzerland
[2] Univ Zurich, Inst Social & Prevent Med, Div Biostat, CH-8006 Zurich, Switzerland
[3] Univ Hosp Bern, Dept Cardiol, CH-3010 Bern, Switzerland
[4] Univ Zurich, Ctr Integrat Human Physiol, Zurich, Switzerland