Background The aim of preparticipation cardiac screening of athletes is to detect cardiovascular disease at an early stage to prevent sudden cardiac death and sudden cardiac arrest. Few studies focus on consequences of false negative findings.

Objective The main objective of this study was to identify cardiovascular incidents in a cohort of male professional football players with negative screening results.

Design Retrospective eight years follow-up study.

Setting Follow-up of systematic preparticipation cardiac screening completed prior to the 2008 football season of 604 players cleared for full participation in the Norwegian professional leagues, including player and family history, electrocardiography and echocardiography.

Patients (or Participants) All players who suffered severe cardiovascular incidents during 8 years of follow-up.

Interventions (or Assessment of Risk Factors) Media search with key words football and cardiovascular incidents in Norway from January 1st 2008 until February 13th 2016. We collected medical records from players with disease and compared preparticipation cardiac screening results with outcome.

Main Outcome Measurements Players from the original cohort who suffered sudden cardiac death or arrest, angina pectoris or myocardial infarction, transitory ischemic attack, cerebral haemorrhage or infarction, atrial flutter or fibrillation, blood clot, myocarditis or pericarditis.

Results Six players with negative screening results, median age 30 years (27–36), had experienced cardiovascular incidents during follow-up. Three players had suffered sudden cardiac arrest, one myocardial infarction, one transitory ischemic attack and one atrial flutter. Four of the incidents happened during or straight after a match, and one during training.

Conclusions More than 1 in 100 players with negative screening results suffered severe cardiovascular incidents, included three sudden cardiac arrests, within 8 yrs of follow up. Mandatory preparticipation cardiovascular screening of professional soccer teams in Norway was not able to prevent this.