Sudden Cardiac Death: Lessons Learned from Cardiac Implantable Rhythm Devices

Trials have demonstrated that implantable-cardioverter defibrillators (ICDs) are effective in preventing sudden cardiac death (SCD). The degree of left ventricular dysfunction is the only parameter to identify primary prevention populations at higher risk of SCD in which ICDs may reduce longitudinal mortality risk. Clinical application of current stratification approaches based on left ventricular ejection fraction (LVEF) alone has failed to prevent most SCD in the general population. This lack of specificity has resulted in a significant number of potentially unnecessary ICDs. Future studies should focus on newer risk markers to improve the predictive value of LVEF and SCD prevention.