Sudden cardiac arrest due to ventricular arrhythmias, with an estimated annual incidence of 350,000 events, is a condition with significant implications for public health, accounting for 40-50% of all cardiovascular deaths in the United States. A cornerstone of this program is the Oregon Sudden Unexpected Death Study (Oregon SUDS), the largest community-based, (population approximately 1 million residents) comprehensive evaluation of its kind. Established in 2002 and currently funded by the National Heart, Lung, and Blood Institute and the American Heart Association, this ongoing multidisciplinary study uses a population-based, case-control design. The Oregon SUDS continues to yield information about novel clinical, genetic and biochemical pathways involved in the genesis of ventricular arrhythmias, with goals of enhancing the methods of preventing and managing sudden cardiac arrest and advancing the understanding of the mechanisms of pulseless electrical activity and ventricular fibrillation. As of 2015, the Oregon SUDS has been expanded to include Ventura County, California (pop. 850,000) under the umbrella of the PRESTO Network. The two population cohorts are now being leveraged as discovery and replication samples. In a recently published study, a novel clinical algorithm for avertable or treatable sudden cardiac death was discovered in Oregon SUDS and replicated in Ventura PRESTO. Ventricular fibrillation (VF) and pulseless ventricular tachycardia (VT) are potentially treatable with defibrillation, thereby averting sudden cardiac death (SCD). Targeting an intermediate risk population, we developed a novel and user-friendly clinical prediction algorithm (VFRisk) for avertable SCD. Constructed with 13 clinical, ECG and echocardiographic variables, VFRisk performed well and was successfully validated in internal and external datasets. The algorithm substantially outperformed left ventricular ejection fraction (LVEF) ≤ 35% and performed equally well across the LVEF spectrum. These findings have the potential to enhance primary prevention, especially in patients with midrange or preserved LVEF.