McAlister FA, et al. - Because cryptogenic strokes are often the first clinical sign of undiagnosed atrial fibrillation (AF), researchers evaluated whether parental AF in young adults is a risk factor for stroke. Using linked administrative databases from April 1, 1972, to March 31, 2016, they conducted a population-based cohort study involving 325,333 offspring (age ≥ 18 years) with ≥ 1 linked parent (n=582,195). Using multivariable Cox proportional hazards models, the link between parental history of AF and stroke or transient ischemic attack in the offspring was examined. After adjusting for demographics, a region of residence, socioeconomic status, and other stroke risk factors in offspring, parental AF was linked to AF in their offspring in young adulthood. Parental AF was found to be related to increased risk of AF in offspring during early adulthood and other cardiovascular risk factors, leading to increased risk of stroke.