Figure 4.
This figure is based on the following assumptions: 1) annualized average stroke recurrence risk is 2%; 2) degree of risk heterogeneity is moderate (extreme quintile risk ratio is 20); 3) 60% of recurrent strokes are caused by paradoxical embolism; 4) PFO devices are 100% effective in preventing recurrent paradoxical embolism; and 5) PFO devices are associated with a small degree of treatment-related stroke risk (2 in 1000 per year).