Prevalence of patent foramen ovale in the Greek population is high and impacts on the interpretation of the risk of paradoxical embolism (RoPE) score

Abstract

Background: The risk of paradoxical embolism (RoPE) score calculates the probability that patent foramen ovale (PFO) is causally related to stroke (PFO attributable fraction, PFOAF), based on PFO prevalence in patients with cryptogenic stroke (CS) compared with that in the general population. The latter has been estimated at 25%; however, PFO prevalence in nonselected populations varies widely. Methods: Since PFO prevalence in Greece remains unknown, we evaluated it and we calculated PFOAF stratified by RoPE score in a cohort of patients with CS ⩽55 years old. PFO was detected according to the international consensus transcranial Doppler (TCD) criteria in 124 healthy subjects (H), in 102 patients with CS, and in 56 patients with stroke of known cause (nonCS). Each subject underwent unilateral middle cerebral artery recording after infusion of agitated saline, at rest, and after a controlled Valsalva maneuver. We characterized PFO as large (>20 microbubbles or curtain), moderate (11–20), and small (⩽10). Results: PFO was detected in 42.7% of H, 49% of CS, and 25% of nonCS ( p = 0.013). Large PFOs were numerically higher in CS [28.4% (29/102)] compared with H [19.3% (24/124); p = 0.1] and to nonCS [7.1% (4/56), p = 0.04]. The median RoPE score in patients with CS and PFO was seven. Even patients with very high RoPE score (9–10) had moderate PFOAF (57%). For any individual stratum up to RopE score 8, PFOAF was <33%. Conclusions: PFO prevalence in the Greek population is much higher than the widely accepted 25%. PFO may be the cause of stroke in one out of nine Greek patients with CS. Among Greek CS patients who harbor a PFO, the latter is causal in one out of five. The established RoPE score cutoff of ⩾7 for having a probable PFO-associated stroke may overestimate the probability in patients deriving from populations with high PFO prevalence.

Large regional variation in cardiac closure procedures to prevent ischemic stroke in Switzerland a population-based small area analysis

“…The average Swiss, German, and Italian PFO closure rates (average 5 per 100,000 persons) appears to be substantially higher than in France (2.9 per 100,000) and the UK (0.5 per 100,000) [ 13 ]. While differing procedure rates across countries could be caused by health care system related differences [ 29 ] or differences in the prevalence of PFO [ 30 ] and the PFO detection rates, the high regional variation in PFO closure within Switzerland, a country with a homogenous health care system and good access to care, is unclear. With a low variation in stroke rates across Switzerland [ 33 ] and assuming similar patient preferences across Swiss regions, the variation is most likely partially due to differing local practice patterns [ 57 ].…”

“…system related differences [29] or differences in the prevalence of PFO [30] and the PFO detection rates, the high regional variation in PFO closure within Switzerland, a country with a homogenous health care system and good access to care, is unclear. With a low variation in stroke rates across Switzerland [33] and assuming similar patient preferences across Swiss regions, the variation is most likely partially due to differing local practice patterns [57].…”

“…Compared to other European countries, Switzerland and Germany had substantially higher PFO closure rates in 2018 [ 13 ]. Various factors may explain variation in PFO closure rates across countries including differing health care system related factors (e.g., access to specialists and reimbursement) [ 29 ], variation in the prevalence of PFO and PFO detection rates across countries [ 30 , 31 ], and the uptake of novel interventions. Switzerland has universal health care coverage, good access to care, the same nationwide reimbursement system, and a very low regional variation in cardiovascular mortality [ 32 ] and stroke rate [ 33 ], indicating similar cardiovascular disease incidences across Swiss regions.…”

Prevalence and characteristics of patent foramen ovale in a sample of Egyptian population: a computed tomography study

“…Universally about a quarter of adults have PFO [ 2 , 3 ]. A study on Greek population showed a much higher prevalence (42.7% of healthy population, and 49% of patients with cryptogenic stroke) [ 4 ]. No data exist regarding the prevalence of PFO in the general population in Egypt.…”

Connection between right-to-left shunt and photosensitivity: a community-based cross-sectional study

“…Meanwhile, the incidence of a right-to-left shunt (RLS) is ~50–60% in migraineurs, which is similar to that of photophobia ( 7 , 8 ). RLS allows micro-emboli, air emboli, and partial unoxygenated venous blood to enter the systemic circulation directly, which can trigger cortical spreading depression (CSD) ( 9 , 10 ).…”