Stroke: the combination of a patent foramen ovale and atrial septal aneurysm increased the risk of a recurrent stroke

Clinical bottom line (level 1b)

  1. One in twenty-five patients aged 18 to 55 with no clear cause for a stroke have another within 3 years
  2. Patients with a stroke and both a patent foramen ovale and atrial septal aneurysm were at increased risk for another stroke within 3 years.
  3. A patent foramen ovale alone or an atrial septal aneurysm alone did not clearly increased the risk of a recurrent stroke.
Mas et al: New Engl J Med 2001; 345 : 1740-1746
Expires December 2003

The study

Inception cohort study with objective outcomes, adjusted for confounding factors, validated in an independent set of patients.

Setting: 30 neurology departments, Europe

581 patients (aged mean 42, 57% male) with an ischaemic stroke and evidence of a patent foramen ovale or atrial septal aneurysm or both (48%); or no clear cause found (52%)

Excluded if
  • other cause for stroke found on work-up
  • follow-up impractical or compliance uncertain
  • contraindication to aspirin
  • aged < 18, > 55
  • incomplete work-up


Factors studied:
  • hypertension, diabetes, smoking, hypercholesterolaemia

    All patients had blood tests (including thrombophilia screen), 12-lead ECG and echocardiogrpahy, and either angiography, MR angiography or cervical and transcranial ultrasonography.

    Cox proportional-hazards analysis was used to adjust for confounding factors.

    99.7 followed for mean 3 years
    Outcomes studied:
  • recurrent stroke: no atrial septal abnormality
  • recurrent stroke: patent foramen ovale alone
  • recurrent stroke: atrial septal aneurysm alone
  • recurrent stroke: patent foramen ovale and atrial septal aneurysm

    The evidence

    outcome time to outcome number of patients/total number %
    (95% CI)    		 NNF
    (95% CI)
    recurrent stroke: no atrial septal abnormality mean 3 years 12/304 3.9%
    (1.8% to 6.1%)    		 25
    (16 to 57)
    recurrent stroke: patent foramen ovale alone mean 3 years 216/6 2.8%
    (0.6% to 5.0%)    		 36
    (20 to 170)
    recurrent stroke: atrial septal aneurysm alone mean 3 years 0/10 0.0%
    (0.0% to 26%)    		 -
    (4 to infinity)
    recurrent stroke: patent foramen ovale and atrial septal aneurysm mean 3 years 6/51 12%
    (2.9% to 21%)    		 9
    (5 to 34)

    • Patent foramen ovale and atrial septal aneurysm:
      • hazard ratio for recurrent stroke: 4.17 (95% CI: 1.47 to 11.8)
      • hazard ratio for recurrent stroke or TIA: 3.91 (95% CI: 1.59 to 9.59)

    Comments

    1. Patent foramen ovale or atrial septal aneurysm alone were not associated with recurrent stroke.
    2. The degree of shunting was no clearly associated with recurrent stroke.

    Citation

    1. Mas J-L, Arquizan C, Lamy C, et al: recurrent cerebrovascular events with patent foramen ovale, atrial septal aneurysm or both. New Engl J Med 2001; 345 : 1740-1746
    Search Terms: hand-search
    Contributor: Chris Ball, December 2001
    Reviewer:

    Clinical Question.
    Patient stroke
    Intervention or Exposure patent foramen ovale or atrial septal aneurysm
    Outcome recurrent stroke