Patent foramen ovale closure, antiplatelet therapy or anticoagulation therapy alone for management of cryptogenic stroke
Health technology assessment
|Published
Patent foramen ovale (PFO) represents an opening in the heart placing people at risk of ischemic stroke. This report evaluates catheter-based PFO closure as an alternative treatment to antiplatelet therapy or anticoagulation for patients with a PFO having suffered a stroke.
Key message
Patent foramen ovale (PFO) represents an opening in the heart placing people at risk of ischemic stroke. This report evaluates catheter-based PFO closure as an alternative treatment to antiplatelet therapy or anticoagulation for patients with a PFO having suffered a stroke.
Our findings:
- PFO closure plus antiplatelet therapy probably results in a large decrease in ischemic stroke, when compared to antiplatelet therapy alone (8.7% absolute risk reduction, moderate certainty evidence)
- There may be little or no difference in the risk for ischemic stroke when comparing PFO closure to anticoagulation (low certainty evidence)
- Compared to anticoagulation, PFO closure will probably result in fewer cases of major bleeding (2% absolute risk reduction, moderate certainty evidence)
- PFO closure comes with an increased risk of adverse events (3.6%), such as procedure-related complications and atrial fibrillation
- PFO closure is very likely a cost-effective treatment alternative to medical management
- Assuming available capacity, the annual budget impact of national implementation is NOK 34 million
- PFO closure introduces both patient and operator to radiation comparable to other routine procedures
- PFO closure may require additional investments in increased intervention capacity and likely also a need for additional diagnostic investigations in Norwegian hospitals
Summary
Background
Some people have an opening in the partition between the anterior ventricles, a patent foramen ovale (PFO). Such an opening is relatively common and most individuals will never notice any ailments. However, in some individuals, a PFO can lead to an ischemic stroke.
If a patient subsequently to an ischemic stroke is carefully examined and no other causes of the stroke are identified, but a PFO is detected, then closing the PFO may be a treatment option to prevent new embolic strokes. Today's treatment is drug prevention with platelet inhibitor or anticoagulation.
Objective
The purpose of this report is to investigate whether PFO closure is an effective and cost-effective alternative to medical treatment.
Method
The commission of this report contained a new systematic overview of the efficacy and safety of PFO closure compared to treatment with platelet inhibitors and anticoagulation. In line with our methods, we conducted a systematic search for other systematic reviews published in 2018. We chose the systematic overview with relevant comparator and which had the most participants and most recent literature search.
We developed a health economic model in dialogue with clinical experts. The model is a Markov model with a lifetime perspective. Included in the model is the effect of measures on the outcomes of ischemic stroke and large bleeding. The model also includes a number of sequelae states defined based on the modified ranking scales (mRS). Input data for the model is based on published literature. Health effects and costs are discounted by 4%. The absolute shortfall for patients with PFO and a previous ischemic stroke receiving the current treatment is calculated as specified in the guidelines of the Norwegian Medicines Agency.
The Norwegian Radiation and Nuclear Safety Authority have carried out assessment of radiation effects of introduction. Possible organisational consequences are outlined based on assumptions and input from clinical experts. Cardiologists and neurologists in the clinical expert group have added their own paragraphs to the chapter on organisational consequences.
Results
We identified 18 potentially relevant studies, of which 13 were systematic reviews. 11 of these 13 compared PFO closure with medical treatment, but did not distinguish between type of drug in the comparator. Two studies report separate efficacy estimates for comparison with platelet inhibitors and anticoagulation, one of which had a higher number of participants and a recent literature search.
The chosen systematic overview indicates that PFO closure in patients under the age of 60 with stroke reduces the risk of new stroke compared to platelet inhibition (OR: 0.12, 95% CI: 0.04-0.27, moderate quality of documentation). Compared with anticoagulation treatment, the effect of PFO closure on stroke is more uncertain (OR: 0.44. 95% CI: 0.08-3.83, low quality of documentation). However, PFO closure is likely to result in fewer serious bleedings than anticoagulant treatment.
PFO in persons with a previous stroke is calculated to provide an absolute shortfall of 14.8 years in good health (quality adjusted life years, QALYs) compared to the normal population.
PFO closure leads to a large gain in the form of QALYs and cost savings over a lifetime perspective. As an alternative to treatment with platelet inhibitors, PFO closure has been estimated to give a 98% probability of being cost-effective alternative. Compared to anticoagulation, the health benefits and cost savings are less, but still large compared to other technologies. Compared to anticoagulation, PFO has an estimated probability of 80% to be a cost-effective alternative. The uncertainty in cost-effectiveness is less than the uncertainty in single outcomes of clinical efficacy, as both the effect of fewer ischemic strokes; fewer large bleeds and the effect of minor sequelae are here captured in a single, pooled estimate.
Budget effect per year of PFO closure is likely to be approximately NOK 34 million. The estimate does not include any investment in increased capacity.
PFO closure introduces patient and operator for ionizing radiation compared to medical treatment. The dose levels are comparable to other common cardiac procedures and will be eligible for PFO closure.
A national introduction of PFO closure as a method will lead to the need for training as well as increased capacity for diagnostics and treatment.
Conclusion
Compared to platelet inhibitors, PFO closure is clinically effective in preventing new strokes in patients under the age of 60 with cryptogenic stroke and PFO. Compared to anticoagulation, the effect on the prevention of new stroke is uncertain, however, PFO closure will probably lead to fewer cases of major bleedings.
PFO closure is very likely a cost-effective alternative to drug treatment.
The radiation effects are comparable to other cardiac procedures.
The national introduction of PFO closure will implicate organisational consequences in the form of increased need for training, increased capacity for diagnostics and treatment. Organisational consequences should be considered to be investigated further by the Regional Health Authorities before implementation.
