Prevalence of PFO
Patent foramen ovale (PFO) is the most common structural heart defect, with a prevalence of nearly 25 percent in the general population.1 In a portion of these adults, by maintaining a direct communication between the right- and left-sided circulation, PFO can serve as a conduit for paradoxical embolization.2
Existing data show there is a strong association between the presence of patent foramen ovale and cryptogenic stroke independent of age, and that paradoxical embolism is a cause of stroke (Figure 1).3 Percutaneous closure aims to reduce the risk of recurrent thromboembolic events with less procedural morbidity and faster recovery time than that associated with open heart surgery.
Figure 1: Prevalence of PFO is three times more common in cryptogenic stroke than stroke of known cause.3
RESPECT clinical trial
The RESPECT clinical trial was initiated to assess patent foramen ovale (PFO) closure with the AMPLATZER™ PFO Occluder plus medical management compared to medical management alone in the prevention of recurrent cryptogenic strokes in patients with PFO.
The RESPECT trial demonstrated that, for well-selected patients with a history of cryptogenic stroke and PFO, closure with the AMPLATZER PFO Occluder is a safe and effective treatment option for secondary stroke prevention in these otherwise young and healthy patients.4-6
Study results include:7
- The per-protocol analysis (compares patients based on the randomized assignment but who adhered to all significant protocol requirements) showed a 63% relative risk reduction for recurrent ischemic stroke among patients who received device closure with the AMPLATZER PFO Occluder compared to medical management alone.
- 99.1% of patients were successfully implanted in a first procedure.
- The rate of procedure- or device-related serious adverse events in the device arm was less than 5%.
- Analysis of extended follow-up data showed a significant relative risk reduction of 54% in recurrent ischemic strokes of undetermined mechanism (cryptogenic) among patients who received device closure with the AMPLATZER PFO Occluder compared to medical management alone.