Clinical outcomes of secondary prevention strategies for young patients with cryptogenic stroke and patent foramen ovale

Prognosis of Cryptogenic Stroke With Patent Foramen Ovale at Older Ages and Implications for Trials: A Population-Based Study and Systematic Review

Importance

Patent foramen ovale (PFO) closure may prevent recurrent stroke after cryptogenic transient ischemic attack (TIA) or stroke (TIA/stroke) in patients aged 60 years or younger. Patent foramen ovale is associated with cryptogenic stroke in the older population, but risk of recurrence is unknown. Data on prognosis of patients receiving medical treatment at older ages (≥60 years) are essential to justify trials of PFO closure.

Objective

To examine the age-specific risk of recurrence in patients with cryptogenic TIA/stroke with PFO.

Design, Setting, and Participants

A prospective study was nested in the population-based Oxford Vascular Study between September 1, 2014, and March 31, 2019, with face-to-face follow-up for 5 years. A total of 416 consecutive patients with a diagnosis of cryptogenic TIA or nondisabling stroke, screened for PFO at a rapid-access TIA/stroke clinic, were included. A systematic review and meta-analysis of cohort studies reporting on ischemic stroke recurrence after cryptogenic TIA/stroke in patients with PFO who were receiving medical therapy alone, or with PFO vs no-PFO was conducted. Sample size calculation for future trials on PFO closure was performed for patients aged 60 years or older.

Exposures

Patent foramen ovale and age as modifiers of risk of recurrent stroke after cryptogenic TIA/stroke in patients receiving only medical therapy.

Main Outcomes and Measures

Risk of ischemic stroke recurrence in patients with cryptogenic TIA/stroke and PFO receiving medical therapy only, and in patients with vs without PFO, stratified by age (<65 vs ≥65 years), as well as sample-size calculation for future trials of PFO closure in patients aged 60 years or older.

Results

Among the 153 Oxford Vascular Study patients with PFO (mean [SD] age, 66.7 [13.7] years; 80 [52.3%] men), recurrent ischemic stroke risk (2.05 per 100 patient-years) was similar to the pooled estimate from a systematic review of 23 other studies (9 trials and 14 observational studies) (2.00 per 100 patient-years; 95% CI, 1.55-2.58). However, there was heterogeneity between studies (P < .001 for heterogeneity), owing mainly to risk increasing with mean cohort age (meta-regression: R2 = 0.31; P = .003). In the pooled analysis of 4 studies including patients with or without PFO, increased risk of stroke recurrence with PFO was seen only at age 65 years or older (odds ratio, 2.5; 95% CI, 1.4-4.2; P = .001 for difference; P = .39 for heterogeneity). The pooled ischemic stroke risk was 3.27 per 100 patient-years (95% CI, 2.59-4.13) in 4 cohorts with mean age 60 years or older. Assuming the more conservative 2.0 per 100 patient-years ischemic stroke risk in the PFO nonclosure arms of future trials in patients aged 60 years or older, projected sample sizes were 1080 per arm for 80% power to detect a 33% relative risk reduction.

Conclusions and Relevance

The findings of this study suggest that age is a determinant of risk of ischemic stroke after cryptogenic TIA/stroke in patients with PFO, such that trials of PFO closure at older ages are justified; however, projected sample sizes are large.

The role of echocardiography in the embolic stroke of undetermined source

: Echocardiography plays an important role both in the diagnosis and the treatment/prevention of embolic stroke of undetermined source and should be performed as soon as possible for preventing ischemic stroke recurrencies, which occur more frequently during the first week after the first ischemic event. Early identification of the cause of a transient ischemic attack or stroke is indeed a primary goal for the neurologist in the Stroke Unit and requires specific diagnostic strategies. Echocardiography, together with other diagnostic tools such as carotid and transcranial ultrasounds, provides this information promptly. In particular, echocardiography might be able to detect the main sources of the embolic stroke, such as atrial fibrillation, ventricular akinesia, aortic atheroma plaques and/or cardiac shunts. The present review discusses the importance and the practical role of echocardiography as a crucial diagnostic tool for detecting the main source of emboli in the setting of the acute stroke.

High Eosinophil Rates in Patients With Right-to-Left Shunts: An Expected Role, or an Unexpected Risk?

Background and objective Eosinophils are associated with thromboembolic events. Since eosinophils are eliminated in the pulmonary vasculature, right-to-left shunt (RLS) through patent foramen ovale may increase eosinophils in the peripheral blood. In this report, we evaluated the eosinophils of patients with regard to the presence of RLS and its quantity. Patients and methods In this retrospective observational study, we analyzed the complete blood cell count (CBC) of patients with RLS (n=47) and without RLS (n=31) diagnosed by contrast echocardiography (CE). RLS was identified as mild (5-10 bubbles) and moderate shunt (10-25 bubbles). Results Age and CBC were not significantly different between the groups, with the exception of eosinophils. Patients with RLS had higher eosinophils percentage compared to patients without RLS (3.1 ±1.5 vs. 1.7 ±0.7, p=0.001). Additionally, eosinophils percentage was significantly higher in the mild RLS group (2.4 ±0.9 vs. 1.7 ±0.7, p=0.016) and the moderate RLS group (4.3 ±1.6 vs. 1.7 ±0.7, p=0.001) compared to normal subjects. Also, it was significantly higher in the moderate RLS group compared to the mild group (4.3 ±1.6 vs. 2.4 ±0.9, p=0.001). Conclusions Eosinophils percentage was higher in patients with mild and moderate RLS compared to normal individuals. Moreover, the eosinophil rate was higher in patients with moderate RLS than in patients with mild RLS.

Long-term efficacy after closure of patent foramen ovale for ischemic neurological events in young adults: A systematic review and meta-analysis

BACKGROUND

The efficacy of patent foramen ovale (PFO) closure remains controversial, and it is unclear which patient groups are best benefited. We performed this meta-analysis to clarify the efficacy of PFO closure of younger patients for prevention of recurrent ischemic neurological events.

METHODS

We systematically searched for studies of PFO closure for younger patients under the age of 55, and pooled available data on PFO closure of younger vs older patients and on PFO closure of younger patients vs medical therapy. The primary endpoints were the composite outcome of recurrent ischemic neurological events [stroke and/or transient ischemic attack (TIA)]. The secondary endpoints included recurrent stroke, TIA, atrial fibrillation (AF) and bleeding events. We calculated the odds ratios (OR) and 95% confidence interval (CI) using fixed-effect and random-effect models.

RESULTS

Three randomized controlled trials (RCT) and 13 observational studies were eligible. Compared with older patients undergoing PFO closure, younger patients undergoing closure had a lower risk of composite outcome (OR: 0.40, 95% CI: 0.28 to .56; P < .001) and AF (OR: 0.25, 95% CI: 0.10-0.61; P = .003). Compared with medical therapy, PFO closure of younger patients reduced the risk of composite outcome (OR: 0.50, 95% CI: 0.33-0.75; P<.001); there was no statistical difference in total complications of AF and bleeding events (OR: 2.15, 95% CI: 0.15-30.37; P = .57). Separate analysis of stroke and TIA showed that PFO closure in younger patients was more effective in preventing stroke (OR: 0.45, 95% CI: 0.28-0.72; P < .001) and TIA (OR: 0.35, 95% CI: 0.21-0.58); P < .001) compared with older patients. Compared with medical therapy, PFO closure of younger patients reduced the risk of stroke (OR: 0.26, 95% CI: 0.13-0.51; P < .001); but there was no difference in the risk of TIA (OR: 1.07, 95% CI: 0.16-7.01; P = .94).

CONCLUSIONS

Compared with PFO closure of older patients and medical therapy, PFO closure of younger patients can benefit more for the prevention of recurrent ischemic neurological events. Our results indicate that PFO closure is the best treatment strategy for younger patients under the age of 55.

Ultrasound-guided removal of organized thrombi using biopsy forceps in dialysis patients with arterio-venous access occlusion

INTRODUCTION

As a countermeasure against the organized thrombi frequently observed in vascular access occlusion, we devised a percutaneous excision method for organized thrombi under superficial ultrasound guidance using biopsy forceps. The Radial JawTM 3 (2 mm) biopsy forceps of Boston Scientific Corporation was used. The usefulness of this method was investigated.

METHOD

The following protocol, which is suitable for endovascular treatment, was prepared and used: (1) all procedures were performed under ultrasound guidance and (2) use of the forceps was assisted via a long sheath in cases involving a complicated bloodstream.

SUBJECTS

Among 564 cases of arterio-venous access occlusion that received treatment at this hospital between May 2014 and April 2017, the subjects of this study were 468 cases who could be followed up. Thrombectomy of an organized thrombus using the biopsy forceps was performed 194 times in 138 cases. Biopsy forceps were used in the initial treatment in a total of 115 cases, including 71 cases of acute occlusion of an autologous vein, 3 cases of chronic occlusion of an autologous vein, and 41 cases of acute occlusion of a prosthetic vessel.

RESULTS

The initial success rate for all cases of occlusion was 97.2%. The initial success rate for cases in which biopsy forceps were used was 98.2%. For cases using biopsy forceps, the primary patency rates were 47.1% at 3 months, and the secondary patency rates (until occlusion) were 89.1% at 3 months.

CONCLUSION

This method was considered to be a valuable choice as a countermeasure against organized thrombi.

Patent foramen ovale closure versus medical therapy for stroke prevention: A systematic review and meta-analysis of randomized controlled trials

Background: Previous randomized trials on patent foramen ovale (PFO) closure versus medical therapy for stroke prevention were inconclusive. Recently, two new randomized trials and new findings from an extended follow-up of a previous trial have been published on this topic. We conducted a systematic review and meta-analysis of randomized trials comparing PFO closure with medical therapy for stroke prevention.

Methods: PubMed and Cochrane Library were searched until 16 ^th September 2017.  The following search terms were used for PubMed: "patent foramen ovale" AND (stroke OR embolism) and "randomized" AND "Trial". For Cochrane Library, the following terms were used: "patent foramen ovale" AND "closure" AND (stroke OR embolism).

Results: A total of 91 and 55 entries were retrieved from each database using our search strategy respectively, of which six studies on five trials met the inclusion criteria. This meta-analysis included 1829 patients in the PFO closure arm (mean age: 45.3 years; 54% male) and 1972 patients in the medical therapy arm (mean age: 45.1 years; 51% male). The median follow-up duration was 50 ± 30 months. When compared to medical therapy, PFO closure significantly reduced primary endpoint events with a risk ratio [RR] of 0.60 (95% CI: 0.44-0.83, P < 0.0001; I²: 15%). It also reduced stroke (RR: 0.50, 95% CI: 0.35-0.73, P < 0.0001; I²: 32%) despite increasing the risk of atrial fibrillation/flutter (RR: 1.90, 95% CI: 1.23-2.93, P < 0.01; I²: 43%). However, it did not reduce transient ischemic accident events (0.75; 95% CI: 0.51-1.10, P = 0.14; I²: 0%), all-cause bleeding (RR: 0.89; 95% CI: 0.44-1.78, P = 0.74; I²: 51%) or gastrointestinal complications (RR: 0.92; 95% CI: 0.32-2.70, P = 0.88; I²: 0%).

Conclusions: PFO closure significantly reduces risk of stroke when compared to medical treatment and should therefore be considered for stroke prevention in PFO patients.

Patent foramen ovale closure versus medical therapy for stroke prevention: A systematic review and meta-analysis of randomized controlled trials

Background: Previous randomized trials on patent foramen ovale (PFO) closure versus medical therapy for stroke prevention were inconclusive. Recently, two new randomized trials and new findings from an extended follow-up of a previous trial have been published on this topic. We conducted a systematic review and meta-analysis of randomized trials comparing PFO closure with medical therapy for stroke prevention. Methods: PubMed and Cochrane Library were searched until 16 th September 2017.  The following search terms were used for PubMed: "patent foramen ovale" AND (stroke OR embolism) and "randomized" AND "Trial". For Cochrane Library, the following terms were used: "patent foramen ovale" AND "closure" AND (stroke OR embolism). Results: A total of 91 and 55 entries were retrieved from each database using our search strategy respectively, of which six studies on five trials met the inclusion criteria. This meta-analysis included 1829 patients in the PFO closure arm (mean age: 45.3 years; 54% male) and 1972 patients in the medical therapy arm (mean age: 45.1 years; 51% male). The median follow-up duration was 50 ± 30 months. When compared to medical therapy, PFO closure significantly reduced primary endpoint events with a risk ratio [RR] of 0.60 (95% CI: 0.44-0.83, P < 0.0001; I 2: 15%). It also reduced stroke (RR: 0.50, 95% CI: 0.35-0.73, P < 0.0001; I 2: 32%) despite increasing the risk of atrial fibrillation/flutter (RR: 1.90, 95% CI: 1.23-2.93, P < 0.01; I 2: 43%). However, it did not reduce transient ischemic accident events (0.75; 95% CI: 0.51-1.10, P = 0.14; I 2: 0%), all-cause bleeding (RR: 0.89; 95% CI: 0.44-1.78, P = 0.74; I 2: 51%) or gastrointestinal complications (RR: 0.92; 95% CI: 0.32-2.70, P = 0.88; I 2: 0%). Conclusions: PFO closure significantly reduces risk of stroke when compared to medical treatment and should therefore be considered for stroke prevention in PFO patients.