Meta-analysis of Randomized Controlled Trials on Patent Foramen Ovale Closure Versus Medical Therapy for Secondary Prevention of Cryptogenic Stroke

Machine learning in a real-world PFO study: analysis of data from multi-centers in China

PURPOSE

The association of patent foreman ovale (PFO) and cryptogenic stroke has been studied for years. Although device closure overall decreases the risk for recurrent stroke, treatment effects varied across different studies. In this study, we aimed to detect sub-clusters in post-closure PFO patients and identify potential predictors for adverse outcomes.

METHODS

We analyzed patients with embolic stroke of undetermined sources and PFO from 7 centers in China. Machine learning and Cox regression analysis were used.

RESULTS

Using unsupervised hierarchical clustering on principal components, two main clusters were identified and a total of 196 patients were included. The average age was 42.7 (12.37) years and 64.80% (127/196) were female. During a median follow-up of 739 days, 12 (6.9%) adverse events happened, including 6 (3.45%) recurrent stroke, 5 (2.87%) transient ischemic attack (TIA) and one death (0.6%). Compared to cluster 1 (n = 77, 39.20%), patients in cluster 2 (n = 119, 60.71%) were more likely to be male, had higher systolic and diastolic blood pressure, higher body mass index, lower high-density lipoprotein cholesterol and increased proportion of presence of atrial septal aneurysm. Using random forest survival (RFS) analysis, eight top ranking features were selected and used for prediction model construction. As a result, the RFS model outperformed the traditional Cox regression model (C-index: 0.87 vs. 0.54).

CONCLUSIONS

There were 2 main clusters in post-closure PFO patients. Traditional cardiovascular profiles remain top ranking predictors for future recurrence of stroke or TIA. However, whether maximizing the management of these factors would provide extra benefits warrants further investigations.

Incidence and time course of atrial fibrillation following patent foramen ovale closure

OBJECTIVES

Determine the true incidence and time course of atrial fibrillation (AF) after patent foramen ovale closure (PFOc) using implantable loop recorders (ILR) placed during cryptogenic stroke evaluation.

BACKGROUND

Published trials report a 2%-6.6% incidence of postimplant atrial fibrillation (PIAF) after PFOc, which is probably a gross underestimation, as only patients presenting in AF were captured. Episodes of paroxysmal and silent AF would have been missed.

METHODS

Of 761 patients who underwent PFOc at a single center between January 2016 and December 2020, 35 patients had an ILR implanted before PFOc, without documentation of AF, and had ≥1 month of monitoring post-PFOc. The incidence, onset, and conclusion of AF episodes were determined from a review of patient records.

RESULTS

The mean duration of ILR monitoring was 54.6 ± 39.4 weeks after PFOc. AF occurred in 13/35 (37%) patients. PFOc patients who developed PIAF were older than those who did not (62 ± 11 vs. 52 ± 14 years, p = 0.03). In 12/13, the initial PIAF event occurred within 4 weeks of PFOc, with the greatest frequency around 2 weeks and conclusion by 12 weeks in all. No recurrent strokes occurred during ILR monitoring.

CONCLUSION

The actual incidence of PIAF was far greater than previously reported and was significantly associated with older age at PFOc. The timing of PIAF onset and termination were consistent with a postimplant inflammatory mechanism. The higher actual PIAF incidence underscores its low stroke potential in this population. A larger prospective trial is required to validate these preliminary results.

Effect of Patent Foramen Ovale Closure After Stroke on Circulatory Biomarkers

OBJECTIVE

To determine the influence of patent foramen ovale (PFO) closure on circulatory biomarkers.

METHODS

Consecutive patients with PFO-related stroke were prospectively enrolled and followed with serial sampling of cardiac atrial and venous blood pre- and post-PFO closure over time. Candidate biomarkers were identified by mass spectrometry in a discovery cohort first, and lead candidates were validated in an independent cohort.

RESULTS

Patients with PFO-related stroke (n = 254) were recruited and followed up to 4 years (median 2.01; interquartile range 0.77-2.54). Metabolite profiling in the discovery cohort (n = 12) identified homocysteine as the most significantly decreased factor in intracardiac plasma after PFO closure (false discovery rate 0.001). This was confirmed in a validation cohort (n = 181), where intracardiac total homocysteine (tHcy) was immediately reduced in patients with complete closure, but not in those with residual shunting, suggesting association of PFO shunting with tHcy elevation (β 0.115; 95% confidence interval [CI] 0.047-0.183; p = 0.001). tHcy reduction was more dramatic in left atrium than right (p < 0.001), suggesting clearance through pulmonary circulation. Long-term effect of PFO closure was also monitored and compared to medical treatment alone (n = 61). Complete PFO closure resulted in long-term tHcy reduction in peripheral blood, whereas medical therapy alone showed no effect (β -0.208; 95% CI -0.375∼-0.058; p = 0.007). Residual shunting was again independently associated with persistently elevated tHcy (β 0.184; 95% CI 0.051-0.316; p = 0.007).

CONCLUSIONS

PFO shunting may contribute to circulatory tHcy elevation, which is renormalized by PFO closure. PFO is not just a door for clots, but may itself enhance clot formation and injure neurovasculature by clot-independent mechanisms. Biomarkers such as tHcy can potentially serve as cost-effective measures of residual shunting and neurovascular risk for PFO stroke.

Neurological Complications of Cardiac Procedures

Neurological complications after cardiac surgery and percutaneous cardiac interventions are not uncommon. These include periprocedural stroke, postoperative cognitive dysfunction after cardiac surgery, contrast-induced encephalopathy after percutaneous interventions, and seizures. In this article, we review the incidence, pathophysiology, diagnosis, and management of these complications. Improved understanding of these complications could lead to their prevention, faster detection, and facilitation of diagnostic workup and appropriate treatment.

Role of PFO Closure in Ischemic Stroke Prevention

PURPOSE OF REVIEW

To highlight recent advancements in the management of acute ischemic stroke patients with patent foramen ovale (PFO).

RECENT FINDINGS

One significant recent development was publication of long-term follow-up data from the RESPECT trial demonstrating evidence in favor of PFO closure over medical management. This data subsequently led to FDA approval for AMPLATZER™ septal occluder in the treatment of patients aged 18 to 60 years with both PFO and no other determined etiology for ischemic stroke, otherwise referred to as embolic stroke of undetermined source. Several subsequent closure trial results have recently been published, which also demonstrated benefit of PFO closure over medical management for ischemic stroke risk reduction in select patients. Based on the results of the more recently published REDUCE trial, the FDA granted approval for the GORE™ septal occluder. There is current, well-established evidence that PFO closure for secondary stroke prevention is effective in select cases.

Who benefits from percutaneous closure of patent foramen ovale vs medical therapy for stroke prevention? In-depth and updated meta-analysis of randomized trials

BACKGROUND

A few randomized clinical trials (RCT) and their meta-analyses have found patent foramen ovale closure (PFOC) to be beneficial in prevention of stroke compared to medical therapy. Whether the benefit is extended across all groups of patients remains unclear.

AIM

To evaluate the efficacy and safety of PFOC vs medical therapy in different groups of patients presenting with stroke, we performed this meta-analysis of RCTs.

METHODS

Electronic search of PubMed, EMBASE, Cochrane Central, CINAHL and ProQuest Central and manual search were performed from inception through September 2018 for RCTs. Ischemic stroke (IS), transient ischemic attack (TIA), a composite of IS, TIA and systemic embolism (SE), mortality, major bleeding, atrial fibrillation (AF) and procedural complications were the major outcomes. Random-effects model was used to perform analyses.

RESULTS

Meta-analysis of 6 RCTs including 3560 patients showed that the PFOC, compared to medical therapy reduced the risk of IS [odds ratio: 0.34; 95% confidence interval: 0.15-0.78; P = 0.01] and the composite of IS, TIA and SE [0.55 (0.32-0.93); P = 0.02] and increased the AF risk [4.79 (2.35-9.77); P < 0.0001]. No statistical difference was observed in the risk of TIA [0.86 (0.54-1.38); P = 0.54], mortality [0.74 (0.28-1.93); P = 0.53] and major bleeding [0.81 (0.42-1.56); P = 0.53] between two strategies. Subgroup analyses showed that compared to medical therapy, PFOC reduced the risk of stroke in persons who were males, ≤ 45 years of age and had large shunt or atrial septal aneurysm.

CONCLUSION

In certain groups of patients presenting with stroke, PFOC is beneficial in preventing future stroke compared to medical therapy.

Updated Meta-analysis on the Closure of Patent Foramen Ovale in Reduction of Stroke Rates: the DEFENSE-PFO Trial Does not Change the Scenario

Objective

We aimed to analyze whether patent foramen ovale (PFO) closure reduces the risk of stroke, assessing also some safety outcomes after the publication of a new trial.

Introduction

The clinical benefit of closing a PFO has been an open question, so it is necessary to review the current state of published medical data in regards to this subject.

Methods

MEDLINE, EMBASE, CENTRAL/CCTR, SciELO, LILACS, Google Scholar and reference lists of relevant articles were used to search for randomized controlled trials (RCTs) that reported any of the following outcomes: stroke, death, major bleeding or atrial fibrillation. Six studies fulfilled our eligibility criteria and included 3560 patients (1889 for PFO closure and 1671 for medical therapy.

Results

The risk ration (RR) for stroke in the “closure” group compared with the “medical therapy” showed a statistically significant difference between the groups, favouring the “closure” group (RR 0.366; 95%CI 0.171–0.782, P=0.010). There was no statistically significant difference between the groups regarding the safety outcomes, death and major bleeding, but we observed an increase in the risk of atrial fibrillation in the “closure” group (RR 4.131; 95%CI 2.293–7.443, P<0.001). We also observed that the larger the proportion of effective closure, the lower the risk of stroke.

Conclusion

This meta-analysis found that stroke rates are lower with percutaneously implanted device closure than with medical therapy alone, being these rates modulated by the rates of hypertension, atrial septal aneurysm and effective closure. The publication of a new trial did not change the scenario in the medical literature.

Are we there yet with patent foramen ovale closure for secondary prevention in cryptogenic stroke? A systematic review and meta-analysis of randomized trials

Background:

We performed a meta-analysis to evaluate the benefit of patent foramen ovale closure in stroke prevention.

Methods:

We searched Medline/PubMed, EMBASE, Web of Science and Cochrane central database for randomized control trials assessing the incidence of recurrent stroke after patent foramen ovale closure when compared to medical therapy. Pooled odds ratio and 95% confidence intervals were calculated using a random effects model. The heterogeneity among studies was tested using the χ² test and inconsistency was quantified using the I² statistic.

Results:

Our search strategy yielded 71 articles. We included five studies with a total of 3440 patients. Median age in the device group was 45 (43, 5.5) years and in the medical group was 45 (44.5, 46) years; 52% were male, 27.7% of patients had an atrial septal aneurysm, 25% had hypertension, and 20.5% had diabetes mellitus. The median follow-up time was 44 (34.5–50) months. The pooled odds ratio of recurrent stroke, transient ischemic attack and composite end point of stroke + transient ischemic attack + peripheral embolism in the patent foramen ovale closure versus medical therapy group were 0.4 (95% confidence interval 0.25–0.63, I² = 57.5%), 0.93 (95% confidence interval 0.61–1.42, I² = 0%), and 0.6 (95% confidence interval 0.44–0.82, I² = 0%), respectively. The incidence of atrial fibrillation was found to be significantly higher in the patent foramen ovale closure group with odds ratio of 6 (95% confidence interval 3.13–11.4, I² = 33.5%). On subgroup analysis, patent foramen ovale closure appeared to benefit males and patients with a large shunt. Number needed to treat to prevent one recurrent stroke with patent foramen ovale closure is 42. Number needed to harm to cause one atrial fibrillation with patent foramen ovale closure is 39.

Conclusion:

This meta-analysis of randomized trials concludes that percutaneous patent foramen ovale closure is effective in recurrent stroke prevention especially in males and in those with a large shunt.

Secondary prevention of cryptogenic stroke in patients with patent foramen ovale: a systematic review and meta-analysis

The aim of our study is to compare patent foramen ovale (PFO) closure versus medical treatment and antiplatelet versus anticoagulant therapy in patients with cryptogenic stroke (CS) and PFO. We conducted a systematic review and meta-analysis with trial sequential analysis (TSA) of randomized trials. Primary outcomes are stroke or transient ischemic attack (TIA) and all-cause mortality. Secondary outcomes are peripheral embolism, bleeding, serious adverse events, myocardial infarction and atrial dysrhythmias. We performed an intention to treat meta-analysis with a random-effects model. We include six trials (3677 patients, mean age 47.3 years, 55.8% men). PFO closure is associated with a lower recurrence of stroke or TIA at a mean follow-up of 3.88 years compared to medical therapy [risk ratio (RR) 0.55, 95% CI 0.38-0.81; I² = 40%]. The TSA confirms this result. No difference is found in mortality (RR 0.74, 95% CI 0.35-1.60; I² = 0%), while PFO closure is associated with a higher incidence of atrial dysrhythmias (RR 4.55, 95% CI 2.16-9.60; I² = 25%). The rate of the other outcomes is not different among the two groups. The comparison between anticoagulant and antiplatelet therapy shows no difference in terms of stroke recurrence, mortality and bleeding. There is conclusive evidence that PFO closure reduces the recurrence of stroke or TIA in patients younger than 60 years of age with CS. More data are warranted to assess the consequences of the increase in atrial dysrhythmias and the advantage of PFO closure over anticoagulants.

Rivaroxaban or aspirin for patent foramen ovale and embolic stroke of undetermined source: a prespecified subgroup analysis from the NAVIGATE ESUS trial

BACKGROUND

Patent foramen ovale (PFO) is a contributor to embolic stroke of undetermined source (ESUS). Subgroup analyses from previous studies suggest that anticoagulation could reduce recurrent stroke compared with antiplatelet therapy. We hypothesised that anticoagulant treatment with rivaroxaban, an oral factor Xa inhibitor, would reduce the risk of recurrent ischaemic stroke compared with aspirin among patients with PFO enrolled in the NAVIGATE ESUS trial.

METHODS

NAVIGATE ESUS was a double-blinded, randomised, phase 3 trial done at 459 centres in 31 countries that assessed the efficacy and safety of rivaroxaban versus aspirin for secondary stroke prevention in patients with ESUS. For this prespecified subgroup analysis, cohorts with and without PFO were defined on the basis of transthoracic echocardiography (TTE) and transoesophageal echocardiography (TOE). The primary efficacy outcome was time to recurrent ischaemic stroke between treatment groups. The primary safety outcome was major bleeding, according to the criteria of the International Society of Thrombosis and Haemostasis. The primary analyses were based on the intention-to-treat population. Additionally, we did a systematic review and random-effects meta-analysis of studies in which patients with cryptogenic stroke and PFO were randomly assigned to receive anticoagulant or antiplatelet therapy.

FINDINGS

Between Dec 23, 2014, and Sept 20, 2017, 7213 participants were enrolled and assigned to receive rivaroxaban (n=3609) or aspirin (n=3604). Patients were followed up for a mean of 11 months because of early trial termination. PFO was reported as present in 534 (7·4%) patients on the basis of either TTE or TOE. Patients with PFO assigned to receive aspirin had a recurrent ischaemic stroke rate of 4·8 events per 100 person-years compared with 2·6 events per 100 person-years in those treated with rivaroxaban. Among patients with known PFO, there was insufficient evidence to support a difference in risk of recurrent ischaemic stroke between rivaroxaban and aspirin (hazard ratio [HR] 0·54; 95% CI 0·22-1·36), and the risk was similar for those without known PFO (1·06; 0·84-1·33; p_interaction=0·18). The risks of major bleeding with rivaroxaban versus aspirin were similar in patients with PFO detected (HR 2·05; 95% CI 0·51-8·18) and in those without PFO detected (HR 2·82; 95% CI 1·69-4·70; p_interaction=0·68). The random-effects meta-analysis combined data from NAVIGATE ESUS with data from two previous trials (PICSS and CLOSE) and yielded a summary odds ratio of 0·48 (95% CI 0·24-0·96; p=0·04) for ischaemic stroke in favour of anticoagulation, without evidence of heterogeneity.

INTERPRETATION

Among patients with ESUS who have PFO, anticoagulation might reduce the risk of recurrent stroke by about half, although substantial imprecision remains. Dedicated trials of anticoagulation versus antiplatelet therapy or PFO closure, or both, are warranted.

FUNDING

Bayer and Janssen.