Cardiac right-to-left shunt subtypes in Chinese patients with cryptogenic strokes: a multicenter case-control study

Contrast-enhanced transcranial doppler versus contrast transthoracic echocardiography for right-to-left shunt diagnosis

RLS can be diagnosed using US, CT angiography, and right heart catheterization. However, most reliable diagnostic modality remains undetermined. c-TCD was more sensitive than c-TTE in the diagnosis of RLS. This was true especially for the detection of provoked shunts or mild shunts. c-TCD can be used as the preferred screening method for RLS.

Evaluation of right-to-left shunt on contrast-enhanced transcranial Doppler in patent foramen ovale-related cryptogenic stroke: Research based on imaging

BACKGROUND

Cardiogenic embolism caused by patent foramen ovale (PFO) is a common etiology of cryptogenic stroke (CS), particularly in young and middle-aged patients. Studies about right-to-left shunt (RLS) detection using contrast-enhanced transcranial Doppler (c-TCD) are numerous. According to the time phase and number of microbubbles detected on c-TCD, RLS can be classified and graded. We hypothesized that the characteristics of an infarction lesion on diffusion-weighted imaging differs when combining the type and grade of RLS on c-TCD in patients with PFO-related CS.

AIM

To explore the characteristics of infarction lesions on diffusion-weighted imaging when combining the RLS type and grade determined by c-TCD.

METHODS

We retrospectively evaluated CS patients from August 2015 to December 2019 at a tertiary hospital. In total, 111 PFO-related CS patients were divided according to whether RLS was permanent (microbubbles detected both at resting state and after the Valsalva maneuver) or latent (microbubbles detected only after the Valsalva maneuver) on c-TCD. Each group was subdivided into small, mild and large RLS according to the grade of shunt on c-TCD. A normal control group was composed of 33 patients who suffered from simple dizziness. Intragroup and intergroup differences were analyzed in terms of clinical, laboratory and diffusion-weighted imaging lesion characteristics. The correlation between RLS grade evaluated by c-TCD and size of PFO determined by transesophageal echocardiography were also analyzed.

RESULTS

In 111 patients with PFO-related CS, 68 had permanent RLS and 43 had latent RLS. Clinical characteristics and laboratory tests were not significantly different among the permanent RLS, latent RLS and normal control groups. The proportion of patients with multiple territory lesions in the permanent RLS group (50%) was larger than that in the latent RLS group (27.91%; P = 0.021). Posterior circulation was more likely to be affected in the latent RLS group than in the permanent RLS group (30.23% vs 8.82%, P = 0.004). Permanent-large and latent-large RLS were both more likely to be related to multiple (P_trend = 0.017 and 0.009, respectively), small (P_trend = 0.035 and 0.006, respectively) and cortical (P_trend = 0.031 and 0.033, respectively) lesions. The grade of RLS evaluated by c-TCD was correlated to the size of PFO determined by transesophageal echocardiography (r = 0.758, P < 0.001).

CONCLUSION

Distribution of the infarct suggested the possible type of RLS. Multiple, small and cortical infarcts suggest large RLS induced by a large PFO.

Surgical vs. drug therapy in patients with patent foramen ovale and cryptogenic stroke

OBJECTIVE

This study aimed to investigate the effectiveness of risk scoring for predicting stroke recurrence after percutaneous patent foramen ovale (PFO) closure or medication therapy in patients with PFO and a history of cryptogenic stroke.

METHODS

This study included 559 patients with PFO and cryptogenic stroke who were treated in our hospital from January 2013 to January 2018 and were followed up for 15-72 months. After calculating the risk scores for stroke recurrence, we randomly divided the patients into two groups (ratio, 1:1): Patients in one group underwent PFO closure and those in the other received drug therapy.

RESULTS

Patients in the PFO closure group had a lower risk of recurrent stroke than those in the drug therapy group (1.1% vs. 4.2%). Moreover, serious bleeding was less frequent in the PFO closure group than in the drug therapy group (0% vs. 3.2%), although the incidence of atrial fibrillation or flutter did not significantly differ between the groups (p = 0.67). Interestingly, a subgroup analysis revealed no inter-treatment group difference in the rate of cryptogenic stroke recurrence among patients with risk scores of 0-1. By contrast, PFO closure yielded superior outcomes among patients with risk scores of ≥2.

CONCLUSION

Compared with drug therapy, PFO closure reduced the risk of recurrent stroke among patients with a risk score of ≥2 and reduced the incidence of serious bleeding without increasing the risk of new-onset atrial fibrillation or atrial flutter.

Clinical and infarction patterns of PFO-related cryptogenic strokes and a prediction model

Objectives

The higher than expected PFO rate in CS patients has raised concerns that paradoxical embolism maybe the pathophysiologic mechanism for strokes. However, only a small proportion of pathogenic PFOs cause CS. Therefore, accurate recognition of patients with pathogenic PFOs among all CS patients could guide clinical decision making in selecting the most appropriate treatment. The aim of this study was to devise a new algorithm to stratify cryptogenic stroke (CS) patients into pathogenic patent foramen ovale (p‐PFO)‐ and non‐p‐PFO‐related patients.

Methods

A total of 1201 patients with acute ischemic stroke were recruited from two different medical centers, and 253 CS patients were identified. Of the 253 patients, 111 were diagnosed with PFO using contrast transcranial Doppler. Data on medical histories, neuroimaging and laboratory tests were compared in CS patients with or without PFO.

Results

Compared with PFO‐negative CS patients, PFO‐positive CS patients showed younger onset age, lower incidence of hypertension and dyslipidemia, characteristic infarction pattern in magnetic resonance imaging and specifically altered platelet activity and coagulation function. Based on the above information, we constructed a PFO judgment formula (Hr‐PFOJ) by means of feature weight estimation and predictive performance evaluation to predict pathogenic PFO in CS patients with a sensitivity of 76.3% and a specificity of 66.5%.

Interpretations

Hr‐PFOJ judgment formula is a useful screening tool for identification of patients with pathogenic PFO who may benefit from PFO‐related treatment.

Right-to-left shunt and subclinical ischemic brain lesions in Chinese migraineurs: a multicentre MRI study

Background

Migraine is considered as a risk factor for subclinical brain ischemic lesions, and right-to-left shunt (RLS) is more common among migraineurs. This cross-sectional study assessed the association of RLS with the increased prevalence of subclinical ischemic brain lesions in migraineurs.

Methods

We enrolled 334 migraineurs from a multicentre study from June 2015 to August 2016. Participants were all evaluated using contrast-enhanced transcranial Doppler, magnetic resonance imaging (MRI), and completed a questionnaire covering demographics, the main risk factors of vascular disease, and migraine status. RLS was classified into four grades (Grade 0 = Negative; Grade I = 1 ≤ microbubbles (MBs) ≤ 10; Grade II = MBs > 10 and no curtain; Grade III = curtain). Silent brain ischemic infarctions (SBI) and white matter hyperintensities (WMHs) were evaluated on MRI.

Results

We found no significant differences between migraineurs with RLS and migraineurs without RLS in subclinical ischemic brain lesions.SBI and WMHs did not increase with the size of the RLS(p for trend for SBI = 0.066, p for trend for WMHs = 0.543). Furthermore, curtain RLS in migraineurs was a risk factor for the presence of SBI (p = 0.032, OR = 3.47; 95%CI: 1.12−10.76). There was no association between RLS and the presence of WMHs.

Conclusion

Overall, RLS is not associated with increased SBI or WMHs in migraineurs. However, when RLS is present as a curtain pattern, it is likely to be a risk factor for SBIs in migraineurs.

Trial registration

No. NCT02425696; registered on April 21, 2015.

Electronic supplementary material

The online version of this article (10.1186/s12883-018-1022-7) contains supplementary material, which is available to authorized users.

Right-to-left shunt detection using contrast-enhanced transcranial Doppler: A comparison of provocation maneuvers between coughing and a modified Valsalva maneuver

Contrast-enhanced transcranial Doppler (c-TCD) has been used to detect right-to-left shunts (RLS) because it is highly sensitive and cost-effective. The use of provocation maneuvers, such as physiologic maneuvers (e.g., coughing) and the Valsalva maneuver (VM) to transiently increase right atrial pressure and induce RLS increases the sensitivity of RLS detection. In this study, we sought to determine whether coughing is as effective as the VM in aiding the detection of RLS. We evaluated 162 subjects for RLS, using c-TCD under three different conditions: (i) resting state, (ii) coughing, and (iii) modified VM (m-VM), which involved blowing into a tube connected to a sphygmomanometer at 40 mmHg for 10 s. The positive rate of RLS detection with the m-VM was significantly higher than that with coughing. In addition, a difference between the two maneuvers was observed in terms of the degree of RLS seen. The m-VM should be widely used to detect RLS, because it is reliable, standardized, and cost-effective.

Right-to-Left Shunt Does Not Increase the Incidence of Silent Lacunar Infarcts in Patients with Migraine

Right-to-left shunt (RLS) is associated with cryptogenic stroke and migraine. Herein we investigated the relationship between RLS and silent lacunar infarcts in patients with migraine. A total of 263 patients with migraine who met eligibility criteria were enrolled from January 2010 to December 2011, among which 127 subjects fell into RLS group. Baseline demographics were comparable between RLS and non-RLS groups (P > 0.05). The incidence of silent lacunar infarcts in RLS group was not significantly different from that of the non-RLS group (25.2% versus 21.3%, P > 0.05). Furthermore, we found that the incidence of silent lacunar infarcts in permanent and latent RLS subgroups was comparable with non-shunt RLS subgroup (28.6% versus 24% versus 21.3%, P > 0.05). Similarly, the incidence of silent lacunar infarcts in the non-RLS group, mild-shunt group, and large-shunt group was also comparable (21.3% versus 23.8% versus 29.3%, P > 0.05). In addition, RLS did not increase the incidence of silent lacunar infarcts in migraine patients with elder age (<50 years age group: 15.8% versus 17.9%; ≥50 years age group: 53.1% versus 37.5%, both P > 0.05). In conclusion, RLS does not increase the incidence of silent lacunar infarcts in patients with migraine. Further prospective studies are warranted to validate this finding.