High frequency of silent pulmonary embolism in patients with cryptogenic stroke and patent foramen ovale

BACKGROUND AND PURPOSE

Deep vein thrombosis and pulmonary embolism (PE) prove venous embolic activity and enforce the suspicion of paradoxical embolism in patients with stroke with patent foramen ovale. Because it has implications in secondary prevention, we investigated the frequency of silent PE in such a cohort of patients.

METHODS

Patients with cryptogenic stroke or transient ischemic attack and patent foramen ovale who underwent a ventilation perfusion scintigraphy were identified from a stroke registry. Blinded from clinical data, ventilation perfusion scintigraphy scans were re-evaluated independently by 2 experts. Patients showing at least a subsegmental defect were considered as having silent PE. Factors potentially associated with PE were analyzed.

RESULTS

The evaluation included 151 patients. Median age was 55.2 years and 59.9% were male. In 56 (37%) patients, silent PE was found; a deep vein thrombosis was evident in 11 (7%) patients. Atrial septal aneurysm was identified in 39 patients and hypermobile atrial septum in 37 patients. Atrial septal aneurysm and hypermobile atrial septum were independently associated with PE. In females, intake of oral contraceptives showed certain association with PE (6 of 25 versus 3 of 40; P=0.07).

CONCLUSIONS

Silent PE frequently occurs in patients with cryptogenic stroke and patent foramen ovale, particularly when atrial septal aneurysm or hypermobile atrial septum are present.

Decrease in shunt volume in patients with cryptogenic stroke and patent foramen ovale

BACKGROUND

In patients with patent foramen ovale (PFO) there is evidence supporting the hypothesis of a change in right-to-left shunt (RLS) over time. Proven, this could have implications for the care of patients with PFO and a history of stroke. The following study addressed this hypothesis in a cohort of patients with stroke and PFO.

METHODS

The RLS volume assessed during hospitalisation for stroke (index event/T0) was compared with the RLS volume on follow-up (T1) (median time between T0 and T1 was 10 months). In 102 patients with a history of stroke and PFO the RLS volume was re-assessed on follow-up using contrast-enhanced transcranial Doppler/duplex (ce-TCD) ultrasound. A change in RLS volume was defined as a difference of ≥20 microembolic signals (MES) or no evidence of RLS during ce-TCD ultrasound on follow-up.

RESULTS

There was evidence of a marked reduction in RLS volume in 31/102 patients; in 14/31 patients a PFO was no longer detectable. An index event classified as cryptogenic stroke (P < 0.001; OD = 39.2, 95% confidence interval 6.0 to 258.2) and the time interval to the follow-up visit (P = 0.03) were independently associated with a change in RLS volume over time.

CONCLUSIONS

RLS volume across a PFO decreases over time, especially in patients with cryptogenic stroke. These may determine the development of new strategies for the management in the secondary stroke prevention.

Effect of daytime, weekday and year of admission on outcome in acute ischaemic stroke patients treated with thrombolytic therapy

BACKGROUND

Since doubts were raised, if a challenging medical procedure such as acute stroke treatment including thrombolysis with recombinant tissue plasminogen activator (rTPA) is available with identical standard and outcome 24 h and 7 days a week our aim was to examine if acute stroke patients defined by onset-admission time (OAT) of <or= 3 h were treated differently or had distinct outcome when admitted during off duty hours (day versus night and weekend versus weekdays) and if any differences in treatment or outcome were apparent when comparing patients admitted in the year 2003 with patients admitted in the year 2006.

METHODS

We analyzed 2003-2006 data of a prospective registry and grouped patients by time, day, and year of admission. The evaluation was limited to patients that were diagnosed with ischaemic stroke and with OAT of <or= 3 h. Medical and sociodemographic items, use of thrombolytic treatment, complications during clinical course and place of discharge were obtained. Clinical state on admission and discharge was assessed using the modified Rankin scale. Comparison with chi-square test, t-test and logistic regression was performed.

RESULTS

Patient's characteristics, rate of thrombolysis, and outcome were independent from time or day of admission. Proportion of patients with good clinical state at discharge increased significantly from 2003 to 2006 together with a higher rate of rTPA treatment without increase of intracranial hemorrhage. Proportion of patients discharged in good clinical condition after rTPA treatment increased from 34% to 44%.

CONCLUSIONS

Stroke treatment in potential candidates for thrombolytic therapy revealed no impairment on weekend or at night already in 2003. During 4 years, it was possible to increase rate of rTPA treatment from 8.9% to 21.8% without increment of complications or death, confirming that rTPA is safe and can be implemented with full daily and weekly coverage.

Paradoxical brain embolism caused by an arterial-venous fistula: a diagnostic pitfall

The transesophageal echocardiography (TEE) and contrast-enhanced transcranial Doppler/Duplex ultrasonography (ceTCD) are complementary methods for diagnosing a right to left shunt across a patent foramen ovale. We report on a case of paradoxical embolism across a subclavian arterial-venous fistula. This case underlines the necessity of performing the ceTCD, as in this condition the right to left shunt could be detected by means of ceTCD, whereas the TEE reveals regular findings.

Diagnostic and prognostic value of contrast-enhanced ultrasound in acute stroke

In the last decade transcranial color-coded sonography (TCCS) was established as a routine in neurovascular departments for the evaluation of brain-supplying vessels in cerebrovascular diseases. TCCS has demonstrated feasibility and validity for the evaluation of the basal cerebral arteries, especially for the middle cerebral artery (MCA). In some patients an insufficient bone window may limit the diagnostic power. The application of microbubble agents can overcome this limitation in most patients. Beside the demonstration of vessel pathology such as stenosis and occlusion, TCCS also provides prognostic information. In the case of proximal MCA occlusion shown by TCCS within 6 hours of stroke, nearly 90 % of the patients suffered an unfavorable outcome. Furthermore TCCS is suitable for monitoring thrombolysis in acute stroke to detect whether there is recanalization of the affected vessel. The possibility for bedside examination, the non-invasiveness and the cost-effectiveness are features which make TCCS an optimal tool for the evaluation of cerebral vessels in acute ischemic stroke.