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Criteria for stability on angiography are the following (all to be assessed in a perpendicular view to the device;
Fig. 3.8):
a) No dislocation during vigorous wiggling
b) Positive Pacman sign
c) Confirmation that the right disc is fully in the right atrium (by contrast medium)
d) Confirmation that the left disc is entirely in the left atrium (by recirculated contrast medium from the pulmonary
vasculature in the left atrium (levophase); Fig. 3.9)
If these criteria are confirmed, the device is released. If an ASA was present, the device may move considerably
upon release and the above-mentioned criteria should be reassessed by a second contrast medium.
Thebesian ridge: The Thebesian ridge extends from the coronary sinus at the entry of the inferior vena cava to the
lateral free wall of the right atrium (Chapter 16). If the valve is prominent, it will protrude into the right atrium
FIGURE 3.8 Confirming correct device position by a positive Pacman sign, indicating that the upper part of the device is pushed apart by the
muscular septum secundum (red line) with angiographic confirmation that the right disc is fully in the right atrium (yellow line).
FIGURE 3.9 Left: A large and prominent Thebesian ridge can divert contrast away from the interatrial septum and give a wrong impression of
device dislocation. Right: Following the contrast medium through to the levophase, the border of the left atrium (dotted line) can be identified and
the left disc (and indirectly also the right disc) can be documented in the correct position.
II. DIAGNOSIS AND IMAGING ASSESSMENT OF PFO
3. ANGIOGRAPHY, TRANSTHORACIC, TRANSESOPHAGEAL, AND INTRACARDIAC ECHOCARDIOGRAPHY36
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and can interfere with injected contrast through a suboptimally positioned sheath such that the contrast medium does
not reach the interatrial septum. Upon confirmation of a stable device position, the operator who is unaware of the
presence of the Thebesian valve can get the false impression that the device is entirely in the left atrium (Fig. 3.9). How-
ever, correct device positioning can be confirmed either by paying attention to the recirculated contrast medium in the
left atrium (levophase) or by another contrast medium with the sheath repositioned lower or closer to the device.
Postprocedural Assessment of Device Position
Before discharge, a TTE to confirm correct positioning of the PFO-occluding device is performed in some centers.
The question to be answered by the TTE is whether the device has remained seated in place and whether pericardial
fluid has accumulated.
Three optimal views will answer this question:
- Parasternal short axis view
- Apical 4-chamber view
- Subcostal view (Fig. 3.10)
With improved procedural technique, safety, and more experience with PFO device closure, the yield of a pre-
discharge TTE is now minimal, with fewer centers currently performing it.
Follow-Up Imaging
After 2e6 months, follow-up imaging should be performed. The questions that need to be answered are whether
(1) there is a significant residual shunt requiring closure or (2) a thrombus can be found on the device. The first
question can be answered by a TTE (better Valsalva maneuver for the required bubble test than with TEE). Some
centers still prefer to perform a TEE because it also reliably shows small residual shunts and thrombus on the device.
With the use of Amplatzer(-like) devices, device-thrombus is an exceedingly rare phenomenon. The incidence
was 0%e0.2% in the large landmark studies [7,8]. Therefore, a TEE is not mandatory if Amplatzer-type devices
were used and a simple TTE is usually sufficient, particularly in younger patients.
Residual shunt detection requires injection of agitated saline or echocardiographic contrast mediumdif necessary
from the leg. A rare exception is a residual shunt detected by a Doppler signal. The risk for such a residual shunt is
higher if larger devices have been used. Large devices are more likely to be used when there is a demanding anatomy
such as in patients with ASA or other PFO complexities. The ASA remains mobile between the 2 device discs and can
prevent adequate closure. In such circumstances, the chance for spontaneous closure with longer follow-up is very
low, and a second device pushing the septum primum to the left sided disc, or simply closing the remaining channel,
can resolve the residual shunt [9] (see below).
Small residual shunts will not be seen by TTE, either by a bubble test or by color Doppler, but they are not clin-
ically relevant. Transcranial Doppler is very sensitive for residual shunts but is unable to distinguish between trans-
pulmonary and residual PFO shunting.
FIGURE 3.10 Transthoracic echocardiogram before hospital discharge depicting a device in the correct position, as visualized in the
subcostal view.
II. DIAGNOSIS AND IMAGING ASSESSMENT OF PFO
IMAGING STAGES 37
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Special Situations
Role of Intracardiac Echocardiography
Intracardiac echocardiography (ICE) allows for imaging of the PFO and its surrounding structures that are rele-
vant for PFO closure. The advantage of ICE over TEE is that it does not require sedation or intubation but can be
performed on an awake patient. For PFO closure, 2D ICE is sufficient, although current technology allows acquisi-
tion of 3D-ultrasound images. Chapter 15 discusses the ICE-guided technique for percutaneous PFO closure.
The access for the ICE probe requires a second venous puncture on the same (right) or contralateral side. The role
for ICE during PFO closure is debatable, as it does not add any significant benefit over fluoroscopy alone and is
hampered by relevant additional costs and potential access complications, not to mention distraction of the operator
having to manipulate and interpret the additional diagnostic tool. Chapter 2 discusses the advantages and limita-
tions of ICE use during PFO closure.
PFO Closure Without Prior (Transesophageal) Echocardiography
Several clinical circumstances exist where no preprocedural TEE or TTE are available (Table 3.3). These consist of
situations of inaccessibility of pictures, with relative contraindications to perform a TEE, and where ad hoc PFO
closure is performed. In the latter, PFO closure could be deferred and a TEE performed. Given the simplicity, safety,
and efficacy of ad hoc PFO closure, it can (under certain circumstances and after discussing the treatment options
with the patient) be undertaken without preprocedural echocardiography.
For device selection, the following questions need to be answered by angiography (Chapter 16):
- Thickness of the septum secundum
- Presence of an ASA
- Length of the PFO tunnel
For this purpose, a right atriogram is performed in at least a left anterior oblique or lateral projection before
performing the PFO closure. If there is no concern about an acute thrombus trapped in the PFO, the PFO can be
crossed with a guidewire and the PFO sheath advanced into the right atrium. The dilator is then withdrawn in
case a long wire is used. In case of a normal length guidewire, the sheath is advanced into the left atrium before
withdrawal of the dilator and the guidewire. The short guidewire is subsequently readvanced into the left atrium,
to allow retraction of the sheath back to the right atrium without losing access to the left atrium. A contrast medium
injection is performed with the sheath tip close to the PFO but low enough to also assess the mobility of the septum
primum. A default angulation for imaging the PFO could be 10 degrees left anterior oblique with 10
cranial tilt. This
angulation has a high likelihood to be parallel to the interatrial septum. Contrast medium (minimum of 10 mL ) is
injected through the sheath. This allows the operator to assess the thickness of the septum secundum, the presence of
an ASA, as well as to get an idea of the length of the PFO tunnel (Fig. 3.11). Balloon-sizing is not required. In some
patients, the septum secundum is even visible without contrast injections. Device selection and the remainder of the
implantation steps remain the same.
In-Hospital Complications
PFO device closure is considered the safest therapeutic procedure in interventional cardiology. Procedural in-
hospital complications are exceedingly rare.
TABLE 3.3 Situations Where PFO Closure Can Be Undertaken Without Previous Echocardiography.
Contraindications for TEE Esophageal varices
Difficult pharyngeal anatomy
Patient condition prohibits TEE (e.g., danger of aspiration)
Patient refuses TEE
Ad hoc PFO closure Accidentally found PFO (e.g., right heart catheterization)
Patients with embolic myocardial infarction during coronary angiography
TEE, transesophageal echocardiography.
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Air Aspiration or Air Embolism
Air aspiration can occur in patients with low right and left atrial pressure, where the operator does not pay attention
to holding the outside end of the sheath lower than the level of the heart. Intraprocedural TEE or ICE often detect small
air bubbles while flushing the sheath with saline. They can also detect larger air accumulations in the left heart cham-
bers. Such larger amounts of air can also be detected by fluoroscopy. Most often, this complication is detected by its
sequelae: symptoms of myocardial ischemia (typically ST-segment elevation in the inferior leads, since the right cor-
onary artery is most often affected due to its anterior takeoff) or cerebral ischemia (transient ischemic attack). Intuba-
tion for TEE guidance could potentially hide this problem, since the patient is unable to communicate symptoms. The
large majority of these respective symptoms resolve within a few minutes without further measures. The authors have
never seen or heard of a case where such a large amount of air entered the circulation during PFO closure, that resus-
citation, use of a heart lung machine, or treatment in a hyperbaric chamber became necessary.
Device Residing Partially in the Tunnel of the PFO
In case too small a PFO occluder was used for PFO closure, the right disc can partially slip into the PFO tunnel,
particularly after disconnecting the device from the delivery cable. This can be anticipated by the aspect of the
septum secundum barely entering the space between the crania l disc parts or provoked before release during the
push-and-pull test. As it often happens after release, any concern of the device slipping off the septum secundum
should initiate a change for a larger device . The absence of a Pacman-sign (with the upper parts of the PFO discs
being parallel, not being splayed by the septum secundum) should always raise the concern of possible device dislo-
cation and prompt a thorough contrast medium study or, if available, echocardiographic examination to assess the
situation (Fig. 3.2; Chapter 16).
The main risk of this complication is not device embolization (since the full diameter of the right disc is larger than
the PFO slit in most cases), but a low complete closure rate (about 50%). Therefore, the device should be replaced by
a larger one if not yet disconnected. If already disconnected, it can be snared, recaptured, and replaced by a larger
device at a small risk of embolization while trying to catch it. A better alternative is to accept this position and
perform a second intervention in patients with significant residual shunting at follow-up [9].
PFO Occluder Embolization
Device embolization is rare (less than 1 in 1000) and almost exclusively occurs when the device is erroneously
deployed in the right or left atrium. Embolization occurs immediately or early (within hours) and will be detected
on a predischarge TTE. It can be prevented by assessing proper position before release, for instance, with a vigorous
push-and-pull test. Likewise, a correct and stable position by contrast angiographic imaging or an intraprocedural
TEE or ICE before release virtually exclude the risk of device embolization.
FIGURE 3.11 Assessment of the anatomy of the PFO by angiography in a left anterior oblique view. The short arrow points to the atrial septal
aneurysm. LA, left atrium; RA, right atrium; SP, septum primum; SS, septum secundum.
II. DIAGNOSIS AND IMAGING ASSESSMENT OF PFO
IMAGING STAGES 39
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Left-sided embolization occurs when the left disc is not fully withdrawn to the interatrial septum and/or when
the right-sided disc is not deployed under tension and is erroneously opened on the left side. Right-sided emboli-
zation may occur if the left disc is partially pulled through the PFO tunnel and deployed on the right side. Another
rare reason for embolization is a tear in the septum primum. This almost never occurs without prior balloon sizing.
An embolized device rarely causes symptoms and almost invariably can be snared, either in the pulmonary or
systemic vasculature, and then extracted.
Reclosure in Case of a Significant Residual Shunt [9]
A residual shunt is detected during follow-up as described above. It almost exclusively occurs in patients with
ASA. Since spontaneous closure is un likely to occur with longer follow-up, the leak should be closed if it is relevant
or if the patient prefers complete closure.
The precise nature of the leak can be depicted best by angiography. A diagnostic multipurpose catheter is best
suited to engage the PFO from the right atrial side (usually underneath the caudal part of the right disc) and to
demonstrate the leak. The leak can then be crossed by the diagnostic catheter alone, by a 0.035
00
regular or Terumo
wire. Rarely, it requires a 0.014
00
coronary wire, followed by the diagnostic catheter. A second PFO occluder is first
anchored in the left atrium by the left atrial disc and then the device is deployed parallel to the first device or inside
the PFO tunnel, to push the septum primum to the left-sided disc of the initial PFO occluder (Fig. 3.12). If there is a
tapered remaining channel between the discs, an Amplatzer Vascular Plug II can be inserted through the diagnostic
catheter without ever crossing over to the left atrium (Chapter 16).
PFO Closure after Left Atrial Appendage Occlusion
Left atrial appendage occlusion in the presence of a PFO can be carried out without the need of a transseptal punc-
ture, by attaining left atrial access through the PFO [10]. The patient should be informed and PFO closure recommen-
ded at the same time. Ideally, compatible devices are used, such that the left atrial appendage occluder delivery cable
and sheath can also be used for PFO closure. PFO closure with the Amplatzer devices can be performed easily with
such a nondedicated sheath (Fig. 3.13).
Left Atrial Ablation, Left Atrial Appendage Closure, or Other Left Atrial Catheter Intervention after
PFO Closure
PFO closure does not preclude later transseptal left atrial access. In fact, the PFO device is an excellent marker for
a safe puncture site (Fig. 3.14) [11].
FIGURE 3.12 Closure of a residual shunt (left) with a second Amplatzer PFO Occluder (right). The right disc fills up the remaining channel
and is squeezed so that it looks like a pear instead of a disc.
II. DIAGNOSIS AND IMAGING ASSESSMENT OF PFO
3. ANGIOGRAPHY, TRANSTHORACIC, TRANSESOPHAGEAL, AND INTRACARDIAC ECHOCARDIOGRAPHY40
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SUPPLEMENTARY MATERIALS
Supplementary data related to this article can be found online at https://doi.org/10.1016/B978-0-12-816966-7.
00003-8.
References
[1] Nietlispach F, Meier B. Percutaneous closure of patent foramen ovale: an underutilized prevention. Eur Heart J 2016;37:2023e8.
[2] Nietlispach F, Meier B. Percutaneous closure of patent foramen ovale: safe and effective but underutilized. Expert Rev Cardiovasc Ther 2015;
13:121e3.
[3] Mahmoud AN, Elgendy IY, Agarwal N, Tobis JM, Mojadidi MK. Identification and quantification of patent foramen ovale-mediated shunts:
echocardiography and transcranial Doppler. Interv Cardiol Clin 2017;6:495e504.
[4] Mojadidi MK, Roberts SC, Winoker JS, Romero J, Goodman-Meza D, Gevorgyan R, Tobis JM. Accuracy of transcranial Doppler for the
diagnosis of intracardiac right-to-left shunt: a bivariate meta-analysis of prospective studies. JACC Cardiovasc Imaging 2014;7:236e50.
[5] Billinger M, Schwerzmann M, Rutishauser W, Wahl A, Windecker S, Meier B, Seiler C. Patent foramen ovale screening by ear oximetry in
divers. Am J Cardiol 2013;111:286e90.
FIGURE 3.13 Use of the 14-F double-curved TorqVue 45
45
sheath for patent foramen ovale closure immediately after left atrial
appendage occlusion through this sheath.
FIGURE 3.14 Transseptal puncture after patent foramen ovale closure. In a left anterior oblique projection with the occluder device in profile.
The dotted line indicates a safe area for a transseptal puncture, ideally just at the caudal rim of the device. The transseptal needle may have to be
additionally bent to reach the site.
II. DIAGNOSIS AND IMAGING ASSESSMENT OF PFO
REFERENCES 41
https://t.me/med1917
[6] Yamashita E, Murata T, Goto E, Fujiwara T, Sasaki T, Minami K, Nakamura K, Kumagai K, Naito S, Kario K, Oshima S. Inferior vena cava
compression as a novel maneuver to detect patent foramen ovale: a transesophageal echocardiographic study. J Am Soc Echocardiogr
2017;30:292e9.
[7] Carroll JD, Saver JL, Thaler DE, Smalling RW, Berry S, MacDonald LA, Marks DS, Tirschwell DL, RESPECT I. Closure of patent foramen ovale
versus medical therapy after cryptogenic stroke. N Engl J Med 2013;368:1092e100.
[8] Meier B, Kalesan B, Mattle HP, Khattab AA, Hildick-Smith D, Dudek D, Andersen G, Ibrahim R, Schuler G, Walton AS, Wahl A, Windecker S,
Ju
¨
ni P, PC TI. Percutaneous closure of patent foramen ovale in cryptogenic embolism. N Engl J Med 2013;368:1083e91.
[9] Susuri N, Obeid S, Ulmi M, Siontis GCM, Wahl A, Windecker S, Nietlispach F, Meier B, Praz F. Second transcatheter closure for residual shunt
following percutaneous closure of patent foramen ovale. EuroIntervention 2017;13:858e66.
[10] Koermendy D, Nietlispach F, Shakir S, Gloekler S, Wenaweser P, Windecker S, Khattab AA, Meier B. Amplatzer left atrial appendage
occlusion through a patent foramen ovale. Catheter Cardiovasc Interv 2014;84:1190e6.
[11] Zaker-Shahrak R, Fuhrer J, Meier B. Transseptal puncture for catheter ablation of atrial fibrillation after device closure of patent foramen
ovale. Catheter Cardiovasc Interv 2008;71:551e2.
II. DIAGNOSIS AND IMAGING ASSESSMENT OF PFO
3. ANGIOGRAPHY, TRANSTHORACIC, TRANSESOPHAGEAL, AND INTRACARDIAC ECHOCARDIOGRAPHY42
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CHAPTER
4
Definition of Cryptogenic Stroke, the RoPE
Score, and Assessment of Embolic Stroke of
Undetermined Source
Preetham Kumar
1
, M. Khalid Mojadidi
2
, Jonathan M. Tobis
1
,
Bernhard Meier
3
, David Thaler
4
1
University of California, Los Angeles, Los Angeles, CA, United States;
2
Virginia Commonwealth University, Richmond,
VA, United States;
3
University Hospital Bern, Bern, Switzerland;
4
Tufts University School of Medicine,
Boston, MA, United States
OUTLINE
Introduction 45
The RoPE Study 46
RoPE Score Validation 51
RoPE Score Adjusted for AnatomicaleFunctional
PFO Features 52
Embolic Stroke of Undetermined Source
53
Conclusion
54
References
55
INTRODUCTION
The prevalence of patent foramen ovale (PFO) in the general population is approximately 25%, but 40%e60% of
patients with cryptogenic stroke are found to have a PFO [1]. This increased frequency of PFO in cryptogenic stroke
suggested that PFO could have an etiological role in some cryptogenic strokes. However, the initial randomized clin-
ical trials that evaluated the efficacy and safety of percutaneous PFO closure for the prevention of recurrent crypto-
genic stroke (2012 CLOSURE I, 2013 PC trial, and 2013 RESPECT) could not demonstrate, with statistical
significance, that PFO closure was superior to medical therapy in an intention-to-treat analysis [2e4]. These earlier
randomized trials of PFO closure for cryptogenic stroke are discussed in detail in Chapter 6. Yet, an unequivocal
benefit of PFO closure in patients with cryptogenic stroke was documented in 2017e18, when subsequent random-
ized trial reports (2017 Long-Term RESPECT, 2017 REDUCE, 2017 CLOSE, and 2018 DEFENSE-PFO) demonstrated
superiority of PFO closure over standard of care medical therapy (Chapter 7) [5e8]. Although most neurologists
conceded that at least a portion of cryptogenic strokes were due to PFO functioning as a pathway for a paradoxical
embolus to reach the brain, the neurologic and cardiologic societies took a conservative approach and warned
against mechanical PFO closure as an advisable therapy after a cryptogenic stroke [9]. The guidelines did not
acknowledge that the early trials demonstrated noninferiority of PFO closure compared with medical therapy.
45
PFO Closure for Stroke, Myocardial Infarction, Peripheral Embolism, Migraine, and Hypoxemia
Copyright © 2020 Elsevier Inc. All rights reserved.https://doi.org/10.1016/B978-0-12-816966-7.00004-X
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Moreover, since paradoxical embolism was treated as a diagnosis of exclusion, all other known causes of stroke had
to be evaluated and rejected before it was concluded that the PFO was causally related to the stroke. Thus, the diag-
nosis of paradoxical embolism was met with overzealous skepticism, with many influential neurologists claiming
that the PFO was just an “innocent bystander” that had no relation to the index stroke, and therefore, should not
be closed. Articles discussed the likelihood that hitherto undetected paroxysmal atrial fibrillation (AF) would be
a more likely etiology for the cryptogenic stroke, and therefore, should be investigated with more stringent rhythm
monitoring, including placement of subcutaneous cardiac monitors for several months [10,11]. There are no studies
comparing the likelihood that a systemic embolism is due to AF associated with different anatomical variables
versus PFO with different anatomical variables.
Other potential mechanisms of stroke may be present in patients even if they indeed had a PFO-related stroke,
including lacunar disease, hypercoagulable states, and aortic or carotid atheroma with the potential for embolism.
One system commonly used to categorize the etiology of stroke is the TOAST (Trial of Org 10172 in Acute Stroke
Treatment) classification, which, on the basis of clinical features and results of diagnostic studies, such as brain im-
aging with computed tomography (CT) or magnetic resonance (MR), cardiac imaging (echocardiography), Doppler
imaging of extracranial arteries, arteriography, and laboratory assessments for a prothrombotic state, denotes 5 sub-
types of ischemic stroke: (1) large-artery atherosclerosis, (2) cardioembolism, (3) small-artery occlusion (e.g., lacunar
infarct), (4) stroke of other determined etiology, and (5) stroke of undetermined etiology (i.e., cryptogenic stroke)
[12]. Of note, the TOAST classification does not recognize paradoxical embolism mediated by a right-to-left shunt
(i.e., PFO, atrial septal defect, or pulmonary arteriovenous malformation) as a culprit of stroke in any of the first
4 categories. Similarly, there is no recognition of paroxysmal AF even though persistent AF is characterized as
cardioembolism. This implies that both the subgroups of stroke patients with a right-to-left shunt and those with
paroxysmal AF would fall under the category of “stroke of undetermined etiology” (i.e., cryptogenic stroke) under
the TOAST classification.
The EMBRACE (30-Day Cardiac Event Monito r Belt for Recording Atrial Fibrillation After a Cerebral Ischemic
Event) trial randomized patients with cryptogenic stroke to a standard of care 24-hour cardiac monitor or 30-day
event-triggered loop recorder to assess for occult AF. It found a significantly higher prevalence of paroxysmal
AF in the cryptogenic stroke patients monitored for 30 days versus those monitored for only 24 hours after stroke
(16.1% vs. 3.2%, 95% CI 8.0e17.6, P < .001) [10]. This finding emphasized the importance of long-term cardiac moni-
toring to assess for the presence of paroxysmal AF in cryptogenic stroke patients and, if present, initiating appro-
priate anticoagulation for the prevention of recurrent stroke. The EMBRACE study was interpreted by some
people as further evidence that PFO was unlikely to be causally related to stroke, and it should, therefore, not be
treated with percutaneous closure. Of note, AF has no impact on the risk of a PFO to mediate paradoxical embolism,
and the average age of patients in the EMBRACE trial was 72.5 years, an elderly patient population expected to have
a higher prevalence of AF, as compared to the younger (age 60 years) cryptogenic stroke patients enrolled in the
PFO closure trials.
To address the quandary of when to consider PFO as the guilty offender and when to exclude it as an innocent
bystander, the RoPE (Risk of Paradoxical Embolism) study was designed to assist physicians in making the appro-
priate diagnosis [13,14].
THE RoPE STUDY
In 2013, the RoPE (Risk of Paradoxical Embolism) study, an international collaboration led by David Kent and
David Thaler of Tufts University, provided a series of mathematical models that could be used to (1) stratify patients
by the conditional probability that an index cryptogenic stroke was PFO-related and (2) predict the likelihood that a
stroke would recur [13,14].
The objective of the first mathematical model was to estimate the patient-specific probability that a PFO was path-
ogenically related to the index stroke by determining the “PFO propensity.” This was achieved by constructing a data-
base of patients with cryptogenic stroke, both with and without PFO, by combining existing cohort studies, and
reviewing the patient characteristics. A database was built consisting of cryptogenic stroke subjects with PFO
(n ¼ 1274) and without PFO (n ¼ 1749) based on 12 different cohort studies [15]. Ta ble 4.1 lists the clinical, echocardio-
graphic, and radiological variables of interest. An atrial septal aneurysm (ASA) was defined as a hypermobile intera-
trial septum that resulted in an excursion of at least 10 mm from the midline plane of the septum into either the right or
left atrium with each heartbeat. Of note, while ASA occurs in 2.2% of the general population, it occurs in approxi-
mately 20%e45% of patients with PFO [16,17]. This underlines the plausible hypothesis that an ASA prevents fusion
4. DEFINITION OF CRYPTOGENIC STROKE, THE RoPE SCORE46
III. STROKE AND PFO
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of the septum secundum with the septum primum and thus predisposes to the presence of a PFO. The physiological
shunt size of a PFO was determined by the number of bubbles that cross the PFO on transesophageal echocardiogra-
phy, with large shunts defined as the appearance of 20 microbubbles in the left atrium after an agitated saline injec-
tion. Tabl e 4.2 summarizes the characteristics of cryptogenic stroke patients with and without PFO. Although sex
distribution was similar between the 2 groups, cryptogenic stroke patients with PFO were considerably younger
and less likely to have conventional risk factors of atherosclerosis (e.g., diabetes, coronary artery disease, hypertension,
hypercholesterolemia, smoking, or history of cerebrovascular events) compared to cryptogenic stroke patients without
PFO. On neuroimaging, cryptogenic stroke patients with PFO had fewer findings of prior stroke, and the infarcts were
more likely to be large (>1e1.5 cm) and superficial, compared to stroke patients without PFO.
The objective of the second mathematical model was to estimate the patient-specific risk of stroke recurrence. This
was achieved by analyzing the clinical, radiographic, and echocardiographic characteristics of patients with both a
cryptogenic stroke and PFO.
The objective of the third mathematical model was to create a composite index based on the patient-specific PFO
propensity (model 1) and patient-specific stroke recurrence risk (model 2). This was achieved by combining both
TABLE 4.1 Initial Clinical, Echocardiographic, and Radiological Variables of Interest in Cryptogenic Stroke Patients With PFO
(Adapted from [13]).
Variable Type Variable
Clinical Age
Gender
Race
History of the following (prior to index stroke)
Migraines
Hypertension
Diabetes
Prior cerebral ischemia
Coronary artery disease
Obesity
Hypercholesterolemia
Smoking status
Antithrombotic medications
Deep vein thrombosis
Pulmonary embolism
Hypercoagulable states
Antithrombotic medications after index event
National Institutes of Health Stroke Severity Score
Echocardiographic Hypermobility of interatrial septum (ASA)
Interatrial shunting at rest (not during Valsalva maneuver)
Volume of interatrial shunt (maximum number of bubbles in left atrium)
Anatomical PFO size
Spontaneous Doppler flow seen on color
Radiological CT/MR imaging of cerebral infarct at time of index stroke (yes/no)
Number of prior cerebral infarcts
Anatomical location of index and prior infarct(s)
ASA, atrial septal aneurysm; CT, computed tomography; MR, magnetic resonance; PFO, patent foramen ovale.
THE RoPE STUDY 47
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