Prior Stroke in PFO Patients Is Associated With Both PFO-Related and -Unrelated Factors

Background and Purpose: To identify factors associated with prior stroke at presentation in patients with cryptogenic stroke (CS) and patent foramen ovale (PFO).

Methods: We studied cross-sectional data from the International PFO Consortium Study (NCT00859885). Patients with first-ever stroke and those with prior stroke at baseline were analyzed for an association with PFO-related (right-to-left shunt at rest, atrial septal aneurysm, deep venous thrombosis, pulmonary embolism, and Valsalva maneuver) and PFO-unrelated factors (age, gender, BMI, hypertension, diabetes mellitus, hypercholesterolemia, smoking, migraine, coronary artery disease, aortic plaque). A multivariable analysis was used to adjust effect estimation for confounding, e.g., owing to the age-dependent definition of study groups in this cross-sectional study design.

Results: We identified 635 patients with first-ever and 53 patients with prior stroke. Age, BMI, hypertension, diabetes mellitus, hypercholesterolemia, coronary artery disease, and right-to-left shunt (RLS) at rest were significantly associated with prior stroke. Using a pre-specified multivariable logistic regression model, age (Odds Ratio 1.06), BMI (OR 1.06), hypercholesterolemia (OR 1.90) and RLS at rest (OR 1.88) were strongly associated with prior stroke.Based on these factors, we developed a nomogram to illustrate the strength of the relation of individual factors to prior stroke.

Conclusion: In patients with CS and PFO, the likelihood of prior stroke is associated with both, PFO-related and PFO-unrelated factors.

Abstract 205: Preceding Valsalva Maneuver Significantly Associated With Pathogenic Patent Foramen Ovale (PFO) in Patients With Cryptogenic Stroke

Background: In patients with cryptogenic stroke (CS), a patent foramen ovale (PFO) can be incidental or pathogenic. The Risk of Paradoxical Embolism (RoPE) score has been developed to determine the likelihood that a PFO is pathogenic or incidental using clinical variables. We hypothesize that echocardiographic features and conditions promoting paradoxical embolism differ between patients with pathogenic and incidental PFOs.

Methods: The International PFO Consortium collects clinical, radiological and echocardiographic data of patients with CS and PFO. In the original RoPE score, a value of 0-6 was classified as a low RoPE score and 7-10 as a high score. Since information on cortical versus deep stroke location (one of the items on the RoPE score) was not available, we used two alternative approaches to stratify for PFO pathogenicity. In a first approach, we used a 9-point score and lowered the cut-off for dichotomization by 1 point (RoPE score 0-5 vs 6-9). In a second approach, patients with a RoPE score of 6 were excluded since they could either be classified as low or high RoPE score depending on stroke location. The associations between RoPE stratum and echocardiographic features (atrial septal aneurysm (ASA), right-to-left shunt (RLS) at rest and large RLS) as well as conditions promoting paradoxical embolism (deep vein thrombosis (DVT), pulmonary embolism (PE) and Valsalva maneuver (VM) were studied.

Results: We analyzed 1044 CS patients with a PFO. Average age was 55 (SD 16) and 635 patients (61%) were male. Preceding VM was more frequent in patients with a high vs low RoPE score in both analyses: 11% vs 5% (OR: 2.1 95%CI 1.3-4.3) and 10% vs 5% (OR: 2.0 95%CI 1.2-3.6). The distribution of ASA (35% vs 34% and 32% vs 34%, in the first and the second analysis respectively), RLS at rest (28% vs 28% and 29% vs 28%), large RLS (67% vs 66% and 65% vs 66%), PE (2% vs 2% and 1% vs 2%), and DVT (4% vs 4% and 3% vs 4%) did not differ by RoPE stratum.

Conclusion: In patients with CS, preceding VM was significantly associated with pathogenic PFO, while echocardiographic features or conditions promoting paradoxical embolism were not. The formation of a significant right-to-left pressure gradient at the atrial septum level appears to play a substantial role in the pathogenicity of PFO.

Abstract WP228: Stratification of Patent Foramen Ovale (PFO) Pathogenicity Using the RoPE Score Differs in Women and Men

Background: A patent foramen ovale (PFO) discovered in patients with cryptogenic stroke (CS) may be incidental or pathogenic. Recently, a Risk of Paradoxical Embolism (RoPE) score has been proposed to stratify patients by their PFO pathogenicity. Based on this score, the probability that a PFO is incidental (rather than pathogenic) increases with advancing age, deep stroke location, or the presence of cardiovascular risk factors (RF). Given that RF accumulate at a later age in women than in men, we hypothesize that there are gender differences in the variables used for RoPE score calculation.

Methods: The distribution of RF (history of hypertension, diabetes or stroke/TIA, current smoking, and age categories as defined in the original RoPE score publication) was compared by sex in the entire cohort of 1044 CS patients as well as within the groups with low (0-5) and high (7-10) RoPE scores (due to lacking information on cortical versus deep stroke location, we excluded all patients with a RoPE score of 6, since they could be either classified with low or high RoPE score depending on stroke location). Furthermore, for each patient we calculated the age impact ratio (AIR): the points assigned for the corresponding age category divided by the RoPE score. Gender comparisons of AIR were drawn in the entire cohort and within the RoPE score strata.

Results: Average age was 55.5 years and 635 patients (61%) were male. In the entire cohort, the distribution of age categories and RF as well as AIR did not differ between men and women. In the higher RoPE stratum (PFO likely pathogenic), women were younger than men (median, 38 years vs 45 years, P=0.036). The distribution of RF and the AIR did not differ between sexes. In the lower PFO stratum (PFO likely incidental), men were younger than women (median, 62 years vs 66 years, P=0.011). The AIR was lower in women than in men (mean, 0.24 vs 0.29, P=0.013). There were no gender differences in the distribution of RF.

Conclusions: There are significant gender differences in age among patients with CS and PFO, with women being younger than men in the higher RoPE stratum and vice versa in the lower RoPE stratum. More women than men are classified as having an incidental PFO because of their advancing age rather than the accumulation of RF.

Abstract 208: Vascular Risk Factors But Not Transesophageal Echocardiography (TEE) Features Are Associated With Stroke Recurrence in Patients With Cryptogenic Stroke (CS) and Patent Foramen Ovale (PFO)

Background and purpose: Recurrent ischemic stroke in patients with CS and PFO has been proposed as a marker of increased risk for paradoxical embolism. It is unclear, whether the excess risk is driven by specific features of the PFO (right-to-left shunt (RLS) size, RLS at rest, associated atrial septum aneurysm (ASA)) or the presence of vascular risk factors (vRF). We compare the prevalence of vRF, TEE features, and baseline medications in PFO patients with first-ever versus multiple CS.

Methods: From September 2008 to March 2013, the International PFO Consortium enrolled 993 patients with ischemic stroke or transient ischemic attack (TIA) and newly diagnosed PFO. In this analysis of baseline data, we included 386 patients with first-ever CS and no radiological evidence of prior cerebral ischemia (first-ever CS group, mean age, 52y) as well as 71 patients with recurrent CS and multiple ischemic lesions on CT and/or MRI (multiple CS group, mean age, 59y). Patients with TIA as index event, those with first-ever CS but additional “silent” ischemic lesions on imaging as well as those with recurrent CS without radiological findings of prior cerebral ischemia were excluded. We used nonparametric tests for independent samples and the Bonferroni correction for multiple comparisons.

Results: Age > 55y (63% vs. 44%, P=0.001), hypertension (52% vs. 30%, P=0.001), hyperlipidemia (64% vs. 44%, P=0.003), and coronary artery disease (15% vs. 3%, P=0.001) were significantly more frequent in the multiple CS than in the first-ever CS group. The frequencies of male gender, current smoking, diabetes, migraine with or without aura, associated ASA, RLS size, and RLS at rest did not differ between groups. At baseline, patients with multiple CS were more likely to be on antiplatelets (50% vs. 18%), antihypertensive (51% vs. 22%) or lipid lowering drugs (44% vs. 10%, P=0.001 for each comparison) than patients with first-ever CS. The frequency of anticoagulant treatment did not differ between groups.

Conclusions: In patients with CS, vRF but not specific PFO features were associated with recurrent cerebral ischemic events. The ongoing prospective part of the International PFO Consortium will likely shed light upon the role of vRF control for secondary stroke prevention in patients with PFO.