Shamoun, Fadi

Summary: Background: Peripheral arterial disease (PAD) increases cardiovascular (CV) morbidity and mortality, but remains underdiagnosed and undertreated. Several trials support low-dose direct oral anticoagulant (DOAC) use in PAD treatment, although this has yet to be widely adopted in clinical practice. Patients and methods: We conducted a retrospective study of patients who underwent ankle-brachial index testing (ABI) from 1996 – 2020 at Mayo Clinic. We included patients with PAD defined by abnormal ABI (<1.0 or >/=1.4). Primary outcomes evaluated were myocardial infarcts (MI), ischemic strokes (IS), critical limb ischemia (CLI)/amputation, bleeding events and all-cause mortality. DOAC and warfarin use were each compared to no anticoagulant use for the outcomes using univariate analysis and multivariate analysis. Results: 22,162 patients had abnormal ABI readings; 1,266 were on warfarin and 269 were on DOAC for any indication. Both the DOAC and warfarin groups showed significant a decrease in all-cause mortality. The DOAC group showed superior mortality outcomes with HR 0.50 [95% CI 0.40–0.63], p-value <0.001 compared to warfarin with HR 0.88 [95% CI 0.81–0.96], p-value <0.004. There appeared to be a similar trend for MI and CLI/amputation however this was not statistically significant. IS was similar with only warfarin being statistically significant. The DOAC group had improved bleeding outcomes compared to the warfarin group, HR 0.53 (95% CI 0.24–0.85), p-value 0.007. Notably, the addition of ASA for both AC groups resulted in significant HR >1. Conclusions: Our study shows that anticoagulation use, particularly DOACs, is associated with decreased all-cause mortality in patients with PAD. There appears to be a favorable trend for DOACs in MI, IS and CLI/amputation. Lastly, DOACs were found to have superior outcomes with bleeding events.

Bicuspid aortic valve (BAV) and thoracic aortic aneurysms and dissections (TAAD) are recognized in syndromic connective tissue diseases (CTD), but most cases occur sporadically. The extent to which non-syndromic BAV or TAAD predisposes to additional arteriopathies, particularly in younger individuals, remains unclear. We retrospectively analyzed 1438 patients (mean age = 48.0, 67.7% female), excluding those with CTDs. Participants were ≤60 years old and categorized by the presence of BAV and/or TAAD. We examined co-existing arterial pathologies, including fibromuscular dysplasia, spontaneous coronary artery dissection, abdominal aortic aneurysms (AAA), mesenteric, peripheral extremity, and carotid/cerebral arteriopathies. Overall, 44.6% had either BAV or TAAD, and 27.2% had multiple arteriopathies. While vascular diseases were frequently noted, odds ratios demonstrated no significantly increased risk of extra-aortic arteriopathies in the BAV or TAAD cohorts. AAA exhibited a non-significant trend toward higher prevalence in TAAD patients. These findings support current guidelines recommending targeted imaging (transthoracic echocardiography of the aortic root and ascending aorta) over comprehensive “head-to-pelvis” screening for non-syndromic BAV or TAAD patients without additional risk factors. Ongoing genetic analyses may elucidate whether particular variants predispose to multi-site aneurysms or dissections. Consequently, targeted surveillance remains appropriate, with broader imaging reserved for patients with genetic or clinical indicators of higher risk.

ABSTRACT The alpha 1 and 2 chains of type IV collagen, encoded by the COL4A1 (MIM 120130) and COL4A2 (MIM 120090) respectively, play essential roles in the vascular basement membranes. Pathogenic variants in COL4A1 / COL4A2 are associated with autosomal dominant cerebral angiopathies. The clinical manifestations of COL4A1 / COL4A2 ‐related disorders include: aneurysms, intracerebral hemorrhage, polymicrogyria, porencephaly, heterotopia, periventricular leukomalacia, epilepsy, and neurodevelopmental disorders. COL4A1 pathogenic variants that are in exons 24 and 25 have been associated with hereditary angiopathy, nephropathy, aneurysms, and cramps. The multisystemic phenotypes of COL4A1 / COL4A2 ‐related disorders are increasingly being studied. Animal models have suggested that COL4A2 ‐related disorders may also manifest with a variable combination of multisystemic abnormalities affecting the eyes, muscles, and kidneys. Okano and colleagues recently reported a case of recurrent episodes of rhabdomyolysis in a 2‐year‐old with COL4A1 ‐related disorder raising fundamental questions on mechanisms of COL4A1 / COL4A2 variants in muscle homeostasis. To date, rhabdomyolysis has not been associated with COL4A2 ‐related disorder in humans. Rhabdomyolysis is a medical emergency, where there is elevated creatine kinase (CK) level in the blood and increased excretion of myoglobin in urine, due to skeletal muscle damage and release of intracytoplasmic proteins into systemic circulation. Rhabdomyolysis is a serious medical condition. It require intensive care management due to an increased risk of some life‐threatening complications [including disseminated intravascular coagulation, renal failure, and severe hyperkalemia]. Herein, we report a case of rhabdomyolysis in an adult with COL4A2 ‐related structural brain malformations (including polymicrogyria and heterotopia).

Introduction/Background: Loeys-Dietz syndrome (LDS) is a rare autosomal dominant aortic aneurysm syndrome characterized by arterial tortuosity resulting in arterial aneurysms and dissections, with unique craniofacial and skeletal features including bifid uvula, cleft palate and hypertelorism. While the presence of atrial fibrillation (Afib) and arrhythmias have been reported in LDS patients, limited investigation has been completed regarding the associated risk and severity of vascular complications in relationship to these arrhythmias1,2. Research Questions/Hypothesis: Are there any differences in vascular outcomes in patients with LDS when experiencing various forms of tachyarrhythmia? Goals/Aims: To evaluate the relationship between various types of arrhythmias and vascular outcomes in patients with LDS, including arterial dissection, stroke, revascularization, and death. Methods/Approach: A large sample of LDS patients (n=436) from a single tertiary referral center was assessed for ICD-10 diagnoses of arrhythmia and outcomes of interest. Arrhythmias assessed included Afib, atrial flutter (AFL), premature ventricular contractions (PVCs), and supraventricular tachycardia (SVT). Outcomes were arterial dissection, hemorrhagic and ischemic stroke, revascularization, and all-cause mortality. Results/Data: Our cohort (n=436) had an average age of 47 and was 57.8% female. A total of 26 patients had a documented history of tachyarrhythmia: 16 (3.4%) Afib, 2 (0.5%) AFL, 6 (1.4%) SVT, and 2 (0.5%) PVC. LDS patients with Afib were at significantly higher risk of arterial dissection (25% vs 6.0%, OR: 5.3, p<0.01), revascularization (18.8% vs 3.3%, OR: 8.1, p<0.01), stroke (25% vs 3.6%, OR: 9.0, p<0.001), and death (25% vs 4.3%, OR: 7.4, p<0.01) compared to those without a documented history of arrhythmia. Other arrhythmia types evaluated were not significant. Predictors of any arrhythmia type included hypertension (78% vs 31%, OR: 1.5, p<0.001) and heart failure (39% vs 5.0%, OR: 2.3, p<0.001). Conclusion: Although rare, Afib in LDS patients is associated with adverse vascular outcomes and mortality compared to those without a history of arrhythmia. Furthermore, the magnitude of increased risk is striking. Early identification and management of Afib in LDS patients may be critical in mitigating the risk of potential vascular complications.

Introduction/Background: Fibromuscular Dysplasia (FMD) is a non-atherosclerotic vascular disease that primarily affects medium-sized arteries and is characterized by abnormal cell development in the artery walls. Recent studies have suggested that various connective tissue features may be prevalent in patients with FMD, however the clinical significance of these findings on the disease course are uncertain. Research Questions/Hypothesis: We hypothesized that the presence of connective tissue features in patients with FMD might indicate a more severe disease course, potentially associated with increased severity of vascular complications. Goals/Aims: To evaluate the association between connective tissue features and the severity of vascular complications in FMD patients on outcomes including dissections and stroke. Methods/Approach: This cross-sectional study involved 2,454 patients diagnosed with FMD at a tertiary referral center. Patients were classified into two groups based on the presence (n=324) or absence (n=2130) of connective tissue features (pectus deformity of any kind, scoliosis, pneumothorax, inguinal hernia, uterine rupture, bowel perforation, Achilles tendon rupture). We evaluated the incidence of dissections and ischemic or hemorrhagic strokes using odds ratios and chi-squared tests. Results/Data: The cohort consisted of 2,454 participants with an average age of 64.8 years, of whom 89.1% were female and 92.4% identified as White. When comparing groups with and without connective tissue features, there were no significant differences in the prevalence of aneurysms at any site. Among the subgroup of FMD patients with connective tissue features (n=234), prevalent conditions included pectus (12.35%), scoliosis (47.22%), pneumothorax (16.67%), inguinal hernia (13.58%), uterine rupture (16.36%), bowel perforation (6.48%), and Achilles tendon rupture (1.85%). Vascular outcome analysis showed significant differences: the odds of experiencing a stroke were higher in patients with these features (odds ratio: 1.60; P-value: <0.01), whereas the odds of experiencing dissections were lower (odds ratio: 0.77; P-value: 0.03). Conclusion: The presence of connective tissue features in patients with FMD is associated with 60% higher odds of experiencing a stroke, equivalent to a 1.6-fold increase, compared to those without these features. This association may represent a novel finding in the literature, warranting further investigation.

Introduction: Peripheral artery disease impacts 202 million patients worldwide and is commonly diagnosed via ankle-brachial index. PAD is associated with endothelial dysfunction, which is also common to venous thromboembolism formation. Despite the suspected overlap in pathogenesis, few studies exist investigating the association between these pathologies. We investigated whether PAD with low or elevated ABI is an independent risk factor for VTE. Methods: We reviewed medical records of patients ≥18 years old undergoing ABI measurement with or without PAD symptoms from 01/01/1996 to 08/31/2018 and classified patients by ABI: severely low (ABI 0.00-0.39), moderately low (0.40-0.69), mildly low (0.70-0.90), borderline (0.91-0.99), normal (1.00-1.40), and elevated (>1.40). The primary outcome was incident VTE event after ABI measurement, defined as deep vein thrombosis or pulmonary embolism. Multivariable Cox proportional regression was used to calculate hazard ratios (HR) with 95% confidence intervals after adjusting for age, sex, active smoking, cancer or VTE history, thrombophilia, anticoagulation, and revascularization within 14 days of VTE. Results: In 39,384 unique patients (mean age 66.3±14.2 years, median follow-up 34 months), 5,141 VTE events were observed. Increased VTE risk was observed in PAD patients with severely low ABI (HR 1.26, 95%CI [1.02, 1.29]) compared to patients with normal ABI after multivariable regression. Patients with elevated ABI did not demonstrate an increased risk of VTE. Conclusions: Patients with severe PAD are at higher risk for VTE than patients with normal ABI, which may be due to a multifactorial pathophysiology of profound endothelial injury as well as immobility due to claudication. Further exploration of VTE incidence in patients with severe PAD stratified by functional status is warranted to determine the optimal strategy to minimize thromboembolic morbidity and mortality in this population.

Summary: Background: Peripheral artery disease (PAD) is a risk factor for adverse limb events (LE) and cardiovascular events (CVE) that coexists with type 1 (T1) and 2 (T2) diabetes mellitus (DM). Little is known about comparative risk of LE and CVE in T1/T2 DM patients with PAD. Patients and methods: We queried our database of 40,144 patients ≥18 years old who underwent ankle brachial index (ABI) measurement from 01/1996-02/2020. We isolated T1/T2 DM patients with PAD diagnosed by ankle brachial index (ABI; low [<1.0] or elevated [>1.4]) and retrieved demographics including glycated hemoglobin (HbA1c). Primary outcomes were LE (critical limb ischemia/vascular amputation) and CVE (myocardial infarction/ischemic stroke). All-cause mortality was a secondary outcome. Multivariable Cox proportional regression yielded hazard ratios (HR) with 95% confidence intervals (CI) after adjusting for pertinent risk factors including age, hypertension, hyperlipidemia, smoking, and HbA1c. Results: Our study found 10,156 patients with PAD and DM (34% T1DM, 66% T2DM) with median follow-up time 34 mo (IQR 85 mo). T1DM patients were younger than T2DM (mean age 67 vs. 70 years), with higher median HbA1c (7.7 [IQR 1.9] vs. 6.7% [IQR 1.6]), and more prevalent hypertension, hyperlipidemia, CAD, and CKD. Antiplatelet and statin use was equivocal. Elevated ABI was more common in T1DM (47 vs. 28%). LE occurred in 23% and CVE in 12% patients. LE risk was higher in T1 than T2 DM patients (HR 1.58 [95% CI 1.44, 1.73], p<0.0001), but CVE and all-cause mortality were equivocal. These observations were preserved across ABI and HbA1c subgroup analyses. Conclusions: PAD patients with T1DM had a higher LE risk than those with T2DM, even after adjustment for glycemic control and pertinent risk factors, but CVE risk and all-cause mortality were equivocal. These data suggest a potential role for more intensive LE risk modification in PAD patients with T1DM, but further investigation is needed.

ImportancePatterns of clinical utilization and comparative effectiveness of anticoagulants for cancer-associated thrombosis (CAT) remain largely unexplored.ObjectivesTo assess patterns of and factors associated with anticoagulant use and to evaluate the comparative effectiveness of contemporary anticoagulants in patients with active cancer in a clinical setting.Design, Setting, and ParticipantsThis retrospective cohort study obtained deidentified OptumLabs electronic health record claims data from January 1, 2012, to September 30, 2019. Adult patients (≥18 years of age) with a primary cancer diagnosis (except skin cancer) during at least 1 inpatient or 2 outpatient visits within 6 months before the venous thromboembolism (VTE) date were included. Data were analyzed from April 2020 to September 2021.ExposuresThe patients were grouped according to the anticoagulant prescribed: (1) direct oral anticoagulants (DOACs), (2) low-molecular-weight heparin (LMWH), and (3) warfarin.Main Outcomes and MeasuresOdds ratios (ORs) were used to present the association between factors of interest and utilization of anticoagulants. Main efficacy outcomes included risk of VTE recurrence and all-cause mortality. Main safety outcomes included the risk of hospitalization due to major bleeding. Relative treatment effect estimates were expressed as hazard ratios (HRs) with 95% CIs.ResultsThis study included 5100 patients (mean [SD] age, 66.3 [12.3] years; 2670 [52.4%] women; 799 [15.7%] Black, 389 [7.6%] Hispanic, and 3559 [69.8%] White individuals). Overall, 2512 (49.3%), 1488 (29.2%), and 1460 (28.6%) filled prescriptions for DOACs, LMWH, and warfarin, respectively. The median (IQR) treatment duration was 3.2 (1.0-6.5) months for DOACs, 3.1 (1.0-6.8) months for warfarin, and 1.8 (0.9-3.8) months for LWMH. Patients with lung (OR, 2.07; 95% CI, 1.12-3.65), urological (OR, 1.94; 95% CI,1.08-3.49), gynecological (OR, 4.25; 95% CI, 2.31-7.82), and colorectal (OR, 2.26; 95% CI, 1.20-4.32) cancer were associated with increased prescriptions for LMWH compared with DOACs. LMWH (HR, 1.47; 95% CI, 1.14-1.90) and warfarin (HR, 1.46; 95% CI, 1.13-1.87) were associated with an increased risk of VTE recurrences compared with DOACs. LMWH was associated with an increased risk of major bleeding (HR, 2.27; 95% CI, 1.62-3.20) and higher all-cause mortality (HR, 1.61; 95% CI, 1.15-2.25) compared with DOACs.Conclusions and RelevanceIn this comparative effectiveness study of claims-based data, patients with CAT received anticoagulation for a remarkably short duration in clinical settings. DOACs was associated with a lower risk of VTE recurrence, major bleeding, and mortality. Warfarin may still be considered for patients with contraindications to DOACs and those with poor persistence on LMWH.

Introduction: Peripheral artery disease (PAD) is a risk factor for adverse limb events (LE) and cardiovascular events (CVE) that often coexists with type 1 (T1) and type 2 (T2) diabetes mellitus (DM), which differ mechanistically. There is a paucity of data on comparative risk of LE and CVE in T1DM and T2DM patients with PAD. Methods: We queried our database of 40,144 patients ≥18y old who underwent ankle brachial index (ABI) measurement from 01/1996-02/2020. We isolated patients with T1DM or T2DM and with PAD diagnosed by ABI (low [<1.0] or elevated [>1.4]). We retrieved demographics including hemoglobin A1c (A1c). Primary outcomes were LE (critical limb ischemia or vascular amputation) and CVE (myocardial infarction or ischemic stroke). All-cause mortality was a secondary outcome. Multivariable Cox proportional regression yielded hazard ratios (HR) with 95% confidence intervals (CI) after adjusting for age, sex, A1c, hypertension, hyperlipidemia, coronary artery disease (CAD), chronic kidney disease (CKD), and tobacco use. Results: Our study found 9,271 patients with PAD and DM (36% T1DM, 64% T2DM) with median follow-up time 34 mo (interquartile range [IQR] 85 mo). T1DM patients were younger than T2DM (mean age 67 vs 70y), with higher median A1c (7.7 [IQR 1.9] vs 6.7% [IQR 1.6]), and higher prevalence of hypertension, hyperlipidemia, CAD, and CKD. Antiplatelet and statin use did not differ. Elevated ABI was more common in T1DM (47 vs 27%). LE occurred in 23% and CVE in 12% of patients. LE risk was higher in T1DM patients than T2DM (HR 1.59[95% CI 1.45,1.74], p<0.0001), but CVE and all-cause mortality did not differ significantly. Conclusions: PAD patients with T1DM had a higher LE risk than those with T2DM, even after adjustment for A1c and pertinent risk factors, but CVE risk and all-cause mortality were equivocal. These data suggest a potential role for more intensive LE risk modification in PAD patients with T1DM, but further investigation is needed to minimize limb morbidity.