Mechanical Circulatory Support for High-Risk Percutaneous Coronary Intervention.

PURPOSE OF REVIEW: This review will focus on the indications of mechanical circulatory support (MCS) for high-risk percutaneous coronary intervention (PCI) and then analyze in detail all MCS devices available to the operator, evaluating their mechanisms of action, pros and cons, contraindications, and clinical data supporting their use. RECENT FINDINGS: Over the last decade, the interventional cardiology arena has witnessed an increase in the complexity profile of the patients and lesions treated in the catheterization laboratory. Patients with significant comorbidity burden, left ventricular dysfunction, impaired hemodynamics, and/or complex coronary anatomy often cannot tolerate extensive percutaneous revascularization. Therefore, a variety of MCS devices have been developed and adopted for high-risk PCI. Despite the variety of MCS available to date, a detailed characterization of the patient requiring MCS is still lacking. A precise selection of patients who can benefit from MCS support during high-risk PCI and the choice of the most appropriate MCS device in each case are imperative to provide extensive revascularization and improve patient outcomes. Several new devices are being tested in early feasibility studies and randomized clinical trials and the experience gained in this context will allow us to provide precise answers to these questions in the coming years.

Guidewire fracture during orbital atherectomy for peripheral artery disease: Insights from the Manufacturer and User Facility Device Experience database.

BACKGROUND/OBJECTIVES: Orbital atherectomy (OA) is routinely being used for plaque modification to facilitate percutaneous revascularization in patients with peripheral arterial disease (PAD) and arterial calcification. Guidewire fracture (GWF) during OA, though anecdotally described, has not been studied in a systematic manner. We conducted a review of the Manufacturer and User Facility Device Experience (MAUDE) database to study the reports of wire fracture and its management and consequences. METHODS: We queried the MAUDE database for all events involving the current generation of the OA device: "Diamondback 360 Peripheral Orbital Atherectomy System", and "Stealth 360° Orbital PAD System". RESULTS: We identified 62 reports of GWF during OA for PAD. The superficial femoral artery was the most commonly involved atherectomy site. The wire fractured at the soft tip in a majority of cases (68%). Embolized wire fragments were left in the patient in 36 cases (58%), retrieved percutaneously in 10 cases (16%), and trapped by a stent against the arterial wall in eight cases (13%). Lastly, eight patients (13%) underwent surgery for removal of the wire fragment. CONCLUSIONS: This is the first published report to study the complication of GWF during peripheral OA. GWF is an uncommon but has significant procedural and clinical consequences. It results in a high rate of ancillary rescue procedures (including surgery) and is associated with a higher risk of arterial thrombosis and complications from wire retrieval attempts. The risk of wire fracture may be avoided with carefully adherence to the IFU.

A novel unembalmed human cadaveric limb model for assessing conformational changes in self-expanding nitinol stents in the popliteal artery.

OBJECTIVE: To develop an unembalmed human cadaveric lower limb model as a more realistic environment for testing self-expanding nitinol stents. We studied conformational changes and strain induced by knee flexion in nitinol stents deployed in the popliteal artery (PA). METHODS: One Lifestent® each was deployed into one limb of four cadavers (control group), while the contralateral leg received a different stent (Absolute®, Protégé Everflex®, Supera®, and Gore Viabahn®). The limbs were mounted on a quasi-static knee rig (QKR) and X-ray imaging was performed at pre-defined knee flexion angles. A least-squares solution to the equation of a circle was used to assess radius of curvature at flexion points (FP), and nominal strain was calculated for each stented artery. RESULTS: There were differences but also some similarities in conformational changes seen in the various stents. Knee flexion produced at least two FP in all stents. The mean radius of curvature decreased with increasing degrees of flexion but more so in distal (main) than proximal (accessory) FP (22 mm vs. 11 mm) in all stents. Supera® stent had the greatest relative radii of curvatures, and Absolute® stent had the highest strain value in comparison to the contralateral PA as the control group. CONCLUSION: This study describes a novel human cadaveric limb model for testing self-expanding nitinol stents implanted in the PA. Several parameters of conformational change in the stented PA such as FP formation, FP translocation and strain induced by axial compression were described. These may be useful for developing new stents for the PA location.

Acute kidney injury in patients undergoing endovascular therapy for critical limb ischemia.

BACKGROUND: Similar to coronary angiography and interventions, patients undergoing percutaneous treatment of lower extremity peripheral arterial disease are also at risk of acute kidney injury (AKI). The incidence, risk factors associations, need for dialysis and inhospital mortality related to AKI in patients with critical limb ischemia (CLI) following endovascular therapy is poorly defined. OBJECTIVES: The purpose of this study was to analyze data from the National Inpatient Sample (NIS) to determine the aforementioned outcomes in patients with CLI. METHODS: Using the full NIS admission dataset from 2003 through 2012, ICD-9 codes relevant to comorbid conditions, procedure codes, composite codes for AKI, and inhospital mortality were analyzed using multivariate models. RESULTS: A total of 273,624 patients were included with a mean age of 70.0 ± 27.4 years, 46.0% were female, 57.2% had diabetes, 43.4% had coronary artery disease (CAD), and 29.2% had chronic kidney disease (CKD). The overall rate of AKI was 10.4%, and there was a temporal rise over the analysis period in AKI incidence (p < .001). Age, diabetes, CKD, and heart failure were all associated with AKI (p < .0001). The inhospital mortality rate in the patients with AKI declined over time but was higher than in patients without AKI (6.0% vs. 1.4%), p < .0001. The mortality rate was substantially higher in patients with AKI requiring dialysis as compared to AKI not requiring dialysis (13.4% vs. 5.6%), p < .0001. CONCLUSIONS: AKI is associated with age, CKD, and heart failure. The incidence of AKI following endovascular therapy for CLI is rising and independently associated with inhospital mortality.

Subclinical involvement of common carotid arteries in patients with fibromuscular dysplasia - a case-control study.

Background: Fibromuscular dysplasia (FMD) primarily involves medium-sized arteries, though the entire spectrum of vascular involvement is not fully understood. We hypothesized that larger arteries may also be affected, albeit sub-clinically. Patients and methods: We measured the cross-sectional diameter of the thoracic aorta, abdominal aorta, common iliac arteries (CIA) and common carotid arteries (CCA) in FMD subjects and compared them to matched controls. We retrospectively analyzed records of FMD subjects (n = 74) and of age- and sex- matched controls (n = 74) that underwent computed tomography of the neck, chest or abdomen. Cross-sectional diameters of the thoracic and abdominal aorta, CIA and CCA were measured in a standardized manner by two trained physicians. Results: The FMD group had a significantly greater diameter of the CIA and CCA bilaterally. The measurements (mm) in FMD and control groups were as follows: Right CIA: 10.85 + 1.75 vs. 10.23 + 1.36, p = 0.04, left CIA: 11.01 + 1.93 vs. 10.15 + 1.38, p = 0.007, right CCA: 7.70 + 0.81 vs. 6.80 + 1.10, p < 0.001 and left CCA: 7.70 + 1.10 vs. 6.80 + 1.0, p < 0.001). There was no difference in the diameter between the two groups in the ascending aorta, descending and the abdominal aorta. After adjusting for baseline differences, common carotid arteries (but not common iliac) were significantly larger in FMD group compared with controls. Conclusions: There is sub-clinical involvement of the common carotid arteries in patients with FMD and this manifests as a greater diameter of these arteries compared to age and sex matched controls.

National Trends and Procedural Complications from Endomyocardial Biopsy: Results from the National Inpatient Sample, 2007-2014.

AIM: The aim of this study is to report recent trends in the performance of endomyocardial biopsy (EMB) and its in-hospital complications (and their predictors) in the United States (US). METHOD: We analyzed Nationwide Inpatient Sample (NIS) database from years 2007 through 2014 to identify patients who underwent EMB. Once identified, the patients were subdivided into those with no history of heart transplant (HT) (cohort 1) and those with history of HT (cohort 2). We then studied the major complication of pericardial effusion, hemopericardium or/and cardiac tamponade that required a pericardiocentesis or a pericardial window (CTRPD) following the EMB procedure. RESULTS: We observed a steady increase in the in-patient EMB procedures, with more EMB procedures being performed in males and in Caucasians. In cohort 1, the CTRPD was higher (0.70%) as compared to cohort 2 (0.19; p = 0.01). CTRPD in women was higher compared to men (0.94 vs. 0.53% p = 0.022). Most of the EMB procedures are performed in teaching hospitals. The CTRPD rate was significantly higher in the nonteaching hospitals when compared to teaching hospitals in both cohort 1 and cohort 2 (3.4 vs. 0.53% and 1 vs.0.18%, respectively; p = 0.01 and < 0.001, respectively). The overall mortality in cohort 1 was 4.3% as compared to 2.5% in cohort 2; p = 0.01. In cohort 1, the mortality was significantly higher in the group that had EMB-related complications versus the group without the complications (20 vs. 2.5%; p < 0.001). CONCLUSION: There has been an increase in the number of EMB procedures in the US in recent years. Though the overall risk of CTRPD is very low, the risk is significantly higher in cohort 1, women, and in nonteaching hospitals. The study results provide data benchmarks for assessing EMB outcomes in the US.

A nationwide analysis of 30-day readmissions related to critical limb ischemia.

Objectives There is paucity of information regarding critical limb ischemia-related readmission rates in patients admitted with critical limb ischemia. We studied 30-day critical limb ischemia-related readmission rate, its predictors, and clinical outcomes using a nationwide real-world dataset. Methods We did a secondary analysis of the 2013 Nationwide Readmissions Database. We included all patients with a primary diagnosis of extremity rest pain, ulceration, and gangrene secondary to peripheral arterial disease. From this group, all patients readmitted with similar diagnosis within 30 days were recorded. Results Of the total 25,111 index hospitalization for critical limb ischemia, 1270 (5%) were readmitted with a primary diagnosis of critical limb ischemia within 30 days. The readmission rate was highest (9.5%) for the group that did not have any intervention (revascularization or major amputation) and was lowest for surgical revascularization and major amputation groups (2.6% and 1.3%, P value <0.001 for all groups). Severity of critical limb ischemia at index admission was associated with a significantly higher rate of 30-day readmission. Critical limb ischemia-related readmission was associated with a higher rate of major amputation (29.6% vs. 16.2%, P<0.001), a lower rate of any revascularization procedure (46% vs. 62.6%, P<0.001), and a higher likelihood of discharge to a skilled nursing facility (43.2% vs. 32.2%, P<0.001) compared to index hospitalization. Conclusions In patients with primary diagnosis of critical limb ischemia, 30-day critical limb ischemia-related readmission rate was affected by initial management strategy and the severity of critical limb ischemia. Readmission was associated with a significantly higher rate of amputation, increased length of stay, and a more frequent discharge to an alternate care facility than index admission and thus may serve as a useful quality of care metric in critical limb ischemia patients.

Optimal Medical Management Reduces Risk of Disease Progression and Ischemic Events in Asymptomatic Carotid Stenosis Patients: A Long-Term Follow-Up Study.

BACKGROUND AND PURPOSE: To assess the effect of optimal medical management including atherosclerotic risk factor control on ischemic stroke (IS), transient ischemic attack (TIA), carotid revascularization (CRV), and progression of severity of carotid stenosis (PSCS) in patients with asymptomatic carotid artery stenosis (ACAS). METHODS: We conducted a retrospective analysis of patients with ACAS (who had at least 3 serial carotid duplex ultrasounds) for incidence of IS, TIA, and PSCS. RESULTS: Eight hundred sixty-four patients with a mean follow-up duration of 79 ± 36 months were included. IS/TIA and CRV occurred in 12.2% of the patients and PCSS was observed in 21.5% vessels. On univariate analysis it was found that low-density lipoprotein (LDL) levels >100 mg/dL, no statin or low-potency statins, average systolic blood pressure (SBP) ≥140 mm Hg and/or diastolic blood pressure (DBP) ≥90 mm Hg and history of smoking were predictors of the combined endpoint of IS/TIA/CRV and PSCS. On multivariate analysis, it was found that LDL >100 mg/dL, no statin or low-potency statin, SBP ≥140 mm Hg and/or DBP ≥90 mm Hg, and Hx of smoking were independent predictors of PSCS. Similarly no statin or low-potency statin, SBP ≥140 mm Hg and/or DBP ≥90 mm Hg, Hx of atrial fibrillation/flutter, Hx of chronic kidney disease, and PSCS were independent predictors of IS/TIA. No statin or low-potency statin, SBP ≥140 mm Hg and/or DBP ≥90 mm Hg, diabetes mellitus, baseline carotid artery stenosis ≥70%, and PSCS were found to be independent predictors of combined endpoint IS/TIA and CRV. CONCLUSION: Intensive medical therapy in the patients with ACAS results in lower incidence of IS/TIA, CRV, and PSCS with a significant incremental beneficial effect.

Progression of external and internal carotid artery stenosis is associated with a higher risk of ischemic neurologic events in patients with asymptomatic carotid artery stenosis.

A small percentage of patients with asymptomatic carotid artery stenosis (ACAS) who are on optimal medical management do go on to develop ischemic stroke or transient ischemic attacks (IS/TIA). Several diagnostic tools have been studied to identify those patients who are at increased risk. However, most of these diagnostic tools are not available for routine clinical use or are resource intensive. We performed a retrospective study to assess the incremental value of external carotid artery stenosis progression (ECASP) along with internal carotid artery stenosis progression (ICASP) in predicting risk of ipsilateral IS/TIA in a cohort of patients with ACAS. We conducted a retrospective analysis of patients with ACAS who had at least two serial duplex ultrasounds (DUS) at our center. A total of 356 patients (712 carotid arteries) were included in the study (mean age 74.7±9 years, 49.2% male) with a mean follow-up of 60.7±32.7 months. In univariate analysis, concurrent progression of ICA and ECA stenosis on the same side arteries was associated with a very significant increased risk of ipsilateral IS/TIA (14.7% vs 4.6%, p<0.001). Also, multivariable regression analysis showed that concurrent ECA/ICA progression was an independent predictor of IS/TIA (OR=3.6, 95% CI 1.64-7.8; p=0.001). ECASP along with ICASP is significantly associated with increased risk of ipsilateral IS/TIA and provides incremental risk stratification over that provided by ICASP alone. The ECA is routinely evaluated in clinical practice, and it could serve as an additional marker for identifying higher risk patients with ACAS.

Inverse Correlation of Venous Brain Natriuretic Peptide Levels with Body Mass Index Is due to Decreased Production.

OBJECTIVE: The aim of this paper was to study the association between body mass index (BMI) and coronary sinus (CS) brain natriuretic peptide (BNP) levels in patients with heart failure and reduced systolic function (HFrEF). BACKGROUND: There is an inverse relationship between systemic venous BNP (V-BNP) levels and BMI in patients with HFrEF. It is unclear whether this finding is due to decreased production or due to an increased metabolism of BNP. Since CS-BNP levels reflect BNP production, we hypothesized that assessing the correlation of CS-BNP levels with BMI would provide insight into the mechanism of this inverse relationship of V-BNP and BMI. METHODS: We prospectively enrolled 54 subjects with HFrEF who were to undergo cardiac resynchronization device implantation. CS-BNP, V-BNP, and arterial BNP (A-BNP) levels were measured during the implant procedure. Subjects were divided into 2 groups based on their BMI (group 1: BMI <30 and group 2: BMI ≥30). RESULTS: The mean age of the overall study group was 64 ± 10 years. Average BMI for group 1 was 25.8 ± 2.8 and 36.8 ± 4.6 for group 2 (p < 0.03). A history of hypertension was present in 55% (n = 26) of the subjects, while diabetes was reported in 31% (n = 15). Serum creatinine was 1.0 ± 0.2 mg/dL and TSH 2.1 ± 1.4 mIU/L. 79% of the subjects were receiving ß-blockers, while 94% were receiving angiotensin-converting enzyme inhibitors or angiotensin receptor blockers. The mean CS-BNP, V-BNP, and A-BNP levels in group 2 were significantly lower than in group 1 (286.2 ± 170.5 vs. 417.5 ± 247.5 pg/mL, p = 0.04; 126.6 ± 32.5 vs. 228 ± 96.4 pg/mL, p = 0.01; and 151.9 ± 28.6 vs. 242 ± 88.8 pg/mL, p = 0.04, respectively). Univariate analysis and multivariate regression adjusted for age, diabetes mellitus, sex, glomerular filtration rate, and left atrial size confirmed BMI as an independent predictor of CS-BNP levels (ß = -0.372, p = 0. 03) in our study. CONCLUSIONS: In this study, we demonstrate an inverse relationship between CS-BNP levels and BMI in patients with HFrEF. These findings suggest that the previously established inverse relationship between V-BNP and BMI is due to a decreased cardiac production of BNP in obese patients rather than from increased peripheral metabolism.

Comparison of residual shunt rates in five devices used to treat patent foramen ovale.

OBJECTIVES: To assess the effective closure rate among devices used for transcatheter patent foramen ovale (PFO) closure, and to discuss the management of patients with large residual shunts. BACKGROUND: Several devices are used off-label for transcatheter closure of a PFO in the United States. The rate of residual shunting after PFO closure varies by device. Failure of effective closure poses risk of a recurrent cerebrovascular event, persistent migraine, or recurrent orthodeoxia. METHODS: Patients who underwent PFO closure in the Cardiac Catheterization Laboratory at UCLA between 2001 and 2013 and had baseline and adequate follow-up transcranial Doppler studies following device placement were enrolled in the study. RESULTS: Of 167 patients whose records were analyzed, effective PFO closure occurred in 90% (150/167) of patients. The highest effective closure rate was with the Amplatzer Septal Occluder (ASO; 100%), followed by the Amplatzer Cribriform (93%), Gore Helex (90%), Amplatzer PFO (86%), and CardioSEAL (86%) device. The highest rate of residual shunting was observed after placement of the 30-mm Gore Helex device (55%). Of the 17 patients with a residual shunt, three required a repeat PFO closure procedure due to a significant residual shunt associated with recurrent pulmonary emboli or profound orthodeoxia. All three patients received an ASO which successfully closed the residual shunt. CONCLUSIONS: Transcatheter PFO closure has a high success rate, but a moderate residual shunt occurs in about 10% of cases. The observed incidence of residual shunting after PFO closure is significantly larger with the 30-mm Helex device. © 2014 Wiley Periodicals, Inc.

Antegrade techniques for chronic total occlusion percutaneous coronary intervention.

Antegrade techniques are the foundation of chronic total occlusion (CTO) percutaneous coronary intervention (PCI). Antegrade wiring with the intent to achieve an intraplaque guidewire tracking is not always feasible, and crossing into the extraplaque space with subsequent reentry (antegrade dissection and reentry), might be needed, particularly in more complex occlusions. The present article reviews in detail the antegrade approaches to CTO PCI, focusing on equipment, techniques, and overcoming challenges.

Meta-Analysis of Anticoagulation Therapy for the Prevention of Cardiovascular Events in Patients With Peripheral Arterial Disease.

Peripheral artery disease (PAD) remains a major cause of morbidity and future cardiovascular events despite advancement in the surgical interventions and optimal medical therapy. The aim of our study is to evaluate the efficacy and safety of anticoagulation (AC) therapy for reducing cardiovascular and limb events in patients with PAD. PUBMED, Medline, and Cochrane Library were searched through 2020 for randomized clinical trials comparing major adverse cardiovascular events (MACE) and risk of major bleeding (MB), between AC and standard of care (SOC) therapy, among patients with PAD. Meta-analysis was performed using weighted pooled absolute risk difference (RD) with 95% confidence interval (CI) and fixed effects model for overall and sub-groups of full dose (FD) and low dose (LD) AC therapies. Amongst 17,684 patients from 7 different studies, the addition of AC to SOC therapy was associated with MACE reduction (RD -0.022, 95% CI -0.033 to -0.012, p <0.001) and increased MB (RD 0.02, 95% CI 0.014 to 0.025, p <0.001). For FD, MACE reduction was (RD -0.021, 95% CI -0.042 to 0.001, p = 0.061) and MB (RD 0.036, 95% CI 0.025 to 0.047, p <0.001). For LD, MACE reduction was (RD -0.023, 95% CI -0.035 to -0.011, p <0.001) and MB (RD 0.011, 95% CI 0.005 to 0.017, p <0.001). In conclusion, addition of AC to the current SOC therapy can mitigate future MACE events in patients with PAD albeit at risk of increased bleeding. LD AC is associated with an efficacy/safety net benefit compared to FD AC therapy.

Hemoglobin A1c and Cardiovascular Outcomes Following Percutaneous Coronary Intervention: Insights From a Large Single-Center Registry.

OBJECTIVES: The aim of this study was to evaluate post-percutaneous coronary intervention (PCI) outcomes in relation to pre-procedural glycated hemoglobin (HbA1c) levels from a large, contemporary cohort. BACKGROUND: There are limited data evaluating associations between HbA1c, a marker of glycemic control, and ischemic risk following PCI. METHODS: All patients with known HbA1c levels undergoing PCI at a single institution between 2009 and 2017 were included. Patients were divided into 5 groups on the basis of HbA1c level: ≤5.5%, 5.6% to 6.0%, 6.1% to 7.0%, 7.1% to 8.0%, and >8.0%. The primary endpoint was major adverse cardiac events (MACE), a composite of all-cause death or myocardial infarction (MI), at 1-year follow-up. RESULTS: A total of 13,543 patients were included (HbA1c ≤5.5%, n = 1,214; HbA1c 5.6% to 6.0%, n = 2,202; HbA1c 6.1% to 7.0%, n = 4,130; HbA1c 7.1% to 8.0%, n = 2,609; HbA1c >8.0%, n = 3,388). Patients with both low (HbA1c ≤5.5%) and high (HbA1c >8.0%) levels displayed an increased risk for MACE compared with those with values between 6.1% and 7.0%. Excess risk was driven primarily by higher rates of all-cause death among those with low HbA1c levels, while higher values were strongly associated with greater MI risk. Patterns of risk were unchanged among patients with serial HbA1c levels and persisted after multivariate adjustment. CONCLUSIONS: Among patients undergoing PCI, pre-procedural HbA1c levels display a U-shaped association with 1-year MACE risk, a pattern that reflects greater risk for death in the presence of low HbA1c (≤5.5%) and higher risk for MI with higher values (>8.0%).

Clinical profile and management of patients with acute pulmonary thromboembolism - a single centre, large observational study from India.

Acute pulmonary thromboembolism is associated with high mortality, similar to that of myocardial infarction and stroke. We studied the clinical presentation and management of pulmonary thromboembolism in the Indian population. An analysis of 140 patients who presented with acute pulmonary thromboembolism at a large volume center in India from June 2015 through December 2018 was performed. The mean age of our study population was 50 years with 59% being male. Comorbidities including deep vein thrombosis, diabetes mellitus, hypertension, and chronic obstructive pulmonary disease were present in 52.9%, 40%, 35.7% and 7.14% of patients, respectively. Out of 140 patients, 40 (28.6%) patients had massive pulmonary thromboembolism, 36 (25.7%) sub-massive pulmonary thromboembolism, and 64 (45.7%) had low-risk pulmonary thromboembolism. Overall, in-hospital mortality was 25.7%. Multivariate regression analysis found chronic kidney disease and pulmonary thromboembolism severity to be the only independent risk factors. Thrombolysis was performed in 62.5% of patients with a massive pulmonary thromboembolism and 63.9% of patients with a sub-massive pulmonary thromboembolism. In the massive pulmonary thromboembolism group, patients receiving thrombolytic therapy had lower mortality compared with patients who did not receive therapy (p=0.022), whereas this difference was not observed in patients in the sub-massive pulmonary thromboembolism group. We conclude that patients with acute pulmonary thromboembolism in India presented more than a decade earlier than our western counterparts, and it was associated with poor clinical outcomes. Thrombolysis was associated with significantly reduced in-hospital mortality in patients with massive pulmonary thromboembolism.

Rotational Atherectomy Induced Coronary Perforation of Right Coronary Artery Draining into Middle Cardiac Vein.

Ellis Type III cavity spilling coronary perforation is a rare complication. We report to our knowledge, the first case of rotational atherectomy induced Type III cavity spilling coronary perforation of right posterior descending artery draining into middle cardiac vein, successfully managed by covered stent deployment. (Level of Difficulty: Advanced.).

Clinical Characteristics and In-Hospital Mortality for COVID-19 Across The Globe.

INTRODUCTION: Numerous case series have reported on the baseline characteristics and in-hospital mortality of patients with COVID-19, however, these studies included patients localized in a specific geographic region. The purpose of our study was to identify differences in the clinical characteristics and the in-hospital mortality of patients with a laboratory-confirmed diagnosis of COVID-19 internationally. METHODS: A comprehensive search of all published literature on adult patients with laboratory-confirmed diagnosis of COVID-19 that reported on the clinical characteristics and in-hospital mortality was performed. Groups were compared using a Chi-square test with Yates correction of continuity. A two-tailed p value of less than 0.05 was considered as statistically significant. RESULTS: After screening 516 studies across the globe, 43 studies from 12 countries were included in our final analysis. Patients with COVID-19 in America and Europe were older compared to their Asian counterparts. Europe had the highest percentage of male patients. American and European patients had a higher incidence of co-morbid conditions (p < 0.05 for all variables). In-hospital mortality was significantly higher in America (22.23%) and Europe (22.9%) compared to Asia (12.65%) (p < 0.0001), but no difference was seen when compared with each other (p = 0.49). CONCLUSIONS: There is a significant variation in the clinical characteristics in patients diagnosed with COVID-19 across the globe. In-hospital mortality is similar between America and Europe, but considerably higher than Asia.

Congenital Renal Arteriovenous Malformation: A Rare but Treatable Cause of Hypertension.

BACKGROUND Congenital renal vascular anomalies have been classified into 3 categories: cirsoid, angiomatous, and aneurysmal. These classifications are based on the size, location, and number of vessels involved. Aneurysmal malformations, such as the one reported here, have a single (and dilated) feeding and draining vessel. The prevalence of renal AVMs is estimated at less than 0.04%, making them rare causes of secondary hypertension. CASE REPORT A 29-year-old white woman was seen in the hypertension clinic as a referral from high-risk obstetric clinic for management of hypertension (HTN). A secondary hypertension workup with Doppler waveforms of the renal arteries revealed prominent diastolic flow in the left compared to the right. For confirmation, an MRA was done, which showed a large left renal upper-pole arteriovenous malformation (AVM) with associated vascular shunting and early opacification of the left renal vein. This congenital AVM was identified as the cause of her hypertension. Angiography and coil embolization were performed. The patient's BP normalized within a few days and she was taken off her antihypertensive medications. CONCLUSIONS This case illustrates that a careful review of duplex waveforms beyond just peak velocity and ratios is important to identify uncommon pathologies. This is important, as renal AVMs respond well to embolization, with resolution of hypertension in 59% of patients treated.