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PurposeThe purpose of this paper is to explore and critically review the existing literature on applications of Lean Methodology (LM) and Discrete-Event Simulation (DES) to improve resource utilization and patient experience in outpatient clinics. In doing, it is aimed to identify how to implement LM in outpatient clinics and discuss the advantages of integrating both lean and simulation tools towards achieving the desired outpatient clinics outcomes.Design/methodology/approachA theoretical background of LM and DES to define a proper implementation approach is developed. The search strategy of available literature on LM and DES used to improve outpatient clinic operations is discussed. Bibliometric analysis to identify patterns in the literature including trends, associated frameworks, DES software used, and objective and solutions implemented are presented. Next, an analysis of the identified work offering critical insights to improve the implementation of LM and DES in outpatient clinics is presented.FindingsCritical analysis of the literature on LM and DES reveals three main obstacles hindering the successful implementation of LM and DES. To address the obstacles, a framework that integrates DES with LM has been recommended and proposed. The paper provides an example of such a framework and identifies the role of LM and DES towards improving the performance of their implementation in outpatient clinics.Originality/valueThis study provides a critical review and analysis of the existing implementation of LM and DES. The current roadblocks hindering LM and DES from achieving their expected potential has been identified. In addition, this study demonstrates how LM with DES combined to achieve the desired outpatient clinic objectives.

Balloon aortic valvuloplasty (BAV) is often performed for patients with aortic stenosis who are not candidates for transcatheter aortic valve replacement (TAVR) due to concomitant medical issues. H...

Purpose Increased demand and the pressure to reduce health-care costs have led to longer waiting time for patients to make appointments and during the day of hospital visits. The purpose of this study is to identify opportunities to reduce waiting time using lean techniques and discrete-event simulation (DES). Design/methodology/approach A five-step procedure is proposed to facilitate the effective utilization of lean and DES to improve the performance of the Otolaryngology Head and Neck Surgery Outpatient Clinic at Cleveland Clinic Abu Dhabi. While lean techniques were applied to reduce the potential sources of waste by aligning processes, a DES model was developed to validate the proposed solutions and plan patient arrivals under dynamic conditions and different scenarios. Findings Aligning processes resulted in an efficient patient flow reducing both waiting times. DES played a complementary role in verifying lean solutions under dynamic conditions, helping to plan the patient arrivals and striking a balance between the waiting times. The proposed solutions offered flexibility to improve the clinic capacity from the current 176 patients up to 479 (without violating the 30 min waiting time policy) or to reduce the patient waiting time during the visit from the current 33 min to 4.5 min (without violating the capacity goal of 333 patients). Research limitations/implications Proposing and validating lean solutions require reliable data to be collected from the clinic and such a process could be laborious as data collection require patient and resource tracing without interfering with the regular functions of the clinic. Practical implications The work enables health-care managers to conveniently conduct a trade-off analysis and choose a suitable inter-arrival time – for every physician – that would satisfy their objectives between resource utilization (clinic capacity) and average patient waiting time. Social implications Successful implementation of lean requires a supportive and cooperative culture from all stakeholders involved. Originality/value This study presents an original and detailed application of lean techniques with DES to reduce patient waiting times. The adopted approach in this study could be generalized to other health-care settings with similar objectives.

Background: Heart transplantation remains the treatment of choice for end-stage heart failure patients, owing to the associated dual improvements in quality of life, and prognosis. The discrepancy between higher demand and supply of donor organs is the limiting factor, and is established universally. Increasing consideration of donor populations up to 65 years of age and marginal donor hearts has helped to facilitate the availability of potential grafts. However, grafts from older donors carry the mid-term increased risk of coronary allograft vasculopathy, including donor-transmitted coronary disease. Case report: A 15-year-old female underwent orthotopic heart transplantation for non-ischaemic cardiomyopathy, the donor was a 44-year-old male. The recipient developed anterior wall ischaemia within a year requiring coronary angioplasty and stent implantation to treat the severe obstruction in the left anterior descending coronary artery. However, two months later, the patient was readmitted with in-stent restenosis. Therefore, to optimally revascularise the left anterior descending coronary artery, and minimise risks associated with re-sternotomy, a minimally invasive direct coronary artery by pass grafting of the left internal mammary artery to the left anterior descending artery was performed. Conclusion: Surgical revascularisation in generalised coronary allograft vasculopathy is an inadequate option; repeat heart transplantation is the treatment of choice, albeit given its morbidity, should be reserved for a highly selected patient population. In localised coronary lesions, conventional coronary bypass surgery may be a feasible choice in selected patients with left anterior descending artery lesions. Minimal invasive techniques, such as minimally invasive direct coronary artery bypass grafting rather than robotic techniques, would be preferable for ease of approach and to limit the surgical re-do trauma.

Objective Management of the pandemic caused by the novel coronavirus SARS-CoV-2 challenges both scientists and physicians to rapidly develop, and urgently assess, effective diagnostic tests and therapeutic interventions. The initial presentation of the disease in symptomatic patients is invariably respiratory, with dry cough being the main symptom, but an increasing number of reports reveal multiple-organ involvement. The aim of this review is to summarize the potential role of the renin-angiotensin system activated phagocytes in the pathogenesis of COVID-19 disease. Methods Data for this review were identified by searches of PubMed and references from relevant articles using the search terms “SARS,” “COVID-19,” “renin-angiotensin-system,” “phagocyte,” “reactive free radical,” “antioxidant,” “ARDS,” “thrombosis,” “myocardial,” “ischaemia,” “reperfusion,” “microvascular,” and “ACE2.” Abstracts and reports from meetings were not included in this work. Only articles published in English between 1976 and 2020 were reviewed. Results The cellular target of SARS viruses is the angiotensin-converting enzyme 2, a critical regulating protein in the renin-angiotensin system. The elimination of this enzyme by the viral spike protein results in excessive activation of phagocytes, migration into the tissues via the high endothelial venules, and an oxidative burst. In the case of an overstimulated host immune response, not only devastating respiratory symptoms but even systemic or multiorgan involvement may be observed. Conclusions Early-stage medical interventions may assist in returning the exaggerated immune response to a normal range; however, some therapeutic delay might result in excessive tissue damages, occasionally mimicking a systemic disease with a detrimental outcome.

Guidelines suggest differential management of diabetics and nondiabetics with coronary artery disease (CAD) referred for revascularization, but pre-diabetics, who now comprise up to 20% to 30% of CAD patients, have been excluded from the diabetic group. To address this, we studied long-term cardiac outcomes in 1,323 consecutively drug-eluting stent (DES)-stented patients from prespecified local zip codes, dividing patients into normal-glycemic patients, prediabetics and diabetics, based upon conventional definitions. Patient age was 63±11 years, 65.5% male, mean baseline SYNTAX score of 10.2±6.8 and residual SYNTAX score=3.0±4.6. Only 2.9% of patients were lost to follow up at 10 years. Duration of follow up for alive patients was 124±33 mos. Major adverse cardiac events (MACE) by Kaplan Meier (KM) was similar for normal glycemics and prediabetics (42.9±2.5% vs 38.6±3.1% at 10 years, p=0.35), whereas that for diabetics was worse (56.7±2.6% at 10 years, p

Background: There has been an explosion in the clinical application of transcatheter aortic valve replacement (TAVR) worldwide. While moderate and severe grades of paravalvular regurgitation (PVR) ...

Objectives This study sought to evaluate and assess the extent of serial coronary artery calcification in response to oral calcium supplementation. Background Oral calcium supplements are frequently used despite their cardiovascular safety remaining controversial. Their effects on serial coronary calcification are not well established. Methods In a post hoc patient-level analysis of 9 prospective randomized trials using serial coronary intravascular ultrasound, changes in serial percentage of atheroma volume (PAV) and calcium indices (CaI) were compared in matched segments of patients coronary artery disease who were receiving concomitant calcium supplements (n = 447) and in those who did not receive supplements (n = 4,700) during an 18- to 24-month trial period. Results Patients (mean age 58 ± 9 years; 73% were men; 43% received concomitant high-intensity statins) demonstrated overall annualized changes in PAV and CaI with a mean of −0.02 ± 1.9% (p = 0.44) and a median of 0.02 (interquartile range: 0.00 to 0.06) (p Conclusions Oral calcium supplementation may increase calcium deposition in the coronary vasculature independent of changes in atheroma volume. The impact of these changes on plaque stability and cardiovascular outcomes requires further investigation.

Background As cases of COVID-19 climb worldwide, academic medical centers (AMCs) are scrambling to balance the increasing demand for medical services while maintaining safe learning environments. The scale and nature of the current pandemic, limitations on key resources, risks of transmission, and the impact on trainee wellbeing pose additional challenges to AMCs. We propose a framework for AMCs to utilize in facilitating health system, organization and program-level adjustments to meet the needs of medical trainees during the pandemic. Approach In February 2020, we developed a three-level approach to the pandemic response of training programs at our AMC. The first level involved AMC alignment and engagement with regulatory stakeholders. The second level utilized the graduate medical education committee and leveraged organizational functions such as human resources, finance, and clinical departments. The third level of intervention focused on common approaches used by programs to ensure continuity of learning in the context of dynamic changes in workflows and service operations. Evaluation Outcomes at each level are reported. These include the co-development of a national framework on medical trainee responses to COVID-19, the composition of an operational guidance document, organizational protocols to accommodate novel challenges posed by the pandemic, and multiple program-level interventions. Reflection This methodical approach, employed during a global crisis, was critical in facilitating interventions required to fulfill the mission of AMCs. Future steps include assessing the impact of these changes on trainee performance and the applicability of the approach in diverse settings. Electronic supplementary material The online version of this article (10.1007/s40037-020-00622-z) contains supplementary material, which is available to authorized users.

We used a nationwide cohort to (1) compare characteristics and outcomes of patients who underwent balloon aortic valvuloplasty (BAV) in pre-transcatheter aortic valve transplantation (TAVI) and TAVI eras, (2) examine trends in utilization and outcomes of BAV from 2005 to 2017, (3) assess the association of BAV procedural volume with hospital-based TAVI volume, and (4) understand trends and outcomes of BAV in TAVI and non-TAVI centers in the TAVI era. Pre-TAVI era included hospitalizations from 2005 to 2011, and TAVI era included hospitalizations from 2012 to 2017. In the TAVI era, hospitals were classified into quartiles based on the number of TAVI procedures performed. Trends in volume of BAV procedures from 2012 to 2017 were assessed in non-TAVI and TAVI centers (based on TAVI volume). Between 2005 and 2017, a total of 6,962 hospitalizations for BAV were identified. There were no significant differences in in-hospital mortality or stroke between pre-TAVI and TAVI eras (mortality: pre-TAVI, 8.5% vs TAVI era, 9.3%, p = 0.354; stroke: pre-TAVI, 1.9% vs TAVI era, 1.3%, p = 0.083). However, acute kidney injury was more prevalent in the TAVI era and blood transfusion in the pre-TAVI era. Importantly, patients who underwent BAV in the TAVI era were more likely to have a greater number of co-morbidities and to undergo nonelective procedures. From 2005 to 2017, there was 10-fold increase in utilization of BAV. In the TAVI era, the maximum increase in number of BAV procedures was seen in hospitals with highest TAVI volume. In conclusion, although BAV procedural volume increased approximately 10-fold between 2005 and 2017, with concomitant expansion of TAVI, rates of mortality and stroke have remained stable. Despite this, the rate of BAV utilization continues to increase, thereby indicating a significant opportunity to improve outcomes in this patient population.

OBJECTIVES We sought to compare in-hospital outcomes between patients with and without end-stage renal disease (ESRD) undergoing coronary drug-eluting stent (DES) placement and to model risk of in-hospital adverse postpercutaneous coronary intervention (PCI) events in ESRD patients. BACKGROUND The effect of ESRD on the risk of in-hospital complications after DES PCI is relatively unclear, as is the ability to prospectively stratify risk in this population. METHODS Consecutive patients undergoing first-time DES between April 1, 2003 and June 30, 2018 at a single tertiary care hospital were included in a prospective registry. Outcomes in those with ESRD were compared to those without ESRD. The primary endpoint was in-hospital all-cause mortality; secondary endpoints included in-hospital major adverse cardiac events (MACE)-defined as cardiac death, myocardial infarction, or unplanned revascularization-and major bleeding. Multivariate logistic regression modeling was used to identify factors associated with each outcome and to generate risk scores. RESULTS Among 18,134 patients in the study population, 382 (2.1%) had ESRD. ESRD was associated with increased risk of in-hospital mortality (7.1 vs. 2.9%, p

Management of ST-elevation myocardial infarction complicated by cardiogenic shock (STEMI-CS) has evolved in the last decade. There is paucity of data on readmissions in this study population. We aimed to assess the burden, major etiologies, and resource utilization for 30-day readmissions among patients with STEMI and CS. The Nationwide Readmission Database was queried from 2010 to 2014. All adult patients with an index admission for STEMI-CS were identified using International Classification of Diseases, ninth edition codes. Patient with mortality on index admission and transfers to other hospitals were excluded. A total of 18,659 admissions were identified with primary diagnosis of STEMI-CS for the study duration. Percutaneous coronary interventions was performed in 78.1% and mechanical circulatory devices were utilized in 53.9% with a mean length of stay of 10.6 (±0.2) days and mean cost of hospitalization of $47,744 (±327). Among these, 2,404 (12.9%) patients were readmitted within 30 days. Major etiologies for readmission include congestive heart failure (25.7%), acute myocardial infarction (9.4%), arrhythmias (4.5%), and sepsis (4.2%). The mean length of stay and cost of hospitalization for 30-day readmission were 5.9 (±0.3) days and $17,043 (±590), respectively. Older age, female gender, lower socioeconomic status, and discharge to home health care were significant predictors for readmission. In conclusion, there is a significant burden of 30-day readmission among patients with STEMI-CS. Percutaneous coronary interventions and mechanical circulatory devices were utilized in a majority of index admissions. Congestive heart failure was the single most common reason for 30-day readmission. Patients discharged to skilled nursing facility, patients with private insurance and higher socioeconomic status were less likely to be readmitted. Moreover, readmissions among STEMI-CS patients contribute to significant resource utilization.

Patients of different racial backgrounds may have socioeconomic, cultural, or genetic differences that impact outcomes after percutaneous coronary intervention (PCI). There are limited data beyond 2 to 3 years for Blacks to inform discussions and perhaps improve outcomes. We studied consecutive limus-stent treated patients, having their first PCI at our institution January 2003 to March 2010 in 2 cohorts; Cohort 1: standard 3-year follow-up (n = 3,782, 12.4% Blacks) and Cohort 2: from nearby zip codes with intended detailed follow-up through 8 to 13 years (n = 616, 31.8% Blacks). The primary outcomes of interest were mortality and death/MI/revascularization (DMIR) (Cohort 1) or major adverse cardiac events (cardiac DMIR) (Cohort 2). In all cohorts, Blacks had a higher prevalence of many risk factors. In Cohort 1, 3-year mortalities were 14.6% and 9.6% (p = 0.001) and DMIR were 32.1% and 25.0% (p = 0.001), for Blacks and Whites, respectively. In Cohort 2, over 9.5 ± 2.0 years, treatment intensity was as high or higher for Blacks, but they continued to have higher low-density lipoprotein-cholesterol and blood pressure values. Major adverse cardiac events and mortality at 10 years were higher for Blacks (59.0% vs 48.1%, p = 0.024 and 44.3% vs 23.0%, p0.001). Differences in outcomes, except 10 year mortality, were not significantly different after adjustment for baseline characteristics. Blacks have a higher risk profile at the time of PCI and worse long-term outcomes after drug-eluting stent, most of which is explained by baseline differences.

Introduction Similar to other non-communicable diseases (NCDs), people who develop cardiovascular disease (CVD) typically have more than one risk factor. The clustering of cardiovascular risk factors begins in youth, early adulthood, and middle age. The presence of multiple risk factors simultaneously has been shown to increase the risk for atherosclerosis development in young and middle-aged adults and risk of CVD in middle age. Objective This study aimed to address the interrelationship of CVD risk factors and their accumulation in a large sample of young adults in the United Arab Emirates (UAE). Methods Baseline data was drawn from the UAE Healthy Future Study (UAEHFS), a volunteer-based multicenter study that recruits Emirati nationals. Data of participants aged 18 to 40 years was used for cross-sectional analysis. Demographic and health information was collected through self-reported questionnaires. Anthropometric data and blood pressure were measured, and blood samples were collected. Results A total of 5126 participants were included in the analysis. Comorbidity analyses showed that dyslipidemia and obesity co-existed with other cardiometabolic risk factors (CRFs) more than 70% and 50% of the time, respectively. Multivariate logistic regression analysis of the risk factors with age and gender showed that all risk factors were highly associated with each other. The strongest relationship was found with obesity; it was associated with four-fold increase in the odds of having central obesity [adjusted OR 4.70 (95% CI (4.04–5.46)], and almost three-fold increase odds of having abnormal glycemic status [AOR 2.98 (95% (CI 2.49–3.55))], hypertension (AOR 3.03 (95% CI (2.61–3.52))] and dyslipidemia [AOR 2.71 (95% CI (2.32–3.15)]. Forty percent of the population accumulated more than 2 risk factors, and the burden increased with age. Conclusion In this young population, cardiometabolic risk factors are highly prevalent and are associated with each other, therefore creating a heavy burden of risk factors. This forecasts an increase in the burden of CVD in the UAE. The robust longitudinal design of the UAEHFS will enable researchers to understand how risk factors cluster before disease develops. This knowledge will offer a novel approach to design group-specific preventive measures for CVD development.

Background and aims: We tested the hypothesis that on-treatment HbA1c levels independently associate with coronary atheroma progression and major adverse cardiovascular events (MACE: death, myocardial infarction, cerebrovascular accident, coronary revascularization, or hospitalization for unstable angina) rates. Methods: We performed a post-hoc pooled analysis of data from seven prospective, randomized trials involving serial coronary intravascular ultrasonography (IVUS). The percent atheroma volume (PAV) was calculated as the proportion of the entire vessel wall occupied by atherosclerotic plaque. Using multivariable mixed modeling, we determined the association of on-treatment HbA1c with annualized change in PAV. Cox proportional hazard models were used to assess the association of HbA1c with incidence of MACE. Results: Among 3,312 patients (mean age 58.6±9years, 28.4%women) average on-treatment HbA1c was 6.2±1.1%. Overall, there was no net significant annualized change in PAV (0.12±0.19%, p = 0.52). In a fully adjusted multivariable analysis (following adjustment of age, sex, body mass index, systolic blood pressure, smoking, low- and high-density lipoprotein cholesterol, triglyceride levels, peripheral vascular disease, trial, region, and baseline PAV), higher on-treatment HbA1c levels were independently associated with annualized changes in PAV [beta-estimate (95% confidence interval): 0.13(0.08, 0.19), p

OBJECTIVES This study aimed to evaluate the incidence, treatment, and outcomes of acute myocardial infarction (AMI) following transcatheter or surgical aortic valve replacement (TAVR or SAVR). BACKGROUND Coronary artery disease is common in patients who undergo aortic valve replacement. However, little is known about differences in clinical features of post-TAVR or post-SAVR AMI. METHODS We retrospectively identified post-TAVR or post-SAVR (including isolated and complex SAVR) patients admitted with AMI using the Nationwide Readmissions Database 2012-2017. Incidence, invasive strategy (coronary angiography or revascularization), and in-hospital outcomes were compared between post-TAVR and post-SAVR AMIs. RESULTS The incidence of 180-day AMI was higher post-TAVR than post-SAVR (1.59% vs. 0.72%; p

BACKGROUND: While metformin is recommended as a first-line cardioprotective therapy for type 2 diabetic patients, whether it exerts direct effects on atherosclerotic plaque remains uncertain. The current study characterized coronary plaque microstructures in type 2 diabetic patients who received metformin. METHODS: We retrospectively analyzed 409 non-culprit lipid plaques in 313 type 2 diabetic patients with coronary artery disease (CAD) by using frequency-domain optical coherence tomography (FD-OCT) imaging. FD-OCT derived plaque microstructures were compared in patients stratified according to metformin use. RESULTS: A proportion of 38.6% of study subjects received metformin. Patients receiving metformin more likely exhibited a history of hypertension (79.3% vs. 67.1%, P=0.03) and metabolic syndrome (52.8% vs. 36.4%, P=0.01). On FD-OCT imaging, the prevalence of lipid plaque was lower in the metformin group (66.2% vs. 77.9%, P=0.03). Furthermore, the metformin group demonstrated plaques with a smaller lipid arc (median: 168.7° vs. 208.5°, P=0.008), shorter longitudinal length (media: 5.1 vs. 9.1 mm, P=0.04), and a lower frequency of cholesterol crystal (3.9% vs. 18.2%, P=0.01) and spotty calcification (3.9% vs. 34.8%, P=0.008). These differences remained significant after adjusting for clinical characteristics and glycemic control. However, in patients who received insulin, the favourable effect of metformin on lipid arc was not observed (insulin user: P=0.87; insulin non-user: P=0.009; P value for interaction between two groups, P=0.02). CONCLUSIONS: Metformin use was associated with a lower prevalence of vulnerable plaque features in type 2 diabetic patients with CAD, especially insulin non-user. These findings suggest the potential of metformin to exert direct plaque stabilization effects in type 2 diabetic subjects.

A 44-year-old man presented with symptoms of shortness of breath on exertion. The shortness of breath started after walking for 10 min and made him…, Catheter-induced coronary artery dissection is a serious complication of coronary angiography. Percutaneous intervention is usually indicated in case of large spiral dissections, however, wiring into the true lumen can be challenging. This case reports the novel use of intravascular ultrasound-guided rescue percutaneous coronary intervention for stenting an iatrogenic spiral dissection of the right coronary artery. (Level of Difficulty: Intermediate.), Graphical abstract

In patients with end-stage renal disease (ESRD), surgical aortic valve replacement is associated with higher early and late mortality, and adverse outcomes compared with patients without renal disease. Transcatheter aortic valve replacement (TAVR) offers another alternative, but there are limited reported outcomes.The purpose of this study was to determine the outcomes of TAVR in patients with ESRD.Among the first 72,631 patients with severe aortic stenosis (AS) treated with TAVR enrolled in the Society of Thoracic Surgeons (STS)/American College of Cardiology (ACC) TVT (Transcatheter Valve Therapies) registry, 3,053 (4.2%) patients had ESRD and were compared with patients who were not on dialysis for demographics, risk factors, and outcomes.Compared with the nondialysis patients, ESRD patients were younger (76 years vs. 83 years; p 0.01) and had higher rates of comorbidities leading to a higher STS predicted risk of mortality (median 13.5% vs. 6.2%; p 0.01). ESRD patients had a higher in-hospital mortality (5.1% vs. 3.4%; p 0.01), although the observed to expected ratio was lower (0.32 vs. 0.44; p 0.01). ESRD patients also had a similar rate of major vascular complications (4.5% vs. 4.6%; p = 0.86), but a higher rate of major bleeding (1.4% vs. 1.0%; p = 0.03). The 1-year mortality was significantly higher in dialysis patients (36.8% vs. 18.7%; p 0.01).Patients undergoing TAVR with ESRD are at higher risk and had higher in-hospital mortality and bleeding, but similar vascular complications, when compared with those who are not dialysis dependent. The 1-year survival raises concerns regarding diminished benefit in this population. TAVR should be used judiciously after full discussion of the risk-benefit ratio in patients on dialysis.

Background: Patients with severe aortic stenosis (AS) at intermediate surgical risk, treated with transcatheter aortic valve replacement (TAVR) or surgical aortic valve replacement (SAVR) have simi...

OBJECTIVES We investigated the hemodynamic durability of the transcatheter aortic valves (TAVs) using the updated Valve Academic Research Consortium-2 (VARC-2) criteria. BACKGROUND The updated VARC-2 consensus criteria combine flow-dependent and flow-independent echocardiographic parameters for hemodynamic assessment of TAVR. Data on the hemodynamic durability of TAV and clinical risk factors associated with valve hemodynamic deterioration (VHD) are lacking. METHODS All patients (n = 276) who received TAV between 2006 and 2012 and had ≥2 follow-up echocardiograms were studied. RESULTS During a median follow up period of 3.3 (1.8-4.4) years, 8 patients (3%) developed moderate to severe valve stenosis per the VARC-2 criteria, while 20 had mild stenosis. In a Cox proportional hazards model analysis, moderate to severe stenosis by VARC-2 criteria was associated with younger age (P = 0.03, HR 0.94), absence of dual antiplatelet therapy (DAPT) (P = 0.026, HR 0.18), and lower baseline left ventricular ejection fraction (LVEF) (P = 0.006, HR 0.94). Longitudinal analysis using a mixed effect model showed that presence of stenosis by VARC-2 criteria was associated with an increase in aortic valve mean gradient (P

Background Stroke after transcatheter aortic valve replacement (TAVR) occurs with an incidence of 4–11% and is a particularly devastating adverse event associated with the procedure. Several cerebral protection devices (CPD) have been developed to prevent cerebrovascular events during TAVR. While most studies have shown CPD to be associated with decreased number and volume of lesions on diffusion weighted magnetic resonance imaging , the clinical benefit of these devices remains uncertain. Methods We aimed to use meta-analysis techniques to study the clinical safety and efficacy of these CPD in prospective randomized and non-randomized studies. Data was summarized as Mantel-Haenszel relative risk (RR) and 95% confidence intervals (CI). We used the Higgins' I2 statistic to evaluate heterogeneity. Results We found no evidence of difference between patients with and without CPD [RR 0.70 (95% CI 0.40–1.21)] for the primary composite outcome of stroke and mortality at 30 days. The two groups were also comparable in peri-procedural strokes [RR 0.53 (95% CI 0.27–1.07)], stroke at 30 days [RR 0.69(95% CI 0.38–1.26)], mortality [RR 0.59 (95% CI 0.22–1.59) at 30 days, AKI [RR 0.68(95% CI 0.28–1.62)], major bleeding [RR 0.56 (95% CI 0.26–1.18)], life threating bleeding [0.54 (95% CI 0.19–1.53)] and major vascular complications [RR 0.80 (95% CI 0.52–1.24)]. The risk of strokes within the first week of TAVR was significantly lower in the CPD group [0.56(95% CI 0.33–0.96)]. Conclusion CPD are associated with a decreased incidence of strokes within 1 week of follow-up without showing any evidence of increased risk of other peri-procedural adverse events.

Background: The conventional method of implanting balloon-expandable SAPIEN-3 (S3) valve results in a final 70:30 or 80:20 ratio of the valve in the aorta:left ventricular outflow tract with published rates of permanent pacemaker around 10%. We sought to evaluate whether higher implantation of S3 reduces conduction abnormalities including the need for permanent pacemaker. Methods: We included consecutive patients who underwent transfemoral transcatheter aortic valve replacement using S3 between April 2015 and December 2018 and compared outcomes with typical valve deployment strategy to our more contemporary high deployment technique (HDT). We excluded patients with nontransfemoral access or valve-in-valve. Results: Among 1028 patients, HDT was performed in 406 patients (39.5%). Mean implantation depth under the noncoronary cusp was significantly smaller with HDT compared with conventional technique (1.5±1.6 versus 3.2±1.9 mm; P P =0.216). Thirty-day permanent pacemaker rates were lower with HDT (5.5% versus 13.1%; P P P P =0.804), or moderate-to-severe aortic regurgitation (1% versus 2.7%; P =0.081) at 1 year. HDT was associated with slightly higher 1-year mean gradients (13.1±6.2 versus 11.8±4.9 mm Hg; P =0.042) and peak gradients (25±11.9 versus 22.5±9 mm Hg; P =0.026). However, Doppler velocity index was similar (0.47±0.15 versus 0.48±0.13; P =0.772). Conclusions: Our novel technique for balloon-expandable S3 valve positioning consistently achieves higher implantation resulting in substantial reduction in conduction abnormalities and permanent pacemaker requirement after transcatheter aortic valve replacement without compromising procedural safety or valve hemodynamics. Operators should consider this as an important technique to improve patient outcomes.

Maitha Alkaabi,1 Mecit Can Emre Simsekler,1 Raja Jayaraman,1 Abdulqader Al Kaf,1 Hussam Ghalib,2 Dima Quraini,2 Samer Ellahham,2 E Murat Tuzcu,2 Kudret Demirli3 1Department of Industrial and Systems Engineering, Khalifa University of Science and Technology, Abu Dhabi, United Arab Emirates; 2Heart and Vascular Institute, Cleveland Clinic Abu Dhabi, Abu Dhabi, United Arab Emirates; 3Department of Mechanical, Industrial and Aerospace Engineering, Concordia University, Montreal, CanadaCorrespondence: Mecit Can Emre SimseklerDepartment of Industrial and Systems Engineering, Khalifa University of Science and Technology, P.O. Box 127788, Abu Dhabi, United Arab EmiratesTel +9712 501 8410Fax +971 2 447 2442Email emre.simsekler@ku.ac.aePurpose: Waste identification plays a vital role in lean healthcare applications. While the value stream map (VSM) is among the most commonly used tools for waste identification, it may be limited to visualize the behaviour of dynamic and complex healthcare systems. To address this limitation, system modelling techniques (SMTs) can be used to provide a comprehensive picture of various system-wide wastes. However, there is a lack of evidence in the current literature about the potential contribution of SMTs for waste identification in healthcare processes.Methods: This study evaluates the usability and utility of six types of SMTs along with the VSM. For the evaluation, interview-based questionnaires were conducted with twelve stakeholders from the outpatient clinic at the Heart and Vascular Institute at Cleveland Clinic Abu Dhabi.Results: VSM was found to be the most useful diagram in waste identification in general. However, some SMTs that represent the system behaviour outperformed the VSM in identifying particular waste types, e.g., communication diagram in identifying over-processing waste and flow diagram in identifying transportation waste.Conclusion: As behavioural SMTs and VSM have unique strengths in identifying particular waste types, the use of multiple diagrams is recommended for a comprehensive waste identification in lean. However, limited resources and time, as well as limited experience of stakeholders with SMTs, may still present obstacles for their potential contribution in lean healthcare applications.Keywords: lean healthcare, value stream map, system modelling techniques, waste identification, kaizen, system approaches, healthcare operations

Background: There has been an explosion in the clinical application of transcatheter aortic valve replacement (TAVR) worldwide. While moderate and severe grades of paravalvular regurgitation (PVR) are established as poor prognostic indicators, the impact of mild PVR is unclear. We therefore aimed to compare outcomes after TAVR between those who develop mild PVR versus none or trivial PVR. Methods: We identified 1,098 consecutive patients who underwent TAVR from January 2014 to December 2017. The primary outcome was all-cause mortality using Kaplan Meier curves. The secondary outcomes included heart failure readmissions and the composite endpoints of early safety and clinical efficacy according to VARC-2 definitions. Results: The median age was 82 years, 43% were females, and 94% were Caucasian. The procedure was done through a transfemoral approach, the indication for TAVR was severe AS in 97% of cases, and 72% had an Edwards SAPIEN 3 Transcatheter Heart Valve implanted. Mild PVR was seen in 191 (17.4%) patients, and the rest (82.6%) had no or trivial post-TAVR PVR. Mortality at 30-days and 1 year was similar between none/trivial and mild PVR groups (1.6% vs 1.7%, p = 0.93 & 6.3% vs 8.8%, p = 0.31). HF-related hospitalizations were the same at 30 days as well as 1 year in both groups (1.9% vs 0.8%, p = 0.209 and 4.5% vs 6.3%, p = 0.461). Conclusion: Although mild PVR is seen in approximately one-fifth of patients after TAVR, patients with mild PVR have similar outcomes compared to those with none or trivial PVR. Abbreviations: AR: Aortic Regurgitation; AV: Aortic Valve; HF: Heart Failure; VARC: Valve Academic Research Consortium; LVOT: Left Ventricular Outflow Tract; LVEF: Left Ventricular Ejection Fraction; PVR: Paravalvular Aortic Regurgitation; TAVR: Transcatheter Aortic Valve Replacement; TF: Transfemoral