Lily E. Johnston

Development of a Transplantation Risk Index in Patients With Mechanical Circulatory Support: A Decision Support Tool.

OBJECTIVES The aim of this study was to develop a risk index specific to patients on mechanical circulatory support that accurately predicts 1-year mortality after orthotopic heart transplantation using the United Network for Organ Sharing database. BACKGROUND Few clinical tools are available to aid in the decision between continuing long-term device support and performing transplantation in patients bridging with mechanical circulatory support. METHODS Using a prospectively collected, open cohort, 6,036 patients receiving mechanical circulatory support who underwent orthotopic heart transplantation between 2000 and 2013 were evaluated and randomly separated into derivation (80%) and validation (20%) groups. Multivariate logistic regression models were constructed using variables that improved the explanatory power of the model, which was determined using multiple methods. Points for a simple additive risk index were apportioned on the basis of relative effect on odds of 1-year mortality. RESULTS A 75-point scoring system was created from 9 recipient and 4 donor variables. The average score in the validation cohort was 14.4 ± 7.7, and scores ranged from 0 to 57; these values were similar to those in the derivation cohort. Each 1-point increase predicted an 8.3% increase in the odds of 1-year mortality (odds ratio: 1.08; 95% confidence interval: 1.06 to 1.11). Low (0 to 10), intermediate (11 to 20), and high (>20) risk score cohorts were created, with predicted average 1-year mortalities of 8.6%, 12.8%, and 31%, respectively, in the validation cohort. CONCLUSIONS The investigators present a novel, internally cross-validated risk index that accurately predicts mortality in bridge-to-transplantation patients.

Surgeon, not institution, case volume is associated with limb outcomes after lower extremity bypass for critical limb ischemia in the Vascular Quality Initiative

Objective Studies from large administrative databases have demonstrated associations between institutional case volume and outcomes after lower extremity bypass (LEB). We hypothesized that increased institutional and surgeon volume would be associated with improved outcomes after LEB. Using a national, prospectively collected clinical database, the objective of this study was to determine the effects of both surgeon and institutional volume on outcomes after LEB. Methods The Vascular Quality Initiative (VQI) was queried to identify all LEBs for critical limb ischemia or claudication between 2004 and 2014. Average annual case volume was calculated by dividing an institutions or surgeons total LEB volume by the number of years they reported to the VQI. Institutional and surgeon volumes were analyzed as continuous variables to determine the impact of volume on major adverse cardiac events (MACEs), major adverse limb events (MALEs), graft patency, and amputation‐free survival. Hierarchical regression models were used with cases clustered by surgeon and center. Time‐dependent outcomes were evaluated with multivariable shared frailty Cox proportional hazards models. Results From 2004 to 2014, there were 14,678 LEB operations performed at 114 institutions by 587 surgeons. Average annual institutional volume ranged from 1.0 to 137.5 LEBs per year, with a median of 26.9 (interquartile range, 14‐45.3). Average annual surgeon volume ranged from 1 to 52 LEBs per year with a median of 5.7 (interquartile range, 2.5‐9.3). Institutional LEB volume was not associated with MACEs or MALEs or with loss of patency. However, average annual surgeon volume was independently associated with reduced MALEs and improved primary patency. Institutional and surgeon volume did not predict MACEs. Conclusions In contradistinction to previous studies, there was no relationship in this study between institutional LEB volume and outcomes after LEB. However, greater average annual surgeon volume was associated with improved primary patency and decreased risk of MALEs. Open LEB remains a safe and effective procedure for limb salvage. Limb‐related outcomes in critical limb ischemia and claudication will be optimized if surgeons maintain adequate volume of LEB.

Peripheral Arterial Disease in Sub-Saharan Africa: A Review.

IMPORTANCE Peripheral arterial disease (PAD) causes significant morbidity and is an important risk factor for cardiovascular disease-related mortality. However, the burden of PAD in sub-Saharan Africa is poorly understood. OBJECTIVE To assess epidemiological and clinical reports regarding PAD from sub-Saharan Africa such that the regional epidemiology and management of PAD could be described and recommendations offered. EVIDENCE REVIEW A systematic search in PubMed, Medline, Embase, the Cumulative Index to Nursing and Allied Health Literature, and Google Scholar for reports pertaining to the epidemiology and/or management of PAD in sub-Saharan Africa was performed. Reports that met inclusion criteria were sorted into 3 categories: population epidemiology, clinical epidemiology, and surgical case series. Findings were extracted and described. FINDINGS The search returned 724 records; of these, 16 reports met inclusion criteria. Peripheral arterial disease epidemiology and/or management was reported from 10 of the 48 sub-Saharan African countries. Peripheral arterial disease prevalence ranged from 3.1% to 24% of adults aged 50 years and older and 39% to 52% of individuals with known risk factors (eg, diabetes). Medical management was only described by 2 reports; both documented significant undertreatment of PAD as a cardiovascular disease risk factor. Five surgical case series reported that trauma and diabetes-related complications were the most common indications for vascular surgery. CONCLUSIONS AND RELEVANCE The prevalence of PAD in sub-Saharan Africa may be equal to or higher than that in high-income countries, exceeding 50% in some high-risk populations. In addition to population-based studies that better define the PAD burden in sub-Saharan Africa, health systems should consider studies and action regarding risk factor mitigation, targeted screening, medical management of PAD, and defining essential vascular care.

Good at One or Good at All? Variability of Coronary and Valve Operation Outcomes Within Centers

BACKGROUND The technical expertise required for treatment of coronary and structural heart valve disease differs. Correlation between center-specific mortality rates after coronary artery bypass grafting (CABG) and valve operations has not been demonstrated. This study tested the hypothesis that risk-adjusted outcomes between coronary and valve procedures do not correlate within centers. METHODS Records of patients undergoing isolated CABG, isolated aortic valve replacement (AVR), or isolated mitral valve replacement (MVR) procedures from 2008 to 2015 in a multi-institutional Society of Thoracic Surgeons (STS) database were used to generate observed-to-expected (O/E) ratios for morbidity and death. Ratios were based on the STS predicted risks of morbidity and death and were calculated by procedure for each institution. Linear regression models evaluated the relationship between institutional performance in CABG and valve operations. RESULTS A total of 22,258 records from 18 institutions were analyzed: 17,026 CABG, 3,238 isolated AVR, and 1,994 MVR procedures. With respect to deaths, the correlation coefficients were weak; for AVR and CABG, it was 0.22 and was 0.26 for MVR and CABG. With respect to morbidity, a strong relationship was seen between the morbidity O/E ratios, with coefficients of 1.03 for AVR and 0.97 for MVR, suggesting a nearly 1:1 relationship between morbidities observed in an institutions CABG and valve operations. CONCLUSIONS Sites that perform CABG with low mortality rates may not have similarly low mortality rates with valve operations. Most striking, however, is the nearly identical O/E ratio for morbidity for CABG and valve operations at each center. These findings suggest postoperative care as a major determinant for morbidity after cardiac operation.

Roux-en-Y gastric bypass is safe in elderly patients: a propensity-score matched analysis

BACKGROUND Numerous studies have established the effectiveness of Roux-en-Y gastric bypass (RYGB) for weight loss and co-morbidity amelioration. However, its safety and efficacy in elderly patients remains controversial. OBJECTIVES To evaluate outcomes in patients aged ≥60 years who underwent RYGB compared with nonsurgical controls with the hypothesis that RYGB provides weight loss benefits without differences in survival. SETTING University-affiliated tertiary center. METHODS All patients who underwent RYGB from 1985 to 2015 were identified and divided into elderly (age ≥60) and nonelderly (age <60) groups. A nonsurgical elderly control population was identified using a clinical data repository of outpatient visits to propensity match elderly patients 4:1 on demographic characteristics, co-morbidities, and relevant preoperative substance/medication use. Unpaired appropriate univariate analyses compared each stratified group. Kaplan-Meier survival curves were fitted based on social security death data. RESULTS A total of 2306 patients underwent RYGB. The 107 elderly patients had lower median body mass index (47.0 versus 49.9; P = .007) and higher rates of co-morbidities. Rates of complications did not differ between elderly and nonelderly patients. Elderly surgical patients were propensity matched 4:1 (10,044 controls) yielding 428 well-matched nonsurgical controls. The elderly group demonstrated significant percent reduction in excess body mass index compared with the control group (81.8% versus 10.3%; P < .001). Kaplan-Meier survival analysis with log-rank test demonstrated no difference in midterm survival (P = .63). CONCLUSIONS A significant weight reduction benefit was identified after RYGB in elderly patients without a difference in midterm survival compared with propensity-matched controls, suggesting RYGB is a safe and efficacious weight loss strategy in the elderly.

Estimating risk of adverse cardiac event after vascular surgery using currently available online calculators

Background The decision to proceed with vascular surgical interventions requires evaluation of cardiac risk. Recently, several online risk calculators were created to predict outcomes and to lead to a more informed conversation between surgeons and patients. The objective of this study was to compare and further validate these online calculators with actual adverse cardiac outcomes at a single institution. Methods All patients from January 2011 through December 2015 undergoing carotid endarterectomy (CEA), infrainguinal lower extremity bypass, open abdominal aortic aneurysm (AAA) repair, and endovascular aneurysm repair (EVAR) on the vascular surgical service were included using the Society for Vascular Surgery Vascular Quality Initiative database at our health system. Additional information was collected through retrospective chart review. Each patient was entered through three online risk calculators: (1) the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) estimates the risk of cardiac arrest and myocardial infarction (MI); (2) the Revised Cardiac Risk Index (RCRI) estimates risk of MI, pulmonary edema, ventricular fibrillation, primary cardiac arrest, and complete heart block; and (3) the Vascular Study Group of New England (VSGNE) Cardiac Risk Index estimates risk of postoperative MI only. Observed adverse cardiac events (ACEs) were compared with expected values for each calculator using a χ2 goodness‐of‐fit test. Institutional Review Board exemption was obtained. Results A total of 856 cases were included: 350 CEAs, 210 infrainguinal bypasses, 77 open AAA repairs, and 219 EVARs. For CEA, no risk calculator showed statistically significant variation from the observed values (NSQIP, P = .45; RCRI, P = .17; VSGNE, P = .24). For infrainguinal bypass, NSQIP slightly underpredicted adverse events (P = .054), RCRI strongly underpredicted (P = .002), and VSGNE showed no difference (P = .42). For open AAA repair, NSQIP (P = .51) and VSGNE (P = .98) were adequate predictors, but RCRI strongly underpredicted the adverse events (P ≤ .0001). Finally, EVAR cardiac outcomes showed greater adverse events than predicted by all three calculators (NSQIP, P = .02; RCRI, P = .0002; and VSGNE, P = .025). Pooled data for the entire group documented that the VSGNE proved an accurate tool for prediction (P = .34), whereas ACEs were underpredicted by NSQIP (P = .0055) and RCRI (P ≤ .001). Conclusions Although online cardiac risk calculators of adverse surgical events are easy to use and to reference in broad surgical decision‐making, there is significant variability in their predictability at the procedure and institutional level. Our data suggest that ACEs often occur at a higher rate than expected on the basis of calculated risks profiles, thus creating a platform for future discussion about preoperative evaluation and postoperative care decision‐making models.

Consensus recommendations for essential vascular care in low- and middle-income countries

OBJECTIVE Many low- and middle-income countries (LMICs) are ill equipped to care for the large and growing burden of vascular conditions. We aimed to develop essential vascular care recommendations that would be feasible for implementation at nearly every setting worldwide, regardless of national income. METHODS The normative Delphi method was used to achieve consensus on essential vascular care resources among 27 experts in multiple areas of vascular care and public health as well as with experience in LMIC health care. Five anonymous, iterative rounds of survey with controlled feedback and a statistical response were used to reach consensus on essential vascular care resources. RESULTS The matrices provide recommendations for 92 vascular care resources at each of the four levels of care in most LMICs, comprising primary health centers and first-level, referral, and tertiary hospitals. The recommendations include essential and desirable resources and encompass the following categories: screening, counseling, and evaluation; diagnostics; medical care; surgical care; equipment and supplies; and medications. CONCLUSIONS The resources recommended have the potential to improve the ability of LMIC health care systems to respond to the large and growing burden of vascular conditions. Many of these resources can be provided with thoughtful planning and organization, without significant increases in cost. However, the resources must be incorporated into a framework that includes surveillance of vascular conditions, monitoring and evaluation of vascular capacity and care, a well functioning prehospital and interhospital transport system, and vascular training for existing and future health care providers.