The Utility of PET/CT for the Diagnosis of Periosteal Chondrosarcoma in a Patient With Maffucci's Syndrome.

Maffucci's syndrome is a rare congenital nonhereditary syndrome with less than 300 cases having been reported in the United States. It is characterized by multiple enchondromas, hemangiomas, and rarely lymphangiomas. Enchondromas may undergo malignant transformation to chondrosarcomas. Surveillance plays a vital role in detecting early malignant transformation. Fluorodeoxyglucose (FDG) PET/CT, although falling out of favor, may be utilized as an imaging modality by physicians to determine such transformation, allowing for timely management and intervention. In this report, we share our experience with such a case.

Safety of Outpatient Milrinone Infusion in End-Stage Heart Failure: ICD-Level Data on Atrial Fibrillation and Ventricular Tachyarrhythmias.

BACKGROUND: Milrinone infusion is one of a few select "non-device" therapies for patients with New York Heart Association (NYHA) class IV, stage D heart failure, which has been associated with an increase in ventricular tachyarrhythmia and atrial fibrillation. Milrinone improves hemodynamics and provides symptomatic relief. Many patients with end-stage heart failure die from cardiac pump failure, and the impact of ventricular tachyarrhythmia and atrial fibrillation on their mortality is unclear. METHODS: This is a retrospective study of 98 consecutive patients receiving outpatient milrinone in a single center from 2008 to 2016. The primary endpoint of the study was overall survival on milrinone. Secondary endpoints were incidence of post-milrinone implantable cardioverter defibrillator (ICD) shocks and development of ventricular tachyarrhythmia or atrial fibrillation. RESULTS: Median survival was 581 ± 96 days with no difference between those with prior ventricular tachyarrhythmia and those without at 1 month (92% vs 97%, P = 0.34), 6 months (67% vs 73%, P = 0.75), and 12 months (67% vs 61%, P = 0.88). Seven out of 12 (58%) patients with prior ventricular tachyarrhythmia had ICD shocks, as compared to 5 out of 78 (6.4%) (P <0.001). Thirty-five patients had atrial fibrillation prior to starting milrinone, which decreased to 72% (P <0.05) by the third follow-up time period (7-9 months). Amiodarone use was protective against new onset atrial fibrillation. CONCLUSIONS: Patients with stage D heart failure with a history of ventricular tachyarrhythmia have similar survival on outpatient milrinone compared to those without. However, those with prior ventricular tachyarrhythmia received more ICD shocks for more ventricular tachyarrhythmias. Milrinone remains a viable therapy for patients with stage D heart failure with limited therapeutic options.

Clinical Significance of J Waves in Patients Undergoing Therapeutic Hypothermia for Out-of-Hospital Cardiac Arrest.

BACKGROUND: Hypothermia is associated with the development of J waves. However, little is known about the impact of these electrocardiogram (ECG) findings on the development of ventricular arrhythmias and patient outcomes during therapeutic hypothermia (TH) postresuscitation from out-of-hospital cardiac arrest (OHCA). We investigated the prevalence of J waves in OHCA patients prior to and during TH. Additionally, we explored the incidence of atrial and ventricular arrhythmias and in-hospital mortality for patients with and without J waves either at baseline, during TH, or both. METHODS: We conducted a retrospective analysis of patients who suffered OHCA and underwent TH (goal temperature of 32-34°C). Fifty-nine patients were stratified dependent upon the presence of or the development of J waves on surface ECGs. Descriptive analysis and logistic regression modeling were used to assess the population differences and mortality, respectively, between patients who developed J waves during TH and those who did not. RESULTS: There was no difference in the development of in-hospital atrial or ventricular arrhythmias between patients with J waves present during TH (16%) and those without (17.6%, P = 0.834). Compared to patients without J waves at baseline and during TH, those with J waves present both at baseline and during TH had significantly worse survival (hazard ratio = 12.42, P = 0.046). CONCLUSIONS: While J waves are common ECG findings during TH in patients resuscitated from OHCA, our study demonstrated an increase in mortality for patients with J waves present both at baseline and during TH.

The survival benefit of kidney transplantation in the setting of combined peripheral arterial disease and end-stage renal failure.

Given the deleterious effects of concomitant peripheral arterial disease (PAD) and severe renal disease, a role for aggressive screening and management of PAD in renal failure patients has been suggested. However, limited data exist detailing the impact of PAD on kidney waitlist survival and the potential benefit of transplantation in PAD. Multivariable COX regression and Kaplan-Meier survival models were fit using UNOS data to assess kidney waitlist and post-transplant five-yr survival. Compared to PAD-Dial- (no PAD or dialysis) waitlist survival, PAD+Dial- was associated with a 36%, PAD-Dial+ a 95%, and PAD+Dial+ a 190% increased risk of death. A significant survival benefit of kidney transplantation was identified in the PAD population (p < 0.001, HR = 0.440 comparing post-transplant to waitlist survival). Time to survival benefit (equal mortality between waitlist and post-transplant population) of kidney transplantation in PAD+ was realized 2.5 times sooner in pre-emptive transplantation than transplant after dialysis (154 d vs. 381 d), per unadjusted Kaplan-Meier analysis. To our knowledge, this is the first study to demonstrate a survival benefit of kidney transplantation in the setting of PAD. Pre-emptive transplantation with emphasis on living donation prior to dialysis should be advocated to improve outcomes in this high risk patient population.

Peroxynitrite disrupts endothelial caveolae leading to eNOS uncoupling and diminished flow-mediated dilation in coronary arterioles of diabetic patients.

Peroxynitrite (ONOO(-)) contributes to coronary microvascular dysfunction in diabetes mellitus (DM). We hypothesized that in DM, ONOO(-) interferes with the function of coronary endothelial caveolae, which plays an important role in nitric oxide (NO)-dependent vasomotor regulation. Flow-mediated dilation (FMD) of coronary arterioles was investigated in DM (n = 41) and non-DM (n = 37) patients undergoing heart surgery. NO-mediated coronary FMD was significantly reduced in DM patients, which was restored by ONOO(-) scavenger, iron-(III)-tetrakis(N-methyl-4'pyridyl)porphyrin-pentachloride, or uric acid, whereas exogenous ONOO(-) reduced FMD in non-DM subjects. Immunoelectron microscopy demonstrated an increased 3-nitrotyrosine formation (ONOO(-)-specific protein nitration) in endothelial plasma membrane in DM, which colocalized with caveolin-1 (Cav-1), the key structural protein of caveolae. The membrane-localized Cav-1 was significantly reduced in DM and also in high glucose-exposed coronary endothelial cells. We also found that DM patients exhibited a decreased number of endothelial caveolae, whereas exogenous ONOO(-) reduced caveolae number. Correspondingly, pharmacological (methyl-ß-cyclodextrin) or genetic disruption of caveolae (Cav-1 knockout mice) abolished coronary FMD, which was rescued by sepiapterin, the stable precursor of NO synthase (NOS) cofactor, tetrahydrobiopterin. Sepiapterin also restored coronary FMD in DM patients. Thus, we propose that ONOO(-) selectively targets and disrupts endothelial caveolae, which contributes to NOS uncoupling, and, hence, reduced NO-mediated coronary vasodilation in DM patients.

Obesity and statins are both independent predictors of enhanced coronary arteriolar dilation in patients undergoing heart surgery.

BACKGROUND: A paradoxical inverse relationship between body mass index, morbidity and mortality in patients with ischemic heart disease has been noted; but the underlying mechanisms remain unclear. Given that coronary resistance arteries are the primary regulators of myocardial blood flow, we examined the effects of obesity and medication on dilator function in coronary microvessels. METHODS: Bradykinin-induced coronary dilation was assessed by videomicroscopy in ex vivo coronary arterioles obtained from 64 consecutive patients undergoing heart surgery. Multi-variable linear regression and logistic regression were used to investigate the effects of obesity (BMI ≥ 30 kg/M2) and the influences of medications on vessel responses. RESULTS: In isolated, pressurized (80 mmHg) coronary arterioles of obese and non-obese patient the active (73±4 vs. 79±13 µm) and passive (111 ± 5.5 vs. 118 ± 5.0 µm) diameters were similar. Bradykinin elicited substantial dilation in coronary arterioles, with a similar magnitude in obese and non-obese patients (to 10-8 M: 55 ± 5% vs. 46 ± 5%, P = 0.20), but with significantly enhanced sensitivity in obesity (EC50: 8.2x10-9 M vs. 1.9x10-8 M, respectively, P = 0.03). When adjusted for other risk factors and medications, obesity and statins were determined to be the only positive predictors of enhanced dilation, as assessed with multiple regression analysis. Moreover, obese patients with or without statin exhibited significantly increased coronary dilation to bradykinin, when compared to non-obese patients without statin therapy. CONCLUSIONS: Obesity and statin therapy are independently associated with an enhanced dilator function of coronary arterioles in patients undergoing heart surgery, which may offer a potential mechanism for the better cardiovascular outcome described earlier as the obesity paradox.

Increased tissue angiotensin-converting enzyme activity impairs bradykinin-induced dilation of coronary arterioles in obesity.

BACKGROUND: Bradykinin (BK) is a key mediator regulating coronary blood flow. It is degraded by angiotensin-converting enzyme (ACE), but what is unknown is whether enhanced tissue ACE activity interferes with BK-induced coronary vasodilation in obesity. METHODS AND RESULTS: Coronary arterioles (~100 µm) were isolated from rats on a normal or high-fat diet (HFD) and from lean or obese patients undergoing heart surgery (n=74). We found that BK-induced dilation was diminished in the coronary arterioles of HFD rats, when compared with controls. When administered in vitro, the ACE inhibitor, captopril, restored the coronary dilation response to BK in HFD rats, but did not affect control responses. Abundant ACE expression was detected in coronary endothelium, which was associated with increased ACE activity in HFD arterioles, as measured by increased response to the ACE substrate, angiotensin I. Moreover, we found that in the coronary arterioles of obese patients, BK-induced dilation was augmented by in vitro captopril administration. Correspondingly, ACE activity was increased in the coronary arterioles of obese patients when compared with the non-obese. Logistic regression analysis revealed that obese patients taking ACE inhibitors prior to surgery exhibited an enhanced dilation response to BK. CONCLUSIONS: We demonstrated augmented tissue ACE activity in the coronary arterioles of obese subjects, which leads to reduced coronary dilation response to BK. We provide a rationale for ACE inhibitor therapy in obese patients to improve dilatation of coronary microvessels.

The influence of induction therapy for kidney transplantation after a non-renal transplant.

BACKGROUND AND OBJECTIVES: Non-renal transplant recipients who subsequently develop ESRD and undergo kidney transplantation are medically and immunologically complex due to comorbidities, high cumulative exposure to immunosuppressants, and sensitization to alloantigen from the prior transplant. Although prior non-renal transplant recipients are one of the fastest growing segments of the kidney wait list, minimal data exist to guide the use of antibody induction therapy (IT+) at the time of kidney after lung (KALu), heart (KAH), and liver (KALi) transplant. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: This retrospective cohort study used national registry data to examine IT use and survival after kidney transplantation. Separate multivariate Cox regression models were constructed to assess patient survival for IT+ and IT- KALu (n=232), KAH (n=588), and KALi (n=736) recipients. RESULTS: Use of IT increased during the study period. The percentage of patients considered highly sensitized (panel reactive antibody ≥20%) was not statistically significant between IT+ and IT- groups. IT+ was not associated with improvement in 1- and 10-year patient survival for KALu (P=0.20 and P=0.22, respectively) or for KAH (P=0.90 and P=0.14, respectively). However, IT+ among KALi was associated with inferior patient survival at 1 and 10 years (P=0.04 and P=0.02, respectively). CONCLUSIONS: Use of IT for kidney transplantation among prior non-renal transplant recipients may not offer a survival advantage in KALu or KAH. However, due to limited power, these findings should be interpreted cautiously. IT+ was associated with inferior outcomes for KALi. Use of IT should be judicially reconsidered in this complex group of recipients.

Underutilization of A2 ABO incompatible kidney transplantation.

BACKGROUND: ABO compatibility creates a disadvantage for O and B renal allograft candidates. A2 ABO incompatible transplant may decrease waiting times and generate equivalent graft survival to an ABO compatible transplant. METHODS: Death-censored graft survival was compared between A recipients and O, B, and AB recipients of an A2 allograft with multivariate Cox regression models utilizing data from the United Network of Organ Sharing (UNOS) between 1997 and 2007. RESULTS: Eighty-five percent of A2 kidneys were transplanted into ABO compatible recipients vs. 15% into ABO incompatible recipients. Rates of A2 incompatible kidney transplants did not increase over the study period (14.8% to 14.6%). Mean wait time for A2→O kidneys was 337 vs. 684 d for O→O and for A2→B kidneys, 542 vs. 734 d for B→B. Adjusted relative risk of graft loss at five-yr was similar between O, B, and AB recipients compared to A recipients of an A2 allograft, corresponding to a five-yr graft survival of 84%, 86.2%, 86.1%, and 86.1%, respectively. CONCLUSION: A2 incompatible kidney transplantation is underutilized. Graft outcomes are similar among A2 compatible and incompatible recipients. Shorter waiting time and improved access might be achieved if A2 kidneys are considered in all blood groups.

Microvascular responsiveness in obesity: implications for therapeutic intervention.

UNLABELLED: Obesity has detrimental effects on the microcirculation. Functional changes in microvascular responsiveness may increase the risk of developing cardiovascular complications in obese patients. Emerging evidence indicates that selective therapeutic targeting of the microvessels may prevent life-threatening obesity-related vascular complications, such as ischaemic heart disease, heart failure and hypertension. It is also plausible that alterations in adipose tissue microcirculation contribute to the development of obesity. Therefore, targeting adipose tissue arterioles could represent a novel approach to reducing obesity. This review aims to examine recent studies that have been focused on vasomotor dysfunction of resistance arteries in obese humans and animal models of obesity. Particularly, findings in coronary resistance arteries are contrasted to those obtained in other vascular beds. We provide examples of therapeutic attempts, such as use of statins, ACE inhibitors and insulin sensitizers to prevent obesity-related microvascular complications. We further identify some of the important challenges and opportunities going forward. LINKED ARTICLES: This article is part of a themed section on Fat and Vascular Responsiveness. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.165.issue-3.

Liver transplantation in patients with cystic fibrosis: analysis of United Network for Organ Sharing data.

The improved life expectancy of patients with cystic fibrosis (CF) has led to a change in the impact of liver disease on the prognosis of this population. Liver transplantation has emerged as the procedure of choice for patients with CF and features of hepatic decompensation and for intractable variceal bleeding as a major manifestation. We retrospectively reviewed the United Network for Organ Sharing database to analyze the outcomes of 55 adults and 148 children with CF who underwent liver transplantation, and we compared them to patients who underwent transplantation for other etiologies. We additionally compared the benefits of liver transplantation among patients who underwent transplantation for cystic fibrosis-related liver disease (CFLD) and those who remained on the waiting list. The 5-year survival rates for children and adults undergoing liver transplantation were 85.8% and 72.7%, respectively (P = 0.016). A multivariate Cox regression analysis comparing pediatric and adult CF patients to patients who underwent transplantation for other etiologies noted lower 5-year survival rates (P < 0.0001). However, compared to those remaining on the waiting list, pediatric transplant recipients with CF (hazard ratio = 0.33, 95% confidence interval = 0.16-0.70, P = 0.004) and adult transplant recipients with CF (hazard ratio = 0.25, 95% confidence interval = 0.11-0.57, P = 0.001) gained a significant survival benefit. In conclusion, long-term outcomes in patients with CFLD are acceptable but are inferior in comparison with the outcomes of those undergoing transplantation for other etiologies. Despite such observations, a survival benefit was noted in transplant patients versus those who remained on the waiting list.

Increased availability of angiotensin AT 1 receptors leads to sustained arterial constriction to angiotensin II in diabetes - role for Rho-kinase activation.

BACKGROUND AND PURPOSE: Antagonists of angiotensin AT(1) receptors elicit beneficial vascular effects in diabetes mellitus. We hypothesized that diabetes induces sustained availability of AT(1) receptors, causing enhanced arterial constriction to angiotensin II. EXPERIMENTAL APPROACH: To assess functional availability of AT(1) receptors, constrictions to successive applications of angiotensin II were measured in isolated skeletal muscle resistance arteries (∼150 µm) of Zucker diabetic fatty (ZDF) rats and of their controls (+/Fa), exposed acutely to high glucose concentrations (HG, 25 mM, 1 h). AT(1) receptors on cell membrane surface were measured by immunofluorescence. KEY RESULTS: Angiotensin II-induced constrictions to first applications were greater in arteries of ZDF rats (maximum: 82 ± 3% original diameter) than in those from +/Fa rats (61 ± 5%). Constrictions to repeated angiotensin II administration were decreased in +/Fa arteries (20 ± 6%), but were maintained in ZDF arteries (67 ± 4%) and in +/Fa arteries vessels exposed to HG (65 ± 6%). In ZDF arteries and in HG-exposed +/Fa arteries, Rho-kinase activities were enhanced. The Rho-kinase inhibitor, Y27632 inhibited sustained constrictions to angiotensin II in ZDF arteries and in +/Fa arteries exposed to HG. Levels of surface AT(1) receptors on cultured vascular smooth muscle cells (VSMCs) were decreased by angiotensin II but were maintained in VSMCs exposed to HG. In VSMCs exposed to HG and treated with Y27632, angiotensin II decreased surface AT(1) receptors. CONCLUSIONS AND IMPLICATIONS: In diabetes, elevated glucose concentrations activate Rho-kinase which inhibits internalization or facilitates recycling of AT(1) receptors, leading to increased functional availability of AT(1) receptors and sustained angiotensin II-induced arterial constriction.

Kidney transplantation in patients with a prior heart transplant.

BACKGROUND: Chronic kidney disease among prior heart transplant recipients is a growing problem that is likely to place an increased demand on a limited supply of kidney allografts. Allocation of the limited resource of kidneys for transplantation requires consideration of the demands of fair distribution and optimizing patient and graft survival. The aim of this study was to compare the kidney transplant outcomes among recipients of kidney after prior heart transplantation (KAH, n=456) with kidney transplantation in other clinical settings. METHODS: A retrospective cohort study using United Network for Organ Sharing registry data (1995-2008) was performed comparing renal allograft survival among KAH recipients with patients who underwent simultaneous kidney-heart transplant (SKH, n=252), primary kidney transplant alone (KA1, n=112,882), or repeat kidney transplant alone (KA2, n=14,070). RESULTS: The annual number of KAH recipients more than quadrupled during the study period from 24 in 1995 to 99 in 2008. In a multivariable analysis using Cox regression, allograft survival among KAH recipients was not different from SKH (P=0.16, hazards ratio [HR]=0.79, confidence interval [CI]=0.57-1.10), and KA2 (P=0.11, HR=0.86, CI=0.72-1.04), but it was inferior to KA1 (P<0.001, HR=0.66, CI=0.55-0.80). Patient death accounted for 75.2% of KAH kidney loss. Kidney quality as measured by living or deceased donors (P=0.62) and standard criteria or extended criteria (P=0.87) was not associated with survival; however, there was a trend toward improved survival (P=0.08) among recipients of a preemptive transplant. CONCLUSION: Kidney graft survival among prior heart transplant recipients is inferior to KA1 but similar to other clinical scenarios. Preemptive transplantation with an extended criteria or living donor kidney should be encouraged.

The cumulative effects of cold ischemic time and older donor age on liver graft survival.

INTRODUCTION: To provide greater equity among those awaiting a liver transplant, expanded geographic sharing of cadaveric organs has been proposed. A potential unintended consequence could be an increase in cold ischemia time (CIT), which may be deleterious to organs from older donors. This study sought to quantify the relative risk (RR) associated with increased CIT among older donors. METHODS: A retrospective study examining 18,787 liver transplants within the United Network for Organ Sharing database from 2002 to 2006 was performed. Cox Regression analysis was used to model the RR of graft loss with respect to increased CIT among older donors (>60 years) relative to younger donors (<60 years), while controlling for multiple donor and recipient characteristics. RESULTS: Relative to younger donors with minimal CIT (<6 h), a 73.0% increase in the risk of graft loss was observed for older donors with a CIT between 8 and 10 h, a 56.9% increase for CIT between 10 and 12 h, and a 92.7% increase for a CIT of 12 or more hours. Additionally, the RR of graft loss for older donors with minimal CIT (<6 h) was greater than the RR for younger donors with a CIT between 0 and 12 h. CONCLUSION: The additive effects of increased donor age and cold ischemic time greatly impair graft survival. Quantification of the adverse nature of increasing CIT as a potential consequence of wider geographic organ sharing should be considered as allocation policies are modified to improve recipient equity in the face of an aging donor pool.

Minimizing morbidity of organ donation: analysis of factors for perioperative complications after living-donor nephrectomy in the United States.

BACKGROUND: Expansion of living kidney donation through liberalizing acceptance criteria invites a renewed focus on safety and outcomes. Wide variability exists in reported donor complications, and associated risk factors are ill defined. Use of administrative data can overcome the bias of single-center studies and identify variables associated with untoward events. METHODS: The study population consisted of 3074 living kidney donors from 28 centers during 2004 and 2005. Data from a large healthcare registry were used to retrospectively identify the study cohort. Perioperative complications were identified using ICD-9-CM coding and classified according to the Clavien system. Logistic regression models were constructed to identify donor and center factors associated with complications. RESULTS: There were no perioperative deaths. The overall complication rate was 10.6% and major complications defined by Clavien grade >or=3 was 4.2%. The prevalence of tobacco use, obesity, and hypertension, was 7.8%, 2.4%, and 2.3%, respectively. Age >50 (odds ratio [OR]=1.81, 95% confidence interval [95% CI]=1.25-2.61), tobacco use (OR=1.41, 95% CI=1.02-1.94), obesity (OR=1.92, 95% CI=1.06-3.46), and annual center volume 50 increases complications; however, the risk of major morbidity is small. Use of administrative data represents an important tool to facilitate the reconciliation of an increased need for organ donors with the concern for donor safety.