Automated analysis of limited echocardiograms: Feasibility and relationship to outcomes in COVID-19

Background

As automated echocardiographic analysis is increasingly utilized, continued evaluation within hospital settings is important to further understand its potential value. The importance of cardiac involvement in patients hospitalized with COVID-19 provides an opportunity to evaluate the feasibility and clinical relevance of automated analysis applied to limited echocardiograms.

Methods

In this multisite US cohort, the feasibility of automated AI analysis was evaluated on 558 limited echocardiograms in patients hospitalized with COVID-19. Reliability of automated assessment of left ventricular (LV) volumes, ejection fraction (EF), and LV longitudinal strain (LS) was assessed against clinically obtained measures and echocardiographic findings. Automated measures were evaluated against patient outcomes using ROC analysis, survival modeling, and logistic regression for the outcomes of 30-day mortality and in-hospital sequelae.

Results

Feasibility of automated analysis for both LVEF and LS was 87.5% (488/558 patients). AI analysis was performed with biplane method in 300 (61.5%) and single plane apical 4- or 2-chamber analysis in 136 (27.9%) and 52 (10.7%) studies, respectively. Clinical LVEF was assessed using visual estimation in 192 (39.3%), biplane in 163 (33.4%), and single plane or linear methods in 104 (21.2%) of the 488 studies; 29 (5.9%) studies did not have clinically reported LVEF. LV LS was clinically reported in 80 (16.4%). Consistency between automated and clinical values demonstrated Pearson's R, root mean square error (RMSE) and intraclass correlation coefficient (ICC) of 0.61, 11.3% and 0.72, respectively, for LVEF; 0.73, 3.9% and 0.74, respectively for LS; 0.76, 24.4ml and 0.87, respectively, for end-diastolic volume; and 0.82, 12.8 ml, and 0.91, respectively, for end-systolic volume. Abnormal automated measures of LVEF and LS were associated with LV wall motion abnormalities, left atrial enlargement, and right ventricular dysfunction. Automated analysis was associated with outcomes, including survival.

Conclusion

Automated analysis was highly feasible on limited echocardiograms using abbreviated protocols, consistent with equivalent clinically obtained metrics, and associated with echocardiographic abnormalities and patient outcomes.

Impact of Racial Disparities in Preoperative Cardiovascular Evaluation and Surgical Outcomes in Patients Undergoing Metabolic and Bariatric Surgery: A Retrospective Cohort Analysis

Background

We investigated preoperative referral patterns, rates of cardiovascular testing, surgical wait times, and postoperative outcomes in White versus Black, Hispanic, or other racial or ethnic groups of patients undergoing metabolic and bariatric surgery.

Methods and Results

This was a single center retrospective cohort analysis of 797 consecutive patients undergoing metabolic and bariatric surgery from January 2014 to December 2018; 86% (n=682) were Black, Hispanic, or other racial or ethnic groups. White versus Black, Hispanic, or other racial or ethnic groups had similar baseline comorbidities and were referred for preoperative cardiovascular evaluation in similar proportion (65% versus 68%, P=0.529). Black, Hispanic, or other racial or ethnic groups of patients were less likely to undergo preoperative cardiovascular testing (unadjusted odds ratio [OR], 0.56; 95% CI, 0.33–0.95; P=0.031; adjusted for Revised Cardiac Risk Index OR, 0.59; 95% CI, 0.35–0.996; P=0.049). White patients had a shorter wait time for surgery (unadjusted hazard ratio [HR], 0.7; 95% CI, 0.58–0.87; P=0.001; adjusted HR, 0.7; 95% CI, 0.56–0.95; P=0.018). Reduction in body mass index at 6 months was greater in White patients (12.9 kg/m² versus 12.0 kg/m², P=0.0289), but equivalent at 1 year (14.9 kg/m² versus 14.3 kg/m², P=0.330).

Conclusions

White versus Black, Hispanic, or other racial or ethnic groups of patients were referred for preoperative cardiovascular evaluation in similar proportion. White patients underwent more preoperative cardiac testing yet had a shorter wait time for surgery. Early weight loss was greater in White patients, but equivalent between groups at 12 months.

Abstract P168: Predictors Of Htn Remission Post-bariatric Surgery: A Contemporary Analysis

Introduction: The effect of bariatric surgery on improvement and remission of hypertension (HTN) is well documented. However, the factors that influence HTN remission in this population are poorly understood and have not been investigated in over a decade. We aim to describe predictors of HTN remission post-bariatric surgery in a contemporary patient population.

Methods: All patients who underwent sleeve gastrectomy or Roux-en-Y gastric bypass from January 2014 to December 2018 at an urban academic institution were included in the analysis. Blood pressure (BP) was recorded pre-operatively, 6-month post operation, and 12-month post operation. HTN was defined as BP ≥ 140/90 or patients on anti-hypertensive medications. Remission was defined as BP < 140/90 off all blood pressure medications. Baseline characteristics of patients with and without HTN remission were described. Logistic regression analysis was performed to assess indicators of HTN remission. A p-value of 0.05 was used for all statistical analyses.

Results: Among 844 patients who underwent bariatric surgery, 497 (58.9%) patients had HTN. Among HTN patients 167 (33.6%) had remission at 6 months and 126 (25.4%) had remission at 12 months. The major predictor of HTN remission on multivariate analysis was number of pre-operative medications at 6 months (OR 2.5, 95% CI 2.03 to 3.29) and 12 months (OR 2.6, 95% CI 1.99 to 3.56). Major predictors on univariate analysis at 12 months were CVA (OR 4.3, 95% CI 1.40 to 12.47) and HLD (OR 1.76, 95% CI 1.27 to 2.45).

Conclusion: Number of pre-operative medications is a top predictor of HTN remission. HLD and history of stroke may be present in patients who are less likely to have HTN remission.

Effect of dietary restriction and compensatory growth on performance, carcass characteristics, and metabolic hormone concentrations in Angus and Belgian Blue steers

Compensatory growth (CG) is the ability of an animal to undergo accelerated growth after a period of restricted feeding. However, there is a dearth of information in relation to the effect of genotype on CG response, thus the objective of this study was to evaluate CG response in two contrasting breed types, namely Aberdeen Angus (AN) and Belgian Blue (BB). Crossbred AN × Holstein-Friesian or BB × Holstein-Friesian steers were assigned to one of two treatment groups in a two (genotypes) × two (diets) factorial design. For 99 days, one group (11 AN and 12 BB) was offered a high energy control diet (H-H) whereas the second group (11 AN and 12 BB) was offered an energy restricted diet (L-H). At the end of the differential feeding period (99 days), both groups of animals were then offered a high energy control diet for a further 200 days. All animals were then slaughtered on day-299 of the study. During feed restriction, L-H had lower DM intake (DMI), had greater feed conversion ratio (FCR) and lower plasma concentrations of insulin, IGF-1, leptin, glucose, urea, betahydroxybutyrate and smaller M. longissimus thoracis or lumborum muscle and fat depths compared to H-H steers. During realimentation, there was no difference in DMI between diets; however, L-H had greater live weight gain compared to H-H steers. Overall, H-H consumed greater quantities on a DM basis, however, had a higher FCR compared to L-H steers. By the end of the realimentation period, there was no difference in plasma metabolite or hormone concentrations, linear body measurements, ultrasonically scanned fat depths, carcass conformation, dressing percentage or fat class between H-H and L-H steers. At slaughter, carcass weights were affected by diet with greater values for H-H compared to L-H steers. Genotype affected measures associated with body composition including pelvic width and both muscle and fat depths (P < 0.05). Overall, L-H had a CG (or recovery) index of 0.52 and did not make up for the loss of gains during the differential feeding period; however, M. longissimus thoracis et lumborum, a tissue of high economic value, recovered completely making it a target of interest for further investigation.

Racial and ethnic differences in left atrial appendage occlusion wait time, complications, and periprocedural management

PURPOSE

Non-white patients are underrepresented in left atrial appendage occlusion (LAAO) trials, and racial disparities in LAAO periprocedural management are unknown.

METHODS

We assessed sociodemographics and comorbidities of consecutive patients at our institution undergoing LAAO between 2015 and 2020, then in adjusted analyses, compared procedural wait time, procedural complications, and post-procedure oral anticoagulation (OAC) use in whites versus non-whites.

RESULTS

Among 109 patients undergoing LAAO (45% white), whites had lower CHA₂ DS₂ VASc scores, on average, than non-whites (4.0 vs. 4.8, p = .006). There was no difference in median time from index event (IE) or initial outpatient cardiology encounter to LAAO procedure (whites 10.5 vs. non-whites 13.7 months, p = .9; 1.9 vs. 1.8 months, p = .6, respectively), and there was no difference in procedural complications (whites 4% vs. non-whites 5%, p = .33). After adjusting for CHA₂ DS₂ VASc score, OAC use at discharge tended to be higher in whites (OR 2.4, 95% CI [0.9-6.0], p = .07). When restricting the analysis to those with prior gastrointestinal (GI) bleed, adjusting for CHA₂ DS₂ VASc score and GI bleed severity, whites had a nearly five-fold odds of being discharged on OAC (OR 4.6, 95% CI [1-21.8], p = 0.05). The association between race and discharge OAC was not mediated through income category (total mediation effect 19% 95% CI [-.04-0.11], p = .38).

CONCLUSION

Despite an increased prevalence of comorbidities amongst non-whites, wait time for LAAO and procedural complications were similar in whites versus non-whites. Among those with prior GI bleed, whites were nearly five-fold more likely to be discharged on OAC than non-whites, independent of income.

Cardiovascular safety of fenfluramine in the treatment of Dravet syndrome: Analysis of an ongoing long-term open-label safety extension study

Objective

Fenfluramine, which was previously approved as a weight loss drug, was withdrawn in 1997 when reports of cardiac valvulopathy emerged. The present study was conducted in part to characterize the cardiovascular safety profile of low‐dose fenfluramine when used in a pediatric population to reduce seizure frequency in patients with Dravet syndrome.

Methods

Patients 2‐ to 18‐years‐old with Dravet syndrome who had completed any of three randomized, placebo‐controlled clinical trials of fenfluramine were offered enrollment in this open‐label extension (OLE) study. All patients were treated with fenfluramine starting at a dose of 0.2 mg/kg/day (oral solution dosed twice per day), which was titrated to maximal effect with a dose limit of 0.7 mg/kg/day (maximum 26 mg/day) or 0.4 mg/kg/day (maximum 17 mg/day) in patients receiving concomitant stiripentol. Standardized echocardiographic examinations were conducted at Week 4 or 6 and then every 3 months during the OLE study to monitor cardiac valve function and structure and pulmonary artery pressure. The primary end point for the echocardiography analysis was the number of patients who developed valvular heart disease or pulmonary artery hypertension (PAH) during treatment.

Results

A total of 232 patients were enrolled in the study. The average age of patients was 9.1 ± 4.7 years, and 55.2% were male. The median duration of treatment with fenfluramine was 256 days (range = 58‐634 days), and the mean dose of fenfluramine was 0.41 mg/kg/day. No cases of valvular heart disease or PAH were observed.

Significance

Longitudinal echocardiography over a median 8.4 months of treatment with fenfluramine suggests a low risk of developing cardiac valvulopathy and PAH when used to treat pediatric patients with Dravet syndrome.

Dramatic Aneurysmal Atrial Septum Identified with Intracardiac Echo Complicating Transseptal Puncture

•

Atrial septal aneurysm is a largely underdiagnosed phenomenon.

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Septal anatomy is best delineated using intracardiac echocardiography.

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Septal anatomy is clinically relevant with procedures involving transseptal puncture.

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Atrial septal aneurysms may be associated with supraventricular tachycardias.

Risk of malignancy in resected pancreatic mucinous cystic neoplasms

BACKGROUND

Pancreatic mucinous cystic neoplasms (MCNs) are rare mucin-producing cystic tumours defined by the presence of ovarian-type stroma. MCNs have a malignant potential and thus surgery is frequently performed. The aim of this cohort study was to define better the criteria for surgical resection in patients with MCN.

METHODS

This multicentre retrospective study included all resected MCNs between 2003 and 2015 in participating centres. Lesions without ovarian-type stroma were excluded. Patient characteristics, preoperative findings, histopathology findings and follow-up data were recorded.

RESULTS

The study included 211 patients; their median age was 53 (range 18-82) years, and 202 (95·7 per cent) were women. Median preoperative tumour size was 55 (range 12-230) mm. Thirty-four of the 211 (16·1 per cent) were malignant, and high-grade dysplasia (HGD) was found in a further 13 (6·2 per cent). One-third of MCNs in men were associated with invasive cancer, compared with 15·3 per cent in women. Five cases of malignant transformation occurred in MCNs smaller than 4 cm. All cases of malignancy or HGD were associated with symptoms or features of concern on preoperative cross-sectional imaging. In multivariable analysis, raised carbohydrate antigen 19-9 (odds ratio (OR) 10·54, 95 per cent c.i. 2·85 to 218·23; P < 0·001), tumour size (OR 4·23, 3·02 to 11·03; P = 0·001), mural nodules (OR 3·55, 1·31 to 20·55; P = 0·002) and weight loss (OR 3·40, 2·34 to 12·34; P = 0·034) were independent factors predictive of malignant transformation.

CONCLUSIONS

Small indeterminate MCNs with no symptoms or features of concern may safely be observed as they have a low risk of malignant transformation.

Evolution of Echocardiographic Measures of Cardiac Disease From CKD to ESRD and Risk of All-Cause Mortality: Findings From the CRIC Study

RATIONALE & OBJECTIVE

Abnormal cardiac structure and function are common in chronic kidney disease (CKD) and end-stage renal disease (ESRD) and linked with mortality and heart failure. We examined changes in echocardiographic measures during the transition from CKD to ESRD and their associations with post-ESRD mortality.

STUDY DESIGN

Prospective study.

SETTING & PARTICIPANTS

We studied 417 participants with CKD in the Chronic Renal Insufficiency Cohort (CRIC) who had research echocardiograms during CKD and ESRD.

PREDICTOR

We measured change in left ventricular mass index, left ventricular ejection fraction (LVEF), diastolic relaxation (normal, mildly abnormal, and moderately/severely abnormal), left ventricular end-systolic (LVESV), end-diastolic (LVEDV) volume, and left atrial volume from CKD to ESRD.

OUTCOMES

All-cause mortality after dialysis therapy initiation.

ANALYTICAL APPROACH

Cox proportional hazard models were used to test the association of change in each echocardiographic measure with postdialysis mortality.

RESULTS

Over a mean of 2.9 years between pre- and postdialysis echocardiograms, there was worsening of mean LVEF (52.5% to 48.6%; P<0.001) and LVESV (18.6 to 20.2mL/m^2.7; P<0.001). During this time, there was improvement in left ventricular mass index (60.4 to 58.4g/m^2.7; P=0.005) and diastolic relaxation (11.11% to 4.94% with moderately/severely abnormal; P=0.02). Changes in left atrial volume (4.09 to 4.15mL/m²; P=0.08) or LVEDV (38.6 to 38.4mL/m^2.7; P=0.8) were not significant. Worsening from CKD to ESRD of LVEF (adjusted HR for every 1% decline in LVEF, 1.03; 95% CI, 1.00-1.06) and LVESV (adjusted HR for every 1mL/m^2.7 increase, 1.04; 95% CI, 1.02-1.07) were independently associated with greater risk for postdialysis mortality.

LIMITATIONS

Some missing or technically inadequate echocardiograms.

CONCLUSIONS

In a longitudinal study of patients with CKD who subsequently initiated dialysis therapy, LVEF and LVESV worsened and were significantly associated with greater risk for postdialysis mortality. There may be opportunities for intervention during this transition period to improve outcomes.

Cardiovascular safety of low-dose fenfluramine in Dravet syndrome: a review of its benefit-risk profile in a new patient population

OBJECTIVE

Dravet syndrome (DS) is a rare, treatment-resistant epilepsy syndrome for which current treatment regimens are often ineffective. Fenfluramine is currently in development for treatment of DS, based on reports in the 1980s and 1990s of its anti-epileptic activity in pediatric patients with intractable epilepsy. However, fenfluramine was withdrawn from global markets in 1997 following reports of its association with pulmonary hypertension and heart valve disease in adult patients treated for obesity. This review was conducted to assess cardiac safety of fenfluramine when used at lower doses for treatment of DS.

METHODS

Pubmed was searched for clinical studies of fenfluramine in obese adults who reported incidence of heart valve disease. These data were reviewed against published results from Belgian patients with DS who have been treated with low-dose fenfluramine for up to 28 years.

RESULTS

Nine controlled studies of fenfluramine and related compounds (dexfenfluramine and/or phentermine) which assessed incidence and severity of cardiac valve disease in 3,268 treated patients and 2,017 control subjects have been reported. Mild or greater aortic valve regurgitation was found in 9.6% of treated patients compared with 3.9% of control subjects, and moderate or greater mitral valve regurgitation was found in 3.1% of treated patients and 2.5% of control subjects. Nineteen DS patients have been treated for up to 28 years with 10-20 mg/day fenfluramine, with no clinical signs or symptoms of cardiac valve disease or pulmonary hypertension. Slight and clinically unimportant changes in valve structure have been seen on echocardiography in five patients at some time during the observation period.

CONCLUSIONS

A different benefit-risk relationship appears to be emerging when fenfluramine is used at low doses for extended periods in young patients with DS. Continued cardiac assessments during ongoing Phase 3 clinical trials will provide additional safety information for this potential new and effective treatment.

Differences in right ventricular morphology, not function, indicate the nature of increased afterload in pulmonary hypertensive subjects with normal left ventricular function

BACKGROUND

The aim of study was to assess whether a specific morphology of the right ventricle (RV) by 2D echo predicts the hemodynamic nature of pulmonary hypertension (PH).

METHODS

We reviewed clinical, 2D echo, and hemodynamic data of 100 patients with PH: divided into three groups: PH from pulmonary vascular disease (PH_PVD ; n = 34) with pulmonary vascular resistance (PVR) > 3 mm Hg/L/min (Wood unit [WU]) and pulmonary artery wedge pressure (PAWP) ≤ 15 mm Hg, pulmonary venous hypertension (PVH; n = 33) with PVR < 3 WU and PAWP > 15 mm Hg and PH_MIXED (n = 33) with PVR > 3 WU and PAWP > 15 mm Hg. We analyzed several two-dimensional parameters of right heart morphology and function, including the degree of tapering of the RV diameter from base (just above tricuspid annulus) to apex (level of moderator band) in the apical four-chamber view. P = <.05.

RESULTS

Baseline characteristics were similar in all three groups: age 62 ± 14.4 years, 69% females, 57% Caucasians. Hemodynamics and 2D echo data of PH_PVD vs PVH vs PH_MIXED were as follows: PVR 13 ± 6 vs 2 ± 1 vs 7 ± 2 WU, mean pulmonary artery pressure 53 ± 14 vs 34 ± 8 vs 49 ± 8 mm Hg and cardiac index 2.0 ± 0.5 vs 2.8 ± 0.7 vs 2.2 ± 0.7 L/m² , RV base/apex ratio during systole (sRV_b/a ) 1.3 ± 0.2 vs 2.6 ± 0.5 vs 1.5 ± 0.3. Thus, sRV_b/a was twofold higher in the PVH vs PH_PVD cohort. On ROC analysis, the AUC for sRV_b/a for predicting PVR > 3 WU was 0.873, with optimal cutoff of 1.5.

CONCLUSION

Systolic RV base/apex ratio is a simple 2D index of RV shape that powerfully predicts a PVR > 3 WU and provides powerful discriminating ability between PVH and PH_PVD .

Initial clinical and hemodynamic results of a regional pulmonary thromboendarterectomy program

BACKGROUND

Pulmonary thromboendarterectomy (PTE) is the treatment of choice for eligible patients with chronic thromboembolic pulmonary hypertension (CTEPH). However, access to CTEPH and PTE care is limited. There is a paucity of published data on PTE efficacy and outcomes from alternative, regional centers of excellence in CTEPH and PTE care in the USA, outside a single national and international referral center.

METHODS

We performed a retrospective review of patients undergoing PTE at our institution from June 2013 to December 2016 (42 months), and collected clinical, echocardiographic and hemodynamic data on our patients pre- and post-PTE (N.=71).

RESULTS

Patients age ranged between 20-83 years (mean±SD: 56±16), with 54% of patients female and 61% Caucasians. The predominant symptom was shortness of breath with a median duration of symptoms of 17 months. Following PTE, clinical improvements included a reduction in NYHA class from 3.1±1.1 to 2.2±1.2. There were major improvements in hemodynamics and echocardiographic parameters pre- versus post-PTE: mean pulmonary artery pressure (mmHg) 45±11 to 24±8, cardiac index (L/min/m2) 2.1±0.5 to 2.8±0.5, pulmonary vascular resistance (mmHg/L/min) 8.9±4.5 to 2.8±1.8, ratio of right ventricle (RV): left ventricle (LV) 1.2±0.3 to 0.9±0.2, RV fractional area change (%) 23±14 to 44±13, reduction in the incidence of RV outflow tract Doppler notching and improved pulmonary artery acceleration time (96% to 30%, and 74±19 to 111±21). In-hospital mortality was 4.2% (3 patients).

CONCLUSIONS

Herein, we report for the first time, the improvements in patient functionality, hemodynamics, right heart function and outcomes at a major regional PTE program.

Racial/Ethnic Differences in Left Ventricular Structure and Function in Chronic Kidney Disease: The Chronic Renal Insufficiency Cohort

BACKGROUND

Chronic kidney disease (CKD) is associated with increased risk of cardiovascular disease (CVD) and it is especially common among Blacks. Left ventricular hypertrophy (LVH) is an important subclinical marker of CVD, but there are limited data on racial variation in left ventricular structure and function among persons with CKD.

METHODS

In a cross-sectional analysis of the Chronic Renal Insufficiency Cohort Study, we compared the prevalence of different types of left ventricular remodeling (concentric hypertrophy, eccentric hypertrophy, and concentric remodeling) by race/ethnicity. We used multinomial logistic regression to test whether race/ethnicity associated with different types of left ventricular remodeling independently of potential confounding factors.

RESULTS

We identified 1,164 non-Hispanic Black and 1,155 non-Hispanic White participants who completed Year 1 visits with echocardiograms that had sufficient data to categorize left ventricular geometry type. Compared to non-Hispanic Whites, non-Hispanic Blacks had higher mean left ventricular mass index (54.7 ± 14.6 vs. 47.4 ± 12.2 g/m2.7; P < 0.0001) and prevalence of concentric LVH (45.8% vs. 24.9%). In addition to higher systolic blood pressure and treatment with >3 antihypertensive medications, Black race/ethnicity was independently associated with higher odds of concentric LVH compared to White race/ethnicity (odds ratio: 2.73; 95% confidence interval: 2.02, 3.69).

CONCLUSION

In a large, diverse cohort with CKD, we found significant differences in left ventricular mass and hypertrophic morphology between non-Hispanic Blacks and Whites. Future studies will evaluate whether higher prevalence of LVH contribute to racial/ethnic disparities in cardiovascular outcomes among CKD patients.

Atrial Fibrillation and Risk of ESRD in Adults with CKD

BACKGROUND AND OBJECTIVES

Atrial fibrillation frequently complicates CKD and is associated with adverse outcomes. Progression to ESRD is a major complication of CKD, but the link with atrial fibrillation has not been fully delineated. In this study, we examined the association of incident atrial fibrillation with the risk of ESRD in patients with CKD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We studied participants in the prospective Chronic Renal Insufficiency Cohort Study without atrial fibrillation at entry. Incident atrial fibrillation was identified by study visit ECGs, self-report, and hospital discharge diagnostic codes, with confirmation by physician adjudication. ESRD through 2012 was ascertained by participant self-report, medical records, and linkage to the US Renal Data System. Data on potential confounders were obtained from self-report, study visits, and laboratory tests. Marginal structural models were used to study the potential association of incident atrial fibrillation with risk of ESRD after adjustment for time-dependent confounding.

RESULTS

Among 3091 participants, 172 (5.6%) developed incident atrial fibrillation during follow-up. During mean follow-up of 5.9 years, 43 patients had ESRD that occurred after development of incident atrial fibrillation (11.8/100 person-years) compared with 581 patients without incident atrial fibrillation (3.4/100 person-years). In marginal structural models with inverse probability weighting, incident atrial fibrillation was associated with a substantially higher rate of ESRD (hazard ratio, 3.2; 95% confidence interval, 1.9 to 5.2). This association was consistent across important subgroups by age, sex, race, diabetes status, and baseline eGFR.

CONCLUSIONS

Incident atrial fibrillation was associated with higher risk of developing ESRD in CKD. Additional study is needed to identify potentially modifiable pathways through which atrial fibrillation was associated with a higher risk of progression to ESRD. More aggressive monitoring and treatment of patients with CKD and atrial fibrillation may improve outcomes in this high-risk population.

Sodium Excretion and the Risk of Cardiovascular Disease in Patients With Chronic Kidney Disease

IMPORTANCE

Patients with chronic kidney disease (CKD) are at an increased risk of cardiovascular disease (CVD) compared with the general population. Prior studies have produced contradictory results on the association of dietary sodium intake with risk of CVD, and this relationship has not been investigated in patients with CKD.

OBJECTIVE

To evaluate the association between urinary sodium excretion and clinical CVD events among patients with CKD.

DESIGN, SETTING, AND PARTICIPANTS

A prospective cohort study of patients with CKD from 7 locations in the United States enrolled in the Chronic Renal Insufficiency Cohort Study and followed up from May 2003 to March 2013.

EXPOSURES

The cumulative mean of urinary sodium excretion from three 24-hour urinary measurements and calibrated to sex-specific mean 24-hour urinary creatinine excretion.

MAIN OUTCOMES AND MEASURES

A composite of CVD events defined as congestive heart failure, stroke, or myocardial infarction. Events were reported every 6 months and confirmed by medical record adjudication.

RESULTS

Among 3757 participants (mean age, 58 years; 45% women), 804 composite CVD events (575 heart failure, 305 myocardial infarction, and 148 stroke) occurred during a median 6.8 years of follow-up. From lowest (<2894 mg/24 hours) to highest (≥4548 mg/24 hours) quartile of calibrated sodium excretion, 174, 159, 198, and 273 composite CVD events occurred, and the cumulative incidence was 18.4%, 16.5%, 20.6%, and 29.8% at median follow-up. In addition, the cumulative incidence of CVD events in the highest quartile of calibrated sodium excretion compared with the lowest was 23.2% vs 13.3% for heart failure, 10.9% vs 7.8% for myocardial infarction, and 6.4% vs 2.7% for stroke at median follow-up. Hazard ratios of the highest quartile compared with the lowest quartile were 1.36 (95% CI, 1.09-1.70; P = .007) for composite CVD events, 1.34 (95% CI, 1.03-1.74; P = .03) for heart failure, and 1.81 (95% CI, 1.08-3.02; P = .02) for stroke after multivariable adjustment. Restricted cubic spline analyses of the association between sodium excretion and composite CVD provided no evidence of a nonlinear association (P = .11) and indicated a significant linear association (P < .001).

CONCLUSIONS AND RELEVANCE

Among patients with CKD, higher urinary sodium excretion was associated with increased risk of CVD.

Masked Hypertension and Elevated Nighttime Blood Pressure in CKD: Prevalence and Association with Target Organ Damage

BACKGROUND AND OBJECTIVES

Masked hypertension and elevated nighttime BP are associated with increased risk of hypertensive target organ damage and adverse cardiovascular and renal outcomes in patients with normal kidney function. The significance of masked hypertension for these risks in patients with CKD is less well defined. The objective of this study was to evaluate the association between masked hypertension and kidney function and markers of cardiovascular target organ damage, and to determine whether this relationship was consistent among those with and without elevated nighttime BP.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This was a cross-sectional study. We performed 24-hour ambulatory BP in 1492 men and women with CKD enrolled in the Chronic Renal Insufficiency Cohort Study. We categorized participants into controlled BP, white-coat, masked, and sustained hypertension on the basis of clinic and 24-hour ambulatory BP. We obtained echocardiograms and measured pulse wave velocity in 1278 and 1394 participants, respectively.

RESULTS

The percentages of participants with controlled BP, white-coat, masked, and sustained hypertension were 49.3%, 4.1%, 27.8%, and 18.8%, respectively. Compared with controlled BP, masked hypertension independently associated with low eGFR (-3.2 ml/min per 1.73 m(2); 95% confidence interval, -5.5 to -0.9), higher proteinuria (+0.9 unit higher in log2 urine protein; 95% confidence interval, 0.7 to 1.1), and higher left ventricular mass index (+2.52 g/m(2.7); 95% confidence interval, 0.9 to 4.1), and pulse wave velocity (+0.92 m/s; 95% confidence interval, 0.5 to 1.3). Participants with masked hypertension had lower eGFR only in the presence of elevated nighttime BP (-3.6 ml/min per 1.73 m(2); 95% confidence interval, -6.1 to -1.1; versus -1.4 ml/min per 1.73 m(2); 95% confidence interval, -6.9 to 4.0, among those with nighttime BP <120/70 mmHg; P value for interaction with nighttime systolic BP 0.002).

CONCLUSIONS

Masked hypertension is common in patients with CKD and associated with lower eGFR, proteinuria, and cardiovascular target organ damage. In patients with CKD, ambulatory BP characterizes the relationship between BP and target organ damage better than BP measured in the clinic alone.

Serous cystic neoplasm of the pancreas: a multinational study of 2622 patients under the auspices of the International Association of Pancreatology and European Pancreatic Club (European Study Group on Cystic Tumors of the Pancreas)

OBJECTIVES

Serous cystic neoplasm (SCN) is a cystic neoplasm of the pancreas whose natural history is poorly known. The purpose of the study was to attempt to describe the natural history of SCN, including the specific mortality.

DESIGN

Retrospective multinational study including SCN diagnosed between 1990 and 2014.

RESULTS

2622 patients were included. Seventy-four per cent were women, and median age at diagnosis was 58 years (16-99). Patients presented with non-specific abdominal pain (27%), pancreaticobiliary symptoms (9%), diabetes mellitus (5%), other symptoms (4%) and/or were asymptomatic (61%). Fifty-two per cent of patients were operated on during the first year after diagnosis (median size: 40 mm (2-200)), 9% had resection beyond 1 year of follow-up (3 years (1-20), size at diagnosis: 25 mm (4-140)) and 39% had no surgery (3.6 years (1-23), 25.5 mm (1-200)). Surgical indications were (not exclusive) uncertain diagnosis (60%), symptoms (23%), size increase (12%), large size (6%) and adjacent organ compression (5%). In patients followed beyond 1 year (n=1271), size increased in 37% (growth rate: 4 mm/year), was stable in 57% and decreased in 6%. Three serous cystadenocarcinomas were recorded. Postoperative mortality was 0.6% (n=10), and SCN's related mortality was 0.1% (n=1).

CONCLUSIONS

After a 3-year follow-up, clinical relevant symptoms occurred in a very small proportion of patients and size slowly increased in less than half. Surgical treatment should be proposed only for diagnosis remaining uncertain after complete workup, significant and related symptoms or exceptionally when exists concern with malignancy. This study supports an initial conservative management in the majority of patients with SCN.

TRIAL REGISTRATION NUMBER

IRB 00006477.

Relation of aortic valve calcium to chronic kidney disease (from the Chronic Renal Insufficiency Cohort Study)

Although subjects with chronic kidney disease (CKD) are at markedly increased risk for cardiovascular mortality, the relation between CKD and aortic valve calcification has not been fully elucidated. Also, few data are available on the relation of aortic valve calcification and earlier stages of CKD. We sought to assess the relation of aortic valve calcium (AVC) with estimated glomerular filtration rate (eGFR), traditional and novel cardiovascular risk factors, and markers of bone metabolism in the Chronic Renal Insufficiency Cohort (CRIC) Study. All patients who underwent aortic valve scanning in the CRIC study were included. The relation between AVC and eGFR, traditional and novel cardiovascular risk factors, and markers of calcium metabolism were analyzed using both unadjusted and adjusted regression models. A total of 1,964 CRIC participants underwent computed tomography for AVC quantification. Decreased renal function was independently associated with increased levels of AVC (eGFR 47.11, 44.17, and 39 ml/min/1.73 m2, respectively, p<0.001). This association persisted after adjusting for traditional, but not novel, AVC risk factors. Adjusted regression models identified several traditional and novel risk factors for AVC in patients with CKD. There was a difference in AVC risk factors between black and nonblack patients. In conclusion, our study shows that eGFR is associated in a dose-dependent manner with AVC in patients with CKD, and this association is independent of traditional cardiovascular risk factors.

Association between Inflammation and Cardiac Geometry in Chronic Kidney Disease: Findings from the CRIC Study

Background

Left ventricular hypertrophy (LVH) and myocardial contractile dysfunction are independent predictors of mortality in patients with chronic kidney disease (CKD). The association between inflammatory biomarkers and cardiac geometry has not yet been studied in a large cohort of CKD patients with a wide range of kidney function.

Methods

Plasma levels of interleukin (IL)-1β, IL-1 receptor antagonist (IL-1RA), IL-6, tumor necrosis factor (TNF)-α, transforming growth factor (TGF)-β, high-sensitivity C-Reactive protein (hs-CRP), fibrinogen and serum albumin were measured in 3,939 Chronic Renal Insufficiency Cohort study participants. Echocardiography was performed according to the recommendations of the American Society of Echocardiography and interpreted at a centralized core laboratory.

Results

LVH, systolic dysfunction and diastolic dysfunction were present in 52.3%, 11.8% and 76.3% of the study subjects, respectively. In logistic regression analysis adjusted for age, sex, race/ethnicity, diabetic status, current smoking status, systolic blood pressure, urinary albumin- creatinine ratio and estimated glomerular filtration rate, hs-CRP (OR 1.26 [95% CI 1.16, 1.37], p<0.001), IL-1RA (1.23 [1.13, 1.34], p<0.0001), IL-6 (1.25 [1.14, 1.36], p<0.001) and TNF-α (1.14 [1.04, 1.25], p = 0.004) were associated with LVH. The odds for systolic dysfunction were greater for subjects with elevated levels of hs-CRP (1.32 [1.18, 1.48], p<0.001) and IL-6 (1.34 [1.21, 1.49], p<0.001). Only hs-CRP was associated with diastolic dysfunction (1.14 [1.04, 1.26], p = 0.005).

Conclusion

In patients with CKD, elevated plasma levels of hs-CRP and IL-6 are associated with LVH and systolic dysfunction.

A case-control study comparing the incidence of early symptoms in pancreatic and biliary tract cancer

OBJECTIVES

Pancreatic ductal adenocarcinoma (PDAC) and biliary tract cancers (BTC) are often diagnosed late and at an advanced stage. Population-based screening programmes do not exist and diagnosis is primarily dependent on symptom recognition. Recently symptom-based cancer decision support tools (CDSTs) have been introduced into primary care practices throughout the UK to support general practitioners (GPs) in identifying patients with suspected PDAC. However, future refinement of these tools to improve their diagnostic accuracy is likely to be necessary.

SETTING

The Health Improvement Network (THIN) is a primary care database, which includes more than 11 million electronic patient records, from 562 GP practices in the UK.

PARTICIPANTS

All patients with a diagnosis of PDAC or BTC between 2000 and 2010 were included in the study along with six matched controls; 2773 patients with PDAC, 848 patients with BTC and 15,395 controls.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary aim of this study was to determine the early symptom profiles of PDAC and BTC. Secondary aims included comparing early symptom trends between BTC and PDAC, defining symptom onset in PDAC and evaluating trends in routine blood tests nearest to the time of diagnosis.

RESULTS

In the year prior to diagnosis, patients with PDAC visited their GP on a median of 18 (IQR 11-27) occasions. PDAC was associated with 11 alarm symptoms and BTC with 8. Back pain (OR 1.33 (95% CI 1.18 to 1.49) p<0.001), lethargy (1.42 (95% CI 1.25 to 1.62) p<0.001) and new onset diabetes (OR 2.46 (95% CI 2.16 to 2.80)) were identified as unique features of PDAC.

CONCLUSIONS

PDAC and BTC are associated with numerous early alarm symptoms. CDSTs are therefore likely to be useful in identifying these tumours at an early stage. Inclusion of unique symptoms, symptoms with an early onset and routinely performed blood tests is likely to further improve the sensitivity of these tools.

Serum aldosterone and death, end-stage renal disease, and cardiovascular events in blacks and whites: findings from the Chronic Renal Insufficiency Cohort (CRIC) Study

Prior studies have demonstrated that elevated aldosterone concentrations are an independent risk factor for death in patients with cardiovascular disease. Limited studies, however, have evaluated systematically the association between serum aldosterone and adverse events in the setting of chronic kidney disease. We investigated the association between serum aldosterone and death and end-stage renal disease in 3866 participants from the Chronic Renal Insufficiency Cohort. We also evaluated the association between aldosterone and incident congestive heart failure and atherosclerotic events in participants without baseline cardiovascular disease. Cox proportional hazards models were used to evaluate independent associations between elevated aldosterone concentrations and each outcome. Interactions were hypothesized and explored between aldosterone and sex, race, and the use of loop diuretics and renin-angiotensin-aldosterone system inhibitors. During a median follow-up period of 5.4 years, 587 participants died, 743 developed end-stage renal disease, 187 developed congestive heart failure, and 177 experienced an atherosclerotic event. Aldosterone concentrations (per SD of the log-transformed aldosterone) were not an independent risk factor for death (adjusted hazard ratio, 1.00; 95% confidence interval, 0.93-1.12), end-stage renal disease (adjusted hazard ratio, 1.07; 95% confidence interval, 0.99-1.17), or atherosclerotic events (adjusted hazard ratio, 1.04; 95% confidence interval, 0.85-1.18). Aldosterone was associated with congestive heart failure (adjusted hazard ratio, 1.21; 95% confidence interval, 1.02-1.35). Among participants with chronic kidney disease, higher aldosterone concentrations were independently associated with the development of congestive heart failure but not for death, end-stage renal disease, or atherosclerotic events. Further studies should evaluate whether mineralocorticoid receptor antagonists may reduce adverse events in individuals with chronic kidney disease because elevated cortisol levels may activate the mineralocorticoid receptor.

Update on the management of cholangiocarcinoma

Cholangiocarcinoma (CC) is a rare cancer arising from the epithelium of the biliary tree, anywhere from the small peripheral hepatic ducts to the distal common bile duct. Classification systems for CC typically group tumours by anatomical location into intrahepatic, hilar or extrahepatic subtypes. Surgical resection or liver transplantation remains the only curative therapy for CC, but up to 80% of patients present with advanced, irresectable disease. Unresectable CC remains resistant to many chemotherapeutic agents, although gemcitabine, particularly in combination with other agents, has been shown to improve overall survival. Ongoing investigation of biological agents has also yielded some promising results. Several novel interventional and endoscopic techniques for the diagnosis and management of non-operable CC have been developed: initial results show improvements in symptoms and progression-free survival, but further randomised studies are required to establish their role in the management of CC.

FGF23 modifies the relationship between vitamin D and cardiac remodeling

BACKGROUND

There is growing evidence to support an important role for vitamin D and related hormones, parathyroid hormone and fibroblast growth factor 23 (FGF23), on cardiac remodeling in chronic kidney disease. Our objective was to determine the relationships between vitamin D and cardiac remodeling in chronic kidney disease and the effects of parathyroid hormone and FGF23 on these associations.

METHODS AND RESULTS

In 1431 participants from the Chronic Renal Insufficiency Cohort study, we measured 25-hydroxyvitamin D (25(OH)D), 1,25-dihydroxyvitamin D (1,25(OH)2D), FGF23, and parathyroid hormone and performed quantitative echocardiography. Using linear regression methods, we determined significant negative interactions between 25(OH)D and FGF23 on left ventricular (LV) mass (P=0.016), end-diastolic volume (P=0.029), and end-systolic volumes (P=0.021). In participants with an FGF23 level greater than the median of 123.5 RU/mL, each doubling of 25(OH)D was associated with a 2.5% (95% confidence interval, -4.8, -0.2) lower LV mass. This association was less pronounced with FGF23 levels less than the median (0.4%; 95% confidence interval, -1.9, 2.7). Conversely, in participants with deficient 25(OH)D levels <20 ng/mL, each doubling of FGF23 was associated with a 3.4% (95% confidence interval, 1.2, 5.6) greater LV mass compared with only a 1.6% (95% confidence interval, -0.2, 3.5) difference in participants with sufficient 25(OH)D. Similar findings were observed with 25(OH)D and volumes (P<0.05), and 1,25(OH)2D and LV mass and volumes (P<0.005). There was no effect modification by parathyroid hormone.

CONCLUSIONS

We identified significant interactions among 25(OH)D, 1,25(OH)2D, and FGF23 on cardiac remodeling. Increased LV mass and cavity dilatation were observed with low 25(OH)D and high FGF23. Our findings suggest that consideration of both hormones is crucial to understanding the role of either in cardiac remodeling, and may have important therapeutic implications.

Comparison of transcatheter and surgical aortic valve replacement in severe aortic stenosis: a longitudinal study of echocardiography parameters in cohort A of the PARTNER trial (placement of aortic transcatheter valves)

OBJECTIVES

This study sought to compare echocardiographic findings in patients with critical aortic stenosis following surgical aortic valve replacement (SAVR) or transcatheter aortic valve replacement (TAVR).

BACKGROUND

The PARTNER (Placement of Aortic Transcatheter Valves) trial randomized patients 1:1 to SAVR or TAVR.

METHODS

Echocardiograms were obtained at baseline, discharge, 30 days, 6 months, 1 year, and 2 years after the procedure and analyzed in a core laboratory. For the analysis of post-implantation variables, the first interpretable study (≤6 months) was used.

RESULTS

Both groups showed a decrease in aortic valve gradients and increase in effective orifice area (EOA) (p < 0.0001), which remained stable over 2 years. Compared with SAVR, TAVR resulted in larger indexed EOA (p = 0.038), less prosthesis-patient mismatch (p = 0.019), and more total and paravalvular aortic regurgitation (p < 0.0001). Baseline echocardiographic univariate predictors of death were lower peak transaortic gradient in TAVR patients, and low left ventricular diastolic volume, low stroke volume, and greater severity of mitral regurgitation in SAVR patients. Post-implantation echocardiographic univariate predictors of death were: larger left ventricular diastolic volume, left ventricular systolic volume and EOA, decreased ejection fraction, and greater aortic regurgitation in TAVR patients; and smaller left ventricular systolic and diastolic volumes, low stroke volume, smaller EOA, and prosthesis-patient mismatch in SAVR patients.

CONCLUSIONS

Patients randomized to either SAVR or TAVR experience enduring, significant reductions in transaortic gradients and increase in EOA. Compared with SAVR, TAVR patients had higher indexed EOA, lower prosthesis-patient mismatch, and more aortic regurgitation. Univariate predictors of death for the TAVR and SAVR groups differed and might allow future refinement in patient selection. (THE PARTNER TRIAL: Placement of AoRTic TraNscathetER Valve Trial; NCT00530894).

Proteomic profiling of bovine M. longissimus lumborum from Crossbred Aberdeen Angus and Belgian Blue sired steers varying in genetic merit for carcass weight

Bovine skeletal muscle is a tissue of significant value to the beef industry and global economy. Proteomic analyses offer the opportunity to detect molecular mechanisms regulating muscle growth and intramuscular fat accumulation. The current study aimed to investigate differences in protein abundance in skeletal muscle tissue of cattle from two breeds of contrasting maturity (early vs. late maturing), adiposity, and muscle growth potential, namely, Belgian Blue (BB) × Holstein Friesian and Aberdeen Angus (AA) × Holstein Friesian. Twenty AA (n = 10) and BB (n = 10) sired steers, the progeny of sires of either high or low genetic merit, expressed as expected progeny difference for carcass weight (EPDcwt), and bred through AI, were evaluated as 4 genetic groups, BB-High, BB-Low, AA-High, and AA-Low (n = 5 per treatment). Chemical composition analysis of M. longissimus lumborum showed greater protein and moisture and decreased lipid concentrations for BB-sired compared with AA-sired steers. To investigate the effects of both sire breed and EPDcwt on M. longissimus lumborum, proteomic analysis was performed using 2-dimensional difference gel electrophoresis followed by mass spectrometry. Proteins were identified from their peptide sequences, using the National Center for Biotechnology Information (NCBI) and Swiss-prot databases. Metabolic enzymes involved in glycolysis (glycogen phosphorylase, phosphoglycerate mutase) and the citric acid cycle (aconitase 2, oxoglutarate dehydrogenase) were increased in AA- vs. BB-sired steers. Expression of proteins involved in cell structure, such as myosin light chain isoforms and troponins I and T, were also altered due to sire breed. Furthermore, heat shock protein β-1 and peroxiredoxin 6, involved in cell defense, had increased abundance in muscle of AA-sired relative to BB-sired steers. Protein abundance of glucose-6-phosphate isomerase, enolase-3, and pyruvate kinase was greater in AA-sired animals of High compared with Low EPDcwt. Changes in the expression of these proteins were supported by gene expression analysis using quantitative real-time PCR. This information will aid in our understanding of genetic influences controlling muscle growth and fat accumulation and could contribute to future breeding programs to increase lean tissue gain of beef cattle.

Left ventricular remodeling in human heart failure: quantitative echocardiographic assessment of 1,794 patients

BACKGROUND

The left ventricle (LV) undergoes significant architectural remodeling in heart failure (HF). However, the fundamental associations between cardiac function and LV size and performance have not been thoroughly characterized in this population. We sought to define the adaptive remodeling that occurs in chronic human HF through the detailed analyses of a large quantitative echocardiography database.

METHODS

Baseline echocardiograms were performed in 1,794 patients with HF across a broad range of ejection fraction (EF), from less than 10% to greater than 70%. Core lab measurements of LV volumes and length were made, from which EF, mass, sphericity indices, stroke volume (SV), and stroke work were derived. Spearman correlation coefficients and linear regression methods were used to determine the relationships between remodeling parameters.

RESULTS

The median EF was 28.6% (IQR 21.9-37.0). Across a multitude of parameters of cardiac structure and function, indexed end-systolic volumes (ESVs) explained the greatest proportion of the variance in EF (R =-0.87, P < 0.0001). Systolic sphericity index and LV mass were also strongly correlated with EF (R =-0.62 and -0.63, P < 0.0001), reflective of the alterations in LV shape and size that occur as EF declines. SV was rigorously maintained across a broad spectrum of EF, until the EF fell below 20%, at which point SV decreased significantly (P < 0.0001).

CONCLUSIONS

In chronic HF, the LV undergoes extensive structural adaptive remodeling in order to maintain SV across a broad range of EF. However, when the EF falls below 20%, further modulation of SV is no longer possible through alterations in ventricular architecture.

Cardiovascular disease among hispanics and non-hispanics in the chronic renal insufficiency cohort (CRIC) study

BACKGROUND AND OBJECTIVES

Hispanics are the largest minority group in the United States. The leading cause of death in patients with chronic kidney disease (CKD) is cardiovascular disease (CVD), yet little is known about its prevalence among Hispanics with CKD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We conducted cross-sectional analyses of prevalent self-reported clinical and subclinical measures of CVD among 497 Hispanics, 1638 non-Hispanic Caucasians, and 1650 non-Hispanic African Americans, aged 21 to 74 years, with mild-to-moderate CKD at enrollment in the Chronic Renal Insufficiency Cohort (CRIC) and Hispanic CRIC (HCRIC) studies. Measures of subclinical CVD included left ventricular hypertrophy (LVH), coronary artery calcification (CAC), and ankle-brachial index.

RESULTS

Self-reported coronary heart disease (CHD) was lower in Hispanics compared with non-Hispanic Caucasians (18% versus 23%, P = 0.02). Compared with non-Hispanic Caucasians, Hispanics had a lower prevalence of CAC >100 (41% versus 34%, P = 0.03) and CAC >400 (26% versus 19%, P = 0.02). However, after adjusting for sociodemographic factors, these differences were no longer significant. In adjusted analyses, Hispanics had a higher odds of LVH compared with non-Hispanic Caucasians (odds ratio 1.97, 95% confidence interval, 1.22 to 3.17, P = 0.005), and a higher odds of CAC >400 compared with non-Hispanic African Americans (odds ratio, 2.49, 95% confidence interval, 1.11 to 5.58, P = 0.03). Hispanic ethnicity was not independently associated with any other CVD measures.

CONCLUSIONS

Prevalent LVH was more common among Hispanics than non-Hispanic Caucasians, and elevated CAC score was more common among Hispanics than non-Hispanic African Americans. Understanding reasons for these racial/ethnic differences and their association with long-term clinical outcomes is needed.

FGF23 induces left ventricular hypertrophy

Chronic kidney disease (CKD) is a public health epidemic that increases risk of death due to cardiovascular disease. Left ventricular hypertrophy (LVH) is an important mechanism of cardiovascular disease in individuals with CKD. Elevated levels of FGF23 have been linked to greater risks of LVH and mortality in patients with CKD, but whether these risks represent causal effects of FGF23 is unknown. Here, we report that elevated FGF23 levels are independently associated with LVH in a large, racially diverse CKD cohort. FGF23 caused pathological hypertrophy of isolated rat cardiomyocytes via FGF receptor-dependent activation of the calcineurin-NFAT signaling pathway, but this effect was independent of klotho, the coreceptor for FGF23 in the kidney and parathyroid glands. Intramyocardial or intravenous injection of FGF23 in wild-type mice resulted in LVH, and klotho-deficient mice demonstrated elevated FGF23 levels and LVH. In an established animal model of CKD, treatment with an FGF-receptor blocker attenuated LVH, although no change in blood pressure was observed. These results unveil a klotho-independent, causal role for FGF23 in the pathogenesis of LVH and suggest that chronically elevated FGF23 levels contribute directly to high rates of LVH and mortality in individuals with CKD.

Vascular responses to drug-eluting and bare metal stents in diabetic/hypercholesterolemic and nonatherosclerotic porcine coronary arteries

BACKGROUND

Animal models used to gain insight into the vascular response to drug-eluting stents are generally juvenile and nonatherosclerotic, whereas stents are placed in patients with complex atherosclerosis and comorbidities. Hence, models reflecting these complexities are needed to help elucidate the vascular effects of drug-eluting stents. We compared the vascular responses with bare metal stent (BMS) and paclitaxel-eluting stent (PES) implantation in a diabetic/hypercholesterolemic (DM/HC) porcine model of advanced coronary atherosclerosis with the standard juvenile porcine model.

METHODS AND RESULTS

Two studies using similar stent procedural protocols were performed in either DM/HC (n=20) or domestic swine (non-DM/HC, n=20). Animals pretreated with dual-antiplatelet therapy, underwent BMS or PES implantation (1/artery, 2 stents per animal) and were euthanized 30 or 90 days later. DM/HC resulted in a 24% increase in platelet aggregation (P=0.05 versus baseline), whereas dual-antiplatelet therapy reduced platelet aggregation in both groups (P<0.0001). DM/HC pigs developed substantially greater neointimal area versus non-DM/HC pigs, regardless of stent type, (P=0.004 for BMS at 30 days and P=0.002 at 90 days, P=0.005 for PES at 30 days, P=0.002 at 90 days). Compared with non-DM/HC pigs, reendothelialization was delayed in DM/HC pigs, more so after PES implantation. Increased para-strut leukocytes were observed for PES compared with BMS in the DM/HC pigs at both 30 days (P=0.023) and 90 days (P=0.04). As well, increased T-lymphocyte infiltration was seen in the DM/HC pigs.

CONCLUSIONS

Stent implantation in a DM/HC swine model provides a metabolic environment closer to human disease, including hyperglycemia, hypercholesterolemia, and increased platelet aggregation. This model augmented differences in the vascular response between PES and BMS that are not as clearly evident in the non-DM/HC swine, including increased neointimal area, delayed reendothelialization, and greater, persistent vascular inflammation.

Effect of sire breed and genetic merit for carcass weight on the transcriptional regulation of the somatotropic axis in longissimus dorsi of crossbred steers

The somatotropic axis plays an important role in postnatal growth, development, and differentiation of skeletal muscle. The aim of this study was to examine the effect of sire breed and sire EPD for carcass weight (EPD(cwt)) on the expression of components of the somatotropic axis in LM of beef cattle at slaughter. Crossbred Aberdeen Angus (AA; n = 17) and Belgian Blue (BB; n = 16) steers born to Holstein-Friesian dams and sired by bulls with either high (H) or low (L) EPD(cwt) were used in the study. Thus, there were 4 genetic groups [i.e., BBH (n = 8), BBL (n = 8), AAH (n = 8), and AAL (n = 9)]. Blood samples were collected via jugular venipuncture at regular intervals for analysis of plasma concentrations of IGF-1 and insulin. Total RNA was isolated from LM collected at slaughter, and the mRNA expression of IGF-1, IGF-2, their receptors (IGF-1R; IGF-2R), 6 IGFBP, acid labile subunit (ALS), and GH receptor (GHR) was measured by real-time reverse-transcription quantitative PCR. There was no effect of either sire breed or EPD(cwt) on concentrations of circulating IGF or insulin (P > 0.05). Gene expression of IGF-1R and IGFBP3 was upregulated in AA (P < 0.001) compared with BB, whereas IGF-1 was upregulated in H compared with L animals (P < 0.01). Correlation analysis indicated moderate positive associations between gene expression of IGFBP3 and IGF-1 (r = 0.54; P < 0.001) and IGF-1R (r = 0.48; P < 0.01). In addition, correlation analysis revealed that mRNA expression of IGFBP3 was moderately negatively associated with LM area per kilogram of carcass weight (r = -0.40; P < 0.05). Greater gene expression of IGF-1 and reduced transcript abundance of IGFBP3 in muscle may have a role in increased muscle growth potential in steers during the finishing period. These data will contribute to a better understanding of the molecular control of muscle growth at a tissue level in cattle.

Akt pathway is hypoactivated by synergistic actions of diabetes mellitus and hypercholesterolemia resulting in advanced coronary artery disease

Atherosclerosis is an inflammatory process leading to enhanced cellular proliferation, apoptosis, and vasa vasorum (VV) neovascularization. While both diabetes mellitus (DM) and hypercholesterolemia (HC) predispose to atherosclerosis, the precise interaction of these risk factors is unclear. Akt is a central node in signaling pathways important for inflammation, and we hypothesized that DM/HC would lead to aberrant Akt signaling and advanced, complex atherosclerosis. DM was induced in pigs by streptozotocin and HC by a high-fat diet. Animals were randomized to control (non-DM, non-HC), DM only, HC only, and DM/HC groups. Coronary artery homogenates were analyzed by immunoblotting for proteins involved in the Akt pathway, including phosphorylated (p)-Akt (Ser473), p-GSK-3beta (Ser9), activated NF-kappaB p65, and VEGF. Immunohistochemical staining for Ki67 (cell proliferation), terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL) (apoptosis), and von Willebrand factor (vWF) (neovascularization) was performed. Neovascularization was visualized with micro-computerized tomography (CT). Only DM/HC animals developed advanced atherosclerosis and showed decreased p-Akt (Ser473) and p-GSK-3beta (Ser9) levels (P < 0.01 and P < 0.05, respectively). DM/HC arteries demonstrated increased cellular proliferation (P < 0.001), apoptosis (P < 0.01), and activation of NF-kappaB p65 (P < 0.05). Induction of DM/HC also resulted in significant VV neovascularization by enhanced VEGF expression (P < 0.05), increased vWF staining (P < 0.01), and increased density by micro-CT. In conclusion, DM and HC synergistically resulted in complex atherosclerosis associated with attenuated p-Akt (Ser473) levels. Aberrant Akt signaling correlated with increased inflammation, cellular proliferation, apoptosis, and VV neovascularization. Our results revealed a synergistic effect of DM and HC in triggering abnormal Akt signaling, resulting in advanced atherosclerosis.

Effect of right ventricular function and venous congestion on cardiorenal interactions during the treatment of decompensated heart failure

Recent reports have demonstrated the adverse effects of venous congestion on renal function (RF) and challenged the assumption that worsening RF is driven by decreased cardiac output (CO). We hypothesized that diuresis in patients with right ventricular (RV) dysfunction, despite decreased CO, would lead to a decrease in venous congestion and resultant improvement in RF. We reviewed consecutive admissions with a discharge diagnosis of heart failure. RV function was assessed by multiple echocardiographic methods and those with >or=2 measurements of RV dysfunction were considered to have significant RV dysfunction. Worsening RF was defined as an increase in creatinine of >or=0.3 mg/dl and improved RF as improvement in glomerular filtration rate >or=25%. A total of 141 admissions met eligibility criteria; 34% developed worsening RF. Venous congestion was more common in those with RV dysfunction (odds ratio [OR] 3.3, p = 0.009). All measurements of RV dysfunction excluding RV dilation correlated with CO (p <0.05). Significant RV dysfunction predicted a lower incidence of worsening RF (OR 0.21, p <0.001) and a higher incidence of improved RF (OR 6.4, p <0.001). CO emerged as a significant predictor of change in glomerular filtration rate during hospitalization in those without significant RV dysfunction (r = 0.38, p <0.001). In conclusion, RV dysfunction is a strong predictor of improved renal outcomes in patients with acute decompensated heart failure, an effect likely mediated by relief of venous congestion.

Arterial pulsatile hemodynamic load induced by isometric exercise strongly predicts left ventricular mass in hypertension

Although resting hemodynamic load has been extensively investigated as a determinant of left ventricular (LV) hypertrophy, little is known about the relationship between provoked hemodynamic load and the risk of LV hypertrophy. We studied central pressure-flow relations among 40 hypertensive and 19 normotensive adults using carotid applanation tonometry and Doppler echocardiography at rest and during a 40% maximal voluntary forearm contraction (handgrip) maneuver. Carotid-femoral pulse wave velocity (CF-PWV) was measured at rest. Hypertensive subjects demonstrated various abnormalities in resting and induced pulsatile load. Isometric exercise significantly increased systemic vascular resistance, aortic characteristic impedance (Zc), induced earlier wave reflections, increased augmentation index, and decreased total arterial compliance (TAC; all P < or = 0.01). In hypertensive subjects, CF-PWV was the strongest resting predictor of LV mass index (LVMI) and remained an independent predictor after adjustment for age, gender, systemic vascular resistance, reflection magnitude, aortic Zc, and TAC (beta = 2.52 m/s; P < 0.0001). Age, sex, CF-PWV, and resting hemodynamic indexes explained 48% of the interindividual variability in LVMI. In stepwise regression, TAC (beta = -17.85; P < 0.0001) during handgrip, Zc during handgrip (beta = -150; P < 0.0001), and the change in the timing of wave reflections during handgrip (beta = -0.63; P = 0.03) were independent predictors of LVMI. A model that included indexes of provoked hemodynamic load explained 68% of the interindividual variability in LVMI. Hemodynamic load provoked by isometric exercise strongly predicts LVMI in hypertension. The magnitude of this association is far greater than for resting hemodynamic load, suggesting that provoked testing captures important arterial properties that are not apparent at rest and is advantageous to assess dynamic arterial load in hypertension.

Intracoronary delivery of mesenchymal stem cells at high flow rates after myocardial infarction improves distal coronary blood flow and decreases mortality in pigs

OBJECTIVES

Evaluate the effects of pressure and duration of intracoronary (IC) infusion of mesenchymal stem cells (MSCs) on delivery efficiency and safety after myocardial infarction (MI).

BACKGROUND

Standard IC delivery of MSCs can lead to intravascular plugging and reduced coronary blood flow. The optimal delivery pressure and duration is unknown.

METHODS

Immediately after MI pigs were randomized to 1 of 3 delivery protocols of 5 x 10(7) iron-fluorescent microspheres labeled MSCs, control received 2 ml infusions at 1 ml/min (five times), very high flow rate (VHFR) a single 10 ml infusion at 60 ml/min and the high flow rate (HFR) group a single 10 ml infusion at 20 ml/min. TIMI grade flow was assessed throughout the procedure and at sacrifice (day 14). MSCs distribution was analyzed in isolated hearts by 4.7T MRI. Delivery efficiency was quantified via fluorescent microsphere recovery using a magnetic separation technique and by light microscopy.

RESULTS

TIMI grade flow did not change following MI (all groups TIMI 3). However, following MSCs delivery only 18% (2/11) of control animals had TIMI 3 blood flow vs. 56% (5/9) in VHFR and 67% (4/6) in HFR (P = 0.03). As a consequence, 63% of control animals died within 24 hr, 33% in VHFR and none in HFR (P = 0.02). MSCs delivery in the infarct tissue did not differ between the groups (P = 0.06).

CONCLUSIONS

A single MSCs infusion at 20 ml/min resulted in improved coronary blood flow and decreased mortality, without sacrificing delivery efficiency.

Application of appropriateness criteria in outpatient transthoracic echocardiography

BACKGROUND

Appropriateness criteria were applied to outpatient transthoracic echocardiographic (TTE) studies.

METHODS

Indications were rated as appropriate, inappropriate, or unclassifiable, considering provider-stated indications, previous TTE studies, symptom changes, and patient-stated indications. Clinically important new or unexpected findings were recorded.

RESULTS

Of 368 TTE studies, 206 (56%) were appropriate, 31 (8%) were inappropriate, and 131 (35%) were unclassifiable. Appropriateness was not correlated with patient or provider demographics. In 288 cases with prior TTE studies, there were 92 (32%) important new findings and 63 (22%) unexpected findings, of which 20% were from inappropriately ordered and 31% from unclassifiable TTE studies. Appropriateness was not associated with new (odds ratio, 1.23; 95% confidence interval, 0.48-3.18) or unexpected (odds ratio, 1.15; 95% confidence interval, 0.38-3.52) findings. Provider type and level of training were not correlated with new or unexpected findings.

CONCLUSIONS

Many indications for TTE studies were unclassifiable. A high percentage of inappropriately ordered TTE studies yielded important information. Care must be taken in judging the value of TTE studies solely on the basis of appropriateness criteria.

Future potential of echocardiography in heart failure

Echocardiography represents a convenient, portable and noninvasive method to provide important anatomic and physiologic information to inform the management of heart failure patients. Traditional echo assessments include diagnostic, etiologic and prognostic data from ventricular size, geometry and performance. Newer echocardiographic techniques are receiving greater utilization, however, and promise to further enhance diagnostic abilities in heart failure. This article reviews traditional anatomic assessments, echo-based cardiac hemodynamics, 3D echocardiography, quantification of myocardial tissue mechanics and hand-carried echocardiography. These developments in echocardiography underlie future trends toward echo objectivity, improved imaging of patients with poor acoustic windows, miniaturization and simplicity in focused exams and the expanded application of old and new techniques.

Failure of digital echocardiography to accurately diagnose intracardiac shunts

BACKGROUND

Intravenous agitated saline injection during transthoracic echocardiography assists in the detection of right to left intracardiac and intrapulmonary shunts. Whether digital echocardiography offers comparable sensitivity and specificity to analog tape recording to assess shunts is unknown. Technical differences between methods could lead to significant differences in shunt detection.

METHODS

Agitated saline was injected intravenously at rest and with Valsalva in 189 consecutive patient studies (406 injections). Echocardiographers assessed presence and degree of left ventricle contrast on simultaneously recorded analog tape and digital echocardiography images in blinded fashion.

RESULTS

Digital echocardiography had low overall sensitivity (rest 0.50, valsalva 0.63, late 0.39) compared to analog tape. Longer clip lengths improved sensitivity for detection of late contrast passage (rest 0.50, valsalva 0.67, late 0.46).

CONCLUSION

Digital echocardiography saline contrast studies have poor sensitivity for assessment of intracardiac shunts versus analog tape, and increasing clip length only modestly increases sensitivity. Joint Photographic Experts Group digital compression losses may be an important cause of failure to detect intracardiac shunts, including patent foramen ovale.