End-stage renal disease should not Be considered a contraindication for veno-arterial extracorporeal membrane oxygenation

PURPOSE

This study aims to determine whether end-stage renal disease (ESRD) is a true contraindication for extracorporeal membrane oxygenation in adult patients.

MATERIALS AND METHODS

Adult patients who received VA-ECMO at National Taiwan University Hospital between January 2010 and December 2021 were included. Patients who received regular dialysis before the index admission were included in the ESRD group. The primary outcome was in-hospital mortality.

RESULTS

1341 patients were included in the analysis, 121 of whom had ESRD before index admission. The ESRD group was older (62.3 versus 56.8 years; P < 0.01) and had more comorbidities. Extracorporeal cardiopulmonary resuscitation (ECPR) was used more frequently in the ESRD group (66.1% versus 51.6%; P < 0.001). The ESRD group had higher in-hospital mortality rates (72.7% versus 63.3%; P = 0.03). In the ECPR subgroup, there was no difference of survival between ESRD and others(P = 0.56). In the multivariate Cox regression, ESRD was not an independent predictor for mortality (P = 0.20).

CONCLUSIONS

ESRD was not an independent predictor of in-hospital mortality after VA-ECMO. The survival of ESRD patients was not inferior to those without ESRD when receiving ECPR. Therefore, ESRD should not be considered a contraindication to VA-ECMO in adults.

Computer-assisted image analysis of preexisting histological patterns of the cephalic vein to predict wrist arteriovenous fistula non-maturation

BACKGROUND

We used computer-assisted image analysis to determine whether preexisting histological features of the cephalic vein influence the risk of non-maturation of wrist fistulas.

METHODS

This study focused on patients aged 20-80 years who underwent their first wrist fistula creation. A total of 206 patients participated, and vein samples for Masson's trichrome staining were collected from 134 patients. From these, 94 patients provided a complete girth of the venous specimen for automatic image analysis. Maturation was assessed using ultrasound within 90 days after surgery.

RESULTS

The collagen to muscle ratio in the target vein, measured by computer-assisted imaging, was a strong predictor of non-maturation in wrist fistulas. Receiver operating characteristic analysis revealed an area under the curve of 0.864 (95% confidence interval of 0.782-0.946, p < 0.001). The optimal cut-off value for the ratio was 1.138, as determined by the Youden index maximum method, with a sensitivity of 89.0% and specificity of 71.4%. For easy application, we used a cutoff value of 1.0; the non-maturation rates for patients with ratios >1 and ≤ 1 were 51.7% (15 out of 29 patients) and 9.2% (6 out of 65 patients), respectively. Chi-square testing revealed significantly different non-maturation rates between the two groups (X2 (1, N = 94) = 20.9, p < 0.01).

CONCLUSION

Computer-assisted image interpretation can help to quantify the preexisting histological patterns of the cephalic vein, while the collagen-to-muscle ratio can predict non-maturation of wrist fistula development at an early stage.

Long-term outcomes of mitral valve replacement in dialysis patients: evidence from a nationwide database

BACKGROUND

To compare the late outcomes between mechanical and bioprostheses after isolated mitral valve replacement (MVR) in dialysis-dependent patients.

METHODS

A nationwide propensity-matched retrospective cohort study was conducted involving dialysis patients who underwent primary mitral replacement between 2001 and 2018. Ten-year postoperative outcomes were compared between mitral bioprosthesis and mechanical prosthesis using the Cox proportional hazard model and restricted mean survival time (RMST).

RESULTS

The all-cause mortality was 20.8 and 13.0 events per 100 person-years, with a 10-year RMST of 7.40 and 7.31 years for bioprosthesis and mechanical prosthesis, respectively. Major bleeding was the most common adverse event for both bioprosthesis and mechanical prosthesis, with an incidence rate of 19.5 and 19.1 events per 100 person-years, respectively. The incidence of valve reoperation was higher among those who received bioprosthesis (0.55 events per 100 person-years). After 1:1 matching, the all-cause mortality was 15.45 and 14.54 events per 100 person-years for bioprosthesis and mechanical prosthesis, respectively. The RMST at 10 years was comparable between the two groups after matching (5.10 years for bioprosthesis vs. 4.59 years for mechanical prosthesis), with an RMST difference of -0.03. Further, no difference was observed in the incidence of major adverse valve-related events between bioprosthesis and mechanical valves. However, bioprosthesis was associated with a higher incidence of mitral valve reoperation among all major adverse events (RMST difference -0.24 years, 95% CI -0.48 to -0.01, P =0.047).

CONCLUSIONS

This study found no association between valve selection and long-term survival outcomes in dialysis patients after MVR. However, bioprosthetic valves may be associated with a slightly higher incidence of reoperation, while other valve-related adverse events, including major bleeding and stroke, were comparable between the two types of prostheses.

Validation of the European system for cardiac operative risk evaluation II in a large Taiwan cardiac surgical centre

BACKGROUND

The European System for Cardiac Operative Risk Evaluation (EuroSCORE II) is a well-established scoring system for predicting mortality in cardiac surgery. This system was derived predominantly from a European patient cohort; however, no validation of this system has been conducted in Taiwan. We sought to assess the performance of EuroSCORE II at a tertiary centre.

METHODS

The 2161 adult patients receiving cardiac surgery between 2017 and 2020 in our institution were included.

RESULTS

Overall, the in-hospital mortality rate was 7.89%. The performance of EuroSCORE II was assessed using the area under the receiver operator curve (AUC) for discrimination and the Hosmer-Lemeshow (H-L) test for calibration. Data were analysed for type of surgery, risk stratification, and status of the operation. EuroSCORE II had good discriminative power (AUC=0.854, 95% Confidence Interval (CI): 0.822-0.885) and good calibration (χ2=5.19, p=0.82) for all types of surgery except ventricular assist devices (AUC=0.618, 95% CI: 0.497-0.738). EuroSCORE II also showed good calibration for most types of surgery except coronary artery bypass surgery (CABG) combined procedure (P=0.033), heart transplantation (HT) (P=0.017), and urgent operation (P=0.041). EuroSCORE II significantly underestimated the risk for CABG combined procedure and urgent operations, and overestimated the risk for HT.

CONCLUSION

EuroSCORE II had satisfactory discrimination and calibration power to predict surgical mortality in Taiwan. However, the model is poorly calibrated for CABG combined procedure, HT, urgent operation, and, likely, lower- and higher-risk patients.

Predictors of Left Ventricular Ejection Fraction Improvement in Patients with Early-Stage Heart Failure with Reduced Ejection Fraction

Objectives

To identify the predictors of left ventricular ejection fraction (LVEF) recovery in patients with heart failure with reduced ejection fraction (HFrEF) and compare the mortality rate between patients with HFrEF and heart failure with improved ejection fraction (HFimpEF).

Methods

Patients in a post-acute care program from 2018 to 2021 were enrolled. A series of echocardiograms were arranged during follow-up. Mortality, cardiovascular death and sudden cardiac death events were recorded. A total of 259 patients were enrolled and followed for at least 1 year; 158 (61%) patients fulfilled the criteria of HFimpEF, 87 (33.6%) were defined as having persistent HFrEF, and 14 (5.4%) were defined as having heart failure with mildly reduced ejection fraction. The patients with HFimpEF and persistent HFrEF were included for analysis.

Results

The mean follow-up duration was 1090 ± 414 days, and the median time to LVEF recovery was 159 days (IQR 112-289 days). Multivariate logistic regression analysis showed that beta-blocker prescription was the only independent predictor of HFimpEF [odds ratio (OR) 2.11, 95% confidence interval (CI) 1.10-4.08, p = 0.03]. Diagnosis of ischemic cardiomyopathy (ICM) and QRS duration ≥ 110 ms were negative predictors of HFimpEF (OR 0.49, 95% CI 0.27-0.88, p = 0.02, and OR 0.4, 95% CI 0.21-0.77, p = 0.005, respectively). The patients with HfimpEF had a significantly better prognosis with lower mortality (hazard ratio 0.2, 95% CI 0.08-0.50, log-rank p < 0.001) than the patients with persistent HFrEF.

Conclusions

Beta-blocker prescription was an independent predictor of HFimpEF, while the diagnosis of ICM and QRS duration ≥ 110 ms were negative predictors of HFimpEF. Patients with HfimpEF had a significantly lower mortality rate compared to those with persistent HFrEF.

Long-term outcomes of aortic valve replacement in dialysis patients - a nationwide retrospective cohort study

BACKGROUND

Improved durability of modern biologic prostheses and growing experience with the transcatheter valve-in-valve technique have contributed to a substantial increase in the use of bioprostheses in younger patients. However, discussion of prosthetic valve selection in dialysis patients remains scarce as the guidelines are updated. This study aims to compare long-term outcomes between propensity score-matched cohorts of dialysis patients who underwent primary aortic valve replacement with a mechanical prosthesis or a bioprosthesis.

MATERIALS AND METHODS

Longitudinal data of dialysis patients who underwent primary aortic valve replacement between 1 January 2001 and 31 December 2018, were retrieved from the National Health Insurance Research Database.

RESULTS

A total of 891 eligible patients were identified, of whom 243 ideally matched pairs of patients were analyzed. There was no significant difference in all-cause mortality (hazard ratio 1.11, 95% CI: 0.88-1.40) or the incidence of major adverse prosthesis-related events between the two groups (hazard ratio 1.03, 95% CI: 0.84-1.25). In patients younger than 50 years of age, using a mechanical prosthesis was associated with a significantly longer survival time across 10 years of follow-up than using a bioprosthesis (restricted mean survival time) at 10 years: 7.24 (95% CI: 6.33-8.14) years for mechanical prosthesis versus 5.25 (95% CI: 4.25-6.25) years for bioprosthesis, restricted mean survival time difference 1.99 years, 95% CI: -3.34 to -0.64).

CONCLUSION

A 2-year survival gain in favor of mechanical prostheses was identified in dialysis patients younger than 50 years. The authors suggest mechanical prostheses for aortic valve replacement in these younger patients.

Impact of Previous Conventional Cardiac Surgery on the Clinical Outcomes After Heart Transplantation

The impact of the type, purpose, and timing of prior surgery on heart transplantation (HT) remains unclear. This study investigated the influence of conventional cardiac surgery (PCCS) on HT outcomes. This study analyzed HTs performed between 1999 and 2019 at a single institution. Patients were categorized into two groups: those with and without PCCS. Short-term outcomes, including post-transplant complications and mortality rates, were evaluated. Cox proportional and Kaplan-Meier survival analyses were used to identify risk factors for mortality and assess long-term survival, respectively. Of 368 patients, 29% had PCCS. Patients with PCCS had a higher incidence of post-transplant complications. The in-hospital and 1 year mortality rates were higher in the PCCS group. PCCS and cardiopulmonary bypass time were significant risk factors for 1 year mortality (hazard ratios = 2.485 and 1.005, respectively). The long-term survival rates were lower in the PCCS group, particularly in the first year. In sub-analysis, patients with ischemic cardiomyopathy and PCCS had the poorest outcomes. The era of surgery and timing of PCCS in relation to HT did not significantly impact outcomes. In conclusion, PCCS worsen the HT outcomes, especially in patients with ischemic etiology. However, the timing of PCCS and era of HT did not significantly affect this concern.

Myocardial Flow Assessment After Heart Transplantation Using Dynamic Cadmium-Zinc-Telluride Single-Photon Emission Computed Tomography With 201Tl and 99mTc Tracers and Validated by 13N-NH3 Positron Emission Tomography

BACKGROUND

Cardiac allograft vasculopathy (CAV) is an obliterative and diffuse form of vasculopathy and is the most common cause of long-term cardiovascular mortality in heart transplant patients. This study aimed to investigate the diagnostic performance of ^99mTc and ²⁰¹Tl tracers in the assessment of CAV using cadmium-zinc-telluride (CZT) single-photon emission computed tomography (SPECT) for myocardial blood flow (MBF) and myocardial flow reserve (MFR) quantification, which was further validated using ¹³ N-NH₃ positron emission tomography (PET).

METHODS

Thirty-eight patients with prior heart transplantation who underwent CZT SPECT and ¹³ N-NH₃ PET dynamic scans were included in this study. CZT SPECT with ^99mTc-sestamibi was used in the first 19 patients and ²⁰¹Tl-chloride for the remaining patients. To determine the diagnostic accuracy of angiographically defined moderate-to-severe CAV, the analysis included patients who underwent angiographic examinations within 1 year of their second scan.

RESULTS

There were no significant differences in the patient characteristics between the ²⁰¹Tl and ^99mTc tracer groups. Both ²⁰¹Tl and ^99mTc CZT SPECT-derived stress MBF and MFR values globally and in 3 coronary territories showed good correlations with ¹³ N-NH₃ PET. The ²⁰¹Tl and ^99mTc cohorts did not differ significantly in the correlation coefficients of CZT SPECT versus PET for MBF and MFR, except for stress MBF (²⁰¹Tl:0.95 versus ^99mTc:0.80, P=0.03). ²⁰¹Tl and ^99mTc CZT SPECT were satisfactory for detecting PET MFR <2.0 (²⁰¹Tl area under the curve, 0.92 [0.71-0.99], ^99mTc area under the curve, 0.87 [0.64-0.97]) and angiographically defined moderate-to-severe CAV, and CZT SPECT results were comparable to that of ¹³ N-NH₃ PET (CZT area under the curve, 0.90 [0.70-0.99], PET area under the curve, 0.86 [0.64-0.97]).

CONCLUSIONS

This small study suggests that CZT SPECT using ²⁰¹Tl and ^99mTc tracers showed comparable MBF and MFR, and the results correlated well with those of ¹³ N-NH₃ PET. Hence, CZT SPECT with ²⁰¹Tl or ^99mTc tracers can be used to detect moderate-to-severe CAV in patients with prior heart transplantation. However, validation using larger studies is warranted.

Clinical outcomes of handmade polytetrafluoroethylene trileaflet-valved conduit used for pulmonary valve replacement

OBJECTIVES

To mitigate the shortage of homograft sources, the use of handmade trileaflet expanded polytetrafluoroethylene valves in pulmonary valve replacement has shown excellent results from multicentre studies conducted in Japan. However, world-wide data outside Japan are relatively insufficient. This study presents the long-term results of a single surgeon's use of flipped-back trileaflet method in a 10-year case series.

METHODS

We have developed an efficient way to make a trileaflet-valved conduit utilizing flipped-back method for pulmonary valve replacement and have employed the technique since 2011. Retrospective data were studied between October 2010 and January 2020. Echocardiography, electrocardiogram, Pro-Brain Natriuretic Peptide and Magnetic Resonance Imaging data were analysed.

RESULTS

Fifty-five patients were reviewed and median follow-up duration was 2.9 years. The majority of diagnoses was Tetralogy of Fallot (n = 41), and these patients subsequently underwent secondary pulmonary valve replacement at a median age of 15.6 years. Survival was 92.7% with the longest follow-up period being 10 years. There was no need for reoperation, and freedom from reintervention was 98.0% at 10 years. There were 4 deaths (3 in-hospital and 1 outpatient). One patient eventually received transcatheter pulmonary valve implantation. Postoperative echocardiography showed mild or less pulmonary stenosis and pulmonary regurgitation degree in 92.2% and 92.0% of patients, respectively. Comparable magnetic resonance imaging data (n = 25) showed significant reduction in right ventricular volumes but not in ejection fractions.

CONCLUSIONS

Our series showed satisfactory long-term function of handmade flipped-back trileaflet-valved conduit used in our patients. The simple design is efficiently reproducible without complex fabrication process.

Editor's Choice - Infective Native Aortic Aneurysms: A Delphi Consensus Document on Terminology, Definition, Classification, Diagnosis, and Reporting Standards

OBJECTIVE

There is no consensus regarding the terminology, definition, classification, diagnostic criteria, and algorithm, or reporting standards for the disease of infective native aortic aneurysm (INAA), previously known as mycotic aneurysm. The aim of this study was to establish this by performing a consensus study.

METHODS

The Delphi methodology was used. Thirty-seven international experts were invited via mail to participate. Four two week Delphi rounds were performed, using an online questionnaire, initially with 22 statements and nine reporting items. The panellists rated the statements on a five point Likert scale. Comments on statements were analysed, statements revised, and results presented in iterative rounds. Consensus was defined as ≥ 75% of the panel selecting "strongly agree" or "agree" on the Likert scale, and consensus on the final assessment was defined as Cronbach's alpha coefficient > .80.

RESULTS

All 38 panellists completed all four rounds, resulting in 100% participation and agreement that this study was necessary, and the term INAA was agreed to be optimal. Three more statements were added based on the results and comments of the panel, resulting in a final 25 statements and nine reporting items. All 25 statements reached an agreement of ≥ 87%, and all nine reporting items reached an agreement of 100%. The Cronbach's alpha increased for each consecutive round (round 1 = .84, round 2 = .87, round 3 = .90, and round 4 = .92). Thus, consensus was reached for all statements and reporting items.

CONCLUSION

This Delphi study established the first consensus document on INAA regarding terminology, definition, classification, diagnostic criteria, and algorithm, as well as reporting standards. The results of this study create essential conditions for scientific research on this disease. The presented consensus will need future amendments in accordance with newly acquired knowledge.

Analysis of Left Ventricular Indexes and Mortality Among Asian Adults With Hemodynamically Significant Chronic Aortic Regurgitation

Importance

Chronic hemodynamically significant aortic regurgitation (AR) is associated with excess risk of death, yet data for Asian patients are lacking, and whether Asian patients can abide by Western guidelines as to when aortic valve surgery should be performed is unknown.

Objective

To assess AR presentation and cutoffs of left ventricular ejection fraction (LVEF), LV end-systolic dimension index (LVESDi), and LV end-systolic volume index (LVESVi) that are associated with risk of death in Asian patients with AR.

Design, Setting, and Participants

This retrospective cohort study included consecutive patients with chronic, moderately severe to severe AR from 3 tertiary referral centers (2 in Japan and 1 in Taiwan) from June 11, 2008, through November 19, 2020, with follow-up through November 11, 2021.

Exposures

Aortic regurgitation severity, graded by a comprehensive integrated approach.

Main Outcomes and Measures

The primary outcome was the association between volume-derived LVEF, LVESDi, and LVESVi and all-cause death (ACD). The secondary outcome was the association of these LV indexes with cardiovascular death (CVD). Clinical and echocardiographic data were analyzed retrospectively. A de novo disk-summation method was used to derive LV volumes and volume-derived LVEF.

Results

Of 1259 patients (mean [SD] age, 64 [17] years; 934 [74%] male), 515 (41%) were Japanese and 744 (59%) were Taiwanese. The median follow-up was 4.1 years (IQR, 1.56-7.24 years). The mean (SD) body surface area was 1.67 (0.21) m2; LVEF, 55% (11%); LVESDi, 24.7 (5.7) mm/m2; LVESVi, 50.1 (28.0) mL/m2; and indexed mid-ascending aorta size, 24.7 (5.5) mm/m2. Aortic valve surgery occurred in 483 patients (38%); 240 patients (19%) died during follow-up. Overall mean (SD) 8-year survival was 74% (2%). Separate multivariate models adjusted for covariates demonstrated independent associations of LVEF, LVESDi, and LVESVi with ACD (LVEF: hazard ratio [HR] per 10%, 0.80; 95% CI, 0.70-0.92; P = .002; LVESDi: HR, 1.04; 95% CI, 1.01-1.06; P = .002; LVESVi: HR per 10 mL/m2, 1.11; 95% CI, 1.05-1.17; P < .001) and CVD (LVEF: HR per 10%, 0.69; 95% CI, 0.56-0.85; P < .001; LVESDi: HR, 1.05; 95% CI, 1.01-1.09; P = .01; LVESVi per 10 mL/m2: HR, 1.15; 95% CI, 1.06-1.24; P < .001). In the total cohort, spline curves showed that mortality started to increase for an LVEF of 53% or less, LVESDi of 22 mm/m2 or greater, and LVESVi of 46 mL/m2 or greater for both ACD and CVD. Early surgery was beneficial in 3 strata of LVESDi (<20, 20 to <25, and ≥25 mm/m2) and 2 strata of LVESVi (<46 and ≥46 mL/m2).

Conclusions and Relevance

This multicenter cohort study of Asian patients with hemodynamically significant AR found cutoff values of LVEF, LVESDi, and LVESVi that were associated with increased risk of death. These findings suggest that Western guidelines seem applicable in Asian patients and, most importantly, that indexed LV parameters with a lower cutoff could be used in discriminating patients with excess mortality risk.

A Randomized Trial of Postoperative Handgrip Exercises for Fistula Maturation in Patients With Newly Created Wrist Radiocephalic Arteriovenous Fistulas

Introduction

We aimed to substantiate the benefit of postoperative handgrip exercises (HGEs) in enhancing the maturation of an arteriovenous wrist fistula.

Methods

We randomly assigned 119 patients aged 20 to 80 years who had wrist arteriovenous fistulas (AVFs) to undergo either a basic HGE program (group A), an advanced program (group B), or an advanced-plus upper arm banding program (group C). Outcomes were assessed by ultrasonographic evaluation of the diameter and flow at each follow-up. The attending nephrologist decided the clinical use of the fistula.

Results

We identified no significant differences among the HGE groups in the mean diameter and blood flow 14, 30, 60, and 90 days after the creation of the wrist AVF (P = 0.55, 0.88, 0.21, and 0.19 for the diameter; 0.94, 0.81, 0.49, and 0.56 for the flow, respectively). The intent-to-treat analysis also found no difference in the clinical use of fistulas for hemodialysis (HD) (P = 0.997).

Conclusion

In patients with a newly created wrist AVF, advancing frequency, with or without adding intensity using an upper arm tourniquet, of postoperative HGEs did not enhance the growth of the fistula or increase the rate of clinical use over 3 months. (ClinicalTrials.gov ID: NCT03077815).

Cost-Benefit Analysis of Involving Pharmacist for Medication Therapy Management in a Heart Transplant Clinic

BACKGROUND

Drug-related problems (DRPs) are common in recipients of solid organ transplants. Pharmacist-led medication therapy management (MTM) has cost benefits in kidney and liver transplants; however, whether MTM is also beneficial in heart transplants remains unclear. This study explored the cost benefits of involving pharmacists in the heart transplant clinic.

METHODS

This retrospective study evaluated DRPs for 1 year after implementation of pharmacist-led MTM in a heart transplant clinic. The DRPs were compared between patients receiving transplantation for <1 and >1 year. The risk matrix method was used to assess each DRP in terms of the estimated probability and severity of consequent adverse drug events (ADEs). For cost analysis, both estimated cost savings and avoidance were calculated.

RESULTS

During the 1-year MTM, 372 DRPs were identified by the pharmacist, among which 169 (45%) and 203 (55%) were from patients at <1-year and ≥1-year post-transplant periods, respectively. The 2 post-transplant periods (<1 year and ≥1 year) exhibited significant differences in the distribution of the dosage or frequency problems (30% vs 18%, P = .005) and the suggestion of more appropriate medication (4% vs 10%, P = .024). In all, 92 (29%) DRPs had an ADE probability of >10%; and 63 (17%) DRPs were estimated to cause ADEs with moderate severity or higher. The estimated cost savings and cost avoidance were US $4902 and US $4519, which equaled a cost-benefit ratio of 2.39.

CONCLUSION

Integration of pharmacists into heart transplant clinics could help address DRPs and may have cost benefits.

Change in Abdominal Aortic Aneurysm Sac Diameter After Endovascular Repair: A Single-Center Experience From Taiwan

PURPOSE

The purpose of this study was to investigate the change in the diameter of infrarenal abdominal aortic aneurysm (AAA) sacs after endovascular aortic repair (EVAR) in Taiwanese patients and to depict its association with clinical outcomes.

MATERIALS AND METHODS

This retrospective cohort study was conducted on patients who underwent EVAR for infrarenal AAA between January 2011 and December 2016. All preoperative and follow-up computed tomography (CT) images were reviewed. Postoperative CT angiography was arranged after 1 month and annually thereafter. The maximal diameter on the axial plane and the maximal diameter perpendicular to the centerline on the coronal and sagittal planes were measured. The study examined post-EVAR sac diameter change over time and compared the differences in adverse events (AEs) among groups.

RESULTS

The survey included a total of 191 patients with a median follow-up duration of 2.5 (interquartile range: 1.1-2.9) years. Overall survival rates at 1, 2, and 5 years were 92%, 81%, and 76%, respectively. According to their last CT scans, the patients were categorized into 3 groups as follows: shrinkage, stationary, and enlargement, which comprised 58 (30.4%), 118 (61.8%), and 15 (7.9%) patients, respectively. Pre-EVAR characteristics and sac diameters were similar among the groups. Sac shrinkage was exclusively observed in the first 2 years, whereas sac enlargement developed at all follow-up periods. Patients with sac enlargement had higher incidence rates of endoleaks, complications, and reintervention than the other groups.

CONCLUSION

Based on our observations, post-EVAR sac shrinkage only occurs in the first 2 years; however, post-EVAR sacs may enlarge at any point and even after 5 years. In our study, patients with sac enlargement had higher rates of adverse events and reintervention.

Impact of duration of mechanical support on heart transplantation: Hasty transplantation may not have a good long-term outcome

BACKGROUND

Mechanical circulatory support (MCS) has been widely utilized in critically ill cardiac transplant candidates. Few studies have investigated the impact of duration of MCS before heart transplantation (HTx) on long-term patient survival.

METHODS

A retrospective HTx database was reviewed between 2009 and 2019. Patients who did not or did undergo MCS before HTx were categorized into two groups: (1) A (did not) and (2) B (did), respectively. A receiver operating characteristic (ROC) curve was plotted to assess the cutoff level of MCS duration before HTx in evaluating 5-year survival.

RESULT

A total of 270 HTx patients (group A: 120, group B: 150) were analyzed. Group B patients had a higher percentage of blood type O, a higher incidence of resuscitation, a shorter listing duration, and a higher likelihood of having United Network for Organ Sharing (UNOS) 1A status than group A. The ROC curve revealed 24 days as a good cut-off level for determining the best MCS before HTx timing. Group B was categorized into two subgroups: (1) B1 (MCS < 24 days, n = 65) and (2) B2 (MCS > 24 days, n = 85). B2 had a higher incidence of cardiopulmonary resuscitation (CPR), hemodialysis, longer waiting time after MCS, and better ventricular assist device implantation than B1. However, the survival curves showed that B1 outcomes were significantly worse than in groups A and B2. Groups A and B2 had similar survival curves without an increased incidence of infection.

CONCLUSION

The preliminary data demonstrated that a longer duration of MCS may be associated with better outcomes than urgent HTx.

Streptococcus mutans PrsA mediates AtlA secretion contributing to extracellular DNA release and biofilm formation in the pathogenesis of infective endocarditis

The role of secretion chaperone-regulated virulence proteins in the pathogenesis of infective endocarditis (IE) induced by viridans streptococci such as Streptococcus mutans is unclear. In this study, we investigated the contribution of the foldase protein PrsA, a putative parvulin-type peptidyl-prolyl isomerase, to the pathogenesis of S. mutans-induced IE. We found that a prsA-deficient strain had reduced virulence in terms of formation of vegetation on damaged heart valves, as well as reduced autolysis activity, eDNA release and biofilm formation capacity. The secretion and surface exposure of AtlA in vitro was reduced in the prsA-deficient mutant strain, and complementation of recombinant AtlA in the culture medium restored a wild type biofilm phenotype of the prsA-deficient mutant strain. This result suggests that secretion and surface localization of AtlA is regulated by PrsA during biofilm formation. Together, these results demonstrate that S. mutans PrsA could regulate AtlA-mediated eDNA release to contribute to biofilm formation in the pathogenesis of IE.

Impact of pretransplant bloodstream infection on clinical outcomes after heart transplantation

BACKGROUND

Active bloodstream infection (BSI) is a contraindication for heart transplantation (HT). However, some critical patients with BSI may undergo HT as a life-saving procedure. We aimed to investigate the impact of pretransplant BSI on the clinical outcomes after HT.

METHODS

We enrolled 511 consecutive patients who underwent HT between 1999 and 2019. Patients were divided into two groups based on the presence of BSI within 30 days preoperatively. Forty-three patients (8.4%) with BSI who were clinically stable and had no metastatic infection were considered for HT on an individual basis. In-hospital mortality, incidence of early postoperative BSI, length of postoperative hospital stays, and long-term survival were compared between the groups. Logistic and Cox regression analyses were performed to identify risk factors for in-hospital and 1-year mortality.

RESULTS

Patients with pretransplant BSI had a high incidence of previous cardiopulmonary resuscitation, pretransplant ventilator use, mechanical circulatory support use, renal replacement therapy, United Network for Organ Sharing status 1A, and a prolonged preoperative hospital waiting period. The in-hospital mortality rate was higher in patients with pretransplant BSI (21% versus 12%, p = 0.081), and the mortality rate was very high (33.3%) for those with BSI 0-15 days before HT. In addition, patients with pretransplant BSI had a significantly longer postoperative hospital stay than patients in the control group. However, long-term survival was similar in both groups.

CONCLUSIONS

Although pretransplant BSI was associated with higher in-hospital mortality and prolonged postoperative hospital stay, patients who survived the early period had a similar long-term prognosis. This article is protected by copyright. All rights reserved.

Impact of Pretransplant Renal Replacement Therapy on Clinical Outcome After Isolated Heart Transplantation

End stage renal disease (ESRD) is a contraindication to isolated heart transplantation (HT). However, heart candidates with cardiogenic shock may experience acute kidney injury and require renal replacement therapy (RRT) and isolated HT as a life-saving operation. The outcomes, including survival and renal function, are rarely reported. We enrolled 569 patients undergoing isolated HT from 1989 to 2018. Among them, 66 patients required RRT before HT (34 transient and 32 persistent). The survival was worse in patients with RRT than those without (65.2% vs 84.7%; 27.3% vs 51.1% at 1- and 10-year, p < 0.001 and p = 0.012, respectively). Multivariate Cox analysis identified pre-transplant hyperbilirubinemia (Hazard ratio (HR) 2.534, 95% confidence interval (CI) 1.098–5.853, p = 0.029), post-transplant RRT (HR 5.551, 95%CI 1.280–24.068, p = 0.022) and post-transplant early bloodstream infection (HR 3.014, 95%CI 1.270–7.152, p = 0.012) as independent risk factors of 1-year mortality. The majority of operative survivors (98%) displayed renal recovery after HT. Although patients with persistent or transient RRT before HT had a similar long-term survival, patients with persistent RRT developed a high incidence (49.2%) of dialysis-dependent ESRD at 10 years. In transplant candidates with pretransplant RRT, hyperbilirubinemia should be carefully re-evaluated for the eligibility of HT whereas prevention and management of bloodstream infection after HT improve survival.

The Sequential Change in Left Ventricular Function among Various Cardiovascular Diseases: A 12-Year Study

Background: This 12-year study aimed to compare the longitudinal change in left ventricular diastolic dysfunction (LVDD) between healthy elderly, coronary artery disease (CAD), and hypertension (HTN) patients. Methods: From 2008 to 2020, 1476 patients were included, and 3181 echocardiography examinations were conducted. Finally, 130 participants (36 healthy elderly (79.39 ± 9.51 years old), 51 with CAD (68.31 ± 12.09 years old), and 43 with HTN (68.31 ± 12.09 years old)) with more than a 10-year follow-up period were included in the final analysis. Results: The change in diastolic function was different among these subjects according to the integrated score index (elderly vs. HTN, p = 0.01; CAD vs. HTN, p = 0.01), septal E/e′ ratio (elderly vs. HTN, p < 0.001; CAD vs. HTN, p = 0.01), lateral E/e′ ratio (elderly vs. HTN, p < 0.001; CAD vs. HTN, p < 0.001), and NYHA functional class (elderly vs. HTN, p = 0.03; CAD vs. HTN, p < 0.001). Additionally, per one-year increase in age, the integrated score index increased 0.2 in the healthy elderly, 0.15 in the CAD, and 0.06 in the HTN patients (all p < 0.05). Conclusion: Under aggressive treatment, diastolic function was relatively preserved in HTN subjects with aging in comparison with elderly and CAD subjects.

Outcome of emergency surgery for acute type A aortic dissection in octogenarians

BACKGROUND

Emergency surgery for acute type A aortic dissection (AAAD) was usually avoided or denied in octogenarians because of high surgical mortality. Refined surgical techniques and improved postoperative care have led to an improved in-hospital outcome. However, a significant number of operative survivors suffered from postoperative complications and had compromised quality of life. We sought to assess the clinical outcome of emergency surgery using a standard conservative approach in octogenarians with AAAD.

METHODS

From 2004 to 2021, 123 patients underwent emergency surgery for AAAD by one surgeon using a standard conservative approach with right subclavian artery cannulation, no aortic cross-clamp, selective antegrade cerebral perfusion, moderate systemic hypothermia, reinforced sandwich technique, and a strategy of limited aortic resection. Hospital and late outcomes were assessed in patients with age >80 years.

RESULTS

Eighteen patients (15%) were octogenarians with seven males (39%) and median age of 82 years (range, 80-89). Hypertension was present in six patients (33%). None had diabetes mellitus, Marfan, or bicuspid aortic valve. Dissection was intramural hematoma in six (33%) and DeBakey type I in 15 patients (83%). Cardiac tamponade with shock was present in seven patients (39%). Ascending aortic grafting was performed in 17 patients, and additional hemiarch replacement in one patient. The hospital mortality rate was 17% (3/18). Fourteen patients (82%) were alive and well at discharge.

CONCLUSIONS

Emergency surgery for AAAD using a standard conservative approach showed an improved outcome in octogenarians. The majority of patients could return home with an acceptable living.

The Impact of Pharmacist-Managed Service on Warfarin Therapy in Patients after Mechanical Valve Replacement

OBJECTIVE

To evaluate the impact of pharmacist interventions on international normalized ratio (INR) control during the warfarin initiation phase after mechanical valve replacement.

METHODS

This was a retrospective cohort study conducted in a cardiovascular surgery ward in a tertiary hospital from August 1, 2015, to July 31, 2019. Patients aged ≥20 years who were admitted for mechanical valve replacement were enrolled in this study and further classified into conventional and pharmacist-managed warfarin therapy (PMWT) groups. All participants were prospectively followed up until the first outpatient appointment after valve replacement. The effectiveness outcomes were time in therapeutic range (TTR), time to therapeutic INR, number of patients with therapeutic INR at discharge and at first outpatient appointment, and length of hospital stay. The safety outcome was the number of patients with any supratherapeutic INR during the hospital stay. Multivariate logistic regression analyses were also used to determine the predictors of a therapeutic INR at discharge or with any supratherapeutic INR during admission.

RESULTS

A total of 39 and 33 patients were enrolled in the conventional and PMWT groups, respectively. At discharge, 18 patients (46.2%) in the conventional group and 24 patients (72.7%) in the PMWT group had achieved the therapeutic INR (P=0.023). Compared to the conventional group, fewer patients in the PMWT group had supratherapeutic INR during hospital stay (35.9% vs. 9.0%, P=0.008). No significant differences were found in TTR, time to therapeutic INR, number of patients with therapeutic INR at return appointment, and length of stay between the study groups. In the multivariate regression analyses, PMWT predicted achieving therapeutic INR at discharge (odds ratio (OR) and 95% confidence interval (CI), 3.14 [1.08-9.14]) and was inversely associated with supratherapeutic INRs during admission (OR = 0.21 [0.05-0.82]).

CONCLUSIONS

Among patients admitted for mechanical valve replacement, the implementation of PMWT was associated with optimal therapeutic INR at discharge and no supratherapeutic INR during admission. Therefore, pharmacist participation is essential for improving the quality of warfarin therapy.

Transient bacteremia promotes catheter-related central venous thrombosis through neutrophil extracellular traps

Formation of intravenous catheter-related thrombosis leads to central venous stenosis in patients requiring renal replacement therapy or chemotherapy infusion, yet the triggering or mechanisms remain unclear, especially in patients without symptoms of infection. In this study, we found that neutrophil extracellular traps (NETs) could be detected in the fibrin sheaths from dialysis patients without clinical manifestations of infection. Confocal microscopy revealed bacteria imbedded in NETs in the fibrin sheaths. Thirty-nine of 50 (78%) fibrin sheath specimens contained bacteria detectable by 16S ribosomal RNA genome typing with a predominance of Staphylococcus aureus (69%). In rat models, transient bacteremia of S. aureus induced NETs in enlarged fibrin sheaths, and treatment with DNase I alone significantly reduced both NET and fibrin sheath formation surrounding the catheter. Therefore, transient bacteremia could be a silent trigger that induces NET-related immunothrombosis enhancing catheter-related central venous stenosis.

Outcome of urgent desensitization in sensitized heart transplant recipients

BACKGROUND/PURPOSE

Sensitization, the presence of preformed anti-human antibody in recipients, restricts access to ABO-compatible donors in heart transplant. Desensitization therapy works by reducing preformed antibodies to increase the chances of a negative crossmatch or permit safe transplantation across positive crossmatch. There is no consensus regarding the desensitization protocol in cardiac patients, and the outcome of desensitization remains under debate.

METHODS

Twenty-five consecutive sensitized heart transplant recipients received perioperative desensitization in our institution from 2012 to 2019. One-year patient survival and graft rejection rate were analyzed and compared between sensitized recipients and non-sensitized recipients.

RESULTS

Within the first year after transplant, patient survival in sensitized recipients was 76%. Infection was the major cause of death. The cumulative incidence of rejection was 8% for antibody-mediated rejection and 16% for acute cellular rejection. No significant difference in 1-year survival or rejection rate could be demonstrated between sensitized and nonsensitized recipients.

CONCLUSION

Acceptable early outcomes in patient survival and graft rejection could be anticipated in sensitized heart transplant recipients under a perioperative algorithm using complement-dependent cytotoxicity crossmatch- or panel-reactive antibody-directed urgent immunomodulation strategies, while infection remains the major concern.

PspC domain-containing protein (PCP) determines Streptococcus mutans biofilm formation through bacterial extracellular DNA release and platelet adhesion in experimental endocarditis

Bacterial extracellular DNA (eDNA) and activated platelets have been found to contribute to biofilm formation by Streptococcus mutans on injured heart valves to induce infective endocarditis (IE), yet the bacterial component directly responsible for biofilm formation or platelet adhesion remains unclear. Using in vivo survival assays coupled with microarray analysis, the present study identified a LiaR-regulated PspC domain-containing protein (PCP) in S. mutans that mediates bacterial biofilm formation in vivo. Reverse transcriptase- and chromatin immunoprecipitation-polymerase chain reaction assays confirmed the regulation of pcp by LiaR, while PCP is well-preserved among streptococcal pathogens. Deficiency of pcp reduced in vitro and in vivo biofilm formation and released the eDNA inside bacteria floe along with reduced bacterial platelet adhesion capacity in a fibrinogen-dependent manner. Therefore, LiaR-regulated PCP alone could determine release of bacterial eDNA and binding to platelets, thus contributing to biofilm formation in S. mutans-induced IE.

Surviving and Thriving 1 Year After Cardiac Surgery: Frailty and Delirium Matter

BACKGROUND

We compared 1-year functional outcomes for 4 cardiac surgery patient groups: comparison (without preoperative frailty or postoperative delirium [POD]), frailty only (with preoperative frailty only), POD only (with POD only), and frailty-POD (combined frailty and POD).

METHODS

Consecutive cardiac surgery patients (n = 298) at a university hospital were assessed for preoperative frailty using Fried's phenotype, and POD was assessed daily for 10 days after surgery using the Confusion Assessment Method. Functional outcomes (Barthel Index for activities of daily living [ADL]) and all-cause mortality were evaluated 1-year after surgery.

RESULTS

Preoperative frailty presented in 85 of participants (28.5%) and POD in 38 (12.8%). Frail participants were at increased risk for POD (odds ratio = 4.9; P < .001). Overall, 1-year mortality was 4.0% (n = 12) and functional change was 0.4 ± 11.0 Barthel points. Controlling for age, cardiac risk, and baseline ADL, frailty-only and comparison participants had comparable 1-year functional outcomes. The POD-only group had greater mortality (adjusted hazard ratio = 23.9; P = .01), whereas the combined frailty-POD group had the greatest ADL decline (β = -23.7; P = .01) and the highest mortality (adjusted hazard ratio = 30.2; P = .006) compared with the comparison group.

CONCLUSIONS

Preoperative frailty alone did not negatively affect cardiac surgery patients' functional outcomes up to 1 year, but coexisting frailty and POD led to substantial loss of independence on 3 to 4 ADLs and a 30.2-fold higher likelihood of dying 1 year after surgery. Because frailty led to a 4.9-fold increase in POD risk, frailty may serve as a presurgical screen to identify patients who would likely benefit from delirium prevention and functional recovery programs to maximize 1-year postsurgical outcomes.

Neutrophil Extracellular Traps Enhance Staphylococcus Aureus Vegetation Formation through Interaction with Platelets in Infective Endocarditis

The mechanisms or host factors involved in septic thrombus or vegetation formation in Staphylococcus aureus-induced infective endocarditis (IE) are unclear. Using an experimental endocarditis rat model, here we demonstrated that S. aureus HG001-induced vegetation was composed of bacterial floes encased in aggregated platelets and surrounded by neutrophil extracellular traps (NETs). In vitro data demonstrated that platelets contribute to both biofilm and NET formation. Prophylactic administration of DNase I significantly reduced the size of vegetation induced by methicillin-resistant S. aureus (MRSA) and methicillin-sensitive S. aureus (MSSA) strains, even though MRSA and MSSA isolates express different biofilm phenotypes and NET-induction abilities in the presence of platelets. Moreover, delivery of both DNase I and daptomycin prophylactically and therapeutically produced synergistic effects by reducing vegetation size and bacterial numbers on damaged valve tissues in MRSA-induced IE. Together, these data suggest that NETs contribute to vegetation formation in S. aureus endocarditis and DNase I has the potential to control S. aureus-induced IE in the clinic.

Effects of sarcopenia on functional improvement over the first year after cardiac surgery: a cohort study

Background:

Sarcopenia is linked with poor postoperative outcomes.

Aims:

To evaluate the effects of sarcopenia on first-year functional changes after cardiac surgery.

Methods:

In this prospective cohort study, functional changes (physical activity levels in metabolic equivalent hours/week, 6-minute walking distance in metres, and grip strength in kg) from preoperative baseline to 1, 3, 6 and 12 months postoperatively were compared in adult patients with and without sarcopenia undergoing cardiac surgery at a tertiary medical centre. Presurgical sarcopenia was defined as low muscle mass plus either low strength or poor physical performance (i.e. reduced gait speed). Secondary outcomes (length of hospital stay and 1-year mortality) were compared between sarcopenia and non-sarcopenia groups.

Results:

Sarcopenia presented in 27.7% ( n=67) of 242 participants. Participants with sarcopenia were significantly older, predominantly women, and had lower body mass index and higher cardiac surgery risk (measured by the EuroSCORE II) than those without sarcopenia. For both groups, physical activity levels, walking distance and grip strength steadily improved over the year following cardiac surgery. Independent of EuroSCORE II, changes in physical activity levels, walking distance and grip strength did not differ significantly between the sarcopenia and non-sarcopenia groups 1, 3, 6 and 12 months after surgery. Nevertheless, the sarcopenia group had a significantly longer length of hospital stay than the non-sarcopenia group (19.4 vs. 15.3 days; β=2.9, P=0.02) but 1-year mortality (3.4 vs. 3.9% for non-sarcopenia group) was comparable.

Conclusions:

Despite a longer length of hospital stay for the sarcopenia group, sarcopenia was not a restriction for cardiac surgery given their comparable functional improvement and mortality 1 year following surgery.

Primary Infected Aortic Aneurysm: Clinical Presentation, Pathogen, and Outcome

PURPOSE

Infected aneurysm of the aorta and adjacent arteries is rarely occurring and can be fatal without surgical intervention. Within the medical community, the most efficacious treatment strategy to address infected aortic aneurysm remains controversial. In this study, we have reviewed our treatment experience with 109 patients.

METHODS

We included in our study all consecutive patients treated for primary infected aortic aneurysm at our facility between 1995 and 2011. Aneurysm-related mortality was defined as the presence of in-hospital and late mortality related to infection or postoperative complications.

RESULTS

The median patient age was 72 years (range, 35-88), and 87 (80%) were male. Pathogen was isolated in 101 patients, and the most common microorganism identified was non-typhoid Salmonella in 61 (60%), followed by Staphylococcus aureus in 16 (16%) and Streptococci species in 7 (7%). Eighty-five (78%) patients underwent surgical treatment. Surgery included open repair with in-situ graft replacement in 77 (71%) and endovascular repair in 8 (7%). The aneurysm-related mortality rate was 67% in medically treated and 21% in surgically treated patients, with a median follow-up duration of 31.5 months (range 1-189). Additionally, risk factors for aneurysm-related mortality included old age, chronic lung disease, psoas muscle abscess, short duration of preoperative antibiotics, no operation, and probably endovascular repair.

CONCLUSIONS

Non-typhoid Salmonella was the most common pathogen found in our study group patients with infected aortic aneurysm. It appears that prolonged preoperative antibiotic treatment followed by open in-situ graft replacement remains the preferred and most effective treatment strategy.

KEY WORDS

Infected aortic aneurysm; Outcome; Pathogen; Surgery.

Risk factors and outcome analysis after surgical management of ventricular septal rupture complicating acute myocardial infarction: a retrospective analysis

BACKGROUND

Ventricular septal rupture (VSR) is an uncommon but well-recognized mechanical complication of acute myocardial infarction (AMI). The outcome of VSR remains poor even in the era of reperfusion therapy. We reviewed our experience with surgical repair of post-infarction VSR and analyzed outcomes in an attempt to identify prognostic factors.

METHODS

From October 1995 to December 2013, data from 47 consecutive patients (mean age, 68 ± 9.5 years) with post-infarction VSR who underwent surgical repair at our institute were retrospectively reviewed. The preoperative conditions, morbidity and surgical mortality were analyzed. Multivariate analysis was subsequently carried out by constructing a logistic regression model in order to identify independent predictors of postoperative mortality. Long term survival function were estimated using the Kaplan-Meier method and compared using the log-rank test.

RESULTS

Percutaneous coronary intervention was performed in 17 (36.2%) patients, intra-aortic balloon pump (IABP) was used in 34 (72.3%), and six (12.8%) were supported with extracorporeal membrane oxygenation (ECMO) preoperatively. Forty-one (87.2%) patients received emergent surgical treatment. Concomitant coronary artery bypass grafting was performed in 27 (57.4%) patients. Operative mortality was 36.2% (17 of 47). The survival rate was 59.3% with concomitant CABG and 70% without concomitant CABG (p = 14). Multivariate analysis revealed that the survivors had higher preoperative left ventricular ejection fractions (LVEFs) compared with those who died (51 ± 13.7% vs. 36.6 ± 6.4% , respectively; p < 0.001) and lower European system for cardiac operative risk evaluation II (EuroSCORE II) (22.9 ± 14.9 vs. 38.3 ± 13.9, respectively; p < 0.001). The patients receiving total revascularization has long term survival benefit (p = 0.028).

CONCLUSIONS

Post-infarction VSR remains a serious and challenging complication of AMI in the modern surgical era. The EuroSCORE II can be used for an approximate prediction of operative mortality. Preserved LVEF was associated with better prognosis, while the need for postoperative RRT was associated with higher early and late mortality. Besides, the strategy of total revascularization should be applied to ensure long-term survival benefit.

Methicillin Resistance and Risk Factors for Embolism inStaphylococcus aureusInfective Endocarditis

Objective.

Infective endocarditis caused byStaphylococcus aureusis an ominous prognosis associated with a high prevalence of embolic episodes and neurological involvement. Whether methicillin resistance decreases the risk of embolism in infective endocarditis is unclear. We sought to assess the association between methicillin resistance and risk factors for embolism in S.aureusinfective endocarditis.

Design.

Retrospective chart review. Data from patients with infective endocarditis due to methicillin-resistantS. aureus werecompared with data from patients with endocarditis due to methicillin-susceptibleS. aureus.Logistic regression was used to identify independent risk factors for embolism.

Setting.

A 2,000-bed, university-affiliated tertiary care hospital.

Patients.

Between 1995 and 2005, 123 patients withS. aureusinfective endocarditis were included in the study. There were 74 male patients and 49 female patients, with a median age of 54 years (range, 0-89 years).

Results.

Of 123 infections, 30 (24%) were nosocomial infections, and 14 (11%) were prosthetic valve infections. Of 123S. aureusisolates, 48 (39%) were methicillin resistant. In total, embolism occurred in 45 (37%) of these patients: pulmonary embolism in 22 (18%), cerebral embolism in 21 (17%), and peripheral embolism in 6 (5%). The independent risk factors for an embolism were injection drug use, presence of a cardiac vegetation with a size of 10 mm or greater, and absence of nosocomial infection. For 83 patients with aortic or mitral infective endocarditis, independent risk factors for an embolism were the presence of a cardiac vegetation with a size of 10 mm or greater and endocarditis due to methicillin-susceptibleS. aureus.Overall, in-hospital death occurred for 32 (26%) of 123 Patients. Methicillin-resistant infection was not an independent risk factor for death.

Conclusions.

Methicillin-resistant S.aureusinfection was associated with decreased risk of embolism in left-side endocarditis, but was not associated with in-hospital death.

Endocarditis pathogen promotes vegetation formation by inducing intravascular neutrophil extracellular traps through activated platelets

BACKGROUND

Endocarditis-inducing streptococci form multilayered biofilms in complex with aggregated platelets on injured heart valves, but the host factors that interconnect and entrap these bacteria-platelet aggregates to promote vegetation formation were unclear.

METHODS AND RESULTS

In a Streptococcus mutans endocarditis rat model, we identified layers of neutrophil extracellular traps interconnecting and entrapping bacteria-platelet aggregates inside vegetation that could be reduced significantly in size along with diminished colonizing bacteria by prophylaxis with intravascular DNase I alone. The combination of activated platelets and specific immunoglobulin G-adsorbed bacteria are required to induce the formation of neutrophil extracellular traps through multiple activation pathways. Bacteria play key roles in coordinating the signaling through spleen tyrosine kinase, Src family kinases, phosphatidylinositol-3-kinase, and p38 mitogen-activated protein kinase pathways to upregulate the expression of P-selectin in platelets, while inducing reactive oxygen species-dependent citrullination in the arm of neutrophils. Neutrophil extracellular traps in turn serve as the scaffold to further enhance and entrap bacteria-platelet aggregate formation and expansion.

CONCLUSIONS

Neutrophil extracellular traps promote and expand vegetation formation through enhancing and entrapping bacteria-platelet aggregates on the injured heart valves.

Role of Left Main Coronary Artery Stenosis on Intraoperative Conversion and Mortality in Off-Pump Coronary Artery Bypass

BACKGROUND

Intraoperative conversion is a major threat in off-pump coronary artery bypass (OPCAB). The conversion rate depends on patient selection and surgeon experience. Previous studies have demonstrated the feasibility of OPCAB for patients with left main coronary artery stenosis (LMCAS) ≥ 50%. However, no studies have focused on the role of LMCAS ≥ 90%. We sought to assess the impact of LMCAS ≥ 90% on the conversion rate and mortality in OPCAB.

METHODS

We conducted a retrospective review of 1055 consecutive unselected patients undergoing OPCAB between 2000 and 2012. The patients in our study were divided into 3 groups by the severity of LMCAS.

RESULTS

LMCAS was < 50% in 704, 50-90% in 266, and ≥ 90% in 85 patients. LMCAS was not associated with major postoperative complications and hospital mortality, although preoperative cardiogenic shock was present in 6.3%. Overall, the conversion rate was 10.1%:11.4% in LMCAS < 50%, 5.6% in LMCAS 50-90%, and 14.1% in LMCAS ≥ 90%. Operation status, cardiogenic shock, left ventricular ejection fraction < 30% and operation before 2007 were noted as independent predictors of conversion. The overall hospital mortality rate was 5.1%: 4.8% in LMCAS < 50%, 4.5% in LMCAS 50-90%, and 9.4% in LMCAS ≥ 90%. Operation status, cardiogenic shock, left ventricular ejection fraction < 30% and intraoperative conversion were observed to be independent predictors of mortality. However, LMCAS did not predict either conversion or hospital mortality.

CONCLUSIONS

LMCAS ≥ 90% was not an independent predictor of intraoperative conversion or hospital mortality in OPCAB.

KEY WORDS

Conversion; Left main coronary artery stenosis; Off-pump coronary artery bypass.

Cardiac surgery in patients with liver cirrhosis: Risk factors for predicting mortality

AIM: To evaluate the results of cardiac surgery in cirrhotic patients and to find the predictors of early and late mortality.

METHODS: We included 55 consecutive cirrhotic patients undergoing cardiac surgery between 1993 and 2012. Child-Turcotte-Pugh (Child) classification and Model for End-Stage Liver Disease (MELD) score were used to assess the severity of liver cirrhosis. The online EuroSCORE II calculator was used to calculate the logistic EuroSCORE in each patient. Stepwise logistic regression analysis was used to identify the risk factors for mortality at different times after surgery. Multivariate Cox proportional hazard models were applied to estimate the hazard ratios (HR) of predictors for mortality. The Kaplan-Meier method was used to generate survival curves, and the survival rates between groups were compared using the log-rank test.

RESULTS: There were 30 patients in Child class A, 20 in Child B, and five in Child C. The hospital mortality rate was 16.4%. The actuarial survival rates were 70%, 64%, 56%, and 44% at 1, 2, 3, and 5 years after surgery, respectively. There were no significant differences in major postoperative complications, and early and late mortality between patients with mild and advanced cirrhosis. Multivariate logistic regression showed preoperative serum bilirubin, the EuroSCORE and coronary artery bypass grafting (CABG) were associated with early and late mortality; however, Child class and MELD score were not. Cox regression analysis identified male gender (HR = 0.319; P = 0.009), preoperative serum bilirubin (HR = 1.244; P = 0.044), the EuroSCORE (HR = 1.415; P = 0.001), and CABG (HR = 3.344; P = 0.01) as independent risk factors for overall mortality.

CONCLUSION: Advanced liver cirrhosis should not preclude patients from cardiac surgery. Preoperative serum bilirubin, the EuroSCORE, and CABG are major predictors of early and late mortality.

Blood stream infection in patients undergoing systematic off-pump coronary artery bypass: incidence, risk factors, outcome, and associated pathogens

BACKGROUND

Blood stream infection (BSI) is a major cause of mortality and morbidity for patients undergoing cardiac surgery. However, information is lacking about patients undergoing off-pump coronary artery bypass (OPCAB). The purpose of this study was to assess the incidence, risk factors, outcome and associated pathogens of BSI after OPCAB.

METHODS

One thousand ten consecutive patients undergoing OPCAB between 2001 and 2012 were included in a retrospective case-control study. A propensity-matched control was used for risk factor analysis.

RESULTS

Of the 1,010 patients, 26 patients (2.6%) had 32 episodes of BSI after surgery, which occurred at a median of 14 d after surgery. Gram-negative bacilli and gram-positive cocci were distributed equally. Methicillin-resistant Staphylococcus aureus was the pathogen identified most frequently, and the most common source of infection was a surgical site. The hospital mortality rate was 54%. By univariable analysis, diabetes mellitus, pre-operative renal impairment, pre-operative low hemoglobin, pre-operative endotracheal intubation, dialysis before or after surgery, cardiogenic shock, left ventricular ejection fraction of less than 40%, non-elective surgery, low number of distal anastomoses, atrial fibrillation after surgery, and re-operation for bleeding were significant risk factors. By multivariable analysis, the independent risk factors were left ventricular ejection fraction of less than 40%, low number of distal anastomoses, atrial fibrillation after surgery, and dialysis after surgery.

CONCLUSIONS

Blood stream infections remained a common complication after OPCAB, and the mortality was high. Gram-negative bacilli and gram-positive cocci were distributed equally. Methicillin-resistant S. aureus was the pathogen identified most frequently. Preventive tactics should target likely pathogens and high-risk patients undergoing OPCAB.

Care bundle to prevent methicillin-resistant Staphylococcus aureus sternal wound infection after off-pump coronary artery bypass

Methicillin-resistant Staphylococcus aureus (MRSA) sternal wound infection (SWI) after cardiac surgery is endemic in our hospital. An infection control care bundle with preoperative chlorhexidine showering and povidone iodine paint before bathing was introduced in 2006. From 2001 to 2012, 23 (2.3%) of 1,010 patients undergoing off-pump coronary artery bypass had SWIs. SWI significantly decreased after 2006 (1.4% vs 3.4%, respectively; P = .03). Care bundle was more protective against MRSA infection (2.3% vs 0.5%, respectively; P = .021). SWI remained a common complication after off-pump coronary artery bypass. MRSA infection was most common, and the mortality was high. Care bundle can effectively decrease the incidence of SWI, especially infection caused by MRSA.

Malignant ventricular arrhythmias after off-pump coronary artery bypass

BACKGROUND/PURPOSE

Sustained ventricular tachycardia and ventricular fibrillation (VT/VF) are rare complications after coronary surgery. Off-pump coronary artery bypass (OPCAB) was developed to decrease postoperative complications. No studies to date have specifically addressed VT/VF after OPCAB. We sought to assess the incidence, risk factors, and outcome of VT/VF after OPCAB.

METHODS

The study included a retrospective review of 1010 patients undergoing OPCAB between 2000 and 2012. Data were compared between the VT/VF patients and control patients who were the first cases of OPCAB in each month during the study period and did not have VT/VF.

RESULTS

Twenty-three patients (2.3%) developed VT/VF after OPCAB. The hospital mortality rate was 17.4%. In univariate analysis, the risk factors for VT/VF were old age, rapid heart rate, prolonged corrected QT interval, severe congestive heart failure, poor left ventricular ejection fraction, large left ventricular end-diastolic diameter, chronic kidney disease, preoperative dialysis, low blood hemoglobin level, preoperative intubation, recent myocardial infarction, high European System for Cardiac Operative Risk Evaluation, urgent/emergent operation, use of intra-aortic balloon pump, conversion to on-pump beating heart, postoperative dialysis, and no use of beta-blockers after operation. Multivariate analysis identified preoperative corrected QT interval > 426 milliseconds [odds ratio (OR) = 4.501; 95% confidence interval (CI) = 1.153-17.570] and estimated glomerular filtration rate < 30 mL/minute/1.73 m(2) (OR = 4.876; 95% CI = 1.112-21.374) as independent risk factors.

CONCLUSION

Postoperative VT/VF was rare after OPCAB but was associated with high mortality. Prolonged corrected QT interval and chronic kidney disease were independent risk factors. Recognition of these risk factors, proper prevention, and early intervention may improve survival.

Comparison the prognostic value of galectin-3 and serum markers of cardiac extracellular matrix turnover in patients with chronic systolic heart failure

BACKGROUND

Galectin-3 (Gal-3) shows the ability of survival prediction in heart failure (HF) patients. However, Gal-3 is strongly associated with serum markers of cardiac extracellular matrix (ECM) turnover. The aim of this study is to compare the impact of Gal-3 and serum markers of cardiac ECM turnover on prognostic prediction of chronic systolic HF patients.

METHODS

Serum Gal-3, brain natriuretic peptide (BNP), extracellular matrix including type I and III aminoterminal propeptide of procollagen (PINP and PIIINP), matrix metalloproteinase-2, 9 (MMP-2, 9), and tissue inhibitor of metalloproteinase-1 (TIMP-1) were analyzed. Cox regression analysis was used for survival analysis.

RESULTS

A total of 105 (81 male) patients were enrolled. During 980±346 days follow-up, 17 patients died and 36 episodes of HF admission happened. Mortality of these patients was significantly associated with the log PIIINP (β= 15.380; P=0.042), log TIMP-1(β= 44.530; P=0.003), log MMP-2 (β= 554.336; P<0.001), log BNP (β= 28.273; P=0.034). Log Gal-3 (β= 7.484; P=0.066) is borderline associated with mortality. Mortality or first HF admission of these patients was significantly associated with the log TIMP-1(β= 16.496; P=0.006), log MMP-2 (β= 221.864; P<0.001), log BNP (β= 5.999; P=0.034). Log Gal-3 (β= 4.486; P=0.095) only showed borderline significance. In several models adjusting clinical parameters, log MMP-2 was significantly associated with clinical outcome. In contrast, log Gal-3 was not.

CONCLUSION

The prognostic strength of MMP-2 to clinical outcome prediction in HF patients is stronger than Gal-3.

In vivo metabolic imaging of insulin with multiphoton fluorescence of human insulin-Au nanodots

Functional human insulin-Au nanodots (NDs) are synthesized for the in vivo imaging of insulin metabolism. Benefiting from its efficient red to near infrared fluorescence, deep tissue subcellular uptake of insulin-Au NDs can be clearly resolved through a least-invasive harmonic generation and two-photon fluorescence (TPF) microscope. In vivo investigations on mice ear and ex vivo assays on human fat tissues conclude that cells with rich insulin receptors have higher uptake of administrated insulin. Interestingly, the insulin-Au NDs can even permeate into lipid droplets (LDs) of adipocytes. Using this newly discovered metabolic phenomenon of insulin, it is found that enlarged adipocytes in type II diabetes mice have higher adjacent/LD concentration contrast with small-sized ones in wild type mice. For human clinical samples, the epicardial adipocytes of patients with diabetes and coronary artery disease (CAD) also show elevated adjacent/LD concentration contrast. As a result, human insulin-Au nanodots provide a new approach to explore subcellular insulin metabolism in model animals or patients with metabolic or cardiovascular diseases.

Virtual optical biopsy of human adipocytes with third harmonic generation microscopy

Using the sectioning capability of third harmonic generation (THG) microscopy, we assessed the morphologic features of human adipocytes directly without fixation and labeling. At the plane of the largest cross-sectional area, both area-equivalent circular diameters (AECD) and perimeters of adipocytes were measured, and their statistical distributions were examined. We found, in patients with no cardiovascular risk factors, the average AECD of epicardial adipocytes were 70-90 μm with 11-17 μm standard deviations. In contrast, for patients with coronary artery disease, amounts of small-sized (AECD <40 µm) epicardial adipocytes were observed and the corresponding standard deviations of AECD were increased to 20-29 μm. Our results indicate that the THG tomography platform can be used to explore the histopathological features of adipocytes in clinical scenarios based on its superior resolution for virtual optical biopsy.

Prognostic significance of adipocytokines in systolic heart failure patients

OBJECTIVES

The goal of this study was designed to assess prognostic values of simultaneous measurement of adipocytokines in systolic heart failure (HF) patients.

METHODS

Patients with HF manifestations and left ventricular ejection fraction (LVEF) ≤ 50% were selected in this study. Gender, age, medications and serum biochemical data were recorded upon admissions. Adipocytokines including adiponectin, leptin, resistin, visfatin and retinol binding protein-4 were measured.

RESULTS

A total of 108 (83 males and 25 females) patients were enroled. The age was 62±15 years and mean LVEF was 35%. Twenty patients died during 776±323 days follow-up. In univariate analysis, mortality was found to be associated with the log-transformed values of serum resistin (β=5·616, P=0·04), log-transformed values of serum adiponectin (β=4·377, P=0·038), age (β=1·071, P<0·001), NTHA functional status (β=3·752, P=0·001) and body mass index (β=0·858, P=0·012). Patients with higher level of serum resistin were associated with higher mortality (P=0·012). In multivariate analysis, mortality is associated with log-transformed values of serum resistin (β=3·666, P=0·045), age (β=1·044, P=0·017) and NTHA functional status (β=2·541, P=0·025).

CONCLUSIONS

Serum resistin level was associated with higher mortality in systolic HF patients even after adjusting clinical parameters. Resistin may be an informative risk marker for systolic HF patients.

Incidence, risk factor, and prognosis of end-stage renal disease after heart transplantation in Chinese recipients

BACKGROUND/PURPOSE

End-stage renal disease (ESRD) is an important complication arising after heart transplantation. At least 3-10% of recipients reach ESRD within 10 years after transplant. The incidence of ESRD in Chinese recipients has not been reported. Here we sought to assess the incidence, prognosis, and risk factors for ESRD in Chinese recipients.

METHODS

We conducted a retrospective analysis of 248 heart recipients who survived >1 year from 1998 through 2007. ESRD was defined as the requirement of maintenance dialysis.

RESULTS

Renal dysfunction was present in 20 patients (8%) prior to transplant. With a follow-up duration of 5.8 ± 3.9 years, 30 patients developed ESRD. The cumulative incidence of ESRD after heart transplantation was 2.1% ± 0.9%, 6.5% ± 1.8%, 16.8% ± 3.3%, and 36.5% ± 9.5% at 2, 5, 10, and 15 years after transplant, respectively. Median onset of ESRD was 6.9 years after transplant. Actuarial survival after dialysis was 74.8% ± 8.3%, 66.6% ± 9.2%, and 43.6% ± 12.6% at 1, 2, and 5 years, respectively. Independent risk factors for ESRD included pretransplant serum creatinine (hazard ratio, 1.84; p = 0.001), presence of diabetes prior to transplant (hazard ratio, 2.51; p = 0.017), and old age at transplant (hazard ratio, 1.05; p = 0.008).

CONCLUSION

There was a high incidence of ESRD in Chinese heart recipients. Patients with ESRD had poor prognosis after dialysis.

Autologous mesenchymal stem cells prevent transplant arteriosclerosis by enhancing local expression of interleukin-10, interferon-γ, and indoleamine 2,3-dioxygenase

Transplant arteriosclerosis (TA) remains the major limitation of long-term graft survival in heart transplantation despite the advances in immunosuppressants. Mesenchymal stem cells (MSCs) have been demonstrated to suppress allogeneic immune responses by numerous in vitro studies. However, the immunomodulatory effects of MSCs in vivo are controversial and the underlying molecular mechanisms are not conclusive. In this study, we investigated the therapeutic potential of autologous bone marrow-derived MSCs on TA in a porcine model of femoral artery transplantation. MSCs or saline were injected into the soft tissue surrounding the arterial grafts immediately postanastomosis. Four weeks after transplantation, neointimal formation increased significantly in untreated allografts compared with the MSC-treated grafts as assessed by intravascular ultrasound (maximum luminal area stenosis: 40 ± 12% vs. 18 ± 6%, p < 0.001). Grafts harvested at 4 weeks showed dense perivascular lymphocyte infiltration accompanied by significant intimal hyperplasia in the untreated but not in the MSC-treated allografts. Serial angiographic examination showed that all of the untreated allografts became occluded at the 8th week whereas the majority of the MSC-treated grafts remained patent at the 12th week posttransplantation (n = 12 each group, p < 0.001). Quantitative PCR analysis revealed that Foxp3 expression was comparable between the untreated and the MSC-treated groups. However, expression of interleukin-10 (IL-10), interferon-γ (IFN-γ), and indoleamine 2,3-dioxygenase (IDO) was increased significantly in the MSC-treated allografts compared with that in the allograft controls (p = 0.021 for IL-10, p = 0.003 for IFN-γ, and p = 0.008 for IDO). In conclusion, local delivery of autologous MSCs alleviates TA by inducing allograft tolerance via enhanced expression of IL-10, IFN-γ, and IDO but not Foxp3-positive cells in the vessel wall. These results suggest that MSCs induce immune tolerance by activating the type 1 regulatory T-like cells.

Platelets enhance biofilm formation and resistance of endocarditis-inducing streptococci on the injured heart valve

Infective endocarditis is a typical biofilm-associated infectious disease frequently caused by commensal streptococci, but the contribution of host factors in biofilm formation is unclear. We found that platelets are essential for in vitro biofilm formation by Streptococcus mutans or Streptococcus gordonii grown in human plasma. The biofilms were composed of bacterial floes embedded with platelet aggregates in layers, and a similar architecture was also detected in situ on the injured valves of a rat model of experimental endocarditis. Similar to planktonic cells, the streptococci in biofilms were also able to induce platelet aggregation, which facilitates multilayer biofilm formation. Entrapping of platelets directly enhances the resistance of streptococcal biofilms to clindamycin. Prophylactic antibiotics or aspirin can reduce but not prevent or abolish biofilm formation on injured heart valves. Therefore, the platelet is a host factor for commensal streptococci in the circulation to consolidate biofilm formation and protect bacteria against antibiotics.