Genetic and Functional Profiling of CD16-Dependent Natural Killer Activation Identifies Patients at Higher Risk of Cardiac Allograft Vasculopathy.

BACKGROUND: Cardiac transplantation is an effective therapy for end-stage heart failure. Because cardiac allograft vasculopathy (CAV) is the major cause of late mortality after heart transplant (HT), there is a need to identify markers that reflect inflammatory or cytotoxic immune mechanisms contributing to its onset. Noninvasive and early stratification of patients at risk remains a challenge for adapting individualized therapy. The CD16 (Fc-gamma receptor 3A [FCGR3A]) receptor was recently identified as a major determinant of antibody-mediated natural killer (NK) cell activation in HT biopsies; however, little is known about the role of CD16 in promoting allograft vasculopathy. This study aimed to investigate whether markers that reflect CD16-dependent circulating NK cell activation may identify patients at higher risk of developing CAV after HT. METHODS: Blood samples were collected from 103 patients undergoing routine coronarography angiography for CAV diagnosis (median 5 years since HT). Genomic and phenotypic analyses of FCGR3A/CD16 Fc-receptor profiles were compared in CAV-positive (n=52) and CAV-free patients (n=51). The levels of CD16 expression and rituximab-dependent cell cytotoxic activity of peripheral NK cells in HT recipients were evaluated using a noninvasive NK-cellular humoral activation test. RESULTS: Enhanced levels of CD16 expression and antibody-dependent NK cell cytotoxic function of HT recipients were associated with the FCGR3A-VV genotype. The frequency of the FCGR3A-VV genotype was significantly higher in the CAV+ group (odds ratio, 3.9; P=0.0317) than in the CAV- group. The FCGR3A-VV genotype was identified as an independent marker correlated with the presence of CAV at the time of coronary angiography by using multivariate logistic regression models. The FCGR3A-VV genotype was also identified as a baseline-independent predictor of CAV risk (odds ratio, 4.7; P=0.023). CONCLUSIONS: This study unravels a prominent role for the CD16-dependent NK cell activation pathway in the complex array of factors that favor the progression of transplant arteriosclerosis. It highlights the clinical potential of a noninvasive evaluation of FCGR3A/CD16 in the early stratification of CAV risk. The recognition of CD16 as a major checkpoint that controls immune surveillance may promote the design of individualized NK cell-targeted therapies to limit vascular damage in highly responsive sensitized patients. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01569334.

Prognostic Value of 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in Infective Endocarditis.

BACKGROUND: 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) is commonly used for the diagnosis of infective endocarditis (IE), but its prognostic value remains unknown. OBJECTIVES: This study sought to assess the prognostic value of 18F-FDG PET/CT in prosthetic valve endocarditis (PVE) and native valve endocarditis (NVE). METHODS: This study prospectively included 173 consecutive patients (109 PVE and 64 NVE) with definite left-sided IE who had an 18F-FDG PET/CT and were followed-up for 1 year. The primary endpoint was a composite of major cardiac events: death, recurrence of IE, acute cardiac failure, nonscheduled hospitalization for cardiovascular indication, and new embolic event. RESULTS: 18F-FDG PET/CT was positive in 100 (58%) patients, 83% (n = 90 of 109) in the PVE, and 16% (n = 10 of 64) in the NVE group. At a mean follow-up of 225 days (interquartile range: 199 to 251 days), the primary endpoint occurred in 94 (54%) patients: 63 (58%) in the PVE group and 31 (48%) in the NVE group. In the PVE group, positive 18F-FDG PET/CT was significantly associated with a higher rate of primary endpoint (hazard ratio [HR]: 2.7; 95% confidence interval [CI]: 1.1 to 6.7; p = 0.04). Moderate to intense 18F-FDG valvular uptake was also associated with worse outcome (HR: 2.3; 95% CI: 1.3 to 4.5; p = 0.03) and to new embolic events in PVE (HR: 7.5; 95% CI: 1.24 to 45.2; p = 0.03) and in NVE (HR: 8.8; 95% CI: 1.1 to 69.5; p = 0.02). In the NVE group, 18F-FDG PET/CT was not associated with occurrence of the primary endpoint CONCLUSIONS: In addition to its good diagnostic performance, 18F-FDG PET/CT is predictive of major cardiac events in PVE and new embolic events within the first year following IE.

Pulmonary cyst embolism: a rare complication of hydatidosis.

Hydatid disease is an endemic parasitosis that results from the ingestion of echinococcosis tapeworm eggs. This condition leads to the formation of cysts, mainly in the liver and lungs, and causes life-threatening complications. Cardiac involvement represents only 0.5-2% of the localizations. We report a rare case of a pulmonary cyst embolism that required emergency surgical intervention.

Patient-prosthesis mismatch in new generation trans-catheter heart valves: a propensity score analysis.

Aims: When compared with the former Sapien XT (XT-THV), the Sapien 3 trans-catheter heart valve (S3-THV) embeds an outer annular sealing cuff to prevent para-valvular regurgitation (PVR). The consequences of this new feature on valve haemodynamics have never been evaluated. We aimed to compare both types of prostheses regarding patient-prosthesis mismatch (PPM). Methods and results: Patients who underwent a TAVR for aortic stenosis were retrospectively included. Regression adjustment for the propensity score was used to compare 50 XT-THV patients with 71 S3-THV. At the 1-month follow-up, the mean indexed effective orifice area (iEOA) was 1.12 ± 0.34 cm2/m2 with XT-THV and 0.96 ± 0.27 cm2/m2 with S3-THV. The mean gradient was 11 ± 5 mmHg and 13 ± 5 mmHg, respectively. Nine patients had moderate PPM, and two exhibited severe PPM with XT-THV. Nineteen patients had moderate PPM, and seven demonstrated severe PPM with S3-THV. There was a five-fold increased risk of PPM with S3-THV (OR = 4.98; [1.38-20.94], P = 0.019). S3-THV decreased the iEOA by 0.21 cm2/m2 [-0.21; (-0.38 to - 0.05); P = 0.012] and increased the mean gradient by 4.95 mmHg [4.95; (2.27-7.64); P < 0.001]. The risk of PPM was increased 15.24-fold with 23 mm S3-THV [15.24; (2.92-101.52); P = 0.002] in comparison with the 23 mm XT-THV. PVR were reduced by 98% with S3-THV. Conclusion: There is an increased risk of PPM with 23mm S3-THV in comparison with 23 mm XT-THV. This may be attributable to the additional sub-annular cuff that avoids the risk of PVR. Regarding the increased vulnerability of younger patients to PPM, we provide essential information on the extension of TAVR indication to the younger population.

Rapid-deployment aortic valve replacement for severe aortic stenosis: 1-year outcomes in 150 patients.

OBJECTIVES: This study aimed to evaluate the safety and effectiveness of rapid-deployment aortic valve replacement (RDAVR) for severe aortic stenosis (AS). METHODS: All consecutive patients with severe AS who underwent RDAVR with the EDWARDS INTUITY bioprosthesis were prospectively included in a single-centre, cohort study between July 2012 and April 2015. Clinical examination and transthoracic echocardiography were performed preoperatively and at 1-month and 1-year follow-up. RESULTS: We included 150 patients: mean age 76.8 ± 6.2 years, 68.7% male and mean EuroSCORE II 3.4 ± 3.7%. Implantation was successful in all: 103 (68.7%) had isolated aortic valve replacement (AVR) and 47 (31.3%) had concomitant procedures. For isolated AVR, mean cross-clamp and cardiopulmonary bypass times were 37.6 ± 13.3 and 59.9 ± 20.4 min, respectively. Overall, the 1-year Kaplan-Meier survival rate was 97.1% (95% confidence interval 92.4-98.9%). At 1 year, stroke occurred in 5 patients (3.34%), myocardial infarction in 1 (0.69%), endocarditis in 1 (0.69%), early explantation in 1 (0.67%), pacemaker implantation in 8 (5.6%) and Grade 2 periprosthetic regurgitation in 4 (3.2%; no grade 3 of 4). There were significant decreases from baseline ( P < 0.001) in the proportion at New York Heart Association Class III/V (35.3-4.1%), mean gradient (54.9 ± 17.3 mmHg to 11.3 ± 4.8 mmHg) and mean left ventricular mass index (160.3 ± 44.8 g/m 2 to 118.5 ± 39.4 g/m 2 ). Mean indexed effective orifice area at 1 year was 1.02 ± 0.37 cm 2 /m 2 . Ten patients (6.6%) had severe patient-prosthesis mismatch. CONCLUSIONS: RDAVR for severe AS provided favourable outcomes over 1 year.

Severe right ventricular dysfunction is an independent predictor of pre- and post-transplant mortality among candidates for heart transplantation.

BACKGROUND: Heart transplantation is the gold-standard treatment for end-stage heart failure. However, the shortage of grafts has led to longer waiting times and increased mortality for candidates without priority. AIMS: To study waiting-list and post-transplant mortality, and their risk factors among patients registered for heart transplantation without initial high emergency procedure. METHODS: All patients registered on the heart transplantation waiting list (2004-2015) without initial high emergency procedure were included. Clinical, biological, echocardiographic and haemodynamic data were collected. Waiting list and 1-year post-transplant survival were analysed with a Kaplan-Meier model. RESULTS: Of 221 patients enrolled, 168 (76.0%) were men. Mean age was 50.0±12.0 years. Forty-seven patients died on the waiting list, resulting in mortality rates of 11.2±2.7% at 1 year, 31.9±5.4% at 2 years and 49.4±7.1% at 3 years. Median survival was 36.0±4.6 months. In the multivariable analysis, left ventricular ejection fraction<30% (hazard ratio [HR]: 3.76, 95% confidence interval [CI]: 1.38-10.24; P=0.010) and severe right ventricular systolic dysfunction (HR: 2.89, 95% CI: 1.41-5.92; P=0.004) were associated with increased waiting-list mortality. The post-transplant survival rate was 73.1±4.4% at 1 year. Pretransplant severe right ventricular dysfunction and age>50 years were strong predictors of death after transplantation (HR: 5.38, 95% CI: 1.38-10.24 [P=0.020] and HR: 6.16, 95% CI: 1.62-9.32 [P=0.0130], respectively). CONCLUSIONS: Mortality among candidates for heart transplantation remains high. Patients at highest risk of waiting-list mortality have to be promoted, but without compromising post-transplant outcomes. For this reason, candidates with severe right ventricular dysfunction are of concern, because, for them, transplantation is hazardous.

Expressions of adenosine A2A receptors in coronary arteries and peripheral blood mononuclear cells are correlated in coronary artery disease patients.

BACKGROUND: Altered coronary blood flow occurs in patients with coronary artery disease (CAD). Adenosine strongly impacts blood flow mostly via adenosine A2A receptor (A2AR) expressed in coronary tissues. As part of a systemic regulation of the adenosinergic system, we compared A2AR expression in situ, and on peripheral blood mononuclear cells (PBMC) in CAD patients. METHODS AND RESULTS: Aortic and coronary tissues, and PBMC were sampled in 20 CAD patients undergoing coronary artery bypass surgery and consecutively included. Controls were PBMC obtained from 15 healthy subjects. Expression and activity of A2AR were studied by Western blotting and cAMP measurement, respectively. A2AR expression on PBMC was lower in patients than in controls (0.83±0.31 vs 1.2±0.35 arbitrary units; p<0.01), and correlated with A2AR expression in coronary and aortic tissues (Pearson's r: 0.77 and 0.59, p<0.01, respectively). Basal and maximal cAMP productions following agonist stimulation of PBMC were significantly lower in patients than in controls (120±42 vs 191±65 and 360±113 vs 560±215pg/106 cells, p<0.05, respectively). In CAD patients, the increase from basal to maximal cAMP production in PBMC and aortic tissues was similar (+300% and +246%, respectively). CONCLUSION: Expression of A2AR on PBMC correlated with those measured in coronary artery and aortic tissues in CAD patients, A2AR activity of PBMC matched that observed in aorta, and A2AR expression and activity in PBMC were found reduced as compared to controls. Measuring the expression level of A2AR on PBMC represents a good tool to address in situ expression in coronary tissues of CAD patients.