Evaluation of perivascular fat attenuation with coronary CT angiography in cardiac transplantation patients: an imaging biomarker candidate for prediction of cardiac mortality and re-transplantation.

OBJECTIVES: In cardiac transplant recipients, non-invasive allograft surveillance for identifying patients at risk for graft failure remains challenging. The fat attenuation index (FAI) of the perivascular adipose tissue in coronary computed tomography angiography (CCTA) predicts outcomes in coronary artery disease in non-transplanted hearts; however, it has not been evaluated in cardiac transplant patients. METHODS: We followed 39 cardiac transplant patients with two or more CCTAs obtained between 2010 and 2021. We performed FAI measurements around the proximal 4 cm segments of the left anterior descending (LAD), right coronary artery (RCA), and left circumflex artery (LCx) using a previously validated methodology. The FAI was analyzed at a threshold of - 30 to - 190 Hounsfield units. RESULTS: FAI measurements were completed in 113 CCTAs, obtained on two same-vendor CT models. Within each CCTA, the FAI values between coronary vessels were strongly correlated (RCA and LAD R = 0.67 (p < 0.0001), RCA and LCx R = 0.58 (p < 0.0001), LAD and LCx R = 0.67 (p < 0.0001)). The FAIs of each coronary vessel between the patient's first and last CCTA completed at 120 kV were also correlated (RCA R = 0.73 (p < 0.0001), LAD R = 0.81 (p < 0.0001), LCx R = 0.55 (p = 0.0069). Finally, a high mean FAI value of all three coronary vessels at baseline (mean ≥ - 71 HU) was predictive of cardiac mortality or re-transplantation, however, not predictive of all cause-mortality. CONCLUSION: High baseline FAI values may identify a higher-risk cardiac transplant population; thus, FAI may support the implementation of CCTA in post-transplant surveillance. KEY POINT: • Perivascular fat attenuation measured with coronary CT is feasible in cardiac transplant patients and may predict cardiac mortality or need for re-transplantation.

Transplanted stents: a case report.

BACKGROUND: An optimal donor work-up to exclude preexisting conditions is recommended, but urgency and technical equipment in donor centers must be considered. We report a case of two coronary stents present in the donor heart and the related long-term outcome. CASE PRESENTATION: A 59-year-old European male patient suffering from dilated cardiomyopathy with severely reduced left ventricular function and presenting with NYHA III underwent cardiac transplantation in 2004. At the one-year follow-up, during routine cardiac catheterization, two stents were found, one in the right coronary artery and one in the circumflex artery, in the patient's transplanted heart. As no stent implantation was performed since transplantation, these were present prior to transplantation and had been transplanted without causing clinical signs. One of the stents showed in-stent restenosis, and the patient received an additional stent 7 years after transplantation. The other stent still showed a good result, and no further intervention has been required so far. The patient is currently in good clinical condition. CONCLUSION: This is the first case report of favorable long-term stented coronary arteries prior to transplantation. This case highlights the importance of the donor work-up and meticulous palpation of the coronary arteries during donor evaluation.

Assessment of sympathetic reinnervation after cardiac transplantation using hybrid cardiac PET/MRI: A pilot study.

BACKGROUND: Sympathetic reinnervation after heart transplantation (HTX) is a known phenomenon, which has an impact on patient heart rate variability and exercise capacity. The impact of reinnervation on myocardial structure has not been evaluated yet. PROPOSE: To evaluate the feasibility of simultaneous imaging of cardiac reinnervation and cardiac structure using a hybrid PET/MRI system. STUDY TYPE: Prospective / pilot study. SUBJECTS: Ten patients, 4-21 years after cardiac transplantation. FIELD STRENGTH/SEQUENCE: 3 T hybrid PET/MRI system. Cine SSFP, T1 mapping (modified Look-Locker inversion recovery sequence) pre/postcontrast as well as dynamic [11 C]meta-hydroxyephedrine ([11 C]mHED) PET. ASSESSMENT: All MRI and PET parameters were evaluated by experienced readers using dedicated postprocessing software packages for cardiac MRI and PET. For all parameters a 16-segment model for the left ventricle was applied. STATISTICAL TESTS: Mann-Whitney U-test; Spearman correlations. RESULTS: Thirty-six of 160 myocardial segments showed evidence of reinnervation by PET. On a segment-based analysis, mean native T1 relaxation times were nonsignificantly altered in segments with evidence of reinnervation (1305 ± 151 msec vs. 1270 ± 112 msec; P = 0.1), whereas mean extracellular volume (ECV) was significantly higher in segments with evidence of reinnervation (35.8 ± 11% vs. 30.9 ± 7%; P = 0.019). There were no significant differences in wall motion (WM) and wall thickening (WT) between segments with or without reinnervation (mean WM: 7.6 ± 4 mm vs. group B: 9.3 ± 7 mm [P = 0.13]; WT: 79 ± 63% vs. 94 ± 74% [P = 0.27]) under resting conditions. DATA CONCLUSION: The assessment of cardiac reinnervation using a hybrid PET/MRI system is feasible. Segments with evidence of reinnervation by PET showed nonsignificantly higher T1 relaxation times and a significantly higher ECV, suggesting a higher percentage of diffuse fibrosis in these segments, without impairment of rest WM and WT. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2019;50:1326-1335.

Diminished impact of cytomegalovirus infection on graft vasculopathy development in the antiviral prophylaxis era - a retrospective study.

Evidence concerning an association between cytomegalovirus (CMV) infection and accelerated cardiac allograft vasculopathy (CAV) is inconclusive. Data were analyzed retrospectively from 297 consecutive heart transplants between 1.1.2002 and 31.12.2012. Patients ≤18 years of age, survival, and follow-up ≤1-year post-transplant and patients with early CAV were excluded. CMV-infection was diagnosed and monitored closely in the first year. CAV was diagnosed by coronary angiography via left heart catheterization, and results were categorized according to the International Society of Heart and Lung Transplantation (ISHLT) scoring system. Risk factors for CAV were tested in a multivariable model. Median follow-up was 7.5 years (IQR: 5.6-10.3). CMV infection in the first year after transplantation occurred in 26% of patients (n = 78), CMV disease in 5% (n = 15). CAV ≥1 ISHLT was detected in 36% (n = 108). Incidence of CAV >1 ISHLT and severity of CAV increased over time. No statistically significant association between CMV infection and disease within the first year and risk of CAV after 1-year post-HTx was detected in the univariate (P = 0.16) and multivariable [hazard ratio (HR), 1.36; confidence interval (CI), 0.89-2.07; P = 0.16] Cox regression. In the multivariable Cox regression, donor age (HR, 1.04; 95% CI, 1.02-1.06; P < 0.01) and acute cellular rejection (ACR) ≥2R in the first year after HTx (HR, 1.77; 95% CI, 1.06-2.95; P = 0.03) were independent risk factors for CAV development. In our cohort, CMV infection and disease in the first year after transplantation did not significantly influence the risk of CAV in the long-term follow-up.

First-in-Man Study of a Novel, Balloon-Adjustable Mitral Annuloplasty Ring.

Objectives: Mitral valve repair is the current standard approach for mitral valve regurgitation. However, patients suffering from functional mitral regurgitation have a significant risk of recurrent regurgitation. Adjustable mitral rings may provide a solution for this adverse event. Methods: A single-center, first-in-man clinical study was performed on patients suffering from mitral valve regurgitation. Patients were implanted with the study ring and followed for six months. A balloon catheter can be inserted into the study ring frame at any time after implantation and inflated independently in the areas P1, P2, or P3, which reduces the anterior-posterior diameter. Results: Five patients (75.4 ± 6.1 years; EuroSCORE II 2.1 ± 0.9%; three female) were successfully implanted. Mechanisms of mitral regurgitation were prolapse of the P2-segment in three patients and annular dilation in two patients. Surgical implantation according to the protocol was feasible and is described herein. Median cardiopulmonary bypass time and cross clamp time were 105 (118; 195) and 94 (90; 151) min, respectively. The median intensive care unit stay was 2 (2; 3) days. No perioperative, 30-day, or 6-month mortality was observed, and the repair was stable without residual or recurrent regurgitation ≥ grade 2. All patients reached the primary endpoint without device-related morbidity. Conclusions: Successful implantation was completed in five patients without device-related adverse events. Ring implantation was safe and feasible for all patients. The opportunity of post-implant adjustment to improve leaflet coaptation is a promising new therapeutic strategy that is assessed in a phase II study.

Absolute Lymphocyte Count as a Marker for Cytomegalovirus Infection After Heart Transplantation.

BACKGROUND: Previous studies indicate an association between reduced absolute lymphocyte count (ALC) and cytomegalovirus (CMV) infection after solid organ transplantation and have therefore highlighted the potential of ALC as a simple tool to predict CMV infection in transplant patients. This study aimed to examine the utility of ALC as a valuable marker for CMV infection in heart transplant patients. METHODS: Clinical information and ALC data of all adult patients who received orthotopic heart transplantation at the Medical University of Vienna between January 2004 and May 2019 were collected. We performed a multivariable Cox regression model that incorporates repeated measurements of ALC as a time-varying continuous factor in 2 ways, first as continuous logarithmic factor considering a 50% decrease of ALC levels and second as binary factor using a threshold of 610 cells/µL. RESULTS: One hundred fifty-eight (39%) patients developed CMV infection over the course of 2 y. Patients with lymphopenia were shown to be at higher risk of developing CMV infection both in the continuous approach (HR [per 50% reduction] 1.29; confidence interval [CI], 1.09-1.53; P = 0.003) and the binary approach with a cutoff of 610 cells/µL (HR 1.74; CI, 1.20-2.51; P = 0.003). CONCLUSIONS: This study demonstrated a strong association between reduced ALC and the development of CMV infection after heart transplantation. ALC value monitoring could provide an additional tool to assess individualized CMV risk after solid organ transplantation.

The Ross procedure in adult patients: a single-centre analysis of long-term results up to 28 years.

OBJECTIVES: This study aimed to provide an in-depth insight into our single-centre experience with the Ross procedure. METHODS: All adults who underwent the Ross procedure between 1991 and 2014 were included. Based on the total number of Ross procedures performed by each surgeon at our centre during this 24-year period, surgeon volume was classified as low (<25 procedures), intermediate (25-44 procedures) and high (≥45 procedures). Survival, complications and reinterventions were evaluated. A single cardiologist assessed the pulmonary autograft's function and the neoaortic root diameter by echocardiography. RESULTS: The outcomes of 224 patients {176 men, 48 women; mean age 37.2 [standard deviation (SD) 10.0] years} were analysed. Patients operated on by a low-volume surgeon had 7.22 times higher odds (P < 0.001) for a serious adverse event during the intraoperative or early postoperative course than patients operated on by a high-volume surgeon. Early mortality was 1.8%. Overall survival was 87.3% at 20 years. Compared with the demographically matched general population, the patients' survival was significantly lower (P = 0.002). The cumulative incidence of autograft and right ventricular outflow tract conduit reintervention was 21.5% and 5.9% at 20 years, respectively. Patients with preoperative aortic regurgitation had 6.25 times the subdistribution hazard of autograft reintervention (Bonferroni-adjusted P = 0.042) and a higher neoaortic root z-score [1.37 (SD 2.04) vs 0.17 (SD 1.81), P = 0.004] than patients with aortic stenosis. In patients with preoperative aortic regurgitation, autograft wrapping (remnant aortic wall and/or Vicryl® mesh) was associated with a 74% reduction in the subdistribution hazard of autograft reintervention (Bonferroni-adjusted P = 0.002) and with a reduced incidence of neoaortic root dilatation (P = 0.037). CONCLUSIONS: The Ross procedure performed by a specialized surgeon provides very satisfying long-term results. The higher risk of autograft reintervention in preoperative aortic regurgitation may be counteracted by supporting the autograft.

Long-term performance of pulmonary homografts after the Ross procedure: experience up to 25 years.

OBJECTIVES: The aim of this study was to evaluate the long-term durability and function of pulmonary homografts used for right ventricular outflow tract reconstruction in the Ross procedure at a single centre with 25 years of experience. METHODS: The study included 274 patients (212 male patients and 62 female patients; age 3-59 years), who underwent the Ross procedure between 1991 and 2014. Homograft-related complications and reinterventions were assessed. Homograft haemodynamic function was determined using transthoracic echocardiography undertaken by a single cardiologist. RESULTS: The all-cause 30-day mortality was 1.1% (3 patients), and there were 17 late deaths. One death was associated with a homograft-related complication. During the observation period (median 13.3 years; 3327.5 cumulative patient-years), 21 patients (7.7%) underwent at least 1 right ventricular outflow tract reintervention. Freedom from homograft reintervention was 95.6%, 90.4% and 87.5% at 10, 15 and 20 years, respectively. Paediatric patients had a significant lower rate of freedom from reintervention (log-rank P < 0.001). Remarkably, all patients who underwent reintervention were male (log-rank P = 0.009). Female patients received homografts with a significantly higher (P < 0.001) indexed diameter than male patients, which might be causally related to absent reinterventions in women. The linearized rate of homograft endocarditis was 0.2% per patient-year. At the latest echocardiography (median follow-up time 14.7 years; 164 patients), the peak transhomograft pressure gradient was <40 mmHg in 150 patients (91.5%), and homograft incompetence was none or trivial in 111 patients (67.7%), mild in 49 patients (29.9%) and moderate in 3 patients (1.8%). In 1 patient (0.6%), it was not possible to determine the degree of incompetence. Younger patient age (P < 0.001), a smaller homograft diameter (P = 0.014) and an increase in the body surface area during the follow-up time (P = 0.006) were significantly correlated with a higher peak transhomograft pressure gradient. Men had a significantly higher peak transhomograft pressure gradient than women (P = 0.018). CONCLUSIONS: Pulmonary homografts provide very satisfying long-term results after the Ross procedure. Differences in long-term performance are related to undersizing and young age.

Intermediate-term outcome of 500 consecutive rapid-deployment surgical aortic valve procedures†.

OBJECTIVES: The Edwards INTUITY Valve System is a balloon-expandable bioprosthesis, inspired from the Edwards Magna valve and transcatheter technology, with a subvalvular stent frame to enable rapid deployment. We report a single-centre experience of aortic valve replacement with this novel bioprosthesis. METHODS: Five hundred consecutive patients, of whom 45.6% were female with a mean age of 73.5 [standard deviation (SD) 7.9 years], with severe aortic stenosis who received a rapid deployment aortic valve between May 2010 and July 2017 were included in a prospective and ongoing database. The median follow-up time was 12 months, and the total accumulated follow-up time was 818 patient years. Preoperative characteristics, operative parameters, survival, valve-related adverse events and valve haemodynamics were assessed. RESULTS: Thirty-day mortality was 0.8% (4/500), and overall survival at 1, 3 and 5 years was 94%, 89% and 81%, respectively. A minimally invasive surgical approach was chosen in 236 patients (47%), of which 122 (24%) were operated on through an anterior right thoracotomy. Cross-clamp and cardiopulmonary bypass times for isolated aortic valve replacement were 53 (SD 17) and 89 (SD 29) min for full sternotomy as well as 75 (SD 23) and 110 (SD 31) min for minimally invasive surgery approaches (P < 0.001). Mean gradients at discharge, 1, 3 and 5 years were 13 (SD 5), 11 (SD 4), 12 (SD 5) and 11 (SD 3) mmHg, respectively. New pacemaker implantation was necessary in 8.6% of patients. A single case (0.2%) of structural degeneration was registered after 6 years. Valve explantation for non-structural dysfunction or endocarditis occurred in 9 patients (1.8%). CONCLUSIONS: This rapid deployment aortic valve has shown excellent results concerning haemodynamic performance, durability and safety. Implantation requires specific training, and the rate of pacemaker implantation remains a matter of concern. This novel valve also facilitates minimally invasive approaches and may be beneficial in complex combined procedures.

Cardiac Surgery After Heart Transplantation: Elective Operation or Last Exit Strategy?

BACKGROUND: Because of improved long-term survival after heart transplantation (HTx), late graft pathologies such as valvular disease or cardiac allograft vasculopathy (CAV) might need surgical intervention to enhance longer survival and ensure quality of life. To this date, there exist no guidelines for indication of cardiac surgery other than retransplantation after HTx. METHODS: In this retrospective, single-center study, we evaluated patients who underwent cardiac surgery after HTx at our institution. RESULTS: Between March 1984 and October 2016, 17 (1.16%) of 1466 HTx patients underwent cardiac surgery other than retransplantation after HTx. Indication were valvular disease (n = 7), CAV (n = 6), and other (n = 4). Of these, 29.4% (n = 5) were emergency procedures and 70.6% were elective cases. Median age at time of surgery was 61 years (interquartile range, 52-66 years); 82.4% (n = 14) were male. Median time to surgery after HTx was 9.3 years (2.7-11.1 years). In-hospital, mortality was 11.8% (n = 2); later need of retransplantation was 11.8% (n = 2) due to progressing CAV 3 to 9 months after surgery. One-year survival was 82.35%; overall survival was 47.1% (n = 8) with a median follow-up of 1477 days (416-2135 days). Overall survival after emergency procedures was 209 days (36-1119.5 days) whereas, for elective procedures, it was 1583.5 days (901.5-4319 days). CONCLUSIONS: Incidence of cardiac surgery after HTx in our cohort was low (1.16%) compared with that of other studies. In elective cases, long-term survival was good.