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.

Open Transcatheter Mitral Valve Implantation Into the Native Mitral Valve for Inoperable "Big MAC".

Because of the growing population of older adult patients, the prevalence of severe mitral annulus calcification ("big MAC") is increasing. The surgical techniques used to treat big MACs are technically demanding; despite the technical aspect, up to one-third of patients are considered too high risk for conventional surgery but are candidates for the coulisse technique, which is a procedure that implants a transcatheter valve into a native mitral annulus. The anterior leaflet is unfolded, thus reducing the risk of obstructing the left ventricular outflow tract and for paravalvular leak and avoiding valve migration. Preoperative planning, based on a computed tomography scan, is mandatory.

Long Term Results of the Modified Bentall Procedure With Mechanical and Biological Composite Valve Grafts.

Objectives: Despite the evident shift toward biological prostheses, the optimal choice of valve remains controversial in composite valve graft (CVG) replacement. We investigated long-term morbidity and mortality after CVG implantation in an all-comer cohort with a subgroup analysis of patients aged 50-70 years stratified after valve type. Methods: A total of 507 patients underwent the Bentall procedure with either a mechanical (MCVG, n = 299) or a biological (BCVG n = 208) CVG replacement between 2000 and 2020. A single-center analysis comprising clinical and telephone follow-up was conducted to investigate late mortality and morbidity. Results: The 30-day mortality in all patients [age 56 ± 14 years, 78.1% male, EuroSCORE II 3.12 (1.7; 7.1)] was 5.9%. Patients who were electively operated on had a 30-day mortality of 1.5% (n = 5) while it remained higher in urgent/emergent procedures (n = 25, 15.4%). Survival at 10 and 15 years was 78.19 ± 2.26% and 72.6 ± 3.2%, respectively. In patients aged 50-70 years (n = 261; MCVG = 151, BCVG = 110), survival did not differ significantly between the valve groups (p = 0.419). Multivariable analysis showed no significant impact of valve type on survival (p = 0.069). A time-varying relation with survival was notable, showing a higher risk in the MCVG group in the early postoperative phase, which declined compared to the BCVG group in the course of follow-up. Conclusions: The Bentall technique presents with excellent mortality when performed electively. The type of valve prosthesis showed no statistically significant effect on mortality in patients aged 50-70 years. However, a time-varying relation showing an initially higher risk with MCVG which decreased compared to BCVG at long-term follow-up was notable. Further studies with even longer follow-up of BCVGs will clarify the ideal choice of prosthesis in this patient subset.

Bilateral or unilateral antegrade cerebral perfusion during surgery for acute type A dissection.

OBJECTIVE: The study objective was to investigate outcomes associated with the application of bilateral or unilateral antegrade cerebral perfusion during surgery for acute type A dissection. METHODS: Patients who underwent surgery for type A dissection with the application of antegrade cerebral perfusion between 2009 and 2017 at the Division of Cardiac Surgery, Medical University of Vienna were analyzed retrospectively (bilateral antegrade cerebral perfusion: n = 91, 49.5%; unilateral antegrade cerebral perfusion: n = 93, 50.5%). The primary outcome variable was overall survival. Subgroup analyses were performed in patients requiring antegrade cerebral perfusion durations of 50 minutes or more and less than 50 minutes. Secondary outcome variables were 30-day mortality, adverse outcome, permanent and temporary neurologic deficits, renal replacement therapy, prolonged ventilation, intensive care unit stay, and hospital stay. RESULTS: Multivariable Cox proportional hazards analysis demonstrated no significant association of bilateral antegrade cerebral perfusion with overall survival (hazard ratio, 0.63; 95% confidence interval, 0.34-1.14, P = .126). Propensity score modeling using the method of inverse probability of treatment weighting confirmed this result (hazard ratio, 0.73; 95% confidence interval, 0.33-1.60, P = .428). Bilateral antegrade cerebral perfusion was associated with significantly improved overall survival in patients requiring antegrade cerebral perfusion durations of 50 minutes or more (P = .017). The bilateral antegrade cerebral perfusion and unilateral antegrade cerebral perfusion groups showed comparable rates of secondary outcome variables. CONCLUSIONS: In the present study, bilateral antegrade cerebral perfusion and unilateral antegrade cerebral perfusion are associated with comparable outcomes after surgery for type A dissection. Subgroup analyses suggest that bilateral antegrade cerebral perfusion is associated with superior overall survival in patients requiring antegrade cerebral perfusion durations of 50 minutes or more. An adequately powered prospective randomized controlled trial is required to validate these results.

Concomitant Transapical Transcatheter Aortic Valve Implantation and Transapical Mitral Valve Repair With NeoChord Implantation.

One-third of the patients with severe symptomatic aortic valve stenosis (sAS) present with hemodynamic relevant mitral valve insufficiency (rMI). In patients who undergo conventional surgery, the rMI never would be left untreated; however, in cases of transcatheter aortic valve implantation (TAVI), the impact of rMI is often overlooked and left untreated. The combination of transapical TAVI (TA-TAVI) and NeoChord implantation represents a novel, promising therapeutic option for high-risk-surgery patients with sAS and rMI due to a prolapsed or flailed leaflet. This case report describes 2 patients (1 male, 1 female; mean age 82 years) who underwent TA-TAVI and concomitant NeoChord implantation at our institute. Both presented with sAS and rMI due to a prolapse of the P2 segment of the mitral valve. At first, the TA-TAVI was implanted under angio-guidance, followed by three-dimensional echo-guided implantation of the NeoChords, through the same approach, which was slightly posterior and lateral to the apex. TA-TAVI using an Edwards Sapien 3 (26 mm, n = 1 and 29 mm, n = 1) and NeoChord implantation (2 in the first and 3 in the second patient) was successful in both cases. Post-intervention discharge echo indicated no paravalvular or central insufficiency after the procedure and only a trace of mitral valve insufficiency. TA-TAVI and concomitant NeoChord implantation is a feasible and promising treatment option for high-risk patients with rMI. Despite its technical demands, in experienced hands, it is a safe procedure for those not well suited for surgical intervention.

Strong Signs for a Weak Wall in Tricuspid Aortic Valve Associated Aneurysms and a Role for Osteopontin in Bicuspid Aortic Valve Associated Aneurysms.

Central processes in the pathogenesis of TAV- (tricuspid aortic valve) and BAV- (bicuspid aortic valve) associated ascending thoracic aortic aneurysm (ATAA) development are still unknown. To gain new insights, we have collected aortic tissue and isolated smooth muscle cells of aneurysmal tissue and subjected them to in situ and in vitro analyses. We analyzed aortic tissue from 78 patients (31 controls, 28 TAV-ATAAs, and 19 BAV-ATAAs) and established 30 primary smooth muscle cell cultures. Analyses included histochemistry, immuno-, auto-fluorescence-based image analyses, and cellular analyses including smooth muscle cell contraction studies. With regard to TAV associated aneurysms, we observed a strong impairment of the vascular wall, which appears on different levels-structure and dimension of the layers (reduced media thickness, increased intima thickness, atherosclerotic changes, degeneration of aortic media, decrease of collagen, and increase of elastic fiber free area) as well as on the cellular level (accumulation of fibroblasts/myofibroblasts, and increase in the number of smooth muscle cells with a reduced alpha smooth muscle actin (α-SM actin) content per cell). The pathological changes in the aortic wall of BAV patients were much less pronounced-apart from an increased expression of osteopontin (OPN) in the vascular wall which stem from smooth muscle cells, we observed a trend towards increased calcification of the aortic wall (increase significantly associated with age). These observations provide strong evidence for different pathological processes and different disease mechanisms to occur in BAV- and TAV-associated aneurysms.

Extracellular matrix in ascending aortic aneurysms and dissections - What we learn from decellularization and scanning electron microscopy.

Pathological impairment of elastic fiber and other extracellular matrix (ECM) components are described for the aortic media of ascending thoracic aortic aneurysms (aTAA) but the exact pathological impairment of the structure and its degree still needs further investigations. To evaluate the quantity and quality of elastic fiber sheets and other ECM structures (e.g. collagen), cells were removed from different types of aneurysmal tissues (tricuspid aortic valve [TAV] associated-, bicuspid aortic valve [BAV] associated-aneurysmal tissue and acute aortic dissections [AAD]) using 2.5% sodium hydroxide (NaOH) and compared to decellularized control aortic tissue. Likewise, native tissue has been analysed. To evaluate the 2D- (histological evaluation, fluorescence- and auto-fluorescence based staining methods) and the 3D structure (scanning electron microscopic [SEM] examination) of the medial layer we first analysed for a successful decellularization. After proving for successful decellularization, we quantified the amount of elastic fiber sheets, elastin and other ECM components including collagen. Aside from clearly visible focal elastic fiber loss in TAV-aTAA tissue, decellularization resulted in reduction of elastic fiber auto-fluorescence properties, which is perhaps an indication from a disease-related qualitative impairment of elastic fibers, visible only after contact with the alkaline solution. Likewise, the loss of collagen amount in BAV-aTAA and TAV-aTAA tissue (compared to non-decellularized tissue) after contact with NaOH indicates a prior disease-associated impairment of collagen. Although the amount of ECM was not changed in type A dissection tissue, detailed electron microscopic evaluation revealed changes in ECM quality, which worsened after contact with alkaline solution but were not visible after histological analyses. Apart from the improved observation of the samples using electron microscopy, contact of aneurysmal and dissected tissue with the alkaline decellularization solution revealed potential disease related changes in ECM quality which can partly be connected to already published data, but have to be proven by further studies.

Thoracic endovascular repair for acute complicated type B aortic dissections.

OBJECTIVE: This study retrospectively assessed in-hospital mortality and long-term results of emergency thoracic endovascular aortic repair (TEVAR) for patients with life-threatening acute complicated type B aortic dissection (acTBD). METHODS: Between March 2001 and December 2016, there were 55 patients (40 male; median age, 52 ± 13 years) with an acTBD who were treated with TEVAR for malperfusion (58%), aortic rupture (18%), or persistent untreatable pain with true lumen reduction or rapid aortic diameter enlargement (24%) as a sign of disease progression. The patients were categorized according to clinical appearance into two groups: group A, malperfusion, pending rupture, or rupture; and group B, persistent ongoing pain, rapid enlargement of aortic diameter, or significant changes in the true to false lumen ratio. Four patients (7%) had undergone previous aortic surgery. RESULTS: Technical success (coverage of the primary intimal tear) was achieved in 50 patients (91%). The overall in-hospital mortality rate was 9% (n = 5), and there was a statistically significant difference in early mortality between group A and group B (7% vs 2%; P < .02). Causes of in-hospital death were all aorta related, including a rupture during the procedure and on the first postinterventional day in two patients and redissection (ascending aorta, n = 2; descending aorta, n = 1) with a consequent aortic rupture after TEVAR in the remaining three. Permanent neurologic dysfunction occurred in five patients (stroke, n = 2; paraplegia, n = 3). Overall, 19 patients (34%) developed early endoleaks (type IA, n = 5; type IB, n = 11; type II, n = 2; type IB plus type II, n = 1). Therefore, 5 patients needed early (within 30 days) endovascular intervention because of a type IA (n = 2), type IB (n = 3), or type II endoleak (n = 1) and the rapid progression of aortic diameter, persistent signs of ischemia (n = 2), or rupture (n = 1), whereas the remaining 14 patients were treated conservatively and followed up by computed tomography angiography. Seven patients with early endoleaks needed an endovascular intervention (n = 3) or conventional surgery (n = 4) because of aortic progression in the follow-up period (mean interval after procedure, 92 ± 56 months). The actual survival rates were 87%, 85%, and 75% at 1 year, 2 years, and 5 years, respectively, and freedom from aorta-related death was 87%, 87%, and 77% at 1 year, 2 years, and 5 years, respectively. Freedom from reintervention for any cause using a Kaplan-Meier analysis was 70%, 68%, 68%, and 63% at 6 months, 1 year, 2 years, and 5 years, respectively. CONCLUSIONS: TEVAR of acTBD has been proven to be an excellent treatment modality in this cohort of high-risk patients, with promising midterm and long-term results.