Transcatheter mitral valve implantation versus conventional redo surgery for degenerated mitral valve prostheses and rings in a multicenter registry.

OBJECTIVES: Degeneration of mitral prostheses/rings may be treated by redo surgery, and, recently, by transcatheter valve-in-valve/ring implantation. This multicenter registry presents results of transcatheter valve-in-valve and repeat surgery for prostheses/rings degeneration. METHODS: Data provided by 10 German heart centers underwent propensity score-matched retrospective analysis. The primary endpoint was 30-day/midterm mortality. Perioperative outcome was assessed according to the Mitral Valve Academic Research Consortium criteria. Further, the influence of moderate or greater tricuspid regurgitation (TR) on 30-day/midterm mortality was analyzed. RESULTS: Between 2014 and 2019, 273 patients (79 transcatheter mitral valve-in-valve [TM-ViV] and 194 redo mitral valve replacement [Re-MVR]) underwent repeat procedure for mitral prosthesis/ring degeneration. Propensity score matching distinguished 79 patient pairs. European System for Cardiac Operative Risk Evaluation (EuroSCORE) II-predicted risk was 15.7 ± 13.7% in the TM-ViV group and 15.0% ± 12.7% in the Re-MVR group (P = .5336). TM-ViV patients were older (74.73 vs 72.2 years; P = .0030) and had higher incidence of atrial fibrillation (54 vs 40 patients; P = .0233). Severe TR incidence was similar (17.95% in TM-ViV vs 14.10%; P = .1741). Sixty-eight TM-ViV patients previously underwent mitral valve replacement, whereas 41 Re-MVR patients underwent valve repair (P < .0001). Stenosis was the leading degeneration mechanism in 42 TM-ViV versus 22 Re-MVR patients (P < .0005). The 30-day/midterm mortality did not differ between groups. Moderate or greater TR was a predictor of total (odds ratio [OR], 4.36; P = .0011), 30-day (OR, 3.76; P = .0180), and midterm mortality (OR, 4.30; P = .0378), irrespective of group. CONCLUSIONS: In both groups, observed mortality was less than predicted. Redo surgery enabled treatment of concomitant conditions, such as atrial fibrillation or TR. TR was shown to be a predictor of total, 30-day, and midterm mortality in both groups.

Device-based prevention of neurological events in coronary artery bypass patients with calcified ascending aorta.

Patients with severely calcified aorta undergoing conventional cardiac surgery are at increased risk for postoperative neurologic deficits. Implementation of cerebroprotective devices may substantially reduce or even eliminate the risk of the adverse neurologic events, thus enabling surgical therapy, especially when interventional treatment cannot be considered an alternative option.

Conventional cardiac surgery in patients with end-stage coronary artery disease: yesterday and today.

Surgical therapy of combined coronary artery disease (CAD) and heart failure, also referred to as end-stage CAD, has evolved throughout the years and patients are currently being offered traditional coronary artery bypass grafting (CABG), with or without surgical ventricle restoration (SVR), interventions for ischemic mitral valve regurgitation, heart transplantation or implantation of mechanical cardiovascular support systems. Among surgical methods, operative myocardial revascularization (with or without ventricle restoration) is still playing an important role, aiming at restoration of proper myocardial perfusion, especially if heart muscle viability is present. Facing the donor shortage, CABG may constitute a valuable alternative to transplantation in selected patients. In individuals considered not suitable for surgical revascularization, implantation of mechanical circulatory support (MCS) not only appears as a salvage procedure, but also allows for reevaluation of future therapy directions. This article aims at providing an overview of evolving and current surgical practices in patients with end-stage CAD.

Cardiac conduction abnormalities in patients with degenerated bioprostheses undergoing transcatheter aortic valve-in-valve implantations and their impact on long-term outcomes.

BACKGROUND: The relationship between preoperative cardiac conduction abnormalities (CCA) and long-term outcomes after transcatheter aortic valve-in-valve implantation (TAVI-VIV) remains unclear. The aim of the study was to evaluate the effects of preoperative CCA on mortality and morbidity after TAVI-VIV and to estimate the impact of new-onset CCA on postoperative outcomes. METHODS: Between 2011 and 2020, 201 patients with degenerated aortic bioprostheses were qualified for TAVI-VIV procedures in two German heart centers. Cases with previously implanted permanent rhythm-controlling devices were excluded (n = 53). A total of 148 subjects met the eligibility criteria and were divided into 2 study groups according to the presence of preexisting CCA (CCA (n = 84) and non-CCA (n = 64), respectively). Early and late mortality and morbidity were evaluated. Follow-up functional status was assessed according to New York Heart Association (NYHA) classification. RESULTS: There were no procedural deaths. TAVI-VIV related new-onset CCAs were observed in 35.8% patients. The 30-day permanent pacemaker implantation rate was 1.6% in non-CCA vs 9.5% in CCA group (p = 0.045). Preexisting right bundle-branch block (OR:5.01; 95%CI, 1.05-23.84) and first-degree atrioventricular block (OR:4.55; 95%CI, 1.10-18.73) were independent predictors of new pacemaker implantation. One-year and five-year probability of survival were comparable in CCA and non-CCA groups: 90.3% vs 91.8% and 68.2% vs 74.3%, respectively. Surviving patients with preexisting and new-onset CCA had a worse functional status according to NYHA classification at follow-up. CONCLUSION: Preexisting and new-onset postoperative CCAs did not affect early and late mortality after TAVI-VIV procedures, however, they may have a negative impact on late functional status.

The relationship of atrial fibrillation and tricuspid annular dilation to late tricuspid regurgitation in patients with degenerative mitral repair.

OBJECTIVES: Guidelines do not address preoperative atrial fibrillation when considering adding tricuspid annuloplasty to mitral surgery. Our purpose was to determine the occurrence of late tricuspid regurgitation in patients with less than moderate tricuspid regurgitation undergoing surgery for degenerative mitral regurgitation and the importance of atrial fibrillation and tricuspid annular dilation. METHODS: From 2004 to 2017, 1021 patients underwent surgery for degenerative mitral regurgitation; 869 (85%) had less than moderate tricuspid regurgitation, and 846 (97%) underwent repair. Preoperative atrial fibrillation was present in 199 patients and ablated in 194 patients (97%). Tricuspid annular diameter was measured in 657 of 869 patients (76%). RESULTS: For patients who did not receive tricuspid annuloplasty, recurrent moderate or more late tricuspid regurgitation was 8% (45/576) in the no atrial fibrillation group and 25% (38/154) in the atrial fibrillation group (P < .001; odds ratio, 2.42). In 75.2% of patients (494/657), the tricuspid annulus was less than 4.0 cm; in 17% of patients (112), the tricuspid annulus was 4.0 to 4.4 mm (mean 41.1 mm); and in 7.8% of patients (51), the tricuspid annulus was 45 mm or more (47.8 mm). Only tricuspid diameter 45 mm or more was a risk for late tricuspid regurgitation (P = .002; odds ratio, 3.25). Progression to moderate or higher tricuspid regurgitation was associated with an increase in long-term mortality: unadjusted hazard ratio, 3.58 (2.04-6.29) (P < .001); adjusted hazard ratio, 2.37 (1.23-4.57) (P = .010). CONCLUSIONS: Preoperative atrial fibrillation is an important risk factor for late tricuspid regurgitation despite concomitant ablation surgery. Tricuspid annular dilation was not associated with late tricuspid regurgitation until the annulus was 45 mm or greater. Progression to moderate or greater tricuspid regurgitation was associated with an increase in late mortality.

Unique technical challenges in patients undergoing TAVR for failed aortic homografts.

OBJECTIVE: Surgical reoperation for aortic homograft structural valve degeneration (SVD) is a high-risk procedure. Transcatheter aortic valve replacement (TAVR) for homograft-SVD is an alternative to reoperation, but descriptions of implantation techniques are limited. This study compares outcome in patients undergoing into two groups by the type of previously implanted aortic valve prosthesis: TAVR for failed aortic homografts (TAVR-H) or for stented aortic bioprostheses (TAVR-BP). METHODS: From 2015 to 2017, TAVR was performed in 41 patients with SVD. Thirty-three patients in the TAVR-BP group (six for SVD of valved conduits), and eight patients in the TAVR-H group. The Valve Academic Research Consortium criteria were used for outcome reporting purposes. RESULTS: The patients with TAVR-BP had predominant prosthetic stenosis (94%, p = .002), whereas TAVR-H individuals presented mostly with regurgitation (88%, p = <.001). Patients with TAVR-H received: Sapien-3 (6), Sapien-XT (1), and CoreValve (1) devices. Low, 40% ventricular fixation in relation to homograft annulus was attempted to anchor the prosthesis on the homograft suture-line. One patient with TAVR-BP experienced intraoperative distal prosthesis migration and Type-B aortic dissection, and two patients in the TAVR-H group had late postoperative proximal device migration. In both groups, there was zero 30-day mortality, stroke, or pacemaker implantation. CONCLUSIONS: TAVR for failing aortic homografts may be a feasible and safe alternative to high-risk surgical reintervention. Precise, 40%-ventricular device positioning appears crucial for prevention of late paravalvular leak/late prosthesis migration and minimizing the risk of repeat surgical intervention.

Is 300 Seconds ACT Safe and Efficient during MiECC Procedures?

INTRODUCTION: The recommended minimum activated clotting time (ACT) level for cardiopulmonary bypass (CPB) of 480 seconds originated from investigations with bubble oxygenators and uncoated extracorporeal circulation (ECC) systems. Modern minimal invasive ECC (MiECC) systems are completely closed circuits containing a membrane oxygenator and a tip-to-tip surface coating. We hypothesized that surface coating and the "closed-loop" design allow the MiECC to safely run with lower ACT levels and that an ACT level of 300 seconds can be safely applied without thromboembolic complications. The aim of this study was to investigate the potential risks during application of reduced heparin levels in patients undergoing coronary surgery. METHODS: In this study, 68 patients undergoing coronary artery bypass grafting with MiECC were randomized to either the study group with an ACT target of 300 seconds or the control group with an ACT of 450 seconds. All other factors of MiECC remained unchanged. RESULTS: The study group received significantly less heparin and protamine (heparin [international units] median [min-max], Red_AC: 32,800 [23,000-51,500] vs. Full_AC: 50,000 [35,000-65,000] p < 0.001; protamine [international units], Red_AC: 18,000 [10,000-35,000] vs. Full_AC: 30,000 [20,000-45,000] p < 0.001). The ACT in the study group was significantly lower at the start of MiECC (mean ± standard deviation: study group 400 ± 112 vs. control group 633 ± 177; p < 0.0001). Before termination of CPB the ACT levels were: study group 344 ± 60 versus control group 506 ± 80. In both groups, the values of the endogenous thrombin potential (ETP) decreased simultaneously. None of the study participants experienced thromboembolic complications. CONCLUSION: Since no evidence of increased thrombin formation (ETP) was found from a laboratory standpoint, we concluded that the use of MiECC with a reduced anticoagulation strategy seems possible. This alternative anticoagulation strategy leads to significant reduction in dosages of both heparin and protamine. We can confidently move forward with investigating this anticoagulation concept. However, to establish clinical safety of ACT below 300 seconds, we need larger clinical studies.

Valve-in-valve-prosthesis embolization and aortic dissection: single procedure, double complication.

Transcatheter aortic valve implantation (TAVI) is a recognized treatment method for high-risk patients with aortic stenosis. TAVI is also recommended for structural valve degeneration of a biological valve prosthesis. TAVI-specific complications, such as prosthesis embolization and aortic dissection, are uncommon but potential concerns. A 73-year-old woman presented with structural valve degeneration 14 years after aortic root replacement with a bioprosthetic valved conduit. The patient underwent TAVI valve-in-valve under monitored anaesthesia care. Intraoperatively, the self-expandable prosthesis was difficult to deploy within the valved conduit and ultimately migrated distally. During the technically difficult passage of the prosthesis delivery system through the tortuous aorta, the patient started reporting symptoms suggestive of aortic dissection. An emergency computed tomography scan confirmed type B dissection. Thoracic endovascular aortic repair followed by deployment of a balloon-expandable prosthesis below the self-expandable implant was performed. Careful prosthesis selection in valve-in-valve patients after aortic root replacement is crucial for procedural success.

Left main artery dissection as a clinical sign of the aortic rupture following aortic valve replacement for fulminant aortic endocarditis.

Aortic valve endocarditis with perivalvular abscess formation remains a demanding condition and the results of the surgery are not optimal. Abscess localized in the aortic basis area can weaken the aortic wall, leading to further deterioration and rupture. The presented case allows us to recommend a maximal aggressive approach in patients, in whom the aortic wall seems to be rearranged due to abscess formation. Sometimes only the resection of the abscess hole and replacement of the entire ascending aorta offers a safe therapy option.

Influence of pressure on the endothelium of the saphenous vein coronary artery bypass graft.

The aim of this study was to evaluate the influence of pressure applied while assessing the graft's tightness on the expression of adhesion molecules. Another goal was to find a correlation between the type of fluid (heparynized blood or saline) used during preparation of the conduit and the expression of the adhesion molecules. Saphenous vein fragments were obtained from 48 patients who had undergone coronary artery surgery. Expression of the following particles was evaluated: CD 31, ICAM 1, VCAM 1 and P-selectin. Expression of the CD 31 molecule was described as a percentage of the inner surface of the vessel showing positive immunocytochemical reaction. Expression of the remaining molecules (ICAM 1, VCAM 1, P-selectin) was assessed as the percentage of the surface, determined by CD 31 positive reaction. The expression of the adhesion molecules (ICAM 1, VCAM 1, P-selectin) was higher in the fragments of the vein exposed to pressure. In reference to VCAM 1 the difference, as compared with the control group, was: 250% in the fragments infused with blood and 270% in the fragments infused with saline, respectively. The differences for the ICAM 1 were approximately 300% in both experimental groups and 450% for the P-selectin with subtle differences between the two experimental groups. The loss of the endothelial surface (determined by the expression of the CD 31 antigen) was similar in the specimens flushed either with blood or saline, which indicates that the major cause of damage of the endothelium is influence of pressure on the conduit's wall. Mechanical widening of vessels results in the increased expression of the adhesion molecules on the surface of the endothelial cells, and, as a consequence, leads to rise in the leukocyte adhesion and loss of the functional properties of the transplanted veins.