Sleep apnea in patients undergoing coronary artery bypass grafting: Impact on perioperative outcomes.

Sleep-disordered breathing is common in patients with coronary artery disease undergoing coronary artery bypass grafting. Sleep-disordered breathing is associated with increased perioperative morbidity, arrhythmias (e.g. atrial fibrillation) and mortality. This study investigated the impact of sleep-disordered breathing on the postoperative course after coronary artery bypass grafting, including development of atrial fibrillation. This prospective single-centre cohort study included adults undergoing coronary artery bypass grafting. All were screened for sleep-disordered breathing (polygraphy) and atrial fibrillation (electrocardiogram) preoperatively; those with known sleep-disordered breathing or atrial fibrillation were excluded. Endpoints included new-onset atrial fibrillation, duration of mechanical ventilation, time in the intensive care unit, and postoperative infection. Regression analysis was performed to identify associations between sleep-disordered breathing and these outcomes. A total of 508 participants were included (80% male, median age 68 years). The prevalence of any (apnea-hypopnea index ≥ 5 per hr), moderate (apnea-hypopnea index = 15-30 per hr) and severe (apnea-hypopnea index > 30 per hr) sleep-disordered breathing was 52.9%, 9.3% and 10.2%, respectively. All-cause 30-day mortality was 0.98%. After adjustment for age and sex, severe sleep-disordered breathing was associated with longer respiratory ventilation support (crude odds ratio [95% confidence interval] 5.28 [2.18-12.77]; p < 0.001) and higher postoperative infection rates (crude odds ratio 3.32 [1.45-7.58]; p < 0.005), but not new-onset atrial fibrillation or mortality. New-onset atrial fibrillation was significantly associated with postoperative infection and prolonged hospital stay. The significant associations between sleep-disordered breathing and several adverse outcomes after coronary artery bypass grafting support the need for preoperative sleep-disordered breathing screening in individuals undergoing cardiac surgery.

Impact of Left Atrial Appendage Amputation on Left Atrial Morphology and Rhythm after Off-Pump CABG.

OBJECTIVES: Left atrial appendage (LAA) amputation concomitant to coronary artery bypass grafting (CABG) has become an increasingly performed technique in patients with atrial fibrillation (AF) or with sinus rhythm and a CHA2DS2-VASc score ≥2. However, LAA amputation has come under suspicion to cause postoperative atrial fibrillation (POAF) due to left atrial (LA) dilation. This study aims to assess this assumption in patients undergoing CABG in off-pump technique with and without amputation of the LAA. METHODS: Patients who underwent isolated CABG in off-pump technique without history of AF were retrospectively examined. Cohorts were divided according to the concomitant execution of LAA amputation. LA volume was measured by transthoracic echocardiography and rhythm was analyzed by electrocardiography, medication protocol, and visit documentation. Propensity score (PS) matching was performed based on 20 preoperative risk variables to correct for selection bias. RESULTS: A total of 1,522 patients were enrolled, with 1,267 in the control group and 255 in the LAA amputation group. Occurrence of POAF was compared in 243 PS-matched patient pairs. Neither the unmatched cohort (odds ratio [OR] 0.82; 95% confidence interval or CI [0.61; 1.11], p = 0.19) nor the PS-matched cohort (OR 0.94; 95% CI [0.62; 1.41], p = 0.75) showed significant differences in POAF occurrence. Subgroup analysis of sex, use of ß-blockers, pulmonary disease, ejection fraction, and CHA2DS2-VASc-Score also showed no tendencies. LA volume did not change significantly (p = 0.18, 95% CI [-0.29; 1.51]). CONCLUSION: Surgical amputation of the LAA concomitant to CABG did not lead to LA dilation and has no significant impact on the occurrence of POAF.

New insights into the hemodynamics of pulmonary homograft patients under stress echocardiography: The contribution of pressure recovery.

BACKGROUND: The importance of pulmonary artery pressure recovery (PR) in patients with Ross procedures in whom a homograft substitutes the resected pulmonary valve, is unknown. The aim of the study was to evaluate the occurrence and extent of PR in the pulmonary artery in 65 asymptomatic patients with pulmonary homograft after Ross surgery during rest and exercise. METHODS: Stress echocardiography was performed in 65 pulmonary homograft patients and 31 controls with native pulmonary valves up to 75 W. Right ventricular systolic pressure (RVSP), transvalvular flow, mean pressure gradient (Pmean ), valve resistance, and RV stroke work were determined in the exercise (max. 75 W) and recovery phases in increments of 25 W each. RESULTS: Pulmonary homografts demonstrated significantly elevated Pmean compared to controls at all stages. When considering pressure recovery (absolute and relative PR at rest 3.8 ± 1.8 mm Hg, 42.6 ± 7.2%, respectively) and transvalvular energy loss (EL; at rest 4.5 ± 4.3 mm Hg) the homograft hemodynamics reached the level of controls. In a subgroup of patients with tricuspid regurgitation, resting RVSP was the same in homograft patients and controls (21.3 ± 6.1 vs. 20.4 ± 6.3, p = .62), despite significant different Pmax values. CONCLUSIONS: Ross patients with pulmonary homograft showed systematically increased hemodynamic parameters compared to normal pulmonary valves. These differences were abolished when PR was considered for homograft patients. The equality of RVSP values at rest in both groups shows non-invasive evidence for PR in the pulmonary system after homograft implantation. Therefore, PR appears to be an important measure in calculating the actual hemodynamics in pulmonary homografts.

Impact of high-pressure balloon aortic valvuloplasty on the hydrodynamic result after a transcatheter valve-in-valve procedure.

OBJECTIVES: The aim of this study was to investigate the degree of functional improvement of a transcatheter heart valve (THV) for valve-in-valve after bioprosthetic valve fracture (BVF) of three small surgical aortic valve bioprostheses (SAVBP) using high-pressure balloon aortic valvuloplasty (HP-BAV) under standardized ex-vivo-conditions. METHODS: A THV 26 mm (Evolut R) and SAVBP 21 mm (Perimount Magna Ease, Trifecta, and Epic supra [n = 4] were used. Mean pressure gradient (MPG), effective orifice area (EOA), geometric orifice area (GOA), minimal internal diameter (MID), and pinwheeling index (PWI) were analyzed before and after HP-BAV of the SAVBP using a noncompliant balloon. Fracturing of the SAVBP was done before implantation of the THV and the balloon pressures at the point of fracture were recorded. RESULTS: The Magna Ease and Epic fractured at balloon pressures of 18 and 8 atm, respectively. The Trifecta did not fracture up to a balloon pressure of 30 atm but was dilated. HP-BAV led to increased THV expansion as evident by straightened coaptation lines of the Evolut R 26 mm with reduced PWI, increased MID, and increased GOA in all 21 mm SAVBP. Evolut R showed significantly lower MPG and higher EOA as ViV in all prostheses after HP-BAV (p < 0.001). MPG and EOA of Evolut R differed regarding the SAVBP. Evolut R presented the lowest MPG and highest EOA in Magna Ease and the highest MPG and lowest EOA in Epic supra. CONCLUSIONS: The degree of function improvement of the same THV as ViV after HP-BAV depends on the surgical valve model. Functional improvement can also be achieved without valve fracture.

Mitral Valve Replacement Using Subvalvular Apparatus: A Systematic Review and Meta-Analysis.

BACKGROUND: To assess clinical outcomes among participants undergoing mitral valve replacement with preservation of subvalvular apparatus. METHODS: Electronic databases, including PubMed, Embase, Science Direct, World of Science, Scopus, Biosis, SciElo and Cochrane library, were probed using an extensive search strategy. Studies that reported at least one clinical outcome, such as morbidity, mortality, early 30-day mortality, myocardial failure, survival, late cerebrovascular events, length of stay, or major operative complications (stroke, prolonged ventilation, and reoperation for bleeding, renal failure, and sternal infection) were considered for inclusion. Data was extracted and pooled into a meta-analysis in RevMan (version 5.3) using a random-effects model. RESULTS: A total of 21 studies with 5,106 participants (age range: 27.3-69.2 years) were included in this meta-analysis. Preservation of the subvalvular apparatus during MVR significantly reduces the risk of long-term mortality (OR: 0.46; 95% CI: 0.33-0.64), but not early mortality (OR: 0.76; 95% CI: 0.12-4.93). No significant difference ejection fraction was observed (SMD: 0.10; 95% CI: -0.44-0.64). Similarly, there was no significant difference in the risk of stroke, renal failure, and pneumonia between C-MVR and in the control group. CONCLUSION: MVR with the preservation of subvalvular apparatus improves clinical outcomes, such as long-term mortality, hospital length of stay, pneumonia, and bleeding. There is no significant difference in the risk of stroke, renal failure, or ICU length of stay. However, there is very limited data available with respect to bleeding, sepsis, and nosocomial infections.

Serum albumin in patients undergoing transcatheter aortic valve replacement: A meta-analysis.

Transcatheter aortic valve replacement is becoming a more common therapeutic option for the treatment of aortic stenosis in patients at high risk for invasive surgery, but detecting which patients will benefit clinically can be challenging. Hypoalbuminemia is a useful prognostic marker for chronic inflammation in this population. We carried out a systematic review and meta-analysis of studies evaluating the prognostic value of serum albumin level in patients undergoing transcatheter aortic valve replacement. A literature search of PubMed, Embase, ScienceDirect, Web of Science, SciELO, BIOSIS, Wanfang, and CNKI databases was conducted. Articles published between January 2000 and December 2017 reporting on the prognostic value of low levels of serum albumin in patients undergoing transcatheter aortic valve replacement were analyzed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. 11 studies including 6456 patients met inclusion criteria for meta-analysis. A lower serum albumin level was associated with a lower survival rate at follow-up in patients who underwent transcatheter aortic valve replacement. A sub-group analysis of eight studies reporting adjusted hazard ratios indicated that low serum albumin was independently correlated with increased post-operative mortality. The hazard ratio of mortality risk associated with each 1 g/dL increment in serum albumin level was 0.46, suggesting a potential dose-response relationship between increased serum albumin level and increased survival rate in patients undergoing transcatheter aortic valve replacement. This meta-analysis provides strong evidence for the utility of serum albumin as a prognostic marker in aortic stenosis patients undergoing transcatheter aortic valve replacement, with low serum albumin levels (2.5-3.5 g/dL) suggesting poor prognosis.

Prognostic Factors for Long-Term Survival after Surgical Resection of Primary Cardiac Sarcoma.

BACKGROUND: Primary cardiac sarcoma (CS) is an extremely rare disease. This study aims to identify possible prognostic factors for long-term survival. METHODS: A total of 17 consecutive patients who were treated for primary CS between 2003 und 2018 at two cardiac centers were investigated. Clinical data and histological characteristics of the tumors were analyzed. Long-term follow-up of all patients were performed. RESULTS: The median age was 54 years (range: 23-74). The tumors originated from the left side of the heart in nine patients. Histologically, there were four angiosarcomas, three intimal sarcomas, and three synovial sarcomas. One- and 7-year survivals were 81.9 and 18.2%, respectively. Low expression levels of Ki-67 tended to be associated with increased survival (log-rank p = 0.06). Adjuvant chemotherapy but not radiotherapy regardless of existing metastases was associated with significantly increased survival (log-rank p = 0.001). CONCLUSION: Angiosarcoma was the most common type of CS. The survival of CS patients is poor but prognostic factors, such as Ki-67, may help estimate the course of the disease. Survival could be improved significantly with chemotherapy.

Defibrillator-Heart Pump: An Implantable Ventricular Assist Device With Integrated Defibrillator Component-The First In Vitro Testing.

Left ventricular assist devices (LVADs) are an important therapeutic option for patients with end-stage heart failure waiting for heart transplantation or in older patients as definite therapy for heart failure. Interestingly, about 62% of patients receiving LVADs do not have an automatic implantable cardioverter-defibrillator (AICD) at the time of implantation, although these patients have increased risk of being confronted with dangerous arrhythmia. Therefore, an LVAD system including AICD function is a reasonable alternative for such heart failure patients thereby avoiding a second surgical intervention for AICD implantation. In this article, a newly developed system including LVAD and AICD function is introduced, and we also report its first in vitro testing.

Counteracting negative venous line pressures to avoid arterial air bubbles: an experimental study comparing two different types of miniaturized extracorporeal perfusion systems.

BACKGROUND: Because of its low rate of clinical complications, miniaturized extracorporeal perfusion systems (MEPS) are frequently used in heart centers worldwide. However, many recent studies refer to the higher probability of gaseous microemboli formation by MEPS, caused by subzero pressure values. This is the main reason why various de-airing devices were developed for today's perfusion systems. In the present study, we investigated the potential benefits of a simple one-way-valve connected to a volume replacement reservoir (OVR) for volume and pressure compensation. METHODS: In an experimental study on 26 pigs, we compared MEPS (n = 13) with MEPS plus OVR (n = 13). Except OVR, perfusion equipment was identical in both groups. Primary endpoints were pressure values in the venous line and the right atrium as well as the number and volume of air bubbles. Secondary endpoints were biochemical parameters of systemic inflammatory response, ischemia, hemodilution and hemolysis. RESULTS: One animal was lost in the MEPS + OVR group. In the MEPS + OVR group no pressure values below -150 mmHg in the venous line and no values under -100 mmHg in right atrium were noticed. On the contrary, nearly 20% of venous pressure values in the MEPS group were below -150 and approximately 10% of right atrial pressure values were below -100 mmHg. Compared with the MEPS group, the bubble counter device showed lower numbers of arterial air bubbles in the MEPS + OVR group (mean ± SD: 13444 ± 5709 vs. 1 ± 2, respectively; p < 0.001). In addition, bubble volume was significantly lower in the MEPS + OVR group than in the MEPS group (mean ± SD: 1522 ± 654 µl vs. 4 ± 6 µl, respectively; p < 0.001). The proinflammatory cytokine interleukin-6 and biochemical indices of cardiac ischemia (creatine kinase, and troponin I) were comparable between both groups. CONCLUSIONS: The use of a miniaturized perfusion system with a volume replacement reservoir is able to counteract excessive negative venous line pressures and to reduce the number and volume of arterial air bubbles. This approach may lead to a lower rate of neurological complications.

Surgical ventricular reconstruction and intraoperative cryoablation in a patient with drug-refractory ventricular tachycardia and left ventricular thrombus: a case report.

Background: Despite modern techniques for ablation of ventricular tachycardia (VT), the procedure faces challenges such as deep intramural substrates or inaccessibility of the pericardial space. We aim to present a case of successful surgical treatment of a patient with drug-refractory VT, an apical aneurysm, large left ventricular (LV) thrombus, and recurrent implantable cardioverter defibrillator (ICD) shocks following failed epicardial catheter ablation. Case summary: A 67-year-old male with a history of ischaemic cardiomyopathy was brought to the emergency room after a syncope because of VT. The VT was terminated by an external cardioversion prior to admission. The ICD interrogation showed an episode of sustained monomorphic VT with eight appropriate but mostly ineffective ICD shocks. An echocardiogram revealed an apical aneurysm with a thrombus. Anticoagulation and antiarrhythmic drug therapy were initiated. Days later, the patient suffered recurrent episodes of sustained VTs, refractory to pharmacological therapy, and epicardial ablation; therefore, following aneurysmectomy and thrombus removal, a reconstruction of the LV and surgical endocardial cryoablation were performed. In addition, ICD extraction was done due to recurrent bacteraemia with Staphylococcus aureus. A subcutaneous ICD was later implanted. After surgery, the patient remained free of any VT episodes during 44 months of follow-up. Conclusion: Combined surgical ventricular reconstruction and intraoperative cryoablation may be considered as an alternative, highly effective therapy in patients with drug-refractory VTs in the setting of a LV thrombus.

Ex vivo evaluation of 3 different right ventricular outflow tract substitutes.

OBJECTIVES: The Ross procedure represents an excellent treatment option in younger patients with aortic stenosis but is limited by poor availability of homografts. In this study, we investigated the hydrodynamic performance of 3 different types of right ventricular outflow tract replacement with pericardium or synthetic material. METHODS: Three different types of valved conduits were constructed using pericardium and/or synthetic material (Group PEPE: pericardial cusps and pericardial conduit, Group PEPR: pericardial cusps and Dacron conduit, Group PRPR: expanded polytetrafluoroethylene cusps and Dacron conduit). The conduits were designed according to the Ozaki method. Their hydrodynamic performance (effective orifice area, mean pressure gradient and leakage volume) were evaluated in a mock circulation loop at different hydrodynamic conditions. RESULTS: Hydrodynamic assessment showed significantly larger effective orifice area of PEPE and PEPR compared to PRPR under all conditions and there were no significant differences between PEPE and PEPR [for condition 2: PEPE 2.43 (2.35-2.54) cm2, PEPR: 2.42 (2.4-2.5) cm2, PRPR: 2.08 (1.97-2.21) cm2, adjusted pairwise comparisons: PEPE versus PEPR: P = 0.80, PEPE versus PRPR: P < 0.001, PEPR versus PRPR: P < 0.001]. Mean pressure gradient was significantly lower for PEPE and PEPR compared with PRPR, whereas no significant differences were seen between PEPE and PEPR. Leakage volume was significantly lower for PEPE and PEPR compared with PRPR under all conditions while leakage was similar between PEPE and PEPR. CONCLUSIONS: Pulmonary graft reconstruction with pericardium cusps showed superior hydrodynamic performance compared with polytetrafluoroethylene cusps. Our results suggest that it could be considered as an alternative substitute for right ventricular outflow tract replacement during the Ross procedure.

Clampless off-pump versus conventional coronary artery revascularization: a propensity score analysis of 788 patients.

BACKGROUND: This study aimed to assess if clampless off-pump coronary artery bypass grafting (CABG) decreases risk-adjusted mortality, stroke rate, and morbidity in unselected patients in comparison to conventional CABG. METHODS AND RESULTS: Between July 2009 and November 2010, data of 1282 consecutive patients undergoing isolated CABG were prospectively recorded. In 30.8% (n=395), clampless off-pump revascularization was used, either with the PAS-Port automated central venous anastomosis system (n=310) or as total arterial revascularization without central anastomoses (n=85). Propensity score (PS) matching was performed based on 15 preoperative risk variables to correct for selection bias. In-hospital mortality and stroke rate as primary end point, as well as major complications and follow-up outcome of clampless off-pump (lessOPCAB) and conventional CABG (cCABG) were compared in 394 matched patient pairs (total: 788 patients). The clampless off-pump technique decreased the in-hospital rate of death (odds ratio, 0.25; 95% confidence interval, 0.05-1.18, P=0.080) and stroke (odds ratio, 0.36; 95% confidence interval, 0.13-0.99, P=0.048) significantly. Complications such as low cardiac output syndrome, prolonged ventilation and rethoracotomy were also reduced by lessOPCAB. Over a 2-year follow-up period overall survival, cerebrovascular and major adverse event rate were significantly lower in the lessOPCAB group, while the repeat revascularization rate was comparable. CONCLUSIONS: In a retrospective PS-matched analysis, clampless off-pump CABG lowers mortality, stroke rate and other morbidity in an unselected group of patients with coronary artery disease.

Functional interaction of aortic valve and ascending aorta in patients after valve-sparing procedures.

Pressure recovery (PR) is essential part of the post stenotic fluid mechanics and depends on the ratio of EOA/AA, the effective aortic valve orifice area (EOA) and aortic cross-sectional area (AA). In patients with advanced ascending aortic aneurysm and mildly diseased aortic valves, the effect of AA on pressure recovery and corresponding functional aortic valve opening area (ELCO) was evaluated before and after valve-sparing surgery (Dacron graft implantation). 66 Patients with ascending aortic aneurysm (mean aortic diameter 57 +/- 10 mm) and aortic valve-sparing surgery (32 reimplantation technique (David), 34 remodeling technique (Yacoub)) were routinely investigated by Doppler echocardiography. Dacron graft with a diameter between 26 and 34 mm were implanted. EOA was significantly declined after surgery (3.4 +/- 0.8 vs. 2.6 +/- 0.9cm2; p < 0.001). Insertion of Dacron prosthesis resulted in a significant reduction of AA (26.7 +/- 10.2 vs. 6.8 +/- 1.1cm2; p < 0.001) with increased ratio of EOA/AA (0.14 +/- 0.05 vs. 0.40 +/- 0.1; p < 0.001) and pressure recovery index (PRI; 0.24 +/- 0.08 vs. 0.44 +/- 0.06; p < 0.0001). Despite reduction of EOA, ELCO (= EOA corrected for PR) increased from 4.0 +/- 1.1 to 5.0 +/- 3.1cm2 (p < 0.01) with reduction in transvalvular LV stroke work (1005 +/- 814 to 351 +/- 407 mmHg × ml, p < 0.001) after surgery. These effects were significantly better in patients with Yacoub technique than with the David operation. The hemodynamic findings demonstrate a valve-vessel interaction almost entirely caused by a marked reduction in the ascending AA with significant PR gain. The greater hemodynamic benefit of the Yacoub technique due to higher EOA values compared to the David technique was evident and may be of clinical relevance.

Impact of heart rate, aortic compliance and stroke volume on the aortic regurgitation fraction studied in an ex vivo pig model.

INTRODUCTION: Drug therapy to reduce the regurgitation fraction (RF) of high-grade aortic regurgitation (AR) by increasing heart rate (HR) is generally recommended. However, chronic HR reduction in HFREF patients can significantly improve aortic compliance and thereby potentially decrease RF. To clarify these contrasts, we examined the influence of HR, aortic compliance and stroke volume (SV) on RF in an ex vivo porcine model of severe AR. METHODS: Experiments were performed on porcine ascending aorta with aortic valves (n=12). Compliance was varied by inserting a Dacron graft close to the aortic valve. Both tube systems were connected to a left heart simulator varying HR and SV. AR was accomplished by punching a 0.3 cm2 hole in one aortic cusp. Flow, RF, SV and aortic pressure were measured, aortic compliance with transoesophageal ultrasound probes. RESULTS: Compliance of the aorta was significantly reduced after Dacron graft insertion (0.55%±0.21%/mm Hg vs 0.01%±0.007%/mm Hg, p<0.001, respectively). With increasing HR, RF was significantly reduced in each steady state of the native aorta (HR 40 bpm: 88%±7% vs HR 120 bpm: 42%±10%; p<0.001), but Dacron tube did not affect RF (HR 40 bpm: 87%±8%; p=0.79; HR 120 bpm: 42%±3%; p=0.86). Increasing SV also reduced RF independent of the stiff Dacron graft. CONCLUSION: Aortic compliance did not affect AR in the ex vivo porcine model of AR. RF was significantly reduced with increasing HR and SV. These results affirm that HR lowering and negative inotropic drugs should be avoided to treat severe AR.

Functional performance of 8 small surgical aortic valve bioprostheses: an in vitro study.

OBJECTIVES: Selection of a surgical aortic valve (SAV) bioprosthesis model for the treatment of aortic valve disease remains controversial. The aim of this study was to characterize the functional performance of 8 SAV models in a standardized in vitro setting. METHODS: The hydrodynamic performance of 8 SAVs with labelled size 21 mm (Avalus™, Hancock® II, Mosaic® Ultra™, Perimount®, Perimount® Magna Ease, Epic™ Supra, Trifecta™ GT; Freestyle®), was investigated in a pulse duplicator. Transvalvular pressure gradients and effective orifice area (EOA) were recorded. The geometrical orifice area and physical dimensions of the valves were determined, and new functional dimensions were introduced. RESULTS: Mean pressure gradient (MPG) and EOA differed significantly between the analysed SAVs. The Epic presented with the lowest EOA and highest MPG, while the Trifecta showed the highest EOA and the lowest MPG. We introduce a useful way to determine the minimal internal diameter and a new measure termed 'relative orifice area' to characterize a valve's performance. CONCLUSIONS: SAVs showed significant differences in their hydrodynamic performance despite the same label size. This finding was related to the construction of the valves. We introduce a new measure that characterizes the functional performance of a valve model and size for the treatment of an aortic annulus of a specific size. Our data emphasize that SAV selection should carefully be done using an individual patient approach and that future research is necessary to improve the current generation of SAVs.

Ex vivo evaluation of the Ozaki procedure in comparison with the native aortic valve and prosthetic valves.

OBJECTIVES: We investigated the hydrodynamic performance and cusp kinematics of the Ozaki neocuspidized aortic valve in comparison with the native aortic and prosthetic valves in an ex vivo study. METHODS: Native aortic valves of swine hearts were replaced by aortic valve substitutes, and their hydrodynamic performance (effective orifice area and mean pressure gradient) was evaluated in a mock circulation under defined conditions. The following aortic valve substitutes were investigated: native aortic valve, Ozaki valve, Perimount Magna Ease, Trifecta and St. Jude Medical Masters. All prosthetic valves had a labelled size of 21 mm. RESULTS: The Ozaki valve and native aortic valve showed a similar and significantly larger orifice area than all investigated prosthetic valves particularly at high flow rates. There was no significant difference between the Ozaki valve and the native aortic valve. The native aortic valve and Ozaki valve showed a similar increase in orifice area with increasing flow through the valve while prosthetic valves showed a markedly weaker increase. Similarly, the native and Ozaki valve showed a similar increase in mPG with forward flow which was weaker than prosthetic valves. Cusp kinematics were similar between the native and Ozaki valve, whilst prosthetic valves were clearly distinguishable from them. CONCLUSIONS: The Ozaki procedure showed excellent hydrodynamic performance compared to prosthetic valves and showed similar cusp motion characteristics to the native aortic valve. Our results suggest that the Ozaki neocuspidized valve behaves physiologically in many aspects, which may contribute to beneficial clinical outcomes.

Impact of different valve-in-valve positions on the hydrodynamic performance of the newest-generation self-expanding transcatheter heart valve.

OBJECTIVES: Transcatheter aortic valve-in-valve (ViV) procedures are increasingly performed for the treatment of degenerated surgical aortic valves with a high risk for a redo operation. For an optimal functional result, precise positioning of the transcatheter heart valve (THV) inside the SHV is crucial. The aim of this study was to systematically investigate the impact of implantation depth on the functional result after a ViV procedure in a standardized in vitro setting. METHODS: A THV 23 mm (Evolut PRO) and 3 SHV 21 mm (Perimount Magna Ease, Trifecta and Hancock II) were used for hydrodynamic testing with a constant heartbeat 64/min and a range of 55-105 ml of stroke volume in 5 different positions of the THV. The following parameters were analysed: mean pressure gradient (MPG), effective orifice area (EOA), geometric orifice area, minimal internal diameter and pin-wheeling index. RESULTS: MPG and EOA differed significantly regarding the position of the THV in the same SHV. The highest EOA and the lowest MPG were recorded for Evolut PRO with significance for both parameters in Hancock II at 4 vs 5 mm (P < 0.001), in Magna Ease at 2 mm (vs 3 mm and vs 6 mm, P < 0.001) and in Trifecta at 4 mm (vs 5 and 6 mm, P < 0.001). Leaflet coadaptation, minimal internal diameter and maximal geometric orifice area of the same TAV differ regarding the position of the TAV. CONCLUSIONS: The optimal position for hydrodynamic performance of the THV as ViV differs among specific SHV models. The findings may be useful for planning a ViV procedure using the Evolut PRO THV.

The figure-of-8 aortic valve suturing technique optimizes the effective orifice area of a small aortic annulus-an ex vivo study.

OBJECTIVES: Surgical aortic valve replacement (SAVR) in small annuli carries an elevated risk for the patient-prosthesis mismatch. In this study, we systematically investigated the influence of different implantation techniques including annular enlargement (AE) on the functional result after SAVR in small annuli using a standardized ex vivo model. METHODS: SAVR using the PERIMOUNT Magna Ease® (PME) 21 mm was performed in small porcine aortic roots using 4 implantation techniques: non-everting pledgeted (NE) suture, single interrupted (SI) suture, continuous suture (CS), figure-of-8 (F8) suture, as well as the PME 23 mm after AE using the Nunez method and the NE suture technique (PME23 AE). The effective orifice area (EOA), mean pressure gradient and leakage volume were evaluated using a mock circulation loop in accordance with ISO regulations. RESULTS: Experiments were conducted on 31 porcine aortic roots. PME21 using F8 and PME23 after AE achieved a significantly larger EOA than using NE. PME23 after AE showed a larger EOA than the PME21 using any suture technique, except the F8 [for stroke volume of 74 ml: PME21 NE: 1.68 (1.63-1.72) cm2, PME21 SI: 1.76 (1.68-1.81) cm2 (P = 0.17), PME21 CS: 1.76 (1.65-1.79) cm2 (P = 0.14), PME21 F8: 1.81 (1.70-1.85) cm2 (P = 0.005); PME23 AE: 1.83 (1.73-1.92) cm2 (P < 0.001)]. SI and CS did not result in larger EOA compared with the NE technique. PME21 using SI had a significantly larger leakage volume than using NE and there was no significant difference between other techniques [for stroke volume of 74 ml: PME21 NE: 3.51 (1.85-4.53) ml/stroke, PME21 SI: 6.00 (4.02-7.06) ml/stroke (P < 0.001), PME21 CS: 4.04 (3.60-4.49) ml/stroke (P = 0.10), PME21 F8: 3.16 (1.99-3.62) ml/stroke (P = 0.74), PME23 NE: 2.89 (2.45-4.72) ml/stroke (P = 0.51)]. CONCLUSIONS: The F8 technique with the PME21 achieved a similar EOA as the 1 size larger PME23 using NE after AE. These results suggest that the F8 technique may be an effective surgical modification to improve the haemodynamic result in a small annulus without additional AE.

Impact of pressure recovery on the assessment of pulmonary homograft function using Doppler ultrasound.

Relevant pressure recovery (PR) has been shown to increase functional stenotic aortic valve orifice area and reduce left ventricular load. However, little is known about the relevance of PR in the pulmonary artery. The study examined the impact of PR using 2D-echocardiography in the pulmonary artery distal to the degenerated homograft in patients after Ross surgery. Ninety-two patients with pulmonary homograft were investigated by Doppler echocardiography (mean time interval after surgery 31 ± 26 months). PR was measured as a function of pulmonary artery diameter determined by computed tomography angiography. Homograft orifice area, valve resistance, and transvalvular stroke work were calculated with and without considering PR. PR decreased as the pulmonary artery diameter increased (r = -0.69, p < 0.001). Mean PR was 41.5 ± 7.1% of the Doppler-derived pressure gradient (Pmax ), which resulted in a markedly increased homograft orifice area (energy loss coefficient index [ELCOI] vs. effective orifice area index [EOAI], 1.3 ± 0.4 cm2 /m2 vs. 0.9 ± 0.4 cm2 /m2 , p < 0.001). PR significantly reduced homograft resistance and transvalvular stroke work (822 ± 433 vs. 349 ± 220 mmHg × ml, p < 0.0001). When PR was considered, the correlations of the parameters used were significantly better, and 11 of 18 patients (61%) in the group with severe homograft stenosis (EOAI <0.6 cm2 /m2 ) could be reclassified as moderate stenosis. Our results showed that the Doppler measurements overestimated the degree of homograft stenosis and thus the right ventricular load, when PR was neglected in the pulmonary artery. Therefore, Doppler measurements that ignore PR can misclassify homograft stenosis and may lead to premature surgery.

State-of-the-art: Insights from the Ross Registry.

The treatment of aortic valve disease in young patients is still a major clinical challenge, as the pre-eminent emphasis is on durability and long-term outcomes beyond 10 to 15 years, sometimes >20 to 30 years. The Ross procedure uses the autologous pulmonary valve as an aortic valve substitute and aims to improve valve durability while avoiding anticoagulation and therefore achieve a sustained long-term result with regard to survival, valve functionality, and quality of life. However, this procedure is technically demanding and only performed at a low frequency. Data investigating the Ross procedure are mostly limited to observational studies from single expert centers, while sufficient randomized data are almost completely lacking. Therefore, to create a clinically relevant database of this therapy, the multicenter Ross Registry was founded in 2001. New patients were included, follow-up of past patients continuously updated, and outcomes regularly reported. Throughout recent years, numerous analyses have been performed to characterize this patient population, surgical techniques, risk factors for morbidity and mortality, and most importantly survival outcomes. Currently, more than 2500 patients are included, and the long-term follow-up has reached >25 years in the very first patients who were included. In the most recent study, 2444 adult patients with a mean age of 44.1 ± 11.7 years were analyzed, and it showed that excellent mid-term survival is maintained after 25 years. In addition, the rate of reintervention was lower than reported in patients with xenografts and anticoagulation-related morbidity lower than reported in patients with mechanical valves. In the absence of robust randomized controlled trials, registry data are very important to monitor outcomes and mirror the quality of current practice. Therefore, the Ross Registry provides a unique and important data base regarding treatment of aortic valve disease in young patients.