Computational fluid dynamics in cardiac surgery and perfusion: A review.

Cardiovascular diseases persist as a leading cause of mortality and morbidity, despite significant advances in diagnostic and surgical approaches. Computational Fluid Dynamics (CFD) represents a branch of fluid mechanics widely used in industrial engineering but is increasingly applied to the cardiovascular system. This review delves into the transformative potential for simulating cardiac surgery procedures and perfusion systems, providing an in-depth examination of the state-of-the-art in cardiovascular CFD modeling. The study first describes the rationale for CFD modeling and later focuses on the latest advances in heart valve surgery, transcatheter heart valve replacement, aortic aneurysms, and extracorporeal membrane oxygenation. The review underscores the role of CFD in better understanding physiopathology and its clinical relevance, as well as the profound impact of hemodynamic stimuli on patient outcomes. By integrating computational methods with advanced imaging techniques, CFD establishes a quantitative framework for understanding the intricacies of the cardiac field, providing valuable insights into disease progression and treatment strategies. As technology advances, the evolving synergy between computational simulations and clinical interventions is poised to revolutionize cardiovascular care. This collaboration sets the stage for more personalized and effective therapeutic strategies. With its potential to enhance our understanding of cardiac pathologies, CFD stands as a promising tool for improving patient outcomes in the dynamic landscape of cardiovascular medicine.

Venoarterial Extracorporeal Membrane Oxygenation for Postcardiotomy Shock-Analysis of the Extracorporeal Life Support Organization Registry.

OBJECTIVES: Refractory postcardiotomy cardiogenic shock complicating cardiac surgery yields nearly 100% mortality when untreated. Use of venoarterial extracorporeal membrane oxygenation for postcardiotomy cardiogenic shock has increased worldwide recently. The aim of the current analysis was to outline the trends in use, changing patient profiles, and in-hospital outcomes including complications in patients undergoing venoarterial extracorporeal membrane oxygenation for postcardiotomy cardiogenic shock. DESIGN: Analysis of extracorporeal life support organization registry from January 2010 to December 2018. SETTING: Multicenter worldwide registry. PATIENTS: Seven-thousand one-hundred eighty-five patients supported with venoarterial extracorporeal membrane oxygenation for postcardiotomy cardiogenic shock. INTERVENTIONS: Venoarterial extracorporeal membrane oxygenation. MEASUREMENTS AND MAIN RESULTS: Hospital death, weaning from extracorporeal membrane oxygenation, hospital complications. Mortality predictors were assessed by multivariable logistic regression. Propensity score matching was performed for comparison of peripheral and central cannulation for extracorporeal membrane oxygenation. A significant trend toward more extracorporeal membrane oxygenation use in recent years (coefficient, 0.009; p < 0.001) was found. Mean age was 56.3 ± 14.9 years and significantly increased over time (coefficient, 0.513; p < 0.001). Most commonly, venoarterial extracorporeal membrane oxygenation was instituted after coronary artery bypass surgery (26.8%) and valvular surgery (25.6%), followed by heart transplantation (20.7%). Overall, successful extracorporeal membrane oxygenation weaning was possible in 4,520 cases (56.4%), and survival to hospital discharge was achieved in 41.7% of cases. In-hospital mortality rates remained constant over time (coefficient, -8.775; p = 0.682), whereas complication rates were significantly reduced (coefficient, -0.009; p = 0.003). Higher mortality was observed after coronary artery bypass surgery (65.4%), combined coronary artery bypass surgery with valve (68.4%), and aortic (69.6%) procedures than other indications. Lower mortality rates were observed in heart transplantation recipients (46.0%). Age (p < 0.001), central cannulation (p < 0.001), and occurrence of complications while on extracorporeal membrane oxygenation were independently associated with poorer prognosis. CONCLUSIONS: The analysis confirmed increased use of venoarterial extracorporeal membrane oxygenation for postcardiotomy cardiogenic shock. Mortality rates remained relatively constant over time despite a decrease in complications, in the setting of supporting older patients.

Extracorporeal life support for phaeochromocytoma-induced cardiogenic shock: a systematic review.

INTRODUCTION: Phaeochromocytoma is a catecholamine-secreting tumour associated with clinical presentation ranging from paroxysmal hypertension to intractable cardiogenic shock. Extracorporeal life support, in veno-arterial mode, application in refractory acute heart dysfunction is sharply increasing worldwide. However, its clinical utility in phaeochromocytoma-induced cardiogenic shock remains still unclear. METHODS: A systematic review of published reports was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Statement. Searches were accomplished on PubMed, Embase and Google Scholar to identify articles describing the use of extracorporeal life support in the setting of phaeochromocytoma-induced cardiogenic shock (PROSPERO: CRD42019125225). RESULTS: Thirty-five reports, including 62 patients supported with extracorporeal life support because of intractable phaeochromocytoma crisis, were included for the analysis. Almost all the subjects underwent peripheral cannulation for extracorporeal life support. The median duration of the mechanical circulatory support was 5 days, and most of the patients recovered normal myocardial function (left ventricular ejection fraction ⩾50%). In-hospital survival was 87%. Phaeochromocytoma was removed surgically during extracorporeal life support in 10 patients (16%), while in the remaining after haemodynamic stabilization and weaning from the mechanical support. CONCLUSION: Successful management of phaeochromocytoma-induced cardiogenic shock depends on prompt recognition and immediate treatment of shock. In this scenario, extracorporeal life support may play a significant role allowing cardiac and end-organ recovery and giving time for accurate diagnosis and specific treatment.

Identification of circumferential regional heterogeneity of ascending thoracic aneurysmal aorta by biaxial mechanical testing.

Ascending thoracic aortic aneurysm (ATAA) in patients with bicuspid aortic valve (BAV) can present an asymmetrical aortic dilatation compared with patients with tricuspid aortic valve (TAV). This pattern of aneurysm dilatation led us to hypothesize that biomechanical differences likely induced by regional heterogeneity of material properties can underlie the observed asymmetric enlargement discrepancies between BAV ATAA and TAV ATAA. This study aimed to characterize the mechanical properties and associated aortic tissue stiffness changes along the circumferential direction of aortic rings collected from surgically-repaired patients with ATAA. Biaxial material testing was performed on tissue specimens extrapolated from all aortic quadrants (i.e. anterior, posterior, major and minor curvature of the aorta), and then the tissue stiffness was quantified at both physiological and supra-physiological stress levels (i.e. 142 kPa and 242 kPa, respectively). Tissue stiffness revealed that the major curvature of BAV ATAA is statistically less stiff than the anterior quadrant (276.6 ±â€¯137.1 kPa for BAV ATAA and 830.1 ±â€¯557.1 kPa for BAV ATAA, p = .024, at 142 kPa) and to that of major curvature of TAV ATAA (276.6 ±â€¯137.0 kPa for BAV ATAA and 733.2 ±â€¯391.1 kPa for TAV ATAA, p = .001, at 142 kPa), suggesting local weakening of bicuspid aortic wall. Multiphoton imaging revealed local changes on elastic fiber networks. The recovered material parameters for the Fung-type constitutive model are crucial for reliable stress predictions while the information on regional tissue stiffness changes are fundamental to develop risk stratification strategies not based on aortic size.

Limb ischemia in peripheral veno-arterial extracorporeal membrane oxygenation: a narrative review of incidence, prevention, monitoring, and treatment.

Veno-arterial extracorporeal membrane oxygenation (V-A ECMO) is an increasingly adopted life-saving mechanical circulatory support for a number of potentially reversible or treatable cardiac diseases. It is also started as a bridge-to-transplantation/ventricular assist device in the case of unrecoverable cardiac or cardio-respiratory illness. In recent years, principally for non-post-cardiotomy shock, peripheral cannulation using the femoral vessels has been the approach of choice because it does not need the chest opening, can be quickly established, can be applied percutaneously, and is less likely to cause bleeding and infections than central cannulation. Peripheral ECMO, however, is characterized by a higher rate of vascular complications. The mechanisms of such adverse events are often multifactorial, including suboptimal arterial perfusion and hemodynamic instability due to the underlying disease, peripheral vascular disease, and placement of cannulas that nearly occlude the vessel. The effect of femoral artery damage and/or significant reduced limb perfusion can be devastating because limb ischemia can lead to compartment syndrome, requiring fasciotomy and, occasionally, even limb amputation, thereby negatively impacting hospital stay, long-term functional outcomes, and survival. Data on this topic are highly fragmentary, and there are no clear-cut recommendations. Accordingly, the strategies adopted to cope with this complication vary a great deal, ranging from preventive placement of antegrade distal perfusion cannulas to rescue interventions and vascular surgery after the complication has manifested.This review aims to provide a comprehensive overview of limb ischemia during femoral cannulation for VA-ECMO in adults, focusing on incidence, tools for early diagnosis, risk factors, and preventive and treating strategies.

In-hospital outcomes after emergency or prophylactic veno-arterial extracorporeal membrane oxygenation during transcatheter aortic valve implantation: a comprehensive review of the literature.

Veno-arterial extracorporeal membrane oxygenation (V-A ECMO) has been used to deal with life-threatening complications as well as back-up or active cardiovascular support during high-risk procedures in patients undergoing transcatheter aortic valve implantation (TAVI). PubMed and MEDLINE electronic databases were searched in order to identify studies with emergency or prophylactic V-A ECMO application in association with TAVI procedures. From November 2012 to November 2017, 14 relevant studies were identified that included 5,115 TAVI patients of whom 102 (2%) required V-A ECMO (22 prophylactically, 66 as an emergency and 14 without a reported indication). The reason for emergency V-A ECMO institution was detailed in 64 patients: left ventricle free wall rupture (n = 14), haemodynamic instability (n = 12), ventricular arrhythmias (n = 7), aortic annulus rupture (n = 6), coronary obstruction (n = 6), low left ventricular output (ejection fraction <35%) (n = 5), uncontrollable bleeding (n = 5), severe aortic regurgitation (n = 4), prosthesis embolisation (n = 3), aortic dissection (n = 1) and respiratory failure (n = 1). Femoral arterial and vein cannulation was the most common access technique for V-A ECMO institution. Major bleeding (n = 7) and vascular access complications (n = 7) were reported after ECMO institution. The overall in-hospital survival was 73% (61% in the emergency vs. 100% in the prophylactic group). V-A ECMO support should be available at any centre performing TAVI and provides effective mechanical circulatory support in an emergency setting. We present an algorithm to aid decisions about prophylactic circulatory assistance with V-A ECMO and it should form part of the heart team discussion before a TAVI procedure is undertaken.

Protracted aortic valve closure during peripheral veno-arterial extracorporeal life support: is intra-aortic balloon pump an effective solution?

BACKGROUND: Left ventricular (LV) afterload increase with protracted aortic valve (AV) closure may represent a complication of veno-arterial extracorporeal membrane oxygenation (V-A ECMO). The aim of the present study was to assess the effects of an intra-aortic balloon pump (IABP) to overcome such a hemodynamic shortcoming in patients submitted to peripheral V-A ECMO. METHODS: Among 184 adult patients who were treated with peripheral V-A ECMO support at Medical University Center Maastricht Hospital between 2007 and 2018, patients submitted to IABP implant for protracted AV closure after V-A ECMO implant were retrospectively identified. All clinical and hemodynamic data, including echocardiographic monitoring, were collected and analyzed. RESULTS: During the study period, 10 subjects (mean age 60 years old, 80% males) underwent IABP implant after peripheral V-A ECMO positioning due to the diagnosis of protracted AV closure and inefficient LV unloading as assessed by echocardiography and an absence of pulsation in the arterial pressure wave. Recovery of blood pressure pulsatility and enhanced LV unloading were observed in 8 patients after IABP placement, with no significant differences in the main hemodynamic parameters, inotropic therapy or in the ECMO flow (p=0.48). The weaning rate in this patient subgroup (mean ECMO duration 8 days), however, was only 10%, with another patient finally transplanted, leading to a 20% survival-to-hospital discharge. CONCLUSION: IABP placement was an effective solution in order to reverse the protracted AV closure and impaired LV unloading observed during peripheral V-A ECMO support. However, the impact on the weaning rate and survival needs further investigations.

Pathoanatomic Findings and Treatment During Hypertrophic Obstructive Cardiomyopathy Surgery: The Role of Mitral Valve.

BACKGROUND: To assess the role of the mitral valve apparatus (leaflets, chordae and papillary muscles, (PM)) in left ventricle outflow tract (LVOT) obstruction, and results of the surgical treatment for hypertrophic obstructive cardiomyopathy (HOCM). METHODS: Twenty-eight consecutive patients (58±11years, 53% female) undergoing HOCM surgery from 2007 to 2016 at our institute were retrospectively reviewed. Endpoints included the involvement of the mitral valve in LVOT obstruction, mortality, and changes in clinical and echocardiographic characteristics after HOCM surgery. RESULTS: Secondary chordae tendineae tractioning the anterior mitral leaflet to the interventricular septum, and systolic anterior motion were detected in 78% of the patients. Anomalous, hypertrophied, and fused PM with muscularis trabeculae hypertrophy were found in 50%, 25%, and 35% of the patients, respectively. Four patients had posterior leaflet redundancy. Secondary chordae (92%), PM, and muscularis trabeculae resection (71%), and PM splitting and elongation (28%) were added variably to septal myectomy (100%). Nine procedures (32%) on mitral valve leaflets were performed, involving six posterior and three anterior mitral leaflets. Long-term follow-up was 4±2.8years. There was no hospital mortality, and NYHA was reduced from 3±0.5 to 1±0.7 (p<0.0001), the LVOT gradient from 88±35 to 20±18mmHg (p<0.0001), mitral valve regurgitation from grade 3±1 to 1±0.7 (p<0.0001), and septum thickness from 18±3 to 14±2mm (p<0.0001). CONCLUSIONS: The mitral valve apparatus contributes with all its components variably to LVOT dynamic obstruction thus surgical correction in addition to extended myectomy is recommended to achieve the best outcome.

Three-dimensional parametric modeling of bicuspid aortopathy and comparison with computational flow predictions.

Bicuspid aortic valve (BAV)-associated ascending aneurysmal aortopathy (namely "bicuspid aortopathy") is a heterogeneous disease making surgeon predictions particularly challenging. Computational flow analysis can be used to evaluate the BAV-related hemodynamic disturbances, which likely lead to aneurysm enlargement and progression. However, the anatomic reconstruction process is time consuming so that predicting hemodynamic and structural evolution by computational modeling is unfeasible in routine clinical practice. The aim of the study was to design and develop a parametric program for three-dimensional (3D) representations of aneurysmal aorta and different BAV phenotypes starting from several measures derived by computed-tomography angiography (CTA). Assuming that wall shear stress (WSS) has an important implication on bicuspid aortopathy, computational flow analyses were then performed to estimate how different would such an important parameter be, if a parametric aortic geometry was used as compared to standard geometric reconstructions obtained by CTA scans. Morphologic parameters here documented can be used to rapidly model the aorta and any phenotypes of BAV. t-test and Bland-Altman plot demonstrated that WSS obtained by flow analysis of parametric aortic geometries was in good agreement with that obtained from the flow analysis of CTA-related geometries. The proposed program offers a rapid and automated tool for 3D anatomic representations of bicuspid aortopathy with promising application in routine clinical practice by reducing the amount of time for anatomic reconstructions.

Stanford Type A Acute Retrograde Aortic Dissections: From Surgical to Endovascular Strategy?

Acute type A retrograde aortic dissection is characterized by a port of entry located in the descending aorta near the subclavian take-off, and is currently treated with surgery. Our experience with two patients who underwent a complicated postoperative course stimulated a review of the current literature and discussion of possible alternative strategies in light of recent advances in endovascular treatment.

Systemic or Endoventricular Thrombolysis to Treat HeartWare Left Ventricle Assist Device Thrombosis: A Clinical Dilemma.

Endoventricular thrombolytic procedure (ETP) has been used to treat continuous-flow left ventricle assist device (CF-LVAD) thrombosis. The study aims to investigate the occurrence of complications after ETP. Data were retrospectively reviewed and analyzed in a series of patients who underwent CF-LVAD followed by ETP. Since November 2010, 20 patients underwent HeartWare CF-LVAD implantation at our institute. Four patients (20%) developed pump thrombosis and underwent a total of nine ETPs with tissue plasminogen activator infused into the left ventricle. The mean age was 60.2 ± 9 years. ETP was performed via either the femoral (n = 6) or radial artery (n = 3). Five ETPs (55.5%) were complicated by left and right radial artery occlusion, two by groin hematomas, and one by femoral artery false aneurysm. ETP carries a strong risk of vascular access complications that, in CF-LVAD patients, may add to the already complex clinical profile and economic burden; thus, a less invasive treatment is advisable whenever required.

Surgical Coronary Revascularization in Patients With Underlying Atrial Fibrillation: State-of-the-Art Review.

The number of individuals referred for coronary artery bypass grafting (CABG) with preoperative atrial fibrillation (AF) is reported to be 8% to 20%. Atrial fibrillation is a known marker of high-risk patients as it was repeatedly found to negatively influence survival. Therefore, when performing surgical revascularization, consideration should be given to the concomitant treatment of the arrhythmia, the clinical consequences of the arrhythmia itself, and the selection of adequate surgical techniques. This state-of-the-art review aimed to provide a comprehensive analysis of the current understanding of, advancements in, and optimal strategies for CABG in patients with underlying AF. The following topics are considered: stroke prevention, prophylaxis and occurrence of postoperative AF, the role of surgical ablation and left atrial appendage occlusion, and an on-pump vs off-pump strategy. Multiple acute complications can occur in patients with preexisting AF undergoing CABG, each of which can have a significant effect on patient outcomes. Long-term results in these patients and the future perspectives of this scientific area were also addressed. Preoperative arrhythmia should always be considered for surgical ablation because such an approach improves prognosis without increasing perioperative risk. While planning a revascularization strategy, it should be noted that although off-pump coronary artery bypass provides better short-term outcomes, conventional on-pump approach may be beneficial at long-term follow-up. By collecting the current evidence, addressing knowledge gaps, and offering practical recommendations, this state-of-the-art review serves as a valuable resource for clinicians involved in the management of patients with AF undergoing CABG, ultimately contributing to improved outcomes and enhanced patient care.

Conversion to sternotomy during sternal-sparing coronary artery surgery.

Conversion to a full sternotomy may complicate up to 1.8% of the sternal-sparing coronary artery surgery. Left internal mammary artery injury and anastomotic problems are the common causes. The purpose of this article is to retrospectively review the outcomes of six patients that required conversion to sternotomy during minimally invasive direct coronary artery bypass and also to point out technical aspects in order to avoid such a complication.

Erector spinae plane block versus paravertebral block for postoperative pain management in thoracic surgery: a systematic review and meta-analysis.

INTRODUCTION: The 2018 guidelines for enhanced recovery in thoracic surgery recommend paravertebral block (PVB) for postoperative pain management. However, recent studies demonstrate that erector spinae plane block (ESPB) achieves similar postoperative pain control with reduced block-related complications. EVIDENCE ACQUISITION: We conducted a meta-analysis of randomized controlled trials to evaluate the analgesic efficacy and safety of ESPB versus PVB for pain management after thoracic surgery. PubMed, Embase, and Scopus were searched through December 2022 (PROSPERO registration - CRD42023395593). Primary outcomes were postoperative pain scores, resting at 6, 12, 24, and 48 hours, and at movement at 24 and 48 hours. Secondary outcomes included opioid consumption at 24 and 48 hours, and incidence of postoperative nausea and vomiting or block-related complications in the first 48 hours. EVIDENCE SYNTHESIS: Ten randomized control trials enrolling a total of 624 total patients were included. There were no significant differences in pain scores, resting or at movement, at any time points except reduced resting pain scores at 12 hours with PVB (mean difference [MD]) 0.60, 95% confidence interval [CI] 0.32 to 0.88). Opioid consumption demonstrated no significant differences at 24 hours; PVB reduced opioid consumption at 48 hours (MD 0.40, 95% CI -0.09 to 0.89). There were no significant differences in postoperative nausea or vomiting. ESPB exhibited a nonsignificant trend toward reduced cumulative block-related complications (risk difference [RD] 0.05, 95% CI -0.10 to 0.00). CONCLUSIONS: Compared with PVB, ESPB is safe and demonstrates no clinically significant differences in pain management after thoracic surgery.

Prognostic impact of preoperative atrial fibrillation in patients undergoing heart surgery in cardiogenic shock.

Surgical intervention in the setting of cardiogenic shock (CS) is burdened with high mortality. Due to acute condition, detailed diagnoses and risk assessment is often precluded. Atrial fibrillation (AF) is a risk factor for perioperative complications and worse survival but little is known about AF patients operated in CS. Current analysis aimed to determine prognostic impact of preoperative AF in patients undergoing heart surgery in CS. We analyzed data from the Polish National Registry of Cardiac Surgery (KROK) Procedures. Between 2012 and 2021, 332,109 patients underwent cardiac surgery in 37 centers; 4852 (1.5%) patients presented with CS. Of those 624 (13%) patients had AF history. Cox proportional hazards models were used for computations. Propensity score (nearest neighbor) matching for the comparison of patients with and without AF was performed. Median follow-up was 4.6 years (max.10.0), mean age was 62 (± 15) years and 68% patients were men. Thirty-day mortality was 36% (1728 patients). The origin of CS included acute myocardial infarction (1751 patients, 36%), acute aortic dissection (1075 patients, 22%) and valvular dysfunction (610 patients, 13%). In an unadjusted analysis, patients with underlying AF had almost 20% higher mortality risk (HR 1.19, 95% CIs 1.06-1.34; P = 0.004). Propensity score matching returned 597 pairs with similar baseline characteristics; AF remained a significant prognostic factor for worse survival (HR 1.19, 95% CI 1.00-1.40; P = 0.045). Among patients with CS referred for cardiac surgery, history of AF was a significant risk factor for mortality. Role of concomitant AF ablation and/or left atrial appendage occlusion or more aggressive perioperative circulatory support should be addressed in the future.

Aortic valve replacement for paraprosthetic leak after transcatheter implantation.

Conversion to surgical aortic valve replacement (AVR) has been described as a complication following transcatheter aortic valve implantation. This complication occurs in up to 8% of cases and, to the best of our knowledge, preoperative data and surgical outcomes of such patients have not been properly evaluated. Mild paraprosthetic regurgitation is commonly observed after transcatheter aortic valve implantation and usually leads to a benign clinical course. Unequal distribution of valve calcifications is described as a potential mechanism. We report a case of a perioperative paraprosthetic regurgitation that underwent successful urgent surgical AVR and review the incidence and results of paraprosthetic leaks following transcatheter implantation.

Septal Thickness Does Not Impact Outcome After Hypertrophic Obstructive Cardiomyopathy Surgery (Septal Myectomy and Subvalvular Mitral Apparatus Remodeling): A 15-Years of Experience.

Background: The aim of this study was to assess the impact of septal thickness on long-term outcomes of surgical treatment for hypertrophic obstructive cardiomyopathy (HOCM) and correction of mitral subvalvular anomalies. Methods: Sixty-six consecutive patients (58 ± 12 years, 56% female) undergoing extended septal myectomy and subvalvular mitral apparatus remodeling from 2007 to 2021 were retrospectively reviewed. Patients were divided into 2 groups according to septal thickness: moderate [< 18 mm, 29 patients (44%)] and severe [≥ 18 mm, 37 patients (56%)]. End points included survival, symptom improvement, reduction of left ventricle outflow tract (LVOT) gradient, resolution of mitral regurgitation (MR), and reoperation. Results: The mean interventricular septal thickness was 19 ± 3 mm, 15.8 ± 0.8 mm in patients with moderate and 21.4 ± 3.2 mm in those with severe hypertrophy. Preoperative data, intraoperative variables, postoperative complication rates, pre-discharge echocardiographic and clinical parameters did not differ between the two study groups [except for procedures involving the posterior mitral leaflet (p = 0.033) and septal thickness after myectomy (p = 0.0001)]. Subvalvular apparatus remodeling (secondary chordae of mitral valve resection and papillary muscle and muscularis trabecula procedures including resection, splitting, and elongation) was invariably added to septal myectomy (100%). Four (6%) procedures involved the posterior mitral leaflets. Mitral valve replacement was carried out in two patients (3%, p = 0.4). Reoperation for persistent MR was necessary in one patient (1%, p = 0.4). Neither iatrogenic ventricular septal defect nor in-hospital mortality occurred. During follow-up (mean 4.8 ± 3.8 years), two deaths occurred. NYHA class was reduced from 2.9 ± 0.7 to 1.6 ± 0.6 (p < 0.0001), the LVOT gradient from 89.7 ± 34.5 to 16.3 ± 8.8 mmHg (p < 0.0001), mitral valve regurgitation grade from 2.5 ± 1 to 1.2 ± 0.5 (p < 0.0001), and septal thickness from 18.9 ± 3.7 to 13.9 ± 2.7 mm (p < 0.0001). Conclusions: Regardless of septal thickness, subvalvular apparatus remodeling with concomitant septal myectomy can provide satisfactory long-term outcomes in terms of symptom improvement, LVOT obstruction relief, and MR resolution (without mitral valve replacement in most cases) in patients with HOCM.

Patient-Specific Analysis of Ascending Thoracic Aortic Aneurysm with the Living Heart Human Model.

In ascending thoracic aortic aneurysms (ATAAs), aneurysm kinematics are driven by ventricular traction occurring every heartbeat, increasing the stress level of dilated aortic wall. Aortic elongation due to heart motion and aortic length are emerging as potential indicators of adverse events in ATAAs; however, simulation of ATAA that takes into account the cardiac mechanics is technically challenging. The objective of this study was to adapt the realistic Living Heart Human Model (LHHM) to the anatomy and physiology of a patient with ATAA to assess the role of cardiac motion on aortic wall stress distribution. Patient-specific segmentation and material parameter estimation were done using preoperative computed tomography angiography (CTA) and ex vivo biaxial testing of the harvested tissue collected during surgery. The lumped-parameter model of systemic circulation implemented in the LHHM was refined using clinical and echocardiographic data. The results showed that the longitudinal stress was highest in the major curvature of the aneurysm, with specific aortic quadrants having stress levels change from tensile to compressive in a transmural direction. This study revealed the key role of heart motion that stretches the aortic root and increases ATAA wall tension. The ATAA LHHM is a realistic cardiovascular platform where patient-specific information can be easily integrated to assess the aneurysm biomechanics and potentially support the clinical management of patients with ATAAs.

Right ventricular failure after left ventricular assist device implantation: a review of the literature.

Right ventricular failure (RVF) following left ventricular assist device (LVAD) implantation remains a major complication which may significantly impair patient outcome. The genesis of RVF is, however, multifactorial, and the mechanisms underlying such a condition have not been fully elucidated, making its prevention challenging and the course not always predictable. Although preoperative risks factors can be associated with RV impairment, the physiologic changes after the LV support, can still hamper the function of the RV. Current medical treatment options are limited and sometimes, patients with a severe post-LVAD RVF may be unresponsive to pharmacological therapy and require more aggressive treatment, such as temporary RV support. We retrieved 11 publications which we assessed and divided in groups based on the RV support [extracorporeal membrane oxygenation (ECMO), right ventricular assist device (RVAD), TandemHeart with ProtekDuo cannula]. The current review comprehensively summarizes the main studies of the literature with particular attention to the RV physiology and its changes after the LVAD implantation, the predictors and prognostic score as well as the different modalities of temporary mechanical cardio-circulatory support, and its effects on patient prognosis for RVF in such a setting. In addition, it provides a decision making of the pre-, intra and post-operative management in high- and moderate- risk patients.