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1.
Artif Organs ; 48(5): 550-558, 2024 May.
Article in English | MEDLINE | ID: mdl-38409825

ABSTRACT

BACKGROUND: In conventional left ventricular assist devices (LVAD), a separate outflow graft is sutured to the ascending aorta. Novel device designs may include a transventricular outflow cannula crossing the aortic valve (AV). While transversal ventricular dimensions are well investigated in patients with severe heart failure, little is known about the longitudinal dimensions. These dimensions are, however, particularly critical for the design and development of mechanical circulatory support (MCS) devices with transaortic outflow cannula. METHODS: In an explorative retrospective cohort study at the University Medical Center Freiburg, Germany, the longitudinal cardiac dimensions of patients undergoing computed tomography angiography (CTA) before and, if available, after LVAD implantation were analyzed. Among others, the following dimensions were assessed: (a) apex to AV, (b) apex to mitral valve, (c) AV to sinotubular junction (STJ), (d) apex to STJ, (e) apex to brachiocephalic artery (BCA), and (f) AV to BCA. RESULTS: In total, 44 LVAD patients (36 male, age 55.8 years, height 1.75 m) were included. The longitudinal cardiac dimensions were (a) 114.5 ± 12.1 mm, (b) 108.0 ± 12.4 mm, (c) 20.9 ± 2.9, (d) 135.4 ± 13.4 mm, (e) 206.0 ± 18.3, and (f) 91.5 ± 9.8 mm. Postoperatively, (a) and (b) decreased by 31.5% and 39.5%, respectively (N = 14). CONCLUSIONS: Longitudinal cardiac dimensions may be reduced by up to 40% after LVAD implantation. A better knowledge of these dimensions and their postoperative alterations in LVAD patients may improve surgical planning and help to design MCS devices with transventricular outflow cannula.


Subject(s)
Heart Failure , Heart-Assist Devices , Thoracic Surgical Procedures , Humans , Male , Middle Aged , Retrospective Studies , Aorta, Thoracic/surgery , Aorta , Aortic Valve , Heart-Assist Devices/adverse effects , Heart Failure/surgery , Treatment Outcome
2.
Cardiovasc Ultrasound ; 22(1): 3, 2024 Jan 16.
Article in English | MEDLINE | ID: mdl-38229189

ABSTRACT

BACKGROUND: Swine are frequently used as animal model for cardiovascular research, especially in terms of representativity of human anatomy and physiology. Reference values for the most common species used in research are important for planning and execution of animal testing. Transesophageal echocardiography is the gold standard for intraoperative imaging, but can be technically challenging in swine. Its predecessor, epicardial echocardiography (EE), is a simple and fast intraoperative imaging technique, which allows comprehensive and goal-directed assessment. However, there are few echocardiographic studies describing echocardiographic parameters in juvenile swine, none of them using EE. Therefore, in this study, we provide a comprehensive dataset on multiple geometric and functional echocardiographic parameters, as well as basic hemodynamic parameters in swine using EE. METHODS: The data collection was performed during animal testing in ten female swine (German Landrace, 104.4 ± 13.0 kg) before left ventricular assist device implantation. Hemodynamic data was recorded continuously, before and during EE. The herein described echocardiographic measurements were acquired according to a standardized protocol, encompassing apical, left ventricular short axis and long axis as well as epiaortic windows. In total, 50 echocardiographic parameters and 10 hemodynamic parameters were assessed. RESULTS: Epicardial echocardiography was successfully performed in all animals, with a median screening time of 14 min (interquartile range 11-18 min). Referring to left ventricular function, ejection fraction was 51.6 ± 5.9% and 51.2 ± 6.2% using the Teichholz and Simpson methods, respectively. Calculated ventricular mass was 301.1 ± 64.0 g, as the left ventricular end-systolic and end-diastolic diameters were 35.3 ± 2.5 mm and 48.2 ± 3.5 mm, respectively. The mean heart rate was 103 ± 28 bpm, mean arterial pressure was 101 ± 20 mmHg and mean flow at the common carotid artery was 627 ± 203 mL/min. CONCLUSION: Epicardial echocardiography allows comprehensive assessment of most common echocardiographic parameters. Compared to humans, there are important differences in swine with respect to ventricular mass, size and wall thickness, especially in the right heart. Most hemodynamic parameters were comparable between swine and humans. This data supports study planning, animal and device selection, reinforcing the three R principles in animal research.


Subject(s)
Echocardiography , Ventricular Function, Left , Humans , Female , Animals , Swine , Ventricular Function, Left/physiology , Echocardiography/methods , Hemodynamics , Heart Ventricles/diagnostic imaging
3.
Circulation ; 145(13): 959-968, 2022 03 29.
Article in English | MEDLINE | ID: mdl-35213213

ABSTRACT

BACKGROUND: Cardiac surgery often represents the only treatment option in patients with infective endocarditis (IE). However, IE surgery may lead to a sudden release of inflammatory mediators, which is associated with postoperative organ dysfunction. We investigated the effect of hemoadsorption during IE surgery on postoperative organ dysfunction. METHODS: This multicenter, randomized, nonblinded, controlled trial assigned patients undergoing cardiac surgery for IE to hemoadsorption (integration of CytoSorb to cardiopulmonary bypass) or control. The primary outcome (change in sequential organ failure assessment score [ΔSOFA]) was defined as the difference between the mean total postoperative SOFA score, calculated maximally to the 9th postoperative day, and the basal SOFA score. The analysis was by modified intention to treat. A predefined intergroup comparison was performed using a linear mixed model for ΔSOFA including surgeon and baseline SOFA score as fixed effect covariates and with the surgical center as random effect. The SOFA score assesses dysfunction in 6 organ systems, each scored from 0 to 4. Higher scores indicate worsening dysfunction. Secondary outcomes were 30-day mortality, duration of mechanical ventilation, and vasopressor and renal replacement therapy. Cytokines were measured in the first 50 patients. RESULTS: Between January 17, 2018, and January 31, 2020, a total of 288 patients were randomly assigned to hemoadsorption (n=142) or control (n=146). Four patients in the hemoadsorption and 2 in the control group were excluded because they did not undergo surgery. The primary outcome, ΔSOFA, did not differ between the hemoadsorption and the control group (1.79±3.75 and 1.93±3.53, respectively; 95% CI, -1.30 to 0.83; P=0.6766). Mortality at 30 days (21% hemoadsorption versus 22% control; P=0.782), duration of mechanical ventilation, and vasopressor and renal replacement therapy did not differ between groups. Levels of interleukin-1ß and interleukin-18 at the end of integration of hemoadsorption to cardiopulmonary bypass were significantly lower in the hemoadsorption than in the control group. CONCLUSIONS: This randomized trial failed to demonstrate a reduction in postoperative organ dysfunction through intraoperative hemoadsorption in patients undergoing cardiac surgery for IE. Although hemoadsorption reduced plasma cytokines at the end of cardiopulmonary bypass, there was no difference in any of the clinically relevant outcome measures. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT03266302.


Subject(s)
Cardiac Surgical Procedures , Endocarditis, Bacterial , Endocarditis , Cardiac Surgical Procedures/adverse effects , Cardiac Surgical Procedures/methods , Cytokines , Endocarditis/surgery , Humans , Multiple Organ Failure , Treatment Outcome
4.
BMC Vet Res ; 19(1): 212, 2023 Oct 18.
Article in English | MEDLINE | ID: mdl-37853424

ABSTRACT

BACKGROUND: Anatomic anomalies in the ascending aorta may impair the implantation and testing of cardiovascular devices in humans and animal models. CASE PRESENTATION: We present the rare case of an intra-aortic band in a German Landrace pig. During terminal animal testing, the band hindered the implantation of a left ventricular assist device (LVAD) with transventricular outflow graft across the aortic valve. After lower partial sternotomy, epicardial echocardiography displayed an intraluminal echogenic structure at the sinotubular junction causing unspecific flow turbulences. Under cardiopulmonary bypass, coring of the left ventricular apex was performed. Due to strong resistance in the proximal aorta, accurate positioning of the transventricular LVAD outflow graft was impossible. After euthanasia, necropsy revealed a fibrous band located at the sinotubular junction, dividing the lumen of the ascending aorta. CONCLUSIONS: The occurrence of an intra-aortic band represents an extremely rare case of a most likely congenital anomaly. Awareness of such anomalies is important for planning and performing animal testing. Perioperative echocardiography may help to either remove such anomalies or allow discontinuing the procedure prior to device implantation.


Subject(s)
Aortic Valve Insufficiency , Swine Diseases , Humans , Animals , Swine , Euthanasia, Animal , Aorta/surgery , Aorta, Thoracic , Aortic Valve Insufficiency/veterinary , Models, Animal
5.
Article in English | MEDLINE | ID: mdl-35917823

ABSTRACT

BACKGROUND: Literature demonstrated that procedure volumes affect outcomes of patients undergoing transcatheter aortic valve implantation. We evaluated the outcomes of surgical aortic valve replacement. METHODS: All isolated surgical aortic valve replacement procedures in Germany in 2017 were identified. Hospitals were divided into five groups from ≤25 (very low volume) until >100 (very high volume) annual procedures. RESULTS: In 2017, 5,533 patients underwent isolated surgical aortic valve replacement. All groups were of comparable risk (logistic EuroSCORE, 5.12-4.80%) and age (66.6-68.1 years). In-hospital mortality and complication rates were lowest in the very high-volume group. Multivariable logistic regression analyses showed no significant volume-outcome relationship for in-hospital mortality, stroke, postoperative delirium, and mechanical ventilation > 48 hours. Regarding acute kidney injury, patients in the very high-volume group were at lower risk than those in the very low volume group (odds ratio [OR] = 0.53, p = 0.04). Risk factors for in-hospital mortality were previous cardiac surgery (OR = 5.75, p < 0.001), high-grade renal disease (glomerular filtration rate < 15 mL/min, OR = 5.61, p = 0.002), surgery in emergency cases (OR = 2.71, p = 0.002), and higher grade heart failure (NYHA [New York Heart Association] III/IV; OR = 1.80, p = 0.02). Risk factors for all four complication rates were atrial fibrillation and diabetes mellitus. CONCLUSION: Patients treated in very low volume centers (≤25 operations/year) had a similar risk regarding in-hospital mortality and most complications compared with very high-volume centers (>100 operations/year). Only in the case of acute kidney injury, very high-volume centers showed better outcomes than very low volume centers. Therefore, surgical aortic valve replacement can be performed safely independent of case volume.

6.
Cardiology ; 146(2): 228-237, 2021.
Article in English | MEDLINE | ID: mdl-32966978

ABSTRACT

AIM: The present study analyzes in depth the impact of different calcification patterns on disturbances of the conduction system in transcatheter aortic valve replacement (TAVR) patients. METHODS AND RESULTS: A total of 169 preprocedural TAVR multislice computed tomography scans from consecutive transfemoral (TF) TAVRs performed between 2014 and 2017 using either Edwards SAPIEN or Medtronic Evolut R valves were retrospectively evaluated. The volume, distribution, and orientation of annular and valvular aortic valve calcification were measured and their impact on postoperative conduction disturbances was determined using linear and logistic regression analyses. The total volume of calcification and distribution at the aortic annulus or valve did not influence the conduction system. Oval calcification of the left aortic cusp was independently associated with an elevated risk for an increase in atrioventricular block degree (+0.6, p = 0.03). Moreover, orthogonal calcifications at the level of the aortic annulus were associated with an increased risk for QRS prolongation (+26 ms, p = 0.004) and an increased risk for permanent pacemaker implantation (OR 4.3, p = 0.03) after TF TAVR. This was more pronounced in patients undergoing TF TAVR using a balloon-expandable Edwards SAPIEN 3 valve (QRS +38.195 ms, p < 0.001; OR permanent pacemaker 15.48, p = 0.013). CONCLUSION: Orthogonal annular calcification confers an increased risk for conduction disturbances after TAVR. This is even more pronounced after implantation of balloon-expandable valves.


Subject(s)
Aortic Valve Stenosis , Heart Valve Prosthesis , Transcatheter Aortic Valve Replacement , Aortic Valve/diagnostic imaging , Aortic Valve/surgery , Aortic Valve Stenosis/diagnostic imaging , Aortic Valve Stenosis/surgery , Heart Valve Prosthesis/adverse effects , Humans , Retrospective Studies , Risk Factors , Transcatheter Aortic Valve Replacement/adverse effects , Treatment Outcome
7.
Catheter Cardiovasc Interv ; 95(4): 810-816, 2020 03 01.
Article in English | MEDLINE | ID: mdl-31165569

ABSTRACT

BACKGROUND: Transcatheter aortic valve replacement (TAVR) is routinely used in patients with severe aortic stenosis at increased operative risk. Due to potential technical difficulties, TAVR is not recommended for pure aortic regurgitation (AR). Smaller studies reported its use in AR, but data from big registries are lacking. The present study analyzes the nationwide use of surgical aortic valve replacement (SAVR) and TAVR in patients with AR from 2008 until 2015. METHODS: We identified 138,237 cases of aortic valve replacement in Germany based on ICD and OPS codes. RESULTS: Of 13.2% SAVR-cases and 1.3% of TAVR cases were performed in AR. AR patients undergoing SAVR were younger with lower logistic EuroSCORE (stenosis: 6.1 ± 5.6; AR: 4.5 ± 4.9). Nevertheless, stroke rates, bleedings, prolonged mechanical ventilation, and in-hospital mortality were higher (mortality: stenosis 2.6%, AR: 4.7%). In the TAVR group, patients with AR were at higher operative risk (logistic EuroSCORE: transfemoral (TF)-TAVR: stenosis: 14.3 ± 10.4; AR: 17.3 ± 13.3. Transapical (TA)-TAVR: stenosis: 16.1 ± 11.4; AR: 15.7 ± 12.2). Stroke rates were lower, but bleedings and prolonged ventilation occurred more frequently after TF-TAVR in AR compared to stenosis. The mortality varied markedly (TF-TAVR: 15.2% in 2011; 2.8% in 2015; TA-TAVR: 17.7% in 2012 and 0% in 2014). CONCLUSION: TAVR is off-label used in AR in clinical practice. TAVR seems to be a safe option for AR with regard to in-hospital outcomes. However, further research evaluating long-term outcomes is required to establish the feasibility of TAVR in pure AR.


Subject(s)
Aortic Valve Insufficiency/surgery , Aortic Valve/surgery , Heart Valve Prosthesis Implantation , Transcatheter Aortic Valve Replacement , Aged , Aged, 80 and over , Aortic Valve/diagnostic imaging , Aortic Valve/physiopathology , Aortic Valve Insufficiency/diagnostic imaging , Aortic Valve Insufficiency/mortality , Aortic Valve Insufficiency/physiopathology , Female , Germany , Heart Valve Prosthesis Implantation/adverse effects , Heart Valve Prosthesis Implantation/mortality , Hemodynamics , Hospital Mortality , Humans , Male , Middle Aged , Postoperative Complications/mortality , Postoperative Complications/therapy , Retrospective Studies , Risk Assessment , Risk Factors , Time Factors , Transcatheter Aortic Valve Replacement/adverse effects , Transcatheter Aortic Valve Replacement/mortality , Treatment Outcome
8.
Catheter Cardiovasc Interv ; 96(1): E27-E33, 2020 07.
Article in English | MEDLINE | ID: mdl-31512392

ABSTRACT

OBJECTIVE: Aim of this study was to investigate predictors of survival in unstable patients with high SYNTAX-1-score. BACKGROUND: In significant unprotected left main coronary artery (ULMCA) stenosis, treatment options include percutaneous coronary intervention (PCI) and coronary artery bypass graft (CABG). While CABG is recommended for stable patients with ULMCA stenosis and a SYNTAX-1-score > 32, PCI may be preferable in unstable or high operative risk patients. METHODS: Retrospective single-center all-comers registry study. RESULTS: A total of 142 patients underwent ULMCA-PCI (~72.9 years, 23.2% females, 54.2% survival in 2-year follow-up), 84 of whom had a SYNTAX-1 > 32 (37.4 ± 12.8). Patients in the high-SYNTAX-1-group (score > 32) were more often in an acute condition compared to low-SYNTAX-2-group (score ≤ 32) including acute myocardial infarction (76.2% vs. 57.4%, p = .024), cardiogenic shock (48.2% vs. 14.8%, p = .001), or need for mechanical support (36.1% vs. 11.1%, p = .001). Survival was predicted by the acute condition including cardiogenic shock (OR 0.06 and 0.05) and myocardial infarction (OR 0.03 and 0.34) in both groups. Performance of the SYNTAX-1-score was limited in our patient collective in both groups (c-index 0.65 vs. 0.63) while SYNTAX-2-PCI-score performed better (c-index 0.67 vs. 0.67). EuroScore II had the best discriminative ability (c-index 0.87 vs. 0.78). CONCLUSIONS: The majority of patients undergoing ULMCA-PCI presented in acute conditions with high SYNTAX-1-score, and is therefore underrepresented in clinical trials. Prognosis was best predicted by the acute condition and the EuroScore II. These data suggest that therapy in unstable patients should be guided by clinical condition over the anatomical SYNTAX-1-score.


Subject(s)
Acute Coronary Syndrome/therapy , Coronary Angiography , Coronary Stenosis/therapy , Decision Support Techniques , Health Status Indicators , Percutaneous Coronary Intervention , Acute Coronary Syndrome/diagnostic imaging , Acute Coronary Syndrome/mortality , Aged , Aged, 80 and over , Coronary Stenosis/diagnostic imaging , Coronary Stenosis/mortality , Female , Humans , Male , Middle Aged , Percutaneous Coronary Intervention/adverse effects , Percutaneous Coronary Intervention/mortality , Registries , Retrospective Studies , Risk Assessment , Risk Factors , Time Factors , Treatment Outcome
9.
Clin Infect Dis ; 69(3): 487-494, 2019 07 18.
Article in English | MEDLINE | ID: mdl-30346527

ABSTRACT

BACKGROUND: The impact of valve surgery on outcomes of Staphylococcus aureus infective endocarditis (SAIE) remains controversial. We tested the hypothesis that early valve surgery (EVS) improves survival by using a novel approach that allows for inclusion of major confounders in a time-dependent way. METHODS: EVS was defined as valve surgery within 60 days. Univariable and multivariable Cox regression analyses were performed. To account for treatment selection bias, we additionally used a weighted Cox model (marginal structural model) that accounts for time-dynamic imbalances between treatment groups. To address survivor bias, EVS was included as a time-dependent variable. Follow-up of patients was 1 year. RESULTS: Two hundred and three patients were included in the analysis; 50 underwent EVS. All-cause mortality at day 30 was 26%. In the conventional multivariable Cox regression model, the effect of EVS on the death hazard was 0.85 (95% confidence interval [CI], .47-1.52). Using the weighted Cox model, the death hazard rate (HR) of EVS was 0.71 (95% CI, .34-1.49). In subgroup analyses, no survival benefit was observed in patients with septic shock (HR, 0.80 [CI, .26-2.46]), in NVIE (HR, 0.76 [CI, .33-1.71]) or PVIE (HR, 1.02 [CI, .29-3.54]), or in patients with EVS within 14 days (HR, 0.97 [CI, .46-2.07]). CONCLUSIONS: Using both a conventional Cox regression model and a weighted Cox model, we did not find a survival benefit for patients who underwent EVS in our cohort. Until results of randomized controlled trials are available, EVS in SAIE should be based on individualized decisions of an experienced multidisciplinary team. CLINICAL TRIALS REGISTRATION: German Clinical Trials registry (DRKS00005045).


Subject(s)
Endocarditis, Bacterial/mortality , Endocarditis, Bacterial/surgery , Heart Valves/surgery , Staphylococcal Infections/complications , Staphylococcal Infections/mortality , Female , Heart Valves/microbiology , Hospital Mortality , Humans , Male , Middle Aged , Proportional Hazards Models , Prospective Studies , Risk Factors , Selection Bias , Staphylococcus aureus
10.
Thorac Cardiovasc Surg ; 64(5): 447-9, 2016 Aug.
Article in English | MEDLINE | ID: mdl-25866974

ABSTRACT

In patients with functional/ischemic mitral regurgitation (FMR/IMR), mitral annuloplasty alone frequently results in recurrent regurgitation because of ongoing left ventricular dilatation and recurrent leaflet tethering. Adjunctive subvalvular approaches exist, but the technical shortcomings limit their clinical acceptance. A novel adjunctive technique was applied in three patients: A polytetrafluoroethylene string and noose were anchored to the posteromedial and anterolateral papillary muscle, respectively. The string ends were guided through the noose, exteriorized through the midposterior annulus into the left atrium, and length-adjusted during the saline test. The procedure allowed safe and straightforward papillary muscle repositioning and may stabilize repair results in FMR/IMR patients.


Subject(s)
Mitral Valve Annuloplasty/methods , Mitral Valve Insufficiency/surgery , Mitral Valve/surgery , Myocardial Ischemia/complications , Papillary Muscles/surgery , Suture Techniques , Humans , Mitral Valve/diagnostic imaging , Mitral Valve/physiopathology , Mitral Valve Annuloplasty/adverse effects , Mitral Valve Insufficiency/diagnostic imaging , Mitral Valve Insufficiency/etiology , Mitral Valve Insufficiency/physiopathology , Myocardial Ischemia/diagnosis , Myocardial Ischemia/physiopathology , Papillary Muscles/diagnostic imaging , Papillary Muscles/physiopathology , Polytetrafluoroethylene , Recovery of Function , Suture Techniques/adverse effects , Suture Techniques/instrumentation , Sutures , Treatment Outcome
11.
Inn Med (Heidelb) ; 65(5): 439-446, 2024 May.
Article in German | MEDLINE | ID: mdl-38597993

ABSTRACT

There is a broad spectrum of mitral valve diseases ranging from young patients with rheumatic mitral valve stenosis up to older patients with secondary mitral valve regurgitation and numerous comorbidities. A profound understanding of the etiology, anatomical characteristics of mitral valve diseases and current treatment options is necessary to be able to prepare a patient-centered treatment approach. The interdisciplinary collaboration of referring physicians, interventional cardiologists, cardiac surgeons, heart failure and imaging specialists as well as anesthesiologists is a cornerstone of optimal patient treatment.


Subject(s)
Cardiac Catheterization , Mitral Valve Insufficiency , Humans , Mitral Valve Insufficiency/surgery , Mitral Valve Insufficiency/diagnostic imaging , Cardiac Catheterization/methods , Mitral Valve/surgery , Mitral Valve/pathology , Mitral Valve/diagnostic imaging , Mitral Valve Stenosis/surgery , Mitral Valve Stenosis/diagnostic imaging , Heart Valve Diseases/surgery , Heart Valve Diseases/diagnostic imaging , Heart Valve Prosthesis Implantation/methods
12.
Health Sci Rep ; 7(1): e1777, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38186934

ABSTRACT

Background: Perioperative echocardiography is of paramount importance during cardiac surgery. Nonetheless, in the experimental large-animal setting, it might be challenging obtaining optimal imaging when using conventional imaging acquisition techniques, such as transthoracic and transesophageal screenings. Open-chest surgery allows epicardial echocardiographic assessment with direct contact between probe and heart, thus providing superior quality. Standard protocols regarding the use of epicardial ultrasound in swine for research purposes are lacking. Methods: Epicardial echocardiography was performed in 10 female German Landrace pigs undergoing cardiac surgery. A structured and comprehensive protocol for epicardial echocardiography was elaborated including apical, ventricular long and short axis, as well as epiaortic planes. All experiments were approved by the local board for animal welfare and conducted in accordance with the German animal protection law (TierSchG) and the ARRIVE guidelines. Conclusions: Systematic protocols using epicardial echocardiography may serve as an additional tool to assess cardiac dimensions and function in experimental scenarios with swine models.

13.
Sci Rep ; 14(1): 1869, 2024 01 22.
Article in English | MEDLINE | ID: mdl-38253776

ABSTRACT

Pigs are frequently applied as animal models in cardiovascular research due to their anatomical and physiological similarity to humans. For study planning and refinement, precise knowledge of the cardioaortic dimensions is essential. In a retrospective single-center study, the cardioaortic dimensions and left ventricular function of German Landrace pigs were assessed using cardiac MRI. All parameters were compared between male and female pigs and analyzed for correlation with body weight. In total, 15 pigs were included (7 male and 8 female, weight 60.9 ± 7.0 kg). The left ventricle revealed an end-diastolic diameter of 50.5 ± 4.4 mm and an ejection fraction of 51.2 ± 9.8%. The diameters of the ascending and descending aorta were 21.3 ± 2.3 and 16.2 ± 1.4 mm, respectively. There were no significant differences between male and female pigs, except that males had a smaller end-diastolic left ventricular volume (p = 0.041). A moderate correlation was found between body weight and the aortic annulus diameter (R = 0.57, p = 0.027). In conclusion, cardiac MRI allows precise quantification of porcine cardioaortic dimensions. For medical device testing, size differences between pigs and humans should be considered.


Subject(s)
Heart , Magnetic Resonance Imaging , Humans , Female , Male , Swine , Animals , Retrospective Studies , Heart/diagnostic imaging , Heart Ventricles/diagnostic imaging , Body Weight
14.
Circulation ; 126(11 Suppl 1): S231-8, 2012 Sep 11.
Article in English | MEDLINE | ID: mdl-22965988

ABSTRACT

BACKGROUND: We hypothesized that annuloplasty ring implantation alters mitral annular strains in a normal beating ovine heart preparation. METHODS AND RESULTS: Sheep had 16 radiopaque markers sewn equally spaced around the mitral annulus. Edwards Cosgrove partial flexible band (COS; n=12), St Jude complete rigid saddle-shaped annuloplasty ring (RSA; n=10), Carpentier-Edwards Physio (PHY; n=11), Edwards IMR ETlogix (ETL; n=11), and GeoForm (GEO; n=12) annuloplasty rings were implanted in a releasable fashion. Four-dimensional marker coordinates were obtained using biplane videofluoroscopy with the ring inserted (ring) and after ring release (control). From marker coordinates, a functional spatio-temporal representation of each annulus was generated through a best fit using 16 piecewise cubic Hermitian splines. Absolute total mitral annular ring strains were calculated from the relative change in length of the tangent vector to the annular curve as strains occurring from control to ring state at end-systole. In addition, average Green-Lagrange strains occurring from control to ring state at end-systole along the annulus were calculated. Absolute total mitral annular ring strains were smallest for COS and greatest for ETL. Strains for RSA, PHY, and GEO were similar. Except for COS in the septal mitral annular segment, all rings induced compressive strains along the entire annulus, with greatest values occurring at the lateral mitral annular segment. CONCLUSIONS: In healthy, beating ovine hearts, annuloplasty rings (COS, RSA, PHY, ETL, and GEO) induce compressive strains that are predominate in the lateral annular region, smallest for flexible partial bands (COS) and greatest for an asymmetrical rigid ring type with intrinsic septal-lateral downsizing (ETL). However, the ring type with the most drastic intrinsic septal-lateral downsizing (GEO) introduced strains similar to physiologically shaped rings (RSA and PHY), indicating that ring effects on annular strain profiles cannot be estimated from the degree of septal-lateral downsizing.


Subject(s)
Mitral Valve Annuloplasty/instrumentation , Myocardial Contraction , Prostheses and Implants , Animals , Biomechanical Phenomena , Compressive Strength , Fiducial Markers , Hemodynamics , Male , Prosthesis Design , Reference Values , Sheep , Tensile Strength
15.
Bioengineering (Basel) ; 10(4)2023 Apr 19.
Article in English | MEDLINE | ID: mdl-37106673

ABSTRACT

A novel accessory directing the blood from the outflow of a left ventricular assist device (LVAD) back through the left ventricular apex and across the aortic valve allows LVAD implantation via the left ventricular apex solely but may affect the LVAD performance. We quantified the effect of the accessory on LVAD flow and pressure head in vitro. In a mock circulatory loop, a centrifugal-flow LVAD (HeartMate 3, Abbott, Abbott Park, IL, USA) with (Accessory) and without the accessory (Control) was compared under physiological conditions using a water/glycerol solution as a blood substitute. The pump was operated at 4000, 5200, and 6400 rpm and 5 different resistance levels. Flow, inlet, and outlet pressure were measured, and pressure head was calculated. Compared to the Control, flow and pressure head in the Accessory group were reduced by an overall average of 0.26 L/min and 9.9 mmHg (all speeds and resistance levels). The highest decline in flow and pressure head occurred at the lowest resistance levels. In conclusion, the accessory leads to a reduction of LVAD flow and pressure head that is enhanced by decreases in resistance. Future developments in the LVAD accessory's design may reduce these effects and allow unimpaired LVAD performance and minimally invasive device implantation.

16.
Circulation ; 124(11 Suppl): S81-96, 2011 Sep 13.
Article in English | MEDLINE | ID: mdl-21911823

ABSTRACT

BACKGROUND: Annuloplasty ring or band implantation during surgical mitral valve repair perturbs mitral annular dimensions, dynamics, and shape, which have been associated with changes in anterior mitral leaflet (AML) strain patterns and suboptimal long-term repair durability. We hypothesized that rigid rings with nonphysiological three-dimensional shapes, but not saddle-shaped rigid rings or flexible bands, increase AML strains. METHODS AND RESULTS: Sheep had 23 radiopaque markers inserted: 7 along the anterior mitral annulus and 16 equally spaced on the AML. True-sized Cosgrove-Edwards flexible, partial band (n=12), rigid, complete St Jude Medical rigid saddle-shaped (n=12), Carpentier-Edwards Physio (n=12), Edwards IMR ETlogix (n=11), and Edwards GeoForm (n=12) annuloplasty rings were implanted in a releasable fashion. Under acute open-chest conditions, 4-dimensional marker coordinates were obtained using biplane videofluoroscopy along with hemodynamic parameters with the ring inserted and after release. Marker coordinates were triangulated, and the largest maximum principal AML strains were determined during isovolumetric relaxation. No relevant changes in hemodynamics occurred. Compared with the respective control state, strains increased significantly with rigid saddle-shaped annuloplasty ring, Carpentier-Edwards Physio, Edwards IMR ETlogix, and Edwards GeoForm (0.14 ± 0.05 versus 0.16 ± 0.05, P=0.024, 0.15 ± 0.03 versus 0.18 ± 0.04, P=0.020, 0.11 ± 0.05 versus 0.14 ± 0.05, P=0.042, and 0.13 ± 0.05 versus 0.16 ± 0.05, P=0.009), but not with Cosgrove-Edwards band (0.15 ± 0.05 versus 0.15 ± 0.04, P=0.973). CONCLUSIONS: Regardless of three-dimensional shape, rigid, complete annuloplasty rings, but not a flexible, partial band, increased AML strains in the normal beating ovine heart. Clinical studies are needed to determine whether annuloplasty rings affect AML strains in patients, and, if so, whether ring-induced perturbations in leaflet strain states are linked to repair failure.


Subject(s)
Heart Valve Prosthesis/classification , Heart/physiology , Mitral Valve Annuloplasty/instrumentation , Mitral Valve/physiology , Mitral Valve/surgery , Animals , Heart Rate/physiology , Hemodynamics/physiology , Male , Mitral Valve Annuloplasty/methods , Models, Animal , Prosthesis Design , Sheep , Ventricular Function, Left/physiology
17.
Am J Physiol Heart Circ Physiol ; 302(1): H180-7, 2012 Jan 01.
Article in English | MEDLINE | ID: mdl-22037187

ABSTRACT

Previous studies of transmural left ventricular (LV) strains suggested that the myocardium overlying the papillary muscle displays decreased deformation relative to the anterior LV free wall or significant regional heterogeneity. These comparisons, however, were made using different hearts. We sought to extend these studies by examining three equatorial LV regions in the same heart during the same heartbeat. Therefore, deformation was analyzed from transmural beadsets placed in the equatorial LV myocardium overlying the anterolateral papillary muscle (PAP), as well as adjacent equatorial LV regions located more anteriorly (ANT) and laterally (LAT). We found that the magnitudes of LAT normal longitudinal and radial strains, as well as major principal strains, were less than ANT, while those of PAP were intermediate. Subepicardial and midwall myofiber angles of LAT, PAP, and ANT were not significantly different, but PAP subendocardial myofiber angles were significantly higher (more longitudinal as opposed to circumferential orientation). Subepicardial and midwall myofiber strains of ANT, PAP, and LAT were not significantly different, but PAP subendocardial myofiber strains were less. Transmural gradients in circumferential and radial normal strains, and major principal strains, were observed in each region. The two main findings of this study were as follows: 1) PAP strains are largely consistent with adjacent LV equatorial free wall regions, and 2) there is a gradient of strains across the anterolateral equatorial left ventricle despite similarities in myofiber angles and strains. These findings point to graduated equatorial LV heterogeneity and suggest that regional differences in myofiber coupling may constitute the basis for such heterogeneity.


Subject(s)
Myocardial Contraction , Papillary Muscles/physiology , Ventricular Function, Left , Animals , Biomechanical Phenomena , Cardiac Catheterization , Excitation Contraction Coupling , Fluoroscopy , Heart Ventricles/diagnostic imaging , Papillary Muscles/diagnostic imaging , Sheep , Stress, Mechanical , Stroke Volume , Tantalum , Time Factors , Ventricular Pressure , Video Recording
18.
BMC Cardiovasc Disord ; 12: 103, 2012 Nov 15.
Article in English | MEDLINE | ID: mdl-23151277

ABSTRACT

BACKGROUND: Infective Endocarditis (IE) is considered as a multifaceted problem in every aspect from etiology and presentation to diagnosis and management. Early recognition of this disease and especially its complications, remain a critical task for the cardiologist. Atrial endocarditis is a rare and sometimes unrecognized complication of mitral valve endocarditis. CASE PRESENTATION: We present a 48 year-old male patient who was admitted to our clinic because of recent onset of malaise, fever, jaundice and peripheral edema. Important physical findings were peripheral stigmata of IE in addition to holosystolic murmur over the left sternal border. Transthoracic and transesophageal echocardiophy revealed a severe eccentric MR due to a flailed posterior mitral valve caused by IE. The presence of atrial septal endocarditis caused by jet streaming was also observed. Blood culture was positive for streptococcus oralis and antibiotic therapy was immediately initiated. Considering the large burden of infective tissue, the patient was planned for an early surgical intervention. A minimally invasive resection of the atrial mass, direct closure of the defect, resection of the diseased portions of mitral leaflets and implantation of a biological mitral valve prosthesis was performed. Intra-operative and histological findings confirmed provisional diagnosis by echocardiography. CONCLUSIONS: Together with comprehensive echocardiographic evaluation, attention should be placed on mural vegetations and excluded among all cases of mitral valve endocarditis, particularly those with severe eccentric regurgitant jets.


Subject(s)
Endocarditis/complications , Heart Atria/pathology , Mitral Valve/pathology , Echocardiography , Endocarditis/diagnostic imaging , Endocarditis/therapy , Humans , Male , Middle Aged
19.
ASAIO J ; 68(1): 56-63, 2022 01 01.
Article in English | MEDLINE | ID: mdl-33883509

ABSTRACT

Blood compatible materials are a well-researched scientific field as such materials are required in a wide range of applications, for example, in heart-lung machines or ventricular assist devices. Surfaces coated with certain surface-bound neutral, water-swellable polymer networks have the ability to repel cells such as platelets and exhibit a significantly improved hemocompatibility. In this study, we investigate the interaction of platelets from whole blood with surfaces coated with photochemically generated surface-attached polymer networks based on polydimethyl acrylamide. As substrates medical-grade polyurethanes are used, and the networks are formed and attached to the substrate surfaces through C-H insertion reactions. The hydrogel-coated substrates are perfused with blood for extended periods of time. We show that the polymer coating prevents the adhesion of cells even at longer times of blood contact, regardless of the thickness of the coating employed. The surfaces can be sterilized following a standard autoclave procedure without any loss of function. Additionally, it is shown that the samples can be stored at least for 3 months under varying ambient conditions while retaining their functionality. The excellent blood compatibility, the possibility to coat even rather inert polymeric materials and the ability to handle the materials in an environment typical for a medical application make such coatings a promising candidate for future hemocompatible devices.


Subject(s)
Coated Materials, Biocompatible , Hydrogels , Blood Platelets , Polymers , Surface Properties
20.
Interact Cardiovasc Thorac Surg ; 34(3): 349-353, 2022 02 21.
Article in English | MEDLINE | ID: mdl-34907441

ABSTRACT

OBJECTIVES: To evaluate in-hospital outcomes of concomitant mitral valve replacement (MVR) in patients undergoing conventional aortic valve replacement due to aortic stenosis in a nationwide cohort. METHODS: Administrative data from all patients with aortic stenosis undergoing conventional aortic and concomitant MVR (reason for MVR not specified) between 2017 and 2018 in Germany were analysed. RESULTS: A total of 2597 patients with a preoperative logistic EuroScore of 9.81 (standard deviation: 8.56) were identified. In-hospital mortality was 6.8%. An in-hospital stroke occurred in 3.4%, acute kidney injury in 16.3%, prolonged mechanical ventilation of more than 48 h in 16.3%, postoperative delirium in 15.8% and postoperative pacemaker implantation in 7.6% of the patients. Mean hospital stay was 16.5 (standard deviation: 12.1) days. Age [odds ratio (OR): 1.03; P = 0.019], New York Heart Association class III or IV (OR: 1.63; P = 0.012), previous cardiac surgery (OR: 2.85, P = 0.002), peripheral vascular disease (OR: 2.01, P = 0.031), pulmonary hypertension (OR: 1.63, P = 0.042) and impaired renal function (glomerular filtration rate <15, OR: 3.58, P = 0.001; glomerular filtration rate <30, OR: 2.51, P = 0.037) were identified as independent predictors for in-hospital mortality. CONCLUSIONS: In this nationwide analysis, concomitant aortic and MVR was associated with acceptable in-hospital mortality, morbidity and length of in-hospital stay. The regression analyses may help to identify high-risk patients and further optimize treatment strategies.


Subject(s)
Acute Kidney Injury , Heart Valve Prosthesis Implantation , Acute Kidney Injury/etiology , Aortic Valve/surgery , Heart Valve Prosthesis Implantation/adverse effects , Hospitals , Humans , Mitral Valve/surgery , Postoperative Complications/etiology , Retrospective Studies , Risk Factors , Treatment Outcome
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