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2.
Heart Fail Rev ; 28(2): 297-305, 2023 03.
Article in English | MEDLINE | ID: mdl-34370150

ABSTRACT

Heart failure with preserved ejection fraction (HFpEF) is increasing in prevalence and represents approximately 50% of all heart failure (HF) patients. Patients with this complex clinical scenario, characterized by high filling pressures, and reduced cardiac output (CO) associated with progressive multi-organ involvement, have so far not experienced any significant improvement in quality of life or survival with traditional HF treatment. Left ventricular assist devices (LVAD) have offered a new treatment alternative in terminal heart failure patients with reduced ejection fraction (HFrEF), providing a unique combination of significant pressure and volume unloading together with an increase in CO. The small left ventricular cavity in HFpEF patients challenges left-sided pressure unloading, and new anatomical entry points need to be explored for mechanical pressure and volume unloading. Optimized and pressure/volume-adjusted mechanical circulatory support (MCS) devices for HFrEF patients may conceivably be customized for HFpEF anatomy and hemodynamics. We have developed a long-term MCS device for HFpEF patients with atrial unloading in a pulsed algorithm, leading to a significant reduction of filling pressure, maintenance of pulse pressure, and increase in CO demonstrated in animal testing. In this article, we will discuss HFpEF pathology, hemodynamics, and the principles behind our novel MCS device that may improve symptoms and prognosis in HFpEF patients. Data from mock-loop hemolysis studies, acute, and chronic animal studies will be presented.


Subject(s)
Heart Failure , Humans , Stroke Volume , Quality of Life , Treatment Outcome , Prognosis , Ventricular Function, Left
3.
ASAIO J ; 68(9): 1117-1125, 2022 09 01.
Article in English | MEDLINE | ID: mdl-36066353

ABSTRACT

We have previously demonstrated that accelerometer-based vibration analysis detects thromboembolism and pump thrombosis in HeartWare Left Ventricular Assist Device (HVAD) using the third harmonic frequency (pump_speedx3). Thromboembolism also affected the amplitude of the nonharmonic frequencies. The aim of this study was to determine whether nonharmonic-amplitude (NHA) analysis can improve the diagnosis of thromboembolic complications. An accelerometer was attached to HVAD in three in vitro and seven in vivo experiments. Control interventions, including load and pump speed alternations (n = 107), were followed by thromboembolic events (n = 60). A sliding fast-Fourier-transform was analyzed, and changes in NHAs were quantified in the acute phase and in a steady state. Receiver operating characteristic curves were constructed with cutoff values of NHA to detect thromboembolic events. Positive predictive values were calculated on the basis of a specificity of 1. In the acute phase, NHA change was 6.5 times higher under thromboembolism than under control interventions (p < 0.001). Most thromboembolic events lead to concomitant changes in both NHA and third-harmonic amplitude. Combining the two methods improved the PPV by 8.3%. At steady state, signal changes predominantly demonstrated either NHA or third-harmonic changes. Combined signal analysis improved the PPV by 36%. This method enhanced the detection of thromboembolism and pump thrombosis in the HVAD.


Subject(s)
Heart Failure , Heart-Assist Devices , Thromboembolism , Thrombosis , Accelerometry/methods , Heart Failure/complications , Heart Failure/surgery , Heart-Assist Devices/adverse effects , Humans , Retrospective Studies , Thromboembolism/diagnosis , Thromboembolism/etiology , Thrombosis/diagnosis , Thrombosis/etiology
4.
Eur J Cardiothorac Surg ; 62(3)2022 08 03.
Article in English | MEDLINE | ID: mdl-35894678

ABSTRACT

OBJECTIVES: The objective was to analyse associations between obesity and outcomes after left ventricular assist device (LVAD) implantation. METHODS: A retrospective analysis of the EUROMACS Registry was performed. Adult patients undergoing primary implantation of a continuous-flow LVAD between 2006 and 2019 were included (Medtronic HeartWare® HVAD®, Abbott HeartMate II®, Abbott HeartMate 3™). Patients were classified into 4 different groups according to body mass index at the time of surgery (body mass index <20 kg/m2: n = 254; 20-24.9 kg/m2: n = 1281; 25-29.9 kg/m2: n = 1238; ≥ 30 kg/m2: n = 691). RESULTS: The study cohort was comprised of 3464 patients. Multivariable Cox proportional cause-specific hazards regression analysis demonstrated that obesity (body mass index ≥30 kg/m2) was independently associated with significantly increased risk of mortality (body mass index ≥30 vs 20-24.9 kg/m2: hazard ratio 1.36, 95% confidence interval 1.18-1.57, overall P < 0.001). Moreover, obesity was associated with significantly increased risk of infection and driveline infection. The probability to undergo heart transplantation was significantly decreased in obese patients (body mass index ≥30 vs 20-24.9 kg/m2: hazard ratio 0.59, 95% confidence interval 0.48-0.74, overall P < 0.001). CONCLUSIONS: Obesity at the time of LVAD implantation is associated with significantly higher mortality and increased risk of infection as well as driveline infection. The probability to undergo heart transplantation is significantly decreased. These aspects should be considered when devising a treatment strategy before surgery.


Subject(s)
Heart Failure , Heart-Assist Devices , Adult , Heart Failure/epidemiology , Heart Failure/surgery , Heart-Assist Devices/adverse effects , Humans , Obesity/complications , Obesity/epidemiology , Registries , Retrospective Studies , Treatment Outcome
5.
Clin Transplant ; 35(1): e14152, 2021 01.
Article in English | MEDLINE | ID: mdl-33185913

ABSTRACT

BACKGROUND: While expected need for intensive care after lung transplantation (LTx) does not normally affect organ allocation, it would be useful to estimate whether intensive care capacity is limited. The aim of this study was to assess factors available before LTx to identify predictors of prolonged intensive care unit (ICU) length of stay (LOS) after LTx. METHODS: All bilateral LTx recipients excluding re-transplantation and multi-organ transplantation at Oslo University Hospital from 2000 to 2013 were included (n = 277). Predictive factors for ICU LOS were identified using pre- and perioperative variables. RESULTS: Univariate analyses showed that recipients with pulmonary arterial hypertension, young age, female gender, low body height, low pretransplant actual total lung capacity (aTLC), and recipients who received an oversized donor lung were at risk for long ICU LOS. Patients with emphysema had lower risk of long ICU LOS. In multivariate analyses, a lower aTLC (p < .001) and a higher mean pulmonary artery pressure (mPAP) (p = .004) predicted prolonged ICU LOS. CONCLUSIONS: We found that small recipient lung volume and high mPAP were predictors for prolonged ICU LOS. Our observations may be useful in planning use of resources in LTx, particularly in times of limited intensive care resources.


Subject(s)
Lung Transplantation , Critical Care , Female , Humans , Intensive Care Units , Length of Stay , Retrospective Studies
6.
J Heart Lung Transplant ; 39(12): 1372-1379, 2020 12.
Article in English | MEDLINE | ID: mdl-32917479

ABSTRACT

BACKGROUND: Heart transplantation is limited by the scarcity of suitable donors. Patients with advanced biventricular failure may require biventricular support to provide optimal cardiac output and end-organ perfusion. We highlight the outcomes of using the HeartWare HVAD System (HVAD) in a biventricular configuration. METHODS: This retrospective study included patients implanted with HVAD as a biventricular assist device (BiVAD) between 2009 and 2017 at 12 participating centers. When used as a right ventricular assist device (VAD) (RVAD), the HVAD can be attached to the right ventricle (RV) or the right atrium (RA). Kaplan-Meier survival estimates were calculated comparing the 2 RVAD implant locations. Comparisons were also made between the timing of RVAD implantation (primary vs staged) on adverse event (AE) profiles and survival. RESULTS: Among the 93 patients who were implanted with a HVAD BiVAD, Kaplan-Meier survivals at 1-year and 2-year were 56% and 47%, respectively. Survival was independent of the location of the HVAD RVAD implant or whether there was an interval between left VAD and RVAD implantation. The most common AEs were bleeding (35.5%), infection (25.8%), and respiratory failure (20.4%). CONCLUSIONS: This study illustrated similar survival in patients receiving a primary or staged HVAD BiVAD implant at 1 year and 2 years. This study also established that the locations of the RVAD implant (RV or RA) result in similar AE profiles.


Subject(s)
Atrial Function, Right/physiology , Heart Atria/physiopathology , Heart Failure/surgery , Heart Ventricles/physiopathology , Heart-Assist Devices , Ventricular Function, Right/physiology , Follow-Up Studies , Global Health , Heart Failure/mortality , Heart Failure/physiopathology , Humans , Retrospective Studies , Survival Rate/trends , Treatment Outcome
7.
Circ Heart Fail ; 13(3): e006252, 2020 03.
Article in English | MEDLINE | ID: mdl-32164438

ABSTRACT

BACKGROUND: The paucity of available hearts for transplantation means that more patients remain on durable left ventricular support for longer periods of time. The Registry to Evaluate the HeartWare Left Ventricular Assist System was an investigator-initiated multicenter, prospective, single-arm database established to collect post-Conformité Européene mark clinical information on patients receiving the HeartWare ventricular assist device system as a bridge to transplantation. This registry represents the longest multicenter follow-up of primary left ventricular assist device outcomes. METHODS: Data were collected on 254 commercial implants performed between February 2009 and March 2012 from 9 centers in Europe (7) and Australia (2). Patients were followed to device explant, heart transplantation, or death. The outcomes of patients through July/August 2018 were analyzed. Summary statistics were used to describe patient demographics, adverse events, length of support, and outcomes for this extended-term cohort. RESULTS: A total of 122 patients were on support for >2 years, and 34 patients were on support for >5 years. Twenty nine patients are still alive on support (support ranging from 1213 to 3396 days), and 23 of those are on their original HeartWare ventricular assist device system. Kaplan-Meier survival through 7 years was 51%. Through 6 years, freedom from any stroke was 82%, while freedom from severely disabling stroke was 89%. CONCLUSIONS: Low rates of heart transplant now require longer periods of left ventricular assist device support in patients. This analysis demonstrates that long-term support using a HeartWare ventricular assist device system offers survival of 51% through 7 years.


Subject(s)
Heart Failure/therapy , Heart Transplantation , Heart-Assist Devices , Prosthesis Implantation/instrumentation , Ventricular Function, Left , Waiting Lists , Australia , Europe , Female , Heart Failure/diagnosis , Heart Failure/mortality , Heart Failure/physiopathology , Humans , Male , Middle Aged , Prosthesis Design , Prosthesis Implantation/adverse effects , Prosthesis Implantation/mortality , Recovery of Function , Registries , Retrospective Studies , Time Factors , Treatment Outcome
8.
ASAIO J ; 66(1): 38-48, 2020 01.
Article in English | MEDLINE | ID: mdl-30688692

ABSTRACT

We have recently demonstrated that accelerometer-based pump thrombosis and thromboembolic events detection is feasible in vitro. This article focuses on detection of these conditions in vivo. In an open-chest porcine model (n = 7), an accelerometer was attached to the pump casing of an implanted HeartWare HVAD. Pump vibration was analyzed by Fast Fourier Transform of the accelerometer signals, and the spectrogram third harmonic amplitude quantified and compared with pump power. Interventions included injection of thrombi into the left atrium (sized 0.3-0.4 ml, total n = 35) and control interventions; pump speed change, graft obstruction, and saline bolus injections (total n = 47). Graft flow to cardiac output ratio was used to estimate the expected number of thrombi passing through the pump. Sensitivity/specificity was assessed by receiver operating characteristic curve. Graft flow to cardiac output ratio averaged 66%. Twenty-six of 35 (74%) thrombi caused notable accelerometer signal change. Accelerometer third harmonic amplitude was significantly increased in thromboembolic interventions compared with control interventions, 64.5 (interquartile range [IQR]: 18.8-107.1) and 5.45 (IQR: 4.2-6.6), respectively (p < 0.01). The corresponding difference in pump power was 3 W (IQR: 2.9-3.3) and 2.8 W (IQR: 2.4-2.9), respectively (p < 0.01). Sensitivity/specificity of the accelerometer and pump power to detect thromboembolic events was 0.74/1.00 (area under the curve [AUC]: 0.956) and 0.40/1.00 (AUC: 0.759), respectively. Persistent high third harmonic amplitude was evident at end of all experiments, and pump thrombosis was confirmed by visual inspection. The findings demonstrate that accelerometer-based detection of thromboembolic events and pump thrombosis is feasible in vivo and that the method is superior to detection based on pump power.


Subject(s)
Accelerometry/methods , Heart-Assist Devices/adverse effects , Thromboembolism/etiology , Thrombosis/etiology , Accelerometry/instrumentation , Animals , Disease Models, Animal , Female , Male , Swine
9.
Interact Cardiovasc Thorac Surg ; 30(1): 81-84, 2020 01 01.
Article in English | MEDLINE | ID: mdl-31580433

ABSTRACT

We report 2 continuous flow HeartWareTM left ventricular assist devices successfully used in a patient with advanced heart failure of giant cell myocarditis origin in a biventricular configuration. Despite technical challenges of adapting a left ventricular assist device engineered for systemic pressure to function as a right ventricular assist device, the addition of dynamic banding on the right ventricular assist device outflow graft allowed successful adaptation of afterload. This patient has now been on biventricular configuration support for 9 years, and remains stable to this day.


Subject(s)
Giant Cell Arteritis/complications , Heart Failure/therapy , Heart Ventricles/physiopathology , Heart-Assist Devices , Myocarditis/complications , Ventricular Function, Left/physiology , Female , Follow-Up Studies , Giant Cell Arteritis/diagnosis , Giant Cell Arteritis/physiopathology , Heart Failure/diagnosis , Heart Failure/etiology , Heart Failure/physiopathology , Humans , Middle Aged , Myocarditis/diagnosis , Myocarditis/physiopathology , Time Factors , Treatment Outcome
10.
Psychosom Med ; 81(6): 513-520, 2019.
Article in English | MEDLINE | ID: mdl-31033937

ABSTRACT

OBJECTIVE: Current understanding of the prognostic impact of depression on mortality after heart transplantation (HTx) is limited. We examined whether depression after HTx is a predictor of mortality during extended follow-up. Subsequently, we explored whether different symptom dimensions of depression could be identified and whether they were differentially associated with mortality. METHODS: Survival analyses were performed in a sample of 141 HTx recipients assessed for depression, measured by self-report of depressive symptoms (Beck Depression Inventory - version 1A [BDI-1A]), at median 5.0 years after HTx, and followed thereafter for survival status for up to 18.6 years. We used uni- and multivariate Cox proportional hazard models to examine the association of clinically significant depression (BDI-1A total score ≥10), as well as the cognitive-affective and the somatic subscales of the BDI-1A (resulting from principal component analysis) with mortality. In the multivariate analyses, we adjusted for relevant sociodemographic and clinical variables. RESULTS: Clinically significant depression was a significant predictor of mortality (hazard ratio = 2.088; 95% confidence interval = 1.366-3.192; p = .001). Clinically significant depression also was an independent predictor of mortality in the multivariate analysis (hazard ratio = 1.982; 95% confidence interval = 1.220-3.217; p = .006). The somatic subscale, but not the cognitive-affective subscale, was significantly associated with increased mortality in univariate analyses, whereas neither of the two subscales was an independent predictor of mortality in the multivariate analysis. CONCLUSIONS: Depression measured by self-report after HTx is associated with increased mortality during extended follow-up. Clinical utility and predictive validity of specific depression components require further study.


Subject(s)
Depression/epidemiology , Depressive Disorder/epidemiology , Heart Transplantation , Mortality , Adult , Aged , Cardiomyopathies/surgery , Cardiovascular Diseases/mortality , Cause of Death , Depression/psychology , Depressive Disorder/psychology , Female , Heart Failure/surgery , Humans , Infections/mortality , Male , Middle Aged , Multivariate Analysis , Neoplasms/mortality , Norway/epidemiology , Principal Component Analysis , Proportional Hazards Models
11.
Scand Cardiovasc J ; 53(1): 14-20, 2019 02.
Article in English | MEDLINE | ID: mdl-30776923

ABSTRACT

OBJECTIVES: The purpose of this study was to assess complications and mortality and its predictors, with continuous-flow left ventricular assist devices (CF-LVADs) in the Nordic Countries. DESIGN: This was a retrospective, international, multicenter cohort study. RESULTS: Between 1993 and 2013, 442 surgically implanted long-term mechanical assist devices were used among 8 centers in the Nordic countries. Of those, 238 were CF-LVADs (HVAD or HeartMate II) implanted in patients >18 years with complete data. Postoperative complications and survival were compared and Cox proportion hazard regression analysis was used to identify predictors of mortality. The overall Kaplan-Meier survival rate was 75% at 1 year, 69% at 2 years and 63% at 3 years. A planned strategy of destination therapy had poorer survival compared to a strategy of bridge to transplantation or decision (2-year survival of 41% vs. 76%, p < .001). The most common complications were non-driveline infections (excluding sepsis) (44%), driveline infection (27%), need for continuous renal replacement therapy (25%) and right heart failure (24%). In a multivariate model age and left ventricular diastolic dimension was left as independent risk factors for mortality with a hazard ratio of 1.35 (95% confidence interval (CI) [1.01-1.80], p = .046) per 10 years and 0.88 (95% CI [0.72-0.99], p = .044) per 5 mm, respectively. CONCLUSION: Outcome with CF LVAD in the Nordic countries was comparable to other cohorts. Higher age and destination therapy require particularly stringent selection.


Subject(s)
Heart Failure/mortality , Heart Failure/therapy , Heart-Assist Devices , Ventricular Function, Left , Aged , Disease Progression , Female , Heart Failure/diagnosis , Heart Failure/physiopathology , Heart Transplantation , Heart-Assist Devices/adverse effects , Humans , Male , Middle Aged , Prosthesis Design , Recovery of Function , Retrospective Studies , Risk Assessment , Risk Factors , Scandinavian and Nordic Countries/epidemiology , Time Factors , Treatment Outcome
12.
J Am Soc Echocardiogr ; 32(2): 303-316.e4, 2019 02.
Article in English | MEDLINE | ID: mdl-30293779

ABSTRACT

BACKGROUND: Three-dimensional (3D) echocardiography with multiplanar reconstruction (MPR) is used clinically to quantify the mitral annulus. MPR images are, however, presented on a two-dimensional screen, calling into question their accuracy. An alternative to MPR is an autostereoscopic holographic display that enables in-depth visualization of 3D echocardiographic data without the need for special glasses. The aim of this study was to validate an autostereoscopic display using sonomicrometry as a gold standard. METHODS: In 11 anesthetized open-chest pigs, sonomicrometric crystals were placed along the mitral annulus and near the left ventricular apex. High-fidelity catheters measured left atrial and ventricular pressures. Adjustments of pre- and afterload were done by constriction of the inferior vena cava and the ascending aorta, respectively. Three-dimensional epicardial echocardiography was obtained from an apical view and converted to the autostereoscopic display. A 3D virtual semitransparent annular surface (VSAS) was generated to measure commissure width (CW), septal-lateral length, area of the mitral annular surface, nonplanarity angle, and the annular height-to-commissure width ratio in mid-systole and late diastole. RESULTS: Mitral annular measurements from the 3D VSAS derived from the 3D echocardiographic images and autostereoscopic display correlated well with sonomicrometry over a range of loading conditions: CW length (r = 0.98, P < .00001), septal-lateral length (r = 0.98, P < .00001), annular surface area (r = 0.93, P < .001), nonplanarity angle (r = 0.87, P < .001), and annular height-to-commissure width ratio (r = 0.85, P < .01). The 3D VSAS showed better agreement with the sonomicrometric measurements compared with MPR. CONCLUSIONS: Mitral annular measurements using 3D VSAS correlate well with sonomicrometry over a range of loading conditions and may represent a powerful tool for noninvasive quantification of mitral annular dynamics.


Subject(s)
Atrial Function, Left/physiology , Echocardiography, Three-Dimensional/methods , Echocardiography, Transesophageal/methods , Holography/methods , Mitral Valve/diagnostic imaging , Ventricular Function, Left/physiology , Ventricular Pressure/physiology , Animals , Diastole , Female , Male , Models, Animal , Reproducibility of Results , Swine
13.
J Heart Lung Transplant ; 37(12): 1403-1409, 2018 12.
Article in English | MEDLINE | ID: mdl-30241891

ABSTRACT

BACKGROUND: Throughout the world, the scarcity of donor organs makes optimal allocation systems necessary. In the Scandiatransplant countries, organs for lung transplantation are allocated nationally. To ensure shorter wait time for critically ill patients, the Scandiatransplant urgent lung allocation system (ScULAS) was introduced in 2009, giving supranational priority to patients considered urgent. There were no pre-defined criteria for listing a patient as urgent, but each center was granted only 3 urgent calls per year. This study aims to explore the characteristics and outcome of patients listed as urgent, assess changes associated with the implementation of ScULAS, and describe how the system was utilized by the member centers. METHODS: All patients listed for lung transplantation at the 5 Scandiatransplant centers 5 years before and after implementation of ScULAS were included. RESULTS: After implementation, 8.3% of all listed patients received urgent status, of whom 81% were transplanted within 4 weeks. Patients listed as urgent were younger, more commonly had suppurative lung disease, and were more often on life support compared with patients without urgent status. For patients listed as urgent, post-transplant graft survival was inferior at 30 and 90 days. Although there were no pre-defined criteria for urgent listing, the system was not utilized at its maximum. CONCLUSIONS: ScULAS rapidly allocated organs to patients considered urgent. These patients were younger and more often had suppurative lung disease. Patients with urgent status had inferior short-term outcome, plausibly due to the higher proportion on life support before transplantation.


Subject(s)
Emergencies , Lung Transplantation/methods , Resource Allocation/organization & administration , Tissue and Organ Procurement/organization & administration , Waiting Lists , Adolescent , Adult , Child , Child, Preschool , Female , Follow-Up Studies , Health Plan Implementation/organization & administration , Humans , Infant , Infant, Newborn , Lung Transplantation/mortality , Male , Middle Aged , Scandinavian and Nordic Countries , Survival Rate , Tissue Donors/supply & distribution , Young Adult
14.
Am J Physiol Heart Circ Physiol ; 315(5): H1137-H1147, 2018 11 01.
Article in English | MEDLINE | ID: mdl-30004809

ABSTRACT

Targeted temperature management is part of the standardized treatment for patients in cardiac arrest. Hypothermia decreases cerebral oxygen consumption and induces bradycardia; thus, increasing the heart rate may be considered to maintain cardiac output. We hypothesized that increasing heart rate during hypothermia would impair diastolic function. Human left ventricular trabeculae obtained from explanted hearts of patients with terminal heart failure were stimulated at 0.5 Hz, and contraction-relaxation cycles were recorded. Maximal developed force (Fmax), maximal rate of development of force [(dF/d t)max], time to peak force (TPF), time to 80% relaxation (TR80), and relaxation time (RT = TR80 - TPF) were measured at 37, 33, 31, and 29°C. At these temperatures, stimulation frequency was increased from 0.5 to 1.0 and to 1.5 Hz. At 1.5 Hz, concentration-response curves for the ß-adrenergic receptor (ß-AR) agonist isoproterenol were performed. Fmax, TPF, and RT increased when temperature was lowered, whereas (dF/d t)max decreased. At all temperatures, increasing stimulation frequency increased Fmax and (dF/d t)max, whereas TPF and RT decreased. At 31 and 29°C, resting tension increased at 1.5 Hz, which was ameliorated by ß-AR stimulation. At all temperatures, maximal ß-AR stimulation increased Fmax, (dF/d t)max, and maximal systolic force, whereas resting tension decreased progressively with lowering temperature. ß-AR stimulation reduced TPF and RT to the same extent at all temperatures, despite the more elongated contraction-relaxation cycle at lower temperatures. Diastolic dysfunction during hypothermia results from an elongation of the contraction-relaxation cycle, which decreases the time for ventricular filling. Hypothermic bradycardia protects the heart from diastolic dysfunction and increasing the heart rate during hypothermia should be avoided. NEW & NOTEWORTHY Decreasing temperature increases the duration of the contraction-relaxation cycle in the human ventricular myocardium, significantly reducing the time for ventricular filling during diastole. During hypothermia, increasing heart rate further reduces the time for ventricular filling and in some situations increases resting tension further impairing diastolic function. Modest ß-adrenergic receptor stimulation can ameliorate these potentially detrimental changes during diastole while improving contractile force generation during targeted temperature management.


Subject(s)
Heart Failure/therapy , Heart Rate , Hypothermia, Induced , Myocardial Contraction , Ventricular Function, Left , Adolescent , Adrenergic beta-Agonists/pharmacology , Adult , Cardiac Pacing, Artificial , Cardiomyopathy, Dilated/complications , Cardiomyopathy, Dilated/physiopathology , Diastole , Female , Heart Failure/etiology , Heart Failure/physiopathology , Heart Rate/drug effects , Humans , In Vitro Techniques , Isoproterenol/pharmacology , Male , Middle Aged , Myocardial Contraction/drug effects , Systole , Time Factors , Ventricular Function, Left/drug effects
15.
Transplant Direct ; 4(7): e366, 2018 Jul.
Article in English | MEDLINE | ID: mdl-30046656

ABSTRACT

BACKGROUND: Donation after circulatory death (DCD) can increase the pool of available organs for transplantation. This pilot study evaluates the implementation of a controlled DCD (cDCD) protocol using normothermic regional perfusion in Norway. METHODS: Patients aged 16 to 60 years that are in coma with documented devastating brain injury in need of mechanical ventilation, who would most likely attain cardiac arrest within 60 minutes after extubation, were eligible. With the acceptance from the next of kin and their wish for organ donation, life support was withdrawn and cardiac arrest observed. After a 5-minute no-touch period, extracorporeal membrane oxygenation for post mortem regional normothermic regional perfusion was established. Cerebral and cardiac reperfusion was prevented by an aortic occlusion catheter. Measured glomerular filtration rates 1 year postengraftment were compared between cDCD grafts and age-matched grafts donated after brain death (DBD). RESULTS: Eight cDCD were performed from 2014 to 2015. Circulation ceased median 12 (range, 6-24) minutes after withdrawal of life-sustaining treatment. Fourteen kidneys and 2 livers were retrieved and subsequently transplanted. Functional warm ischemic time was 26 (20-51) minutes. Regional perfusion was applied for 97 minutes (54-106 minutes). Measured glomerular filtration rate 1 year postengraftment was not significantly different between cDCD and donation after brain death organs, 75 (65-76) vs 60 (37-112) mL/min per 1.73 m2 (P = 0.23). No complications have been observed in the 2 cDCD livers. CONCLUSION: A protocol for cDCD is successfully established in Norway. Excellent transplant outcomes have encouraged us to continue this work addressing the shortage of organs for transplantation.

16.
Perfusion ; 33(1): 30-35, 2018 Jan.
Article in English | MEDLINE | ID: mdl-28784030

ABSTRACT

INTRODUCTION: The use of cardiopulmonary bypass is associated with a risk of neurocognitive deficit caused by gaseous microemboli. Flushing the empty bypass circuit with carbon dioxide, which is more soluble than air, may reduce the amount of gaseous microemboli in the priming solution before the initiating of cardiopulmonary bypass. METHOD: We measured the amount of gaseous microemboli in twenty primed bypass circuits. Ten circuits were flushed with carbon dioxide before being primed and ten circuits were non-flushed. All circuits in both groups were primed with crystalloid priming. An ultrasonic clinical bubble counter was used to count gaseous microemboli in the prime for 20 minutes. RESULTS: The median numbers of gaseous microemboli counts were highest during the first minute in both groups, with a significantly lower median value in the group flushed with carbon dioxide (397.5) versus the non-flushed group (1900). In the 20th minute, the median values of gaseous microemboli were significantly lower (p<0.023) in the flushed (0.5) versus non-flushed (10.75) groups. The gaseous microembolic count in the flushed group remained lower than in the non-flushed group when tested minute by minute throughout the whole 20-minute period. CONCLUSION: Flushing the bypass circuits with carbon dioxide before priming significantly decreased the number of gaseous microemboli in the priming solution.


Subject(s)
Cardiopulmonary Bypass/adverse effects , Embolism, Air/etiology , Carbon Dioxide , Humans
17.
ASAIO J ; 64(5): 601-609, 2018.
Article in English | MEDLINE | ID: mdl-29088023

ABSTRACT

Pump thrombosis and stroke are serious complications of left ventricular assist device (LVAD) support. The aim of this study was to test the ability of an accelerometer to detect pump thrombosis and thromboembolic events (TEs) using real-time analysis of pump vibrations. An accelerometer sensor was attached to a HeartWare HVAD and tested in three in vitro experiments using different pumps for each experiment. Each experiment included thrombi injections sized 0.2-1.0 mL and control interventions: pump speed change, afterload increase, preload decrease, and saline bolus injections. A spectrogram was calculated from the accelerometer signal, and the third harmonic amplitude was used to test the sensitivity and specificity of the method. The third harmonic amplitude was compared with the pump energy consumption. The acceleration signals were of high quality. A significant change was identified in the accelerometer third harmonic during the thromboembolic interventions. The third harmonic detected thromboembolic events with higher sensitivity/specificity than LVAD energy consumption: 92%/94% vs. 72%/58%, respectively. A total of 60% of thromboembolic events led to a prolonged third harmonic amplitude change, which is indicative of thrombus mass residue on the impeller. We concluded that there is strong evidence to support the feasibility of real-time continuous LVAD monitoring for thromboembolic events and pump thrombosis using an accelerometer. Further in vivo studies are needed to confirm these promising findings.


Subject(s)
Accelerometry/methods , Heart-Assist Devices/adverse effects , Thrombosis/etiology , Animals , In Vitro Techniques , Swine , Thrombosis/diagnosis
18.
Clin Transplant ; 31(12)2017 Dec.
Article in English | MEDLINE | ID: mdl-29055147

ABSTRACT

BACKGROUND: Cognitive impairment is documented early after heart transplantation (HTx), but we lack data on cognitive function beyond the fourth year post-transplant. Against the background of good long-term survival, this knowledge is necessary to improve clinical care throughout the entire post-transplant period. METHODS: We assessed cognitive function with a neuropsychological test battery in a sample of HTx recipients ≥16 years post-transplant. To improve clinical utility, we also applied adapted consensus criteria for Mild Cognitive Impairment (MCI). Furthermore, we explored sociodemographic and clinical characteristics possibly related to cognitive function. RESULTS: Thirty-seven subjects were included 20.3 (±3.8) years after HTx. Mean age was 57.5 (±14.2) years, and 18.9% were women. Up to 38.9% exhibited impaired test performance (ie, performance at least 1.5 standard deviations below the normative mean) on several individual cognitive measures, especially on measures of processing speed, executive functions, memory, and language functions. One subject was diagnosed with dementia, and 30.1% qualified for MCI. Those with MCI had lower hemoglobin than those without. CONCLUSIONS: A substantial proportion of long-term survivors of HTx might be cognitively impaired. The level of impairment appears comparable to what is defined as MCI in the literature. Modifiable factors related to cognitive impairment might exist.


Subject(s)
Cognition Disorders/etiology , Heart Transplantation/adverse effects , Survivors/statistics & numerical data , Adult , Female , Follow-Up Studies , Humans , Male , Middle Aged , Neuropsychological Tests , Prognosis , Survival Rate
19.
J Cardiovasc Transl Res ; 10(4): 401-410, 2017 Aug.
Article in English | MEDLINE | ID: mdl-28474304

ABSTRACT

In dilated cardiomyopathy (DCM), adverse myocardial remodeling is essential, potentially involving Notch signaling. We hypothesized that secreted Notch ligands would be dysregulated in DCM. We measured plasma levels of the canonical Delta-like Notch ligand 1 (DLL1) and non-canonical Notch ligands Delta-like 1 homologue (DLK1) and periostin (POSN) in 102 DCM patients and 32 matched controls. Myocardial mRNA and protein levels of DLL1, DLK1, and POSN were measured in 25 explanted hearts. Our main findings were: (i) Circulating levels of DLL1 and POSN were higher in patients with severe DCM and correlated with the degree of diastolic dysfunction and (ii) right ventricular tissue expressions of DLL1, DLK1, and POSN were oppositely associated with cardiac function indices, as high DLL1 and DLK1 expression corresponded to more preserved and high POSN expression to more deteriorated cardiac function. DLL1, DLK1, and POSN are dysregulated in end-stage DCM, possibly mediating different effects on cardiac function.


Subject(s)
Cardiomyopathy, Dilated/blood , Cell Adhesion Molecules/blood , Intercellular Signaling Peptides and Proteins/blood , Membrane Proteins/blood , Ventricular Dysfunction, Left/blood , Ventricular Function, Left , Adult , Aged , Biomarkers/blood , Calcium-Binding Proteins , Cardiomyopathy, Dilated/diagnostic imaging , Cardiomyopathy, Dilated/physiopathology , Case-Control Studies , Diastole , Female , Humans , Male , Middle Aged , Severity of Illness Index , Up-Regulation , Ventricular Dysfunction, Left/diagnostic imaging , Ventricular Dysfunction, Left/physiopathology
20.
Interact Cardiovasc Thorac Surg ; 25(2): 177-184, 2017 08 01.
Article in English | MEDLINE | ID: mdl-28444177

ABSTRACT

OBJECTIVES: A transcatheter heart valve technique can be used in failed mitral valve repairs with annuloplasty rings, deterioriated bioprostheses and in mitral annular calcification, all serving as 'docking stations' for balloon-expandable valves. Specially designed transcatheter mitral valve platforms are used in ongoing studies for native mitral valve regurgitation. We present our single centre experience with transcatheter mitral valve implantation-transapical approach procedures in eleven patients. METHODS: Eleven patients were treated between 2011 and 2016. They had severe mitral regurgitation due to either failed repair annuloplasty rings (N = 6), failed bioprostheses (N = 2) or in the native valve (N = 3), all at high risk for open mitral valve surgery. Three different types of transcatheter valves were used: (1) the SAPIEN XT/SAPIEN 3, (2) the Lotus valve and (3) a Tendyne transcatheter mitral valve. Computed tomography reconstruction, echocardiography, 3D printing and bench tests were done in the preoperative evaluation and procedural planning. Transapical approach access was performed via a left minithoracotomy. RESULTS: Implantation success was 100% with no left ventricular outflow tract obstruction. Good haemodynamics and improved New York Heart Association class were demonstrated in all patients. One patient died before 30 days due to sepsis. One patient had a valve thrombosis when switching from Coumadin to new oral anticoagulant and had a second valve implanted into the first one as a 'valve-in-valve' procedure. CONCLUSIONS: The transapical approach is a safe and straight forward procedure for accessing the mitral valve. 'Transcatheter aortic valve implantation' prostheses may be used in redo surgery due to an already sufficient 'docking station'. These specially designed new prostheses may be beneficial for addressing mitral valve regurgitation, but are still under evaluation. Anticoagulation is mandatory.


Subject(s)
Heart Valve Prosthesis Implantation/methods , Minimally Invasive Surgical Procedures/methods , Mitral Valve Insufficiency/surgery , Mitral Valve/surgery , Thoracotomy/methods , Adult , Aged , Female , Humans , Male , Middle Aged , Mitral Valve/diagnostic imaging , Mitral Valve Insufficiency/diagnosis , Printing, Three-Dimensional , Tomography, X-Ray Computed , Treatment Outcome
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