Background. Left ventricular assist devices (LVADs) are increasingly being used to “bridge” patients to heart transplantation.
Methods. Data from 40 consecutive status 1 heart transplantation ...patients treated with intravenous inotrope therapy (n = 20) or the HeartMate LVAD (n = 20) were retrospectively analyzed.
Results. Baseline clinical characteristics were similar in the two groups. At the time of transplantation, LVAD patients had significantly higher blood pressure and sodium with significantly lower blood urea nitrogen and creatinine. After transplantation, renal failure (52.6% versus 16.7%) and right heart failure (31.6% versus 5.6%) occurred more frequently (p < 0.05) in the inotrope group. Six-month survival after transplantation did not significantly differ in the inotrope or LVAD groups (73.7% versus 88.9%) but event-free survival was significantly (p < 0.05) lower in the inotrope group (15.8% versus 55.6%). Total hospital charges were significantly lower in the inotrope group ($213,860 ± $107,560 versus $342,620 ± $104,420), but average daily hospital charges were not different ($3,990 ± $1,300 versus $4,130 ± $2,050).
Conclusions. Status 1 heart transplant patients treated with an LVAD as opposed to inotrope therapy have improved clinical and metabolic function at the time of transplant and improved survival to 6 months after transplant without major complications. Total costs are higher in the LVAD patients but average daily costs are similar.
Patients with acute myocardial infarction (AMI) complicated by cardiogenic shock have a high mortality rate. Current treatment modalities remain suboptimal for these patients.
From April 1995 to ...March 1998, 7 patients were identified as having AMI associated with cardiogenic shock. All received intraaortic balloon pump assistance, in addition to maximal inotropic support.
The mean preoperative cardiac index was 2.0+/-0.3 L/min/m2 and pulmonary capillary wedge pressure was 23+/-6 mm Hg. Three patients received thrombolytic therapy and 4 patients underwent percutaneous transluminal coronary angioplasty without success. Left ventricular assist devices (LVADs) were implanted as bridge therapy to heart transplantation. One patient died from recurrence of a ventricular septal defect during LVAD support. Six patients were transplanted successfully after mean LVAD support of 59+/-33 days. Five patients are alive and well at a mean follow-up of 898+/-447 days. One patient died 3 days after transplantation from acute allograft dysfunction.
Timely application of LVADs as bridge therapy to heart transplantation in these critically ill patients can be lifesaving, and should be investigated further.
1 Cardiovascular Division, Department of Medicine, Minneapolis 55455
2 Informatics Division, Cancer Center, Minneapolis 55455
3 Cardiothoracic Surgery, University of Minnesota, Minneapolis 55455
4 ...Fairview Medical Center, Minneapolis 55455
5 Mayo Clinic, Rochester, Minnesota 55905
Mechanical unloading of the heart with a left ventricular assist device (LVAD) significantly decreases mortality in patients with heart failure. Moreover, it provides a human model to define the critical regulatory genes governing myocardial remodeling in response to significant reductions in wall stress. Statistical analysis of a gene expression library of 19 paired human heart samples harvested at the time of LVAD implant and again at explant revealed a set of 22 genes that were downregulated and 85 genes that were upregulated in response to mechanical unloading with a false discovery rate of less than 1%. The analysis revealed a high percentage of genes involved in the regulation of vascular networks including neuropilin-1 (a VEGF receptor), FGF9, Sprouty1, stromal-derived factor 1, and endomucin. Taken together these findings suggest that mechanical unloading alters the regulation of vascular organization and migration in the heart. In addition to vascular signaling networks, GATA-4 binding protein, a critical mediator of myocyte hypertrophy, was significantly downregulated following mechanical unloading. In summary, these findings may have important implications for defining the role of mechanical stretch and load on autocrine/paracrine signals directing vascular organization in the failing human heart and the role of GATA-4 in orchestrating reverse myocardial remodeling. This unbiased gene discovery approach in paired human heart samples has the potential to provide critical clues to the next generation of therapeutic treatments aimed at heart failure.
microarray; GATA-4; stretch; SDF-1; unloading
The successful use of left ventricular assist devices (LVADs) as a bridge to heart transplantation has prompted our examination of quality of life (QOL) outcomes. The purposes of this study are to ...describe QOL in patients 1 to 2 weeks after LVAD implantation and to compare QOL in a smaller cohort of patients from before to 1 to 2 weeks after surgery.
Data were collected from a convenience sample of 81 patients who completed booklets of questionnaires that measure domains of QOL 1 to 2 weeks after LVAD insertion and from 30 of 81 patients who completed booklets at both the pre-implantation and post-implantation periods. Patients completed booklets of 6 to 8 self-reporting instruments, with acceptable reliability and validity. Data were analyzed using descriptive and comparative statistics (chi-square, Mann-Whitney
U and Wilcoxon signed ranks tests) with
p = 0.01 considered statistically significant.
One to 2 weeks after LVAD implantation, patients were quite satisfied with their lives, experienced moderately low amounts of stress, coped well, and perceived themselves as having good health and QOL, low symptom distress, and moderately low functional disability. Patients reported significantly better QOL, more satisfaction with health and functioning, and were significantly less distressed by symptoms from immediately pre-operatively to post-operatively. However, patients reported significantly more self-care disability and more dissatisfaction with socioeconomic areas of life from before to immediately after surgery. Psychological distress was low and did not change with time.
Given that QOL improved from before to after LVAD implantation, our findings provide a springboard for investigation of the impact of LVADs on long-term QOL outcomes.
1 Lillehei Heart Institute, Division of Cardiology, Department of Medicine, University of Minnesota, Minneapolis, Minnesota 55455
2 Informatics Core, University of Minnesota, Minneapolis, Minnesota ...55455
3 Department of Cardiothoracic Surgery, University of Minnesota, Minneapolis, Minnesota 55455
We screened a compendium of gene profiles from 19 paired human heart samples harvested at the time of implant and explant of a left ventricular assist device (LVAD) for novel genes regulating the Ras/MEK/ERK cascade. From this analysis we identified Sprouty1, an evolutionally conserved gene that acts as an intrinsic inhibitor of the Ras/MEK/ERK pathway. Sprouty1 mRNA and protein were significantly upregulated in the heart in response to mechanical unloading with a LVAD. The upregulation of Sprouty1 in the heart following mechanical unloading was accompanied by a significant decrease in phosphorylated ERK1/2. Gain of function experiments demonstrated that upregulation of Sprouty1 in isolated cardiac myocytes led to a significant decrease and altered kinetics of ERK1/2 phosphorylation. Immunohistochemistry of human hearts revealed that Sprouty1 was also expressed in the microvasculature. Upregulation of Sprouty1 in endothelial cells led to a significant decrease in VEGF-induced endothelial cell proliferation. To our knowledge, these findings are the first to define Sprouty expression in the heart and suggest that Sprouty1 may serve as an intrinsic mediator governing ventricular remodeling through a coordinated coupling of both myocyte and vascular alterations in response to mechanical load.
heart failure; remodeling; genes; molecular biology; signal transduction
This report describes 2 patients with an aortic bioprosthesis. Both patients developed total thrombotic occlusion of the sub-aortic left ventricular outflow tract consequent to insertion of a left ...ventricular assist device (LVAD). Replacing a mechanical valve with a bioprosthesis in patients receiving a left ventricular assist device offers no additional protection against thrombosis of the aortic prosthesis. Pericardial patching below the aortic prosthesis at the time of LVAD implantation may be performed, but will significantly impede or prohibit the native ventricle from ejecting blood and demonstrating any degree of recovery.
We examined whether unloading of the left ventricle with a ventricular assist device (LVAD) can result in normalization of the creatine kinase (CK) abnormalities in the failing human heart.
Left ...ventricular failure is associated with a decrease of myocardial total CK activity and a fetal shift in CK isoform expression that results in an increase in the cytosolic brain type homodimeric-creatine kinase (CK-B) subunit and decreases of the cytosolic muscle-creatine kinase (CK-M) and CK-mitochondrial (CK-Mt) isoforms. The mechanisms of this abnormality are not known.
Total CK activity and CK protein isoform expression (Western blotting) were examined in 11 patients with end-stage cardiomyopathy. In 7 patients, myocardial tissue was also obtained after 4.1 ± 1.1 months of left ventricular assist device (LVAD) support.
Left ventricular unloading produced by LVAD implantation resulted in a 270% ± 114% increase in total CK activity (p < 0.01) that was associated with a 69% ± 18% increase in CK-M protein expression (p < 0.01) and a 121% ± 69% increase in CK-Mt protein expression (p < 0.01), but no significant change in CK-B expression.
Systolic and diastolic unloading provided by the LVAD resulted in increases of total CK activity as well as CK-Mt and CK-M protein expression. The failure of CK-B expression to decrease suggests that abnormalities other than increased loading are responsible for the increase in CK-B expression in the failing heart.
Memory improvement following cardiac transplantation Roman, Deborah D.; Kubo, Spencer H.; Ormaza, Sofia ...
Journal of clinical and experimental neuropsychology,
10/1997, Letnik:
19, Številka:
5
Journal Article
Recenzirano
seventeen patients with severe cardiomyopathy underwent neuropsychological evaluation prior to and at least 1 year after successful heart transplantation. Study candidates were screened, and ...individuals with a history of stroke, cardiac arrest, or medical and neurological conditions which might affect brain function were excluded. Pre-transplant testing revealed normal intelligence and normal attentional, language, and executive abilities but impaired recent memory. Following heart transplant, memory functioning improved significantly, reaching normal levels. Other cognitive abilities remained unchanged. Results suggest that cardiomyopathy is associated with mesial temporal dysfunction, possibly attributable to inadequate or reduced cerebral blood flow and related hypometabolism. This cerebral dysfunction is potentially reversible following successful transplantation, which restores cardiac output and cerebrovascular perfusion.
Análisis de los Ataques de Ingeniería Social en Ecuador Garzón Ibarra, Carlos Santiago; Navas Tapia, Christian Andrés; Illicachi Tene, Angélica María ...
Ciencia Latina Revista Científica Multidisciplinar,
02/2024, Letnik:
8, Številka:
1
Journal Article
Odprti dostop
Este estudio se enfoca en analizar y comprender la naturaleza y el impacto de los ataques de ingeniería social en Ecuador. Su objetivo principal es identificar las tácticas específicas empleadas en ...dichos ataques, evaluar sus efectos en diversos sectores de la sociedad ecuatoriana y proponer estrategias efectivas de prevención y respuesta. Para alcanzar este fin, se adoptó un enfoque metodológico cualitativo y documental, permitiendo una exploración detallada y contextualizada de los ataques. Esto incluye el análisis exhaustivo de una variedad de fuentes documentales, como informes gubernamentales, estudios académicos, estadísticas de ciberseguridad y registros de incidentes. Los hallazgos del estudio indican un aumento preocupante en la frecuencia y sofisticación de los ataques de ingeniería social en Ecuador, destacando una la falta de conciencia y preparación general frente a estas amenazas. Se observa que, mientras el sector privado ha comenzado a implementar medidas de seguridad avanzadas, el sector estatal aún muestra limitaciones en su capacidad de respuesta y prevención. Este contraste subraya la necesidad urgente de fortalecer las estrategias de seguridad cibernética en todo el país, involucrando a múltiples actores, incluidos el gobierno, el sector privado, la academia y la sociedad civil.
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