The implantation of a left ventricular assist device (LVAD) is an important therapeutic tool for patients with end-stage heart failure, which can either help patients transit to the heart transplantation stage or serve as destination therapy until the end of their lives. In recent years, the third generation of LVAD has evolved rapidly and several brands have been marketed both domestically and internationally. The number of LVAD implantations has been increasing and the long-term survival rate of implanted patients has improved, so this device has a broad development perspective. This article summarizes the current status, usage standards and precautions, and common complications after implantation of LVAD, as well as looks forward to the future development of LVAD, hoping to be helpful for researchers who are new to this field.
ObjectiveTo explore the value of transthoracic echocardiography (TTE) to monitor and evaluate aortic insufficiency (AI) within one year after the implantation of the left ventricular assist device (LVAD).MethodsWe retrospectively collected and analyzed the TTE data of 12 patients who received LVAD implantation from 2018 to 2020 in our hospital. All patients were males, with an average age of 43.3±8.6 years. We analyzed temporal changes in the aortic annulus (AA), aortic sinus (AoS), ascending aorta (AAo), the severity of AI and the opening of aortic valve before operation and 1 month, 3 months, 6 months and 12 months after LVAD implantation.ResultsAll 12 patients survived within 1 year after LVAD implantation. One patient was bridged to heart transplantation 6 months after implantation, and two patients did not receive TTE after 3 and 6 months. Compared to pre-implantation, AoS increased at 1 month after implantation (31.58±5.09 mm vs. 33.83±4.69 mm). The inner diameters of AA, AoS and AAo increased at 3, 6 and 12 months after LVAD implantation compared to pre-implantation (P<0.05), but all were within the normal range except for one patient whose AoS slightly increased before operation. After LVAD pump speed was adjusted, the opening of aortic valve improved. The severity of AI increased at 6 and 12 months after LVAD implantation compared to pre-implantation, and increased at 12 months compared to 6 months after LVAD implantation (P<0.05).ConclusionTTE can evaluate aortic regurgitation before and after LVAD implantation and monitor the optimization and adjustment of LVAD pump function, which has a positive impact on the prognosis after LVAD implantation.
Objective To investigate the feasibility of a long-term left ventricular assist device placed in the aortic valve annulus for terminal cardiopathy. Methods An implantable aortic valve pump （23ram outer diameter, weighing 31g） was developed. There were a central rotor and a stator in the device. The rotor was consisted of driven magnets and an impeller, the stator was consisted of a motor coil with an iron core and outflow guide vanes. The device was implanted identical to an aortic valve replacement, occupying no additional anatomic space. The blood was delivered directly from left ventricle to the aortic root by aortic valve pump like natural ventricle, neither connecting conduits nor ＂bypass＂ circuits were necessary, therefore physiologic disturbances of natural circulation was less. Results Aortic valve pump was designed to cycle between a peak flow and zero net flow to approximate systole and diastole. Bench testing indicated that a blood flow of 7L/min with 50 mmHg（1kPa = 7.5mmHg） pressure could be produced by aortic valve pump at 15 000r/min. A diastole aortic pressure of 80mmHg could be maintained by aortic valve pump at 0L/min and the same rotating speed. Conclusions This paper exhibits the possibility that an aortic valve pump with sufficient hemodynamic capacity could be made in 23mm outer diameter, 31g and it could be implantable. This achievement is a great progress to extend the applications of aortic valve pump in clinic and finally in replacing the natural donor heart for heart transplantation. Meanwhile, this is only a little step, because many important problems, such as blood compatibility and durability, require further investigation.
Regurgitation is an abnormal condition happens when left ventricular assist devices (LVADs) operated at a low speed, which causes LVAD to fail to assist natural blood-pumping by heart and thus affects patients’ health. According to the degree of regurgitation, three LVAD’s regurgitation states were identified in this paper: no regurgitation, slight regurgitation and severe regurgitation. Regurgitation index (RI), which is presented based on the theory of dynamic closed cavity, is used to grade the regurgitation of LVAD. Numerical results showed that when patients are in exercising, resting and sleeping state, the critical speed between slight regurgitation and no regurgitation are 6 650 r/min, 7 000 r/min and 7 250 r/min, respectively, with corresponding RI of 0.401, 0.300 and 0.238, respectively. And the critical speed between slight regurgitation and severe regurgitation are 5 500 r/min, 6 000 r/min and 6 450 r/min, with corresponding RI of 0.488, 0.359 and 0.284 respectively. In addition, there is a negative relation correction between RI and rotational speed, so that grading the LVAD’s regurgitation can be achieved by determining the corresponding critical speed. Therefore, the detective parameter RI based on the signal of flow is proved to be able to grade LVAD’s regurgitation states effectively and contribute to the detection of LVAD’s regurgitation, which provides theoretical basis and technology support for developing a LVADs controlling system with high reliability.
As a global disease, heart failure affects at least 26 million people, and its prevalence is still rising. Besides, the mortality rate and readmission rate remain high. Advanced heart failure is the terminal stage of various heart diseases, and often requires some treatments other than drug intervention, such as heart transplantation which is the gold standard for treatment of heart failure. However, limited by the number of donors, the number of heart transplants in the world has reached a bottleneck. There is a huge gap between the number of patients who need heart transplants and patients who get hearts for survival successfully in reality. With the exploration and development of mechanical circulation support devices for more than half a century, they have become a wonderful treatment for patients with advanced heart failure. This article will introduce the latest progress of mechanical circulatory support devices at home and abroad from the aspects of temporary and long-term devices.
A 56-year male patient was implanted with a third generation magnetic levitation HeartCon left ventricular assist device (LVAD) for refractory heart failure through a left antero-lateral thoracotomy. Inflow cannula of the HeartCon blood pump was inserted via the left apex and outflow tract with the artificial blood vessel was sutured to the descending aorta. The operation process was smooth, the LVAD worked stably, and results of left ventricular assist was good. Implantation of HeartCon LVAD through the left antero-lateral thoracotomy is an alternative technique with less surgical complications, less trauma and satisfactory results.
ObjectiveTo compare the perioperative renal function changes in patients undergoing heart transplantation (HT) and left ventricular assist device (LVAD) implantation. MethodsPatients with end-stage heart failure who underwent surgical treatment at Beijing Anzhen Hospital, Capital Medical University from January 2019 to April 2024 were included. According to the surgical method, patients were divided into a HT group and a LVAD group, and the estimated glomerular filtration rate (eGFR) of patients before surgery and postoperative 1, 7, 30, 60 days was compared between the two groups. The patients with preoperative renal dysfunction were subdivided into subgroups for comparison of eGFR changes before surgery and 30 days after surgery between the two groups. ResultsA total of 112 patients were enrolled. There were 78 patients in the HT group, including 61 males and 17 females, aged (44.42±18.51) years. There were 34 patients in the LVAD group, including 30 males and 4 females, aged (54.94±11.37) years. Compared with the HT group, the average age of patients in the LVAD group was greater (P<0.001), body mass index was higher (P=0.008), preoperative eGFR was lower (P=0.009), and the proportions of smokers (P=0.017), alcohol drinkers (P=0.041), and diabetes mellitus (P=0.028) patients were higher. Among patients with preoperative renal dysfunction [eGFR<90 mL/(min·1.73 m2)], compared with the HT group, the postoperative eGFR of the LVAD group was significantly higher than that of the HT group, and it was significantly increased compared with that before surgery; the postoperative eGFR of the HT group was comparable to that before surgery, and more than half of the patients had a lower eGFR than before surgery. Among patients with preoperative renal dysfunction, 11 patients in the HT group received continuous renal replacement therapy, and 8 died early; 2 patients in the LVAD group received continuous renal replacement therapy, and 1 died early. ConclusionFor end-stage heart failure patients with combined renal dysfunction, compared with HT, LVAD implantation enables patients to obtain better renal function benefits.
In China, more than half of heart failure patients are ischemic heart failure patients. And a large proportion of left ventricular assist device implantation patients are also ischemic heart failure patients. However, left ventricular assist device implantation in ischemic heart failure patients is facing with problems such as patient screening, coronary artery disease, small left ventricle, mitral insufficiency, and ventricular aneurysm. There are only a few retrospective studies with small sample sizes abroad trying to provide solutions to these problems. While there is a lack of systematic understanding of this issue in China. Therefore, we provide an overview of the application and progress of left ventricular assist devices in ischemic heart failure patients, aiming to help clinicians have a comprehensive understanding of this issue and provide some guidance.
Percutaneous ventricular assist device (PVAD) is a minimally invasive treatment which can replace the function of the failing heart. It provides circulatory support for patients with severe emergent cardiovascular diseases such as complex coronary artery disease, acute myocardial infarction complicated by cardiogenic shock, and acute decompensated chronic heart failure. PVAD has been developed since the rise of the Hemopump, to the prosperity of the Impella, and increasingly been used as a haemodynamic support to improve prognosis. This article will review the evolution and clinical application of PVAD.
Objective To compare the early outcomes of domestic third-generation magnetically levitated left ventricular assist device (LVAD) with or without concomitant mitral valvuloplasty (MVP). Methods The clinical data of 17 end-stage heart failure patients who underwent LVAD implantation combined with preoperative moderate to severe mitral regurgitation in Fuwai Central China Cardiovascular Hospital from May 2018 to March 2023 were retrospectively analyzed. The patients were divided into a LVAD group and a LVAD+MVP group based on whether MVP was performed simultaneously, and early outcomes were compared between the two groups. Results There were 4 patients in the LVAD group, all males, aged (43.5±5.9) years, and 13 patients in the LVAD+MVP group, including 10 males and 3 females, aged (46.8±16.7) years. All the patients were successful in concomitant MVP without mitral reguragitation occurrence. Compared with the LVAD group, the LVAD+MVP group had a lower pulmonary artery systolic pressure and pulmonary artery mean pressure 72 h after operation, but the difference was not statistically different (P>0.05). Pulmonary artery systolic pressure was significantly lower 1 week after operation, as well as pulmonary artery systolic blood pressure and pulmonary artery mean pressure at 1 month after operation (P<0.01). There was no statistically significant difference in blood loss, operation time, cardiopulmonary bypass time, aortic cross-clamping time, mechanical ventilation time, or ICU stay time between the two groups (P>0.05). The differences in 1-month postoperative mortality, acute kidney injury, reoperation, gastrointestinal bleeding, and thrombosis and other complications between the two groups were not statistically significant (P>0.05). Conclusion Concomitant MVP with implantation of domestic third-generation magnetically levitated LVAD is safe and feasible, and concomitant MVP may improve postoperative hemodynamics without significantly increasing perioperative mortality and complication rates.