Peripheral Artery Disease and Continuous Flow Left Ventricle Assist Device: An Engaging Complement Analysis May Help to Guide Treatment

Use of continuous flow left ventricle assist device (CF‐LVAD) in advanced heart failure (HF) patients results in clinically relevant improvements in survival, functional capacity, and quality of life. Peripheral artery disease (PAD) can occur in patients with CF‐LVAD due to the high rate of concomitance between risk factors for atherosclerosis and HF. Diagnosis of PAD can be difficult in the specific setting of a patient supported by this kind of device because of the marked alteration in waveform morphology and velocity created by the artificial physiology of an LVAD. We report the case of a 53‐year‐old man with HF secondary to ischemic cardiomyopathy supported by the HeartWare HVAD as bridge to transplant, who after the implant developed symptoms suggestive of PAD. We describe additional computational flow analysis for the study of PAD‐related hemodynamic disturbances induced by a CF‐LVAD. Flow simulations enhance the information of clinical image data, and may have an application in clinical investigations of the risk of hemodynamic disturbances induced by LVAD implantation.     

Preconditioning With Levosimendan Before Implantation of Left Ventricular Assist Devices

In this retrospective study, we investigated the impact of preconditioning of the right ventricle with the calcium sensitizer levosimendan immediately before left ventricular assist device (LVAD) implantation on outcome and survival. Nine consecutive LVAD patients (seven suffering from dilative cardiomyopathy and two from ischemic cardiomyopathy) with echocardiographic and invasive evidence of right heart insufficiency received levosimendan with 0.1 μg/kg body weight/min for 24 h before implantation of the assist device (seven HeartWare and two Jarvik 2000). Administration of levosimendan was safe and had not to be discontinued in any patient. We observed no relevant side effects. Twelve‐month survival after implantation of the LVAD was 89% representing a superior outcome compared with the fifth INTERMACS registry data with 75% survival. Two temporary extracorporeal membrane‐oxygenation implantations were necessary due to intraoperative right ventricular dysfunction. Only one patient died 5 weeks after LVAD implantation of multiorgan failure, five patients were successfully transplanted, and three patients underwent LVAD implantation for destination therapy. Levosimendan might improve clinical outcome and survival when used as pretreatment in patients with right heart insufficiency prior to LVAD implantation. However, we recommend a larger controlled trial in the future to confirm our preliminary results.     

Impact of Residual Mitral Regurgitation on Right Ventricular Systolic Function After Left Ventricular Assist Device Implantation

Significant mitral regurgitation (MR) is thought to decrease after left ventricular assist device (LVAD) implantation, and therefore repair of mitral valve is not indicated in current practice. However, residual moderate and severe MR leads to pulmonary artery pressure increase, thereby resulting in right ventricular (RV) dysfunction during follow‐up. We examined the impact of residual MR on systolic function of the right ventricle by echocardiography after LVAD implantation. This study included 90 patients (mean age: 51.7 ± 10.9 years, 14.4% female) who underwent LVAD implantation (HeartMate II = 21, HeartWare = 69) in a single center between December 2010 and June 2014. Echocardiograms obtained at 3–6 months and over after implantation were analyzed retrospectively. RV systolic function was graded as normal, mild, moderate, and severely depressed. MR (≥moderate) was observed in 43 and 44% of patients at early and late period, respectively. Systolic function of the RV was severely depressed in 16 and 9% of all patients. Initial analysis (mean duration of support 174.3 ± 42.5 days) showed a statistically significant correlation between less MR and improved systolic function of RV (P = 0.01). Secondary echocardiographic analysis (following a mean duration of support of 435.1 ± 203 days) was also statistically significant for MR degree and RV systolic dysfunction (P = 0.008). Residual MR after LVAD implantation may cause deterioration of RV systolic function and cause right‐sided heart failure symptoms. Repair of severe MR, in selected patients such as those with severe pulmonary hypertension and depressed RV, may be considered to improve the patient's clinical course during pump support.     

Impella 5.0 as a Second‐Line Mechanical Circulatory Support Strategy After Extracorporeal Life Support

The catheter‐based Impella 5.0 left ventricular assist device is a powerful and less invasive alternative for patients in cardiogenic shock. The use as second‐line therapy in patients with precedent extracorporeal life support (ECLS) has not been described before now. We analyzed our experience of consecutive patients treated with this alternative strategy. From April 2014 to December 2014, eight patients had been implanted as a second‐line option after ECLS support. The reason for the change from ECLS to Impella 5.0 was absence of cardiac recovery for primary weaning and complications of ECLS therapy. The mean time of ECLS support prior to Impella implantation was 12 ± 7 days. The implantation of the Impella 5.0/CP was technically successful in all patients, and the ECLS could be explanted in all eight patients who received Impella implantation as a second‐line treatment. The second‐line Impella 5.0 therapy resulted in two patients who turned into left ventricular assist device (LVAD) candidates, two primary weaning candidates, and four patients who died in the setting of sepsis or absent cardiac recovery and contraindications for durable LVAD therapy. Thereby, the overall hospital discharge survival as well as the 180‐day survival was 50% for Impella 5.0 implantations as second‐line procedure after ECLS. The latest follow‐up survival of this second‐line strategy after ECLS was three out of eight, as one patient died after 299 days of LVAD support due to sepsis. The use of Impella 5.0 constitutes a possible second‐line therapeutic option for those patients who do not show cardiac recovery during prolonged ECLS support or suffer from complications of ECLS therapy. This treatment allows additional time for decisions regarding cardiac recovery or indication for durable LVAD therapy.     

Minimally Invasive Implantation of Continuous Flow Left Ventricular Assist Devices: The Evolution of Surgical Techniques in a Single‐Center Experience

In this work we aimed to evaluate the evolution of our surgical experience with the implantation of a continuous flow left ventricular assist device (LVAD), from the original full sternotomy approach to less invasive surgical strategies including mini‐sternotomy and/or mini‐thoracotomies. We reviewed all consecutive patients implanted with a continuous flow LVAD at our Institute. To exclude the possible bias related to the device used, out of 91 collected LVADs implants, we selected only those patients (n = 42) who received, between 2012 and 2015, the HeartWare HVAD. The analysis focused on the surgical approach used for the LVAD implant. Most of the patients (95%) were affected by dilated or ischemic cardiomyopathy, with an INTERMACS class I‐II in the majority of cases (77%). The LVAD implant was performed through a full sternotomy in 10 patients (24%); the remaining 32 cases (76%) were managed with minimally invasive procedures. These were left mini‐thoracotomy with upper mini‐sternotomy (20 patients, 62%), right and left mini‐thoracotomy (7 patients, 22%), and a recently developed left mini‐thoracotomy with outflow graft anastomosis to the left axillary artery (5 patients, 16%). The most common adverse event on device was right heart failure (26%). Eighteen patients (43%) were transplanted. Overall estimated 24 months survival (on device or after transplant) was 68 ± 7%. The causal analysis, adjusted by propensity score weighting baseline data and sample size, showed that left mini‐thoracotomy with outflow anastomosis to the left axillary artery resulted in a significantly reduced rate of post implant right heart failure (P < 0.01), and mechanical ventilation time (P = 0.049). To conclude, in our series, by applying mini‐invasive implant techniques in the majority of cases, mid‐term survival of continuous flow LVADs in severely compromised patients was satisfactory. In the adjusted analysis, the left anterior mini‐thoracotomy with outflow anastomosis to the left axillary artery showed the most favorable results.     

Bridging to a Long‐Term Ventricular Assist Device With Short‐Term Mechanical Circulatory Support

Implanting short‐term mechanical circulatory support (MCS) devices as a bridge‐to‐decision is increasingly popular. However, outcomes have not been well studied in patients who receive short‐term MCS before receiving long‐term left ventricular assist device (LVAD) support. We analyzed outcomes in our single‐center experience with long‐term continuous‐flow (CF)‐LVAD recipients with pre‐implantation short‐term MCS. From November 2003 through March 2016, 526 patients (mean age, 54.7 ± 13.5 years) with chronic heart failure (mean ejection fraction, 21.7 ± 3.6%) underwent implantation of either the HeartMate II (n = 403) or the HeartWare device (n = 123). Before implantation, 269 patients received short‐term MCS with the TandemHeart, the Impella 2.5/5.0, an intra‐aortic balloon pump (IABP), venoarterial extracorporeal membrane oxygenation (VA‐ECMO), or the CentriMag. The short‐term MCS patients were compared with the CF‐LVAD–only patients regarding preoperative demographics, incidence of postoperative complications, and long‐term survival. The 269 patients received the following short‐term MCS devices: 57 TandemHeart, 27 Impella, 172 IABP, 12 VA‐ECMO, and 1 CentriMag. Survival at 30 days, 6 months, 1 year, and 2 years was 94.2, 87.2, 79.4, and 72.4%, respectively, for CF‐LVAD–only patients versus 91.0, 78.1, 73.4, and 65.6%, respectively, for short‐term MCS + CF‐LVAD patients (P = 0.17). Within the short‐term MCS group, survival at 24 months was poorest for patients supported with VA‐ECMO or the TandemHeart (P = 0.03 for both), and survival across all four time points was poorest for patients supported with VA‐ECMO (P = 0.02). Short‐term MCS was not an independent predictor of mortality in multivariate Cox regression models (hazard ratio = 1.12, 95% confidence interval = 0.84–1.49, P = 0.43). In conclusion, we found that using short‐term MCS therapy—except for VA‐ECMO—as a bridge to long‐term CF‐LVAD support was not associated with poorer survival.     

Changes in Total Cardiac Output and Oxygen Extraction During Exercise in Patients Supported With an HVAD Left Ventricular Assist Device

Following implantation of a left ventricular assist device (LVAD), acceptable functional performance is now being achieved; however, peak VO₂ and peak work load (watts) remain considerably limited. Maximum physical capacity is essentially dependent on generated cardiac output (CO) and arteriovenous oxygen difference (avDO₂). We investigated the changes in CO and avDO₂ during exercise in LVAD patients with an HVAD pump (HeartWare Inc., Framingham, MA, USA). Approximately 6 weeks after implantation, 20 patients (100% male, 60.8 ± 7.3 years old, BMI 25.7 ± 3.3) underwent a six‐minute walk test (6MWT), a cardiopulmonary exercise test (CPET), and noninvasive hemodynamic measurement. The mean six‐minute walking distance (6MWD) was 403 m (68% of predicted), and mean peak VO₂ was 10.9 mL/kg/min (39% of predicted). Mean total CO improved from 3.8 L at rest to 7.0 L at maximum exercise. The mean avDO₂ increased from 7.4 mL/dL (44% of oxygen content) at rest to 13.2 mL/dL (75% of oxygen content) at maximum exercise. There was a significant increase in both total CO (P < 0.01) and avDO₂ (P < 0.05) between rest and sub‐maximum exercise. As exercise levels increased, however, no further significant changes were achieved. Long‐term studies, especially in combination with exercise programs, would be desirable in order to observe the development of these parameters.     

Mechanical support for biventricular failure using the HeartWare (HVAD) pump

The limited availability of organs for transplant has vastly popularized implantation of left ventricular assist devices. Right ventricular failure is a continued problem with an incidence as high as 44 %, significantly decreasing survival after left ventricular assist devices (LVAD) implantation. Survival is significantly better when LVAD patients at high risk for right ventricular failure (RVF) are converted directly to biventricular assist device (BiVAD) therapy instead of LVAD with subsequent right ventricular assist device (RVAD) implantation. The options available for biventricular assistance entail a total artificial heart (TAH) or additional right-sided placement of a continuous flow/pulsatile device which could be para-corporeal or implantable. The HeartWare HVAD (HeartWare International, Framingham, MA) device in a biventricular configuration is a very attractive option. This report details experiences and techniques for implantation of the HVAD in such a configuration.     

Design and Development of Novel Transcatheter Bicaval Valves in the Interventional Treatment of Tricuspid Regurgitation

The concept of heterotopic implantation of transcatheter tricuspid valve is new and has shown promising results thus far. While the Reynolds shear stress values measured in the vicinity of this valve are relatively low, the values at some time points are higher than the threshold of platelet activation. Hence, in this study, we aim to reduce these values with an innovative stent design. It was shown that the Reynolds shear stress values measured were lower than those of valves made of generic stent design and the maximum Reynolds shear stress values in the vicinity of the valves was very low (～10 dynes/cm²). The results also depicted the interesting flow phenomenon of this non‐physiological treatment approach. Thus, this study has shown that bicaval valves could potentially be considered as a minimally invasive option to treat tricuspid regurgitation and valve design improvements could reduce the flow disturbances that were observed.     

HeartWare left ventricular assist device implantation through bilateral anterior thoracotomy

The HeartWare left ventricular assist device (LVAD) is a new addition to the family of second-generation continuous-flow LVADs. The miniaturized dimensions of the HeartWare LVAD provide the opportunity for its safe implantation through nonsternotomy incisions. We present our technique for HeartWare LVAD implantation through bilateral anterior thoracotomy incisions. This technique has proved to be safe and reproducible, with good clinical outcome.     

Minimally Invasive Left Ventricular Assist Device Explantation After Cardiac Recovery: Surgical Technical Considerations

The new generation of left ventricular assist devices (LVADs) has enabled minimally invasive surgical procedures for implantation. Herein we present two alternative approaches for minimally invasive LVAD explantation following cardiac recovery, avoiding a sternotomy and improving patient safety.     

HeartWare Ventricular Assist Device Implantation in Patients With Fontan Physiology

We aim to describe the clinical course of a series of patients with hypoplastic left heart syndrome and refractory systolic heart failure supported with a HeartWare ventricular assist device (HVAD) following Fontan palliation. This is a retrospective review of three consecutive patients supported with a HVAD following Fontan palliation through February 2016. Data include patient characteristics, operative variables, postimplantation hemodynamic/device parameters, event outcomes, and duration of HVAD support. Patient ages were 11.7, 13.5, and 17.5 years, respectively, at the time of HVAD implant. The duration of HVAD support was 148, 272, and 271 days, respectively, of which 86, 222, and 211 were outpatient days. Inflow cannula position was the morphologic right ventricle with depth adjustment and manipulation of the tricuspid subvalvar apparatus to ensure good inflow. Echocardiographic, hemodynamic, and noninvasive oximetric monitoring resulted in high RPM settings for all patients. Despite various complications, all patients were successfully transplanted and discharged home alive. We present three patients bridged to transplantation using the HVAD following Fontan palliation. We demonstrate potential for durable support with transition to outpatient care while awaiting heart transplantation in a subset of patients status post Fontan surgery.     

Direct transaortic transcather valve-in-valve implantation into a mechanical aortic valve prosthesis during left ventricular assist device implantation: description of a surgical technique

The presence of a mechanical aortic valve prosthesis is considered a relative contraindication for left ventricular assist device implantation (LVAD) due to the occurrence of thromboembolic events. Five patients were operated on for LVAD implantation with status post mechanical aortic valve implantation (n = 3 with status post Bentall procedure). After removal of the leaflets, a transcatheter balloon-expandable valve was placed within the mechanical ring in all patients. Three patients were discharged from hospital with a maximum follow-up of 3.3 years. Transaortic transcatheter valve implantation into a mechanical aortic valve during LVAD implantation is a feasible option. It reduces operative times and might also prevent thromboembolic events.     

Combined ablation of atrial fibrillation and minimally invasive mitral valve surgery: a case report

A partial lower inverted J sternotomy and an extended transseptal incision provide excellent exposure for minimally invasive mitral valve surgery. However, the extended trasnsseptal incision causes dividing the sinus node artery, which may result in conduction system disturbance and need for permanent pacemaker implantation. Therefore, there is a challenge in the patient who requires concomitant ablation for atrial fibrillation because of possible conduction system disturbance caused by extended transseptal incision. We describe a new strategy for combined ablation of atrial fibrillation with minimally invasive cardiac surgery by a transseptal approach to the mitral valve through a partial lower sternotomy incision. Cryoablation was performed using a T-shaped cryoprobe with a lesion set of pulmonary vein isolation and ablation of the left and right isthmus in performing mitral annuloplasty, tricuspid annuloplasty, and atrial septal defect closure through a limited sternotomy incision. This technique might minimize possible conduction system disturbance and provide good surgical result for the patients who undergo mitral valve surgery and ablation of atrial fibrillation.     

Minimally invasive tricuspid operation using port access

BACKGROUND: Port-access techniques performed through a right mini-thoracotomy have been extensively described for both the mitral and aortic valves. However, reports of tricuspid valve operations using the port-access approach are rare. A technique for minimally invasive tricuspid valve operation using port access is described. METHODS: Port-access approach was applied to 33 consecutive patients undergoing tricuspid valve repair or replacement. RESULTS: Twelve percent (4 of 33) underwent tricuspid replacement and 88% underwent repair (28 of 33). Perioperative mortality was 6% (2 of 33) and conversion to median sternotomy was 3% (1 of 33). CONCLUSIONS: Port-access tricuspid operations are both feasible and safe with a low conversion rate to conventional median sternotomy.     

Minimalinvasive Strategien zur Implantation von Kunstherzsystemen

Heart transplantation remains the gold standard for patients with end-stage heart failure. Due to the lack of donor organs the increasing use of left ventricular assist devices (LVAD) has gained a paramount role in heart failure surgery. The conventional technique of LVAD implantation involves median sternotomy and connection to a heart-lung machine. More recent approaches show the progressive development of alternative and less invasive implantation techniques, not least because of the radical downsizing of the pump housing of current generation LVAD systems. As a result of the intrapericardial position of LVADs numerous minimally invasive strategies have already been developed. Moreover, the off-pump implantation technique is increasingly being used in some centers. In this study we present the new developments in the field of minimally invasive LVAD surgery and give an insight into the practical approach. Particular attention is given to appropriate patient selection and critical discussion on the possible advantages and disadvantages of each technique.     

Minimally invasive mitral surgery: mitral valve repair with a right-sided partial sternotomy

We describe our concept and the results of mitral valve repair using a right-sided partial sternotomy. We performed mitral valve repair using this method in 50 patients with severe MR between April 1997 and October 1998. In 10 patients in whom good exposure was not attained, we changed to the ordinary full-sternotomy or T-shaped partial sternotomyprocedure. Forty patients with good exposure underwent successful mitral valve repair. The sites of repair were anterior in 15 cases, posterior in 16, and both in 9. There was no mortality, and intraoperative TEE performed in all 40 patients revealed that all had trivial or no regurgitation. The right-sided partial sternotomy (open door method) is a safe and useful method for minimally invasive valve Surgery. A better quality of life compared with traditional median sternotomy can be ensured for patients undergoing minimally invasive cardiac surgery only when receive the best-quality Surgery is performed.     

Is a port-access mitral valve repair superior to the sternotomy approach in accelerating postoperative recovery?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether port-access mitral valve repair reduces the recovery period of patients compared to the conventional sternotomy approach. Using the reported search, 778 papers were identified. Thirteen papers represented the best evidence on the subject and the author, journal, date and country of publication, patient group studied, study type, relevant outcomes, results and study comments and weaknesses were tabulated. The 13 papers demonstrated that patients who undergo minimally invasive mitral valve repair have a shorter ICU and total hospital stay than those who undergo the sternotomy approach. Results vary but mean hospital stays range from 5.6 to 13 days in port-access groups compared to 6.25-15 days in sternotomy groups. Other advantages over the sternotomy approach were reduced postoperative bleeding and pain, shorter time to extubation and a quicker return to daily activities. However, it is consistently reported that operative time is longer, with the increase in bypass time being around 30 min. We conclude that in several cohort studies minimally invasive mitral valve repair is reported to result in a shorter ICU and hospital stay, reduced postoperative bleeding and pain and a shorter time to resuming normal activities. This is at the expense of longer bypass and operative times.     

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

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

Beating Heart Video-Assisted Mitral Valve Surgery: A Useful Technique for High-Risk Patients

Abstract   Background: Beating-heart valve surgery through a sternotomy has been used as an excellent myocardial protection strategy in high risk patients. Minimally invasive approaches have reduced the trauma and enhanced the recovery of patients undergoing heart surgery. We hypothesized that high-risk patients undergoing mitral valve surgery will benefit from a combination of these two approaches. Methods: A 52-year-old male with dilated cardiomyopathy and left ventricular function of 15% was referred for surgery because of congestive heart failure. Results: Using a 4-cm right minithoracotomy and femoral cannulation for cardiopulmonary bypass, successful beating-heart video-assisted mitral valve repair was performed. The adequacy of myocardial protection was confirmed by absence of ischemic electrophysiologic changes. The patient was discharged home on the 6^th postoperative day. Conclusion: Beating-heart strategy can be combined with a minimally invasive approach in patients with severely reduced ventricular function, who require mitral valve surgery.