Jonida Bejko

Hemorrhage and thrombosis with different LVAD technologies: a matter of flow?

BACKGROUND Much of the morbidity and mortality associated with ventricular assist devices (VADs) is due to haemorrhagic and thrombotic complications. To manage antithrombotic therapy, interactions between the patient and pump should be better understood. METHODS We have compared the Jarvik 2000, an axial flow left ventricular assist device (LVAD), with the HeartWare ventricular assist device (HVAD) centrifugal pump, regarding conventional laboratory findings, thromboelastometric and aggregometric tests. RESULTS Patients with the Jarvik 2000 experienced a significant reduction in platelet count following implantation, a phenomenon not seen with the HeartWare model. Conversely, we observed that levels of platelet activation, as assessed by a platelet function analyzer, and activation of the coagulation system, as assessed by thromboelastometry, were significantly greater in the HeartWare group. CONCLUSIONS It seems that axial flow pumps, being more destructive on blood cells, tend to reduce platelet numbers. On the other hand, centrifugal flow is associated with a hypercoagulable state, possibly resulting from the activation of the coagulation system in the absence of platelet destruction.

Impact of vacuum-assisted closure therapy on outcomes of sternal wound dehiscence †

OBJECTIVES Sternal wound dehiscence (SWD) after cardiac surgery is a rare but serious condition associated with considerable costs and morbidity. We sought to evaluate the results of the introduction of vacuum-assisted closure (VAC) therapy in the management of sternal wound dehiscence, compared with those of previous conventional treatments. METHODS We retrospectively collected 7148 patients who underwent cardiac surgery at our institution between January 2002 and June 2012. A total of 152 (2.1%) patients had a sternal wound dehiscence: 107 were treated with conventional treatments (Group A) and 45 were managed with VAC therapy (Group B). Patients were stratified according to preoperative risk factors and type of sternal wound dehiscence (superficial or deep; infected or not) and compared by means of a propensity-matched analysis. A cost analysis was also performed. RESULTS Forty-five patients of each group matched for all preoperative risk factors and type of sternal wound dehiscence. SWD-related mortality rate was significantly lower in Group B (11 vs 0%; P = 0.05). Incidence of mediastinitis (P < 0.0001), sepsis (P = 0.04), delayed SWD infection (P = 0.05), other complication (P = 0.05), surgical sternal revision (P = 0.04) and surgical superficial revision (P < 0.0001) were all significantly lower in Group B. Mean patient cost was 31 106€ in Group A and 24 383€ in Group B, thus achieving a mean saving of 6723€ per patient. CONCLUSIONS In our experience, the use of VAC therapy for the management of SWD was considerably effective in decreasing mortality (SWD related), incidence of complications and need for surgical procedures; thus, leading to a significant reduction of costs.

Nitinol Flexigrip Sternal Closure System and Chest Wound Infections: Insight From a Comparative Analysis of Complications and Costs

BACKGROUND We sought to assess the efficiency of two different sternal closure techniques in preventing sternal wound complications (SWC). A cost analysis was also considered. METHODS Between January 2008 and April 2010, 1,644 consecutive cardiac surgery patients who underwent cardiac surgery in our institute were prospectively collected. A total of 1,072 patients received a standard parasternal wiring technique (group A), and 572 patients received a new method of sternal closure based on the use of thermoreactive nitillium clips (Flexigrip; Praesidia SRL, Bologna, Italy [group B]). We investigated, by a propensity matched analysis, whether the use of standard or nitinol clip closure would impact on sternal wound outcome. RESULTS In all, 464 patients of each group were matched for 17 available risk factors. Overall incidence of SWC was significantly higher in group A (4.1% versus 1.7%; p=0.03). Sternal surgical revision to treat a thoracic instability was required in a significantly higher number of patients in group A (9 patients, 1.9%) and in none of group B (p=0.004). The incidence of sternal instability, secondary to wound infection, was significantly lower in group B (p=0.05). Overall costs were €7,407,296 and €6,896,432 in group A and group B, respectively. Thus, nitinol clip closure technique offered a €510,864 cost saving compared with standard steel wiring technique. CONCLUSIONS The Flexigrip assured a lower incidence of SWC. The use of the nitinol clip favored an improved sternal closure technique preventing mediastinitis. Additionally, the nitinol clip system proved to be cost effective in cardiac surgery.

Valve surgery in octogenarians: does it prolong life?

OBJECTIVES Age-related degenerative heart-valve disease is a health issue in the present era. Octogenarians are frequently affected by concomitant diseases and, with the present lack of resources, the risk/benefit of valvular replacement therapy poses serious medical, economical and political challenge. We analysed the long-term survival of 346 octogenarians who underwent 352 operations between 1 January 1987 and 1 January 2009 and we compared it with the survival of the general population, matched for age, sex and operative year. METHODS The total follow-up was of 1352 years, maximum 15.7 years and was nearly complete except for a single foreigner. Heart diseases, concomitant pathologies, complications and actuarial survival of this study group were compared with 4649 younger counterparts, who received 5416 operations during the same time frame. Octogenarians were sorted by age, sex and operative year and the expected survival was calculated by applying US survival rate and added to the Kaplan-Meier plot for visual comparison. RESULTS A total of 279 aortic, 38 mitral and 35 mitro-aortic valves were replaced or repaired using 357 bioprostheses, 18 mechanical prostheses, 12 reparative operations and 24 re-operations. A total of 75% of patients were younger than 84 years, 95% were younger than 87 years and 99% younger than 90 years. Sex prevalence was 215 female versus 131 male. Operative (30 days) mortality was 5.5% and overall survival was 84.3% at 1 year, 65.4% at 5 years, 27.3% at 10 years and 5.4% at 15 years. The expected survival of the age-, sex-, operative year-matched population was 26.9% at 10 years and 7.9% at 15 years. Female operative mortality was 5.9% and survival was respectively 86.3%, 70.2%, 27.5% and 9.1%, male mortality was 4.5% and survival was respectively 81%, 56.7%, 28.8% and 0% (p=0.16). Expected female survival was 30% at 10 years and 10% at 15 years versus 22% and 5.6%, respectively, in males. Six octogenarians underwent re-operation, with one death. CONCLUSIONS Despite the highest prevalence of concomitant diseases and the requirement of additional resources for the detection and neutralisation of risk factors, heart-valve operations in octogenarians offer excellent results that compare favourably with the expected survival of the age-, sex- and operative year-matched population, particularly after primary operations.

Bilateral mini-thoracotomy off-pump Jarvik 2000 implantation in regional asymmetric paravertebral analgesia

We describe the surgical technique and treatment of a 59-year-old male with cardiogenic shock, who underwent a minimally invasive off-pump ventricular assist device (VAD) implantation with the aid of paravertebral regional analgesia in bilateral mini-thoracotomies as first procedure described in the literature. He was extubated soon after the procedure, in the operating room, with the aim to reduce the right ventricle impairment. These issues are particularly true for patients suffering from pulmonary hypertension and disease, in whom the shortest time of postoperative intubation is fundamental to allow self-inotropic support and recovery of the right ventricle. We illustrate how a minimally invasive implant may improve the clinical outcomes of VAD patients shortening their return time to active life.

Less invasive implantation of HeartWare left ventricular assist device

Mechanical support by means of ventricular assist devices is at present the most promising alternative of efforts aimed at increasing the supply of donor organs. The support of the left dysfunctional ventricle enables appropriate haemodynamic stabilization and recovery of secondary organ failure, often present in these severely ill patients. The current results of left ventricular assist device (LVAD) therapy for bridge to transplantation are excellent when compared with the outcome without the availability of this therapy. Additionally, a rapid extubation of these patients has demonstrated to be efficient in cardiac surgery for faster recovery and rehabilitation. Consequently, in recent years, surgical objectives have become much more clearly defined, and the concept of less invasive cardiac surgery can be applied to make this operation less complicated, anatomically focused with a greater clinical impact. We describe an LVAD implantation technique, applying the concept of less invasive cardiac surgery, consisting in the association of reduced surgical approaches, off-pump implantation and reduced administration of heparin dose, in order to achieve rapid extubation and rehabilitation of the patient, preserving low morbidity, and still meeting all the goals of the standard procedure.

Implantation of the HeartWare HVAD: from full sternotomy to less invasive techniques.

Left ventricular assist devices (LVADs) are increasingly used for the treatment of end-stage congestive heart failure, both as a bridge to transplantation and as destination therapy (1). The HeartWare HVAD (HeartWare Inc, Framingham, MA, USA) is a continuous centrifugal-flow left ventricular assist device with a magnetic levitating rotor pump. The pump weighs just 140 g and its small design allows for intra-pericardial placement. It is powered by two portable batteries that connect to the pump via a driveline tunneled through the abdominal wall, and these can be worn on a belt, allowing out of hospital support (2). The HVAD is currently indicated for use in patients with refractory end stage congestive heart failure. We outline two techniques for implanting the HeartWare HVAD: via a full median sternotomy, and using minimal access incision (Video 1). Video 1 Implantation of the HeartWare HVAD: from full sternotomy to less invasive techniques. Case 1 Clinical vignette A 56-year-old man with refractory shock due to end-stage dilated cardiomyopathy was transferred to our institution. He was initially placed on peripheral veno-arterial Extra-Corporeal Membrane Oxygenator (ECMO), as a bridge to decision, and then underwent implantation of a HeartWare HVAD as a bridge to transplantation. After three months of HVAD support, he underwent successful heart transplantation.

From bench to bedside: Can the improvements in left ventricular assist device design mitigate adverse events and increase survival?

OBJECTIVE In vitro tests demonstrated that the new cone-bearing configuration of the Jarvik 2000 (Jarvik Heart Inc, New York, NY) left ventricular assist device exhibits better hydraulic efficiency than the previous pin-bearing design. We investigated the long-term outcomes of patients who received the Jarvik 2000 left ventricular assist device, depending on bearing design. METHODS A retrospective review of prospectively collected data from 18 centers included in the Italian Registry was performed. From May 2008 to September 2013, 99 patients with end-stage heart failure were enrolled. Patients were divided into 2 groups according to their Jarvik 2000 suspending mechanism: Group pin included patients with pin bearings (May 2008 to June 2010), and group cone included patients with newer cone bearings (July 2010 to September 2013). The 2 groups did not differ significantly in terms of baseline characteristics. RESULTS A total of 30 of 39 patients (group pin) and 46 of 60 patients (group cone) were discharged. During follow-up, 6 patients underwent transplantation, and in 1 patient the left ventricular assist device was explanted. The cumulative incidence competing risk of the entire cohort for noncardiovascular-related death was 28% (20%-40%); the cumulative incidence competing risk for cardiovascular-related death was 56% (42%-73%): 71% in group pin versus 26% in group cone (P = .034). The multivariate analyses confirmed that the pin-bearing design was a risk factor for cardiovascular death, along with Interagency Registry for Mechanically Assisted Circulatory Support class. Right ventricular failures and ischemic and hemorrhagic strokes were significantly higher in group pin. CONCLUSIONS Patients with the new pump configuration showed a better freedom from cardiovascular death and lower incidence of fatal stroke and right ventricular failure. Further studies are needed to prove the favorable impact of pump-enhanced fluid dynamics on long-term results.

Less-invasive off-pump ventricular assist device implantation in regional paravertebral analgesia

We describe the clinical course and treatment of a 58-year-old male with a primary cardiogenic shock, who underwent a minimally invasive off-pump ventricular-assist-device (VAD) implantation with the aid of paravertebral regional analgesia. He was extubated soon after the procedure, in the operating room, with the aim to reduce the right ventricle impairment. We illustrate how a minimally invasive implant may improve the clinical outcomes of VAD patients shortening their return time to active life.

Lvad pump speed increase is associated with increased peak exercise cardiac output and vo2, postponed anaerobic threshold and improved ventilatory efficiency

BACKGROUNDS Peak exercise cardiac output (CO) increase is associated with an increase of peak oxygen uptake (VO2), provided that arteriovenous O2 difference [Δ(Ca-Cv)O2] does not decrease. At anaerobic threshold, VO2, is related to CO. We tested the hypothesis that, in heart failure (HF) patients with left ventricular assistance device (LVAD), an acute increase of CO obtained through changes in LVAD pump speed is associated with peak exercise and anaerobic threshold VO2 increase. METHODS Fifteen of 20 patients bearing LVAD (Jarvik 2000) enrolled in the study successfully performed peak exercise evaluation. All patients had severe HF as shown by clinical evaluation, laboratory tests, echocardiography, spirometry with alveolar-capillary diffusion, and maximal cardiopulmonary exercise testing (CPET). CPETs with non-invasive CO measurements at rest and peak exercise were done on 2days at LVAD pump speed set randomly at 2 and 4. RESULTS Increasing LVAD pump speed from 2 to 4 increased CO from 3.4±0.9 to 3.8±1.0L/min (ΔCO 0.4±0.6L/min, p=0.04) and from 5.3±1.3 to 5.9±1.4L/min (ΔCO 0.6±0.7L/min, p<0.01) at rest and peak exercise, respectively. Similarly, VO2 increased from 788±169 to 841±152mL/min (ΔVO2 52±76mL/min, p=0.01) and from 568±116 to 619±124mL/min (ΔVO2 69±96mL/min, p=0.02) at peak exercise and at anaerobic threshold, respectively. Δ(Ca-Cv)O2 did not change significantly, while ventilatory efficiency improved (VE/VCO2 slope from 39.9±5.4 to 34.9±8.3, ΔVE/VCO2 -5.0±6.4, p<0.01). CONCLUSIONS In HF, an increase in CO with a higher LVAD pump speed is associated with increased peak VO2, postponed anaerobic threshold, and improved ventilatory efficiency.