Diagnosis and Treatment Algorithm for Blood Flow Obstructions in Patients With Left Ventricular Assist Device

BACKGROUND

Thrombosis is an uncommon, but severe complication of left ventricular assist devices (LVADs).

OBJECTIVES

This study analyzed experience with obstruction of blood flow through the LVAD with the purpose of developing optimal diagnosis and treatment of LVAD-related thrombosis.

METHODS

Between October 2009 and July 2015, a total of 652 LVAD were implanted in 557 patients. Blood flow abnormalities in patients with LVAD (n = 524) were identified and classified as "high-power" and "low-flow" events.

RESULTS

Three types of late blood flow obstructions were identified: 1) pre-pump via thrombus obstructing the inflow cannula (26 events; 0.037 events per patient-year); 2) intra-pump (70 events; 0.1 events per patient-year); and 3) post-pump via thrombosis of the outflow graft or stenosis of the anastomosis to the aorta (4 events; 0.006 events per patient-year). Pre-pump obstruction was treated by washout maneuver in 9 cases (success rate, 100%), thrombolysis in 9 patients (success rate, 56%), and pump exchange in 9 cases (success rate, 100%); 1 patient died without treatment and 2 were weaned from LVAD. Intra-pump obstruction was treated by thrombolysis (n = 9; success rate, 33%), pump exchange (n = 53; success rate, 94%), and removal due to myocardial recovery (n = 3; success rate, 100%); 7 patients died without treatment and parameters spontaneously normalized in 2 cases. Post-pump obstruction was treated in 2 patients by stenting (success rate, 100%), and was left untreated in 2 cases.

CONCLUSIONS

We identified 3 types of LVAD-related blood flow obstruction, and developed an algorithm for optimal diagnosis and treatment.

Heartmate 3 fully magnetically levitated left ventricular assist device for the treatment of advanced heart failure -1 year results from the Ce mark trial

Background

The HeartMate 3 Left Ventricular Assist System (LVAS) (St. Jude Medical Inc., St Paul, MN) with full magnetic levitation allows for wide and consistent blood flow paths and an artificial pulse designed for enhanced hemocompatibility. The HeartMate 3 received market approval in the European Union in 2015 following completion of a multicenter study. After reaching the 6-month study endpoint, patients continue to be followed for 2 years with the 1-year results presented herein.

Methods

A prospective, non-randomized study included adults with advanced heart failure and ejection fraction (EF) ≤ 25%, cardiac index (CI) ≤ 2.2 L/min/m2 while not on inotropes, or inotrope dependent, or on optimal medical management for 45/60 days.

Results

Fifty patients—54% bridge to transplant (BTT) and 46% destination therapy (DT)—were enrolled and implanted with the HeartMate 3. At baseline, 92% of the patients were INTERMACS profiles 2–4, with cardiac index 1.8 + 0.5 L/min/m² and 58% were supported with inotropes. At 1 year, 74% of the patients remain on support, 18% expired, 6% transplanted, and 2% explanted. The adverse events include 12% gastrointestinal bleeding, 16% driveline infections, 18% strokes, and 2% outflow graft thrombosis. There was no hemolysis, pump thrombosis or pump malfunction through 1 year. The six-minute walk test distance increased from a mean of 273 m to 371 m (P <0.0001). EQ-5D quality-of-life score increased from a mean of 52.7 to 70.8 (P = 0.0006).

Conclusions

The 1-year HeartMate 3 LVAS results show survival and adverse-event profile are similar to other approved devices, with no pump thrombosis or pump failure. Patient’s functional status and quality of life significantly improved over time.

Trial registration

Clinicaltrials.gov registration number: NCT02170363. Registered June 19, 2014.

Surgical management of driveline infections in patients with left ventricular assist devices

BACKGROUND AND AIM OF THE STUDY

Driveline infections in patients with implantable left ventricular assist devices (VAD) carry increasing risk for pump infection, thromboembolic events, decreased quality of life, and increased hospitalization. We report our experience with a surgical technique for refractory driveline infections without mediastinitis consisting of translocation and wrapping of the driveline with greater omentum tissue.

METHODS

We retrospectively reviewed data of VAD patients who underwent surgical treatment by translocation and wrapping with omentum for severe chronic driveline infection.

RESULTS

Thirteen patients were treated between January 2010 and October 2015; 12 (92%) were male, and the mean age was 56 ± 14 years. Ten patients (77%) were managed with driveline sheathing with omentum and repositioning with a new exit site, and three (23%), suffering from driveline fistula, with driveline covering with omentum maintaining the previous exit site. Three episodes of postoperative bleeding (23%) required surgical revision. Twelve patients (92%) were discharged from the hospital and one (8%) died. Nine patients (69%) were free from infection at the time of discharge, and three (23%) had recurrence of infection within the first postoperative year. Only four patients (31%) required admission to the intensive care unit; overall median hospital stay was 23 days (range 7-205 days).

CONCLUSIONS

Driveline relocation with use of omentum is a feasible and effective procedure in selected cases of chronic severe driveline infection. The risk for perioperative bleeding should be taken into consideration and carefully monitored.

Multicentre clinical trial experience with the HeartMate 3 left ventricular assist device: 30-day outcomes

OBJECTIVES

The objective of this study was to describe the operative experience and 30-day outcomes of patients implanted with the HeartMate 3 Left Ventricular Assist System (LVAS) during the Conformité Européenne (CE) Mark clinical trial.

METHODS

Adult patients met inclusion and exclusion criteria defining advanced-stage heart failure and included the indications of bridge to transplant and destination therapy. Operative parameters, outcomes, adverse events, physical status and quality-of-life parameters were assessed in the first 30 days after LVAS implant.

RESULTS

Fifty patients were implanted with the HeartMate 3 at 10 centres in 6 countries. The 30-day survival rate was 98%. The median operative and cardiopulmonary bypass times were 200 (range: 95-585) min and 84 (range: 47-250) min, respectively. Patients required transfusion with packed red blood cells (3.6 ± 2.3 units), fresh frozen plasma (6.5 ± 5 units) and platelets (2 ± 1 units). Six patients (12%) required reoperation for postoperative bleeding and 10 patients (20%) did not require blood transfusion. The median intensive care time was 6 days (range: 1-112 days) and the total hospital stay was 28 days (range: 14-116 days). The most common adverse events were bleeding (15, 30%), arrhythmia (14, 28%) and infection (10, 20%). There were 2 (4%) strokes.

CONCLUSIONS

The 30-day outcomes following implantation of the HeartMate 3 demonstrates excellent survival with low adverse event rates. The LVAD performed as intended with no haemolysis or device failure.

CLINICALTRIALSGOV IDENTIFIER

NCT02170363. HeartMate 3™ CE Mark Clinical Investigation Plan (HM3 CE Mark).

Aortic Valve Pathology in Patients Supported by Continuous-Flow Left Ventricular Assist Device

BACKGROUND

Continuous-flow left ventricular assist devices (CF-LVAD) may induce pathological changes to the aortic wall and aortic valve. We assessed histological changes in the relevant anatomic structures exposed to continuous flow over time and compared the histological results with clinical features in patients supported with CF-LVAD.

METHODS AND RESULTS

A retrospective histological analysis was performed of 38 explanted hearts supported with CF-LVAD from patients who received heart transplantation between July 2003 and February 2014. Sections of formalin-fixed paraffin-embedded tissue showing the continuity of aortic wall and left-sided valves were examined histologically. Thickness of aorta, aortic root and aortic valve as well as 3 layers of the aortic cusps were measured individually on Elastica van Gieson-stained slides using specific software. Clinical parameters concerning aortic valve dysfunction were evaluated and validated against the histology. The aortic valve spongiosa and fibrosa layers showed no significant differences in thickness with regard to support duration or occurrence of aortic insufficiency. Longer CF-LVAD support duration correlated with a thinner aortic valve ventricularis layer (rS=-0.496).

CONCLUSIONS

Long-term CF-LVAD support appears to cause involution of the ventricularis layer of the aortic valve cusp, consistent with more pronounced degenerative change with longer LVAD exposure, which may be explained by continuous coaptation of the cusps. (Circ J 2016; 80: 1371-1377).

Fully Magnetically Levitated Left Ventricular Assist System for Treating Advanced HF: A Multicenter Study

BACKGROUND

The HeartMate 3 left ventricular assist system (LVAS) is intended to provide long-term support to patients with advanced heart failure. The centrifugal flow pump is designed for enhanced hemocompatibility by incorporating a magnetically levitated rotor with wide blood-flow paths and an artificial pulse.

OBJECTIVES

The aim of this single-arm, prospective, multicenter study was to evaluate the performance and safety of this LVAS.

METHODS

The primary endpoint was 6-month survival compared with INTERMACS (Interagency Registry for Mechanically Assisted Circulatory Support)-derived performance goal. Patients were adults with ejection fraction ≤ 25%, cardiac index ≤ 2.2 l/min/m(2) without inotropes or were inotrope-dependent on optimal medical management, or listed for transplant.

RESULTS

Fifty patients were enrolled at 10 centers. The indications for LVAS support were bridge to transplantation (54%) or destination therapy (46%). At 6 months, 88% of patients continued on support, 4% received transplants, and 8% died. Thirty-day mortality was 2% and 6-month survival 92%, which exceeded the 88% performance goal. Support with the fully magnetically levitated LVAS significantly reduced mortality risk by 66% compared with the Seattle Heart Failure Model-predicted survival of 78% (p = 0.0093). Key adverse events included reoperation for bleeding (14%), driveline infection (10%), gastrointestinal bleeding (8%), and debilitating stroke (modified Rankin Score > 3) (8%). There were no pump exchanges, pump malfunctions, pump thrombosis, or hemolysis events. New York Heart Association classification, 6-min walk test, and quality-of-life scores showed progressive and sustained improvement.

CONCLUSIONS

The results show that the fully magnetically levitated centrifugal-flow chronic LVAS is safe, with high 30-day and 6-month survival rates, a favorable adverse event profile, and improved quality of life and functional status. (HeartMate 3™ CE Mark Clinical Investigation Plan [HM3 CE Mark]; NCT02170363).

Preliminary Results From the C-Pulse OPTIONS HF European Multicenter Post-Market Study

Background

The C-Pulse^® System is an extra-aortic balloon counterpulsation device. It is used to treat patients with heart failure disease in NYHA functional class III or ambulatory class IV.

Material/Methods

We present preliminary site-reported 6-month data from 3 centers in Germany as part of the prospective observational post-market OPTIONS HF study.

Results

Between May 2013 and March 2014, the C-Pulse System was implanted in 8 patients (7 male) with a mean age of 61.6±9.3 years. Four had ischemic and 4 had non-ischemic cardiomyopathy. No stroke, myocardial infarction, major bleeding, or major infection due to the device were reported. One patient developed non-device-related refractory tachycardia with worsening heart failure 12 h after surgery and underwent left ventricular assist device implantation. Within 6 months of observation, functional status improved from NYHA III to II in 5 patients, and 2 remained in NYHA III. Mean left ventricular ejection fraction increased from 24.3±7.9% to 44.5±4.5% (p<0.0001). Mean Kansas City Cardiomyopathy Questionnaire overall score improved from 28.6±19.1 to 59.1±22.5 (p=0.0183). Six-minute walk test was performed in 6 out of 7 patients at follow-up. The mean distance improved from 252.0±85.1 m to 279.2±87.5 m (p>0.05). One patient was weaned off the device after 6 months of support.

Conclusions

The C-Pulse System provides a therapeutic option for patients with moderate-to-severe heart failure and seems to improve quality of life and cardiac function over time.

Rotary Blood Pumps as Long-Term Mechanical Circulatory Support: A Review of a 15-Year Berlin Experience

This article reports our 15-year single-center experience with rotary blood pumps (RBPs) as long-term mechanical circulatory support (MCS) with emphasis on outcomes. For more than 15-year period, we have used various RBPs as bridge to transplantation or to myocardial recovery. Our group performed the first human implantation worldwide of RBCs, the MicroMed DeBakey ventricular assist device in November 1998 in a patient with end-stage heart failure who was supported for 47 days until his death. Based on this initial experience, we recognized the feasibility of providing long-term support and since then it has been our primary armamentarium in treating patients with heart failure. Between 1987 and September 2013, we have implanted 2208 ventricular assist devices ranging from pulsatile to continuous-flow systems, as short-term, long-term, or permanent support in patients with end-stage heart failure. In total, 1009 RBPs were implanted on 908 patients, and their outcomes are reported here. We have shared some milestones in MCS including the first implantation of Jarvik 2000 on the oldest patient (81-year old) in 2008 and the first worldwide implantation of a biventricular HeartWare. Over time, implantation techniques, anticoagulation, and postoperative care have been modified and individualized. A relevant aspect of our experience has been the incidence of pump thrombosis. This is particularly frustrating because the problem has occurred in the setting of full anticoagulation and antiplatelet therapy, guided by strict anticoagulation monitoring. It has become clear to us that the devices are still not perfect. Technical pump failures such as cable breaks also occur, prompting urgent pump exchange, and infection. A 15-year cumulative mortality rate is 46.9%. This report emphasizes that MCS with RBPs has evolved into a routine treatment in heart failure and is a highly feasible option for permanent therapy particularly for elderly patients.