Percutaneous approach to left ventricular assist device decommissioning.

OBJECTIVE: To assess the outcomes of a single-center experience with percutaneous left ventricular assist device (LVAD) decommissioning. BACKGROUND: Patients with LVADs may eventually require their removal, either due to recovery of left ventricular function or recurrent complications. Traditionally, withdrawal of LVAD support has been managed with surgical device explantation, which carries significant procedural risks. Transcatheter LVAD decommissioning, with outflow graft occlusion and driveline transection, has recently been described as an alternative to surgical removal. METHODS: Here, we report on a retrospective cohort of five consecutive cases treated with transcatheter LVAD decommissioning. RESULTS: The procedure was effective in all cases, and no patient experienced procedure-related complications. At midterm follow-up, the three patients who had myocardial function recovery were alive and had not experienced heart failure-related symptoms or complications. CONCLUSION: Percutaneous LVAD decommissioning appears to be a safe and effective approach to LVAD treatment discontinuation.

Device Management and Flow Optimization on Left Ventricular Assist Device Support.

The authors discuss principles of continuous flow left ventricular assist device (LVAD) operation, basic differences between the axial and centrifugal flow designs and hemodynamic performance, normal LVAD physiology, and device interaction with the heart. Systematic interpretation of LVAD parameters and recognition of abnormal patterns of flow and pulsatility on the device interrogation are necessary for clinical assessment of the patient. Optimization of pump flow using LVAD parameters and echocardiographic and hemodynamics guidance are reviewed.

Tolerability and Biological Effects of Long-Acting Octreotide in Patients With Continuous Flow Left Ventricular Assist Devices.

Patients with implanted continuous, nonpulsatile, left ventricular assist devices (LVADs) have increased the occurrence of gastrointestinal bleeding (GIB). Although the pathophysiology is multifactorial, there are few treatments beyond supportive care. Octreotide acetate is a somatostatin analog that reduces GIB in various patient populations. However, there are sparse case series that suggest octreotide acetate may reduce GIB in LVAD patients. This 10 patient, 28 week phase I study evaluated the safety and tolerability of octreotide acetate long-acting release (LAR) 20 mg depot injection every 4 weeks until week 16 after LVAD placement. Secondary aims were occurrence of GIB and measurement of vascular endothelial growth factor, fibrinogen, von Willebrand factor, and platelet aggregation across the study period. Ten patients were enrolled, and eight completed the study. The two study dropouts were not related to octreotide. None of the patients experienced side effects or safety concerns related to octreotide nor did GIB occur in the study population. Vascular endothelial growth factor levels were maintained in the reference range throughout the duration of the study. There did appear to be laboratory evidence of acquired von Willebrand syndrome, with mildly low platelet aggregation studies. In conclusion, octreotide acetate LAR 20 mg depot injection was safe and effective in this population.

Impact of INTERMACS Profile on Clinical Outcomes for Patients Supported With the Total Artificial Heart.

BACKGROUND: Insufficient data delineate outcomes for Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) profile 1 patients with the total artificial heart (TAH). METHODS: We studied 66 consecutive patients implanted with the TAH at our institution from 2006 through 2012 and compared outcome by INTERMACS profile. INTERMACS profiles were adjudicated retrospectively by a reviewer blinded to clinical outcomes. RESULTS: Survival after TAH implantation at 6 and 12 months was 76% and 71%, respectively. INTERMACS profile 1 patients had decreased 6-month survival on the device compared with those in profiles 2-4 (74% vs 95%, log rank: P = .015). For the 50 patients surviving to heart transplantation, the 1-year posttransplant survival was 82%. There was no difference in 1-year survival when comparing patients in the INTERMACS 1 profile with less severe profiles (79% vs 84%; log rank test P = .7; hazard ratio [confidence interval] 1.3 [0.3-4.8]). CONCLUSIONS: Patients implanted with the TAH as INTERMACS profile 1 had reduced survival to transplantation compared with less sick profiles. INTERMACS profile at the time of TAH implantation did not affect 1-year survival after heart transplantation.

Renal Function Recovery with Total Artificial Heart Support.

Heart failure patients requiring total artificial heart (TAH) support often have concomitant renal insufficiency (RI). We sought to quantify renal function recovery in patients supported with TAH at our institution. Renal function data at 30, 90, and 180 days after TAH implantation were analyzed for patients with RI, defined as hemodialysis supported or an estimated glomerular filtration rate (eGFR) less than 60 ml/min/1.73 m. Between January 2008 and December 2013, 20 of the 46 (43.5%) TAH recipients (age 51 ± 9 years, 85% men) had RI, mean preoperative eGFR of 48 ± 7 ml/min/1.73 m. Renal function recovery was noted at each follow-up interval: increment in eGFR (ml/min/1.73 m) at 30, 90, and 180 days was 21 ± 35 (p = 0.1), 16.5 ± 18 (p = 0.05), and 10 ± 9 (p = 0.1), respectively. Six patients (30%) required preoperative dialysis. Of these, four recovered renal function, one remained on dialysis, and one died. Six patients (30%) required new-onset dialysis. Of these, three recovered renal function and three died. Overall, 75% (15 of 20) of patients' renal function improved with TAH support. Total artificial heart support improved renal function in 75% of patients with pre-existing significant RI, including those who required preoperative dialysis.

Pulmonary Hypertension After Heart Transplantation in Patients Bridged with the Total Artificial Heart.

Pulmonary hypertension (PH) among heart transplant recipients is associated with an increased risk of mortality. Pulmonary hemodynamics improves after left ventricular assist device (LVAD) implantation; however, the impact of PH before total artificial heart (TAH) implantation on posttransplant hemodynamics and survival is unknown. This is a single center retrospective study aimed to evaluate the impact of TAH implantation on posttransplant hemodynamics and mortality in two groups stratified according to severity of PH: high (≥3 Woods units [WU]) and low (<3 WU) baseline pulmonary vascular resistance (PVR). Hemodynamic data were obtained from right heart catheterization performed at baseline (before TAH) and posttransplant at 1 and 12 months. Patients in the high PVR group (n = 12) experienced improvement in PVR (baseline = 4.31 ± 0.7; 1-month = 1.69 ± 0.7, p < 0.001; 12-month = 48 ± 0.9, p < 0.001) and transpulmonary gradient (baseline = 15.8 ± 3.3; 1-month = 11.57 ± 5.0, p = 0.07; 12-month = 8.50 ± 4.0, p = 0.008) after transplantation, reaching similar values as the low PVR group at 12 months. The filling pressures improved in the high PVR group after heart transplantation (HT), but remained elevated. There was no significant difference in survival between the two groups at 12 months follow-up. Patients with high PVR who are bridged to transplant with TAH had improvement in PVR at 12 months after transplant, and the degree of PVR did not impact posttransplant survival.

Pregnancy-related allograft rejection following heart transplant.

Current recommendations do not discourage pregnancy in stable, orthotopic heart transplant (OHT) recipients who are more than 1 year posttransplant, although a highly specialized level of care with a multidisciplinary team is recommended. These patients may incur significant risk to themselves, their allograft, and/or their fetuses. Recognition and treatment of posttransplant complications in pregnancy also may be difficult. Although the risk of recurrent pregnancies in patients with peripartum cardiomyopathy (PPCM) is well defined, the risk of pregnancy after a PPCM patient has undergone OHT is unknown. A case of severe allograft rejection in a woman with a history of PPCM who became pregnant nearly 3 years after OHT is presented and her subsequent management is described. The data available on pregnancy after transplant are based on case reports, registry data, and reviews. The decision to become pregnant should be preceded by an extensive discussion including the patient, her partner, her obstetrician, and the transplant team, reviewing potential risks to her health as well as to her allograft and the fetus. Providers should be clear that many questions pertaining to pregnancy after transplant remain unanswered, and the patient should be comfortable going forward in this situation.

Surveillance Endomyocardial Biopsy in the Modern Era Produces Low Diagnostic Yield for Cardiac Allograft Rejection.

BACKGROUND: The changing epidemiology of cardiac allograft rejection has prompted many to question the yield of surveillance endomyocardial biopsy (EMB) in heart transplantation (HT) patients. We sought to determine the yield of EMB in the modern era. METHODS: We evaluated 2597 EMBs in 182 consecutive HT patients who survived to their first EMB. The EMBs were categorized as asymptomatic or clinically driven and were compared based on era of antiproliferative therapy use at our center (early azathioprine era: 1990-2000 vs modern mycophenolate era: 2000-2011). RESULTS: In the modern era, patients had a higher prevalence of risk factors for developing rejection (≥ International Society of Heart and Lung Transplantation grade 2R); however, the frequency of rejection was decreased at all times (0-6 months: 60.2% vs 21.5%, P < 0.001, 6-12 months: 26.8% vs 1.8%, P < 0.001, 12-36 months: 32.3% vs 10.5%, P = 0.006). The yield of asymptomatic EMB decreased in the modern era between 0 and 6 months (10.9% vs 3.12%), 6 to 12 months (17% vs 0%), and years 2 to 3 (6.1% vs 1.5%). In the early era, the odds ratio of rejection during asymptomatic EMB compared to a clinically driven EMB was 0.47 (95% confidence interval, 0.31-0.71) and was decreased in the modern era (0.17 [0.07-0.42], P = 0.04). The probability of detecting rejection on asymptomatic EMB was significantly reduced in the modern era, even after adjustment for tacrolimus and induction therapy (1% vs 8%, P < 0.001). CONCLUSIONS: The clinical yield of surveillance EMB has decreased in the modern era. The EMB in asymptomatic patients longer than 6 months after HT warrants further scrutiny.

The total artificial heart.

The total artificial heart (TAH) is a form of mechanical circulatory support in which the patient's native ventricles and valves are explanted and replaced by a pneumatically powered artificial heart. Currently, the TAH is approved for use in end-stage biventricular heart failure as a bridge to heart transplantation. However, with an increasing global burden of cardiovascular disease and congestive heart failure, the number of patients with end-stage heart failure awaiting heart transplantation now far exceeds the number of available hearts. As a result, the use of mechanical circulatory support, including the TAH and left ventricular assist device (LVAD), is growing exponentially. The LVAD is already widely used as destination therapy, and destination therapy for the TAH is under investigation. While most patients requiring mechanical circulatory support are effectively treated with LVADs, there is a subset of patients with concurrent right ventricular failure or major structural barriers to LVAD placement in whom TAH may be more appropriate. The history, indications, surgical implantation, post device management, outcomes, complications, and future direction of the TAH are discussed in this review.

Mechanical circulatory support devices in the ICU.

The medical community has used implantable mechanical circulatory support devices at increasing rates for patients dying from heart failure and cardiogenic shock. Newer-generation devices offer a more durable and compact option when compared with bulky early-generation devices. This article is a succinct introduction and overview of the hemodynamic principles and complications after device implantation for ICU clinicians. We review the concepts of device physiology, clinical pearls for perioperative management, and common medical complications after device implantation.

Gastrointestinal bleeding in patients with ventricular assist devices is highest immediately after implantation.

Ventricular assist device implantation is associated with gastrointestinal bleeding (GIB); however, outcomes in terms of initial and repeat GIB risk, severity, location of lesions, and endoscopic interventions need to be better defined. Consecutive patients from a database of adult patients with ventricular assist devices (VADs) implanted between January 1, 2000, and December 31, 2010, at a single center were reviewed and followed through May 31, 2011, in a retrospective manner. The GIB events were further classified by severity, lesion location, and lesion type. Hazard analysis models were calculated for the time to GIB events. Of 166 patients with a VAD, 38 patients experienced 84 GIB events. Seventeen patients experienced ≥2 GIB events. Maximal hazard for the first bleeding event was 2.23 events/patient-year at 21 days and declined to the constant hazard by 71 days postimplantation. The hazard for recurrent GIB was greatest immediately after the first GIB event. When considering all GIB events, most lesions (68%) were located in the proximal bowel. Angiodysplasia was the most common lesion type (17.5%) seen on endoscopy when all GIB events were considered, whereas ulcers were the most common type (13.8%) seen in initial GIB events. The actuarial risk of initial GIB events peaks in the first 3 months after VAD implantation followed by a stable lower risk of bleeding. The hazard for recurrent GIB events is substantially increased immediately after the initial GIB.

Improvement in 2-year survival for ventricular assist device patients after implementation of an intensive surveillance protocol.

BACKGROUND: This study was conducted to determine the effect of a disease-management model termed an "intensive surveillance protocol" (ISP) on survival in ventricular assist device (VAD) patients. This intervention consisted of a formalized, protocol-driven, multi-disciplinary team approach to VAD patient follow-up initiated August 1, 2006. The goal was to attain an internal program benchmark of 70% survival at 2 years. Historically, 2-year survival after VAD implant has been sub-optimal, and no patient management algorithms have been formally tested to determine their effect on 2-year survival. METHODS: The study comprised 76 patients, of whom 26 had a VAD as destination therapy (DT) and 50 as a bridge to transplant (BTT), from July 1, 2003, to June 30, 2008. Survival before and after initiation of ISP was compared. A parametric hazard multivariable analysis, with a time-varying covariable for implementation of ISP, was used to evaluate of other factors affecting survival. RESULTS: Survival at 16 months was 100% for DT patients who received a VAD after August 1, 2006 vs 64% for the earlier era (p = 0.06). For BTT, 16- month survival was 71% vs 43% (p = 0.03). Predicted 2-year survival before and after implementation of the ISP improved from 30% to 87% for DT (p = 0.02) and from 20% to 61% for BTT patients (p = 0.01). Predictors of midterm survival by multivariable analysis included ISP (p = 0.004), younger age (p = 0.03), non-emergent implant (p < 0.0001), and isolated left ventricular VAD (p < 0.0001). After adjustment for covariables, the ISP was associated with a 70% reduction in the hazard for death for the entire cohort (p = 0.004). The effect of ISP was also significant in the patients who received the HeartMate XVE (Thoratec, Pleasanton, CA), which spanned both eras of the study. CONCLUSIONS: Survival improved for DT and BTT VAD patients after implementation of the ISP, with a dramatic decrease in hazard for death. Although the transition from pulsatile to axial flow technology occurred during the study period and likely contributed to improved outcomes, the institution of the ISP provided an important and significant contribution to improved survival through a proactive approach to patient management, allowing earlier identification of potential adverse events. For optimal outcomes, VAD patients require intensive follow-up surveillance protocols that have previously become standard in the care of heart transplant patients.

Implantable hemodynamic monitoring devices in heart failure.

The syndrome of heart failure is characterized by symptoms that are relatively insensitive and nonspecific. Physical diagnosis may be unreliable even in the hands of experienced clinicians despite the presence of significantly elevated filling pressures or a significantly depressed cardiac output. Over the past decade, the implantable hemodynamic monitor (IHM) has been developed as means of measuring intracardiac pressures over time and understanding the nuances of the hemodynamic derangements of this condition. With improved ability to accurately assess and monitor filling pressures, clinicians can more precisely adjust therapy with the goal of improving patient symptoms and possibly outcomes. Future directions include using the IHM to assist in management of other cardiovascular diseases, such as pulmonary arterial hypertension, and combining this technology with other implanted devices, such as defibrillators.