Faculty Bibliography

BACKGROUND:Early right-sided heart failure (RHF) after left ventricular assist device (LVAD) implantation is associated with increased mortality, but little is known about patients who develop late RHF (LRHF). We evaluated the incidence, risk factors, and clinical impact of LRHF in patients supported by axial-flow LVADs. METHODS:Data were analyzed from 537 patients enrolled in the HeartMate II (HM II; Thoratec/St. Jude) destination therapy clinical trial. LRHF was defined as the development of clinical RHF accompanied by the need for inotropic support occurring more than 30 days after discharge from the index LVAD implant hospitalization. Clinical variables, quality of life, rehospitalizations, and survival were compared between patients with and without LRHF. RESULTS:LRHF developed in 41 patients (8%), with a median time to LRHF of 480 days. A higher preoperative blood urea nitrogen and increased central venous pressure-to-pulmonary capillary wedge pressure ratio were independent predictors of LRHF. The Michigan and HMII RHF risk scores were both associated with an increased likelihood of LRHF (p < 0.05). Patients with LRHF had worse quality of life according to the Kansas City Cardiomyopathy Questionnaire (61 ± 26 vs 70 ± 21; p < 0.05), poorer functional capacity by 6-minute walk distance (275 ± 189 m vs 312 ± 216 m; p < 0.05), and more rehospitalizations (6 vs 3; p < 0.001). LRHF was associated with decreased survival (p < 0.001). CONCLUSIONS:LRHF is an important complication in patients with LVADs and is associated with worse quality of life, reduced functional capacity, more frequent hospitalizations, and worse survival compared with those without LRHF.

BACKGROUND:Recommended structured clinical practices including implant technique, anti-coagulation strategy, and pump speed management (PREVENT [PREVENtion of HeartMate II Pump Thrombosis Through Clinical Management] recommendations) were developed to address risk of early (<3 months) pump thrombosis (PT) risk with HeartMate II (HMII; St. Jude Medical, Inc. [Thoratec Corporation], Pleasanton, CA). We prospectively assessed the HMII PT rate in the current era when participating centers adhered to the PREVENT recommendations. METHODS:PREVENT was a prospective, multi-center, single-arm, non-randomized study of 300 patients implanted with HMII at 24 participating sites. Confirmed PT (any suspected PT confirmed visually and/or adjudicated by an independent assessor) was evaluated at 3 months (primary end-point) and at 6 months after implantation. RESULTS:The population included 83% men (age 57 years ± 13), 78% destination therapy, and 83% Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) Profile 1-3. Primary end-point analysis showed a confirmed PT of 2.9% at 3 months and 4.8% at 6 months. Adherence to key recommendations included 78% to surgical recommendations, 95% to heparin bridging, and 79% to pump speeds ≥9,000 RPMs (92% >8,600 RPMs). Full adherence to implant techniques, heparin bridging, and pump speeds ≥9,000 RPMs resulted in a significantly lower risk of PT (1.9% vs 8.9%; p < 0.01) and lower composite risk of suspected thrombosis, hemolysis, and ischemic stroke (5.7% vs 17.7%; p < 0.01) at 6 months. CONCLUSIONS:Adoption of all components of a structured surgical implant technique and clinical management strategy (PREVENT recommendations) is associated with low rates of confirmed PT.

Over the past half century, coronary care units have expanded from specialized ischemia arrhythmia monitoring units into intensive care units (ICUs) for acutely ill and medically complex patients with a primary cardiac diagnosis. Patients admitted to contemporary coronary intensive care units (CICUs) are at risk for common and preventable critical care complications, yet many CICUs have not adopted standard-of-care prevention protocols and practices from general ICUs. In this article, we (1) review evidence-based interventions and care bundles that reduce the incidence of ventilator-associated pneumonia, excess sedation during mechanical ventilation, central line infections, stress ulcers, malnutrition, delirium, and medication errors and (2) recommend pragmatic adaptations for common conditions in critically ill patients with cardiac disease, and (3) provide example order sets and practical CICU protocol implementation strategies.

Patients with a durable, continuous-flow left ventricular assist device (LVAD) are commonly prescribed the combination of an oral anticoagulant and an oral antiplatelet agent as prophylaxis against device thrombosis and systemic embolic events. Current International Society of Heart and Lung (ISHLT) guidelines recommend warfarin with an INR goal of 2-3 and concomitant aspirin 81-325 mg daily for patients with a HeartMate II LVAD. Unfortunately, gastrointestinal (GI) bleeding is very common in these patients because of multiple factors including the development of arteriovenous malformations and acquired von Willebrand syndrome. If this bleeding cannot be corrected through interventional measures, it then requires at least temporary, and potentially permanent, cessation of antiplatelet or anticoagulant therapy. Patients who continue to bleed while off all antithrombotic therapies present a clinical challenge. We describe the successful management of a patient with refractory GI bleeding through the use of inhaled desmopressin.

Acquired von Willebrand disease increases bleeding risk in patients implanted with a continuous-flow left ventricular assist device. Lower aspirin (ASA) doses decrease the risk of bleeding without an increased risk of embolic events. No published studies in the United States have compared the incidence of bleeding and thrombotic events between antithrombotic regimens with and without ASA. A single-center, retrospective analysis was conducted of adult patients implanted with a HeartMate II (HM II). Patients received warfarin and ASA 81 mg daily or warfarin alone. The primary end-point was a composite of death, bleeding events, and thrombotic events from the date of HM II implantation to first event or 18 months. Secondary end-points included the individual components of the primary end-point and the proportion of patients alive with HM II or transplanted. The Wilcoxon rank sum test and Fisher's exact test were used for statistical analysis. Of the 76 patients meeting inclusion criteria, 44 received warfarin and ASA and 32 received warfarin alone. Baseline characteristics were similar between groups. Warfarin alone was not associated with an increased risk of the primary composite outcome (53 vs. 59%, respectively, p = 0.64). No significant difference was observed in any bleeding event (34 vs. 43%, respectively, p = 0.48) nor any thrombotic event (9 vs. 11%, respectively, p = 1.00) with warfarin alone compared with warfarin and ASA. Elimination of antiplatelet therapy from the HM II antithrombotic regimen was associated with no significant difference in the composite outcome of bleeding events, thrombotic events, or death, nor the individual components of each end-point.

There is insufficient data on patients with small body size to determine if this should be considered a risk factor for continuous-flow left ventricular assist device (CF-LVAD) support. We sought to evaluate survival outcomes, adverse events, and functional status of CF-LVAD patients with body surface area (BSA) <1.5 m in a large national registry. Adults with BSA < 1.5 m (n = 128) implanted with a HeartMate II (HMII)-LVAD from the Interagency Registry for Mechanically Assisted Circulatory Support registry from April 2008 to December 2012 formed this cohort. Outcomes were compared with HMII bridge to transplant (BTT) and destination therapy (DT) post approval studies. The majority of patients were female (n = 106, 83%). A total of 64% (n = 82) were implanted for BTT and 36% (n = 46) for DT. The median BSA (range) was 1.44 (1.19-1.49) and 1.45 (1.25-1.49) m for BTT and DT, respectively. Overall survival 1 year post implant was 81% +/- 5% for BTT and 84% +/- 6% for DT. The most common adverse events for BTT and DT patients were bleeding (0.91, 0.88 events/patient year) and driveline infection (16%, 0.28 events/patient year). Six months post implantation, 87% of BTT and 77% of DT patients were New York Heart Association functional class I or II. Post implant survival, functional status improvement, and adverse event profile for adult BTT and DT HMII patients with BSA < 1.5 m are favorable and comparable with outcomes published in the overall patient population.