Reliability and construct validity of PROMIS® measures for patients with heart failure who undergo heart transplant

PURPOSE

To evaluate the reliability and construct validity of measures from the Patient-Reported Outcomes Measurement Information System(®) (PROMIS(®)) for patients with heart failure before and after heart transplantation.

METHODS

We assessed reliability of the PROMIS short forms using Cronbach's alpha and the average marginal reliability. To assess the construct validity of PROMIS computerized adaptive tests and short-form measures, we calculated Pearson product moment correlations between PROMIS measures of physical function, fatigue, depression, and social function and existing PRO measures of similar domains (i.e., convergent validity) as well as different domains (i.e., discriminate validity) in patients with heart failure awaiting heart transplant. We evaluated the responsiveness of these measures to change after heart transplant using effect sizes.

RESULTS

Forty-eight patients were included in the analyses. Across the many domains examined, correlations between conceptually similar domains were larger than correlations between different domains of health, demonstrating construct validity. Health status improved substantially after heart transplant (standardized effect sizes, 0.63-1.24), demonstrating the responsiveness of the PROMIS measures. Scores from the computerized adaptive tests and the short forms were similar.

CONCLUSIONS

This study provides evidence for the reliability and construct validity (including responsiveness to change) of four PROMIS domains in patients with heart failure before and after heart transplant. PROMIS measures are a reasonable choice in this context and will facilitate comparisons across studies and health conditions.

Seventh INTERMACS annual report: 15,000 patients and counting

The seventh annual report of the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) summarizes the first 9 years of patient enrollment. The Registry includes >15,000 patients from 158 participating hospitals. Trends in device strategy, patient profile at implant and survival are presented. Risk factors for mortality with continuous-flow pumps are updated, and the major causes/modes of death are presented. The adverse event burden is compared between eras, and health-related quality of life is reviewed. A detailed analysis of outcomes after mechanical circulatory support for ambulatory heart failure is presented. Recent summary data from PediMACS and MedaMACS is included. With the current continuous-flow devices, survival at 1 and 2 years is 80% and 70%, respectively.

High-speed visualization of disturbed pathlines in axial flow ventricular assist device under pulsatile conditions

OBJECTIVE

To investigate potentially prothrombotic flow patterns within an axial flow ventricular assist device under clinically relevant pulsatile hemodynamic conditions.

METHODS

A transparent replica of the HeartMate-II left ventricular assist device (Thoratec, Pleasanton, Calif) was visualized using a high speed camera at both low and high frame rates (125 and 3000 fps). Three steady-state conditions were studied: nominal (4.5 lpm), low flow (3.0 lpm), and high flow (6.0 lpm). Time-varying conditions were introduced with an external pulsatile pump that modulated the flow rate by approximately ± 50% of the mean, corresponding to a pulsatility index of 1.0.

RESULTS

At nominal and high flow rates, the path lines within the upstream region were generally stable, well attached, and streamlined. As the flow rate was reduced below 3.8 lpm, a rapid transition to a chaotic velocity field occurred, exhibiting a large toroidal vortex adjacent to the upstream bearing. The pathlines in the downstream stator section were consistently chaotic for all hemodynamic conditions investigated. It was common to observe tracer particles trapped within recirculation bubbles and drawn retrograde, causing repeated contact with the bearing surfaces. The addition of pulsatility caused the flow field to become periodically chaotic during the diastolic portion of the cardiac cycle depending on the instantaneous flow rate and acceleration.

CONCLUSIONS

The contribution of pulsatility by the native heart may induce a periodic disturbance to an otherwise stable flow field within an axial flow ventricular assist device, particularly during the diastolic and decelerating portion of the cardiac cycle. Potentially prothrombotic flow features were found to occur periodically in the region of the upstream bearing.

Principles of HeartMate II implantation to avoid pump malposition and migration

Proper left ventricular assist device (LVAD) insertion will help maximize LVAD flow and may reduce adverse events such as right heart failure and pump thrombosis. Although no standardized insertion technique has been universally accepted, the goals are: unobstructed inflow cannula, unobstructed outflow graft with avoidance of right ventricular compression, and prevention of pump migration. To achieve these objectives for the HeartMate II LVAD, we delineate four principles: proper pump pocket creation, optimized positioning of inflow cannula and outflow graft, proper pump position in the body, and fixation. These basic principles are easy to implement and have been beneficial in our patients, assuring long-term unobstructed LVAD flow.

Preoperative liver dysfunction influences blood product administration and alterations in circulating haemostatic markers following ventricular assist device implantation

OBJECTIVES

Preoperative liver dysfunction may influence haemostasis following ventricular assist device (VAD) implantation. The Model for End-stage Liver Disease (MELD) score was assessed as a predictor of bleeding and levels of haemostatic markers in patients with currently utilized VADs.

METHODS

Sixty-three patients (31 HeartMate II, 15 HeartWare, 17 Thoratec paracorporeal ventricular assist device) implanted 2001-11 were analysed for preoperative liver dysfunction (MELD) and blood product administration. Of these patients, 21 had additional blood drawn to measure haemostatic marker levels. Cohorts were defined based on high (≥18.0, n = 7) and low (<18.0, n = 14) preoperative MELD scores.

RESULTS

MELD score was positively correlated with postoperative administration of red blood cell (RBC), platelet, plasma and total blood product units (TBPU) , as well as chest tube drainage and cardiopulmonary bypass time. Age and MELD were preoperative predictors of TBPU by multivariate analysis. The high-MELD cohort had higher administration of TBPU, RBC and platelet units and chest tube drainage postimplant. Similarly, patients who experienced at least one bleeding adverse event were more likely to have had a high preoperative MELD. The high-MELD group exhibited different temporal trends in F1 + 2 levels and platelet counts to postoperative day (POD) 55. D-dimer levels in high-MELD patients became elevated versus those for low-MELD patients on POD 55.

CONCLUSIONS

Preoperative MELD score predicts postoperative bleeding in contemporary VADs. Preoperative liver dysfunction may also alter postoperative subclinical haemostasis through different temporal trends of thrombin generation and platelet counts, as well as protracted fibrinolysis.

Sixth INTERMACS annual report: a 10,000-patient database

The sixth annual report of the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) summarizes the first 8 years of patient enrollment. The analysis is based on data from >10,000 patients and updates demographics, survival, adverse events and risk factors. Among patients with continuous-flow pumps, actuarial survival continues to be 80% at 1 year and 70% at 2 years. The report features a comparison of two eras of continuous-flow durable devices in the USA in terms of device strategy, patient profiles, adverse event burden, survival and quality of life.

Gender differences in patterns of emotional distress following heart transplantation

The study provides the first empirical evaluation of gender differences in psychological symptomatology and DSM-III-R major depressive disorder (MDD) across the first year following heart transplantation. An important goal was to identify physical health-related and psychosocial factors that could account for, or mediate, any association between gender and psychological distress. The sample for the present analyses was drawn from a larger cohort of 172 heart recipients and included all 28 women in the cohort plus 118 men who were matched demographically with the group of women. Detailed patient assessments were completed at 2, 7, and 12 months posttransplant. As expected, women's symptom levels were consistently higher than men's. However, while men's symptom levels in all areas declined with time posttransplant, women's distress in the area of depression initially improved but then worsened by the 12-month assessment. The distribution of episodes of MDD showed a temporal pattern of gender differences similar to that of depressive symptoms. The most important mediators of the gender-depression relationship were factors related to early posttransplant daily functional limitations: women reported more impairments in daily activities. Higher levels of such impairments, in turn, predicted subsequently higher depression levels by 12 months posttransplant. Several additional variables pertaining to transplant-related concerns and a low sense of personal mastery-while not serving as mediators-exerted their own independent effects on 12-month depression levels. The findings are relevant to the tailoring of educational and clinical interventions to the individual needs of women and men who receive heart transplants.

Temporal leukocyte numbers and granulocyte activation in pulsatile and rotary ventricular assist device patients

Individual ventricular assist device (VAD) design may affect leukocytes and impact immunity. Few studies have presented leukocyte and infection profiles in VAD patients over the course of the implant period. CD11b (MAC-1) expression on granulocytes is an indicator of activation during inflammation, mediating extravasation and the release of reactive oxygen species in tissue. No reported studies have presented MAC-1 expression on circulating granulocytes in VAD patients. Fifty-six patients implanted at a single center with a HeartMate II (HMII; n = 32), HeartWare (HW; n = 12), or Thoratec pneumatic VAD (PVAD; n = 12) between 1999 and 2011 were followed for 120 days of support. The leukocyte profiles and infectious events of all patients were evaluated; additionally, a subset had MAC-1 expression on circulating granulocytes was measured (HMII n = 9; HW n = 7; PVAD n = 4). All groups exhibited a significant peak in leukocyte numbers at postoperative day (POD) 14 while simultaneously experiencing a significant decrease in hematocrit. HMII patients exhibited a 3.2-fold increase in granulocyte MAC-1 expression at POD 14, and the temporal trend over the implant period differed from that experienced by HW patients. Further, HW patients experienced significantly fewer infection events. Alterations in leukocyte profiles and granulocyte activation experienced by VAD patients appear to be device-specific. Elevations in leukocyte activation may be related to an increased risk for infection, although the specific relationship between these phenomena in this patient group is not known.

Fifth INTERMACS annual report: risk factor analysis from more than 6,000 mechanical circulatory support patients

The 5th annual report of the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) summarizes and analyzes the first 6 years of patient and data collection. The current analysis includes more than 6000 patients and updated risk factors for continuous flow pumps. Among continuous flow pumps, actuarial survival is 80% at 1 year and 70% at 2 years. Quality of life indicators are generally favorable and adverse event burden will likely influence patient selections of advanced heart failure therapies.

Durability of left ventricular assist devices: Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) 2006 to 2011

OBJECTIVES

The present study compared the interval until device exchange or death from pump-related failure in patients with pulsatile versus continuous flow left ventricular assist devices.

METHODS

Data from Interagency Registry for Mechanically Assisted Circulatory Support (June 23, 2006, to March 31, 2011) compared the durability of implanted pulsatile and continuous flow left ventricular assist devices. The durability issues included pump replacement for infection, thrombosis-hemolysis, driveline failure, or pump drive unit failure, and death from driveline or pump drive unit failure.

RESULTS

A total of 3302 left ventricular assist devices were implanted (486 pulsatile, 2816 continuous flow) and 98 pump exchanges or deaths from durability issues (46 pulsatile, 52 continuous flow; 3% of implants). The interval to device issue was greater for the continuous flow than for the pulsatile devices (P < .001). A comparisons of the causes for pump exchange or pump-related death showed (1) greater freedom from pump failure in the continuous flow compared with the pulsatile left ventricular assist devices (10 events/2816 continuous flow implants vs 39 events/486 pulsatile implants; P < .0001); (2) similar exchange or pump-related death for driveline failure (1/486 pulsatile vs 7/2816 continuous flow; P = .82); (3) similar exchange or pump-related death for thrombosis-hemolysis (2/486 pulsatile vs 28/2816 continuous flow; P = .25); and (4) fewer exchanges or pump-related deaths from infection in continuous flow left ventricular assist devices (4/486 pulsatile vs 7/2816 continuous flow; P = .034). Competing outcomes analysis corroborated this finding, with 54% of continuous flow versus 23% of pulsatile patients alive and receiving support at 12 months after implantation.

CONCLUSIONS

The Analysis of Interagency Registry for Mechanically Assisted Circulatory Support data showed greater durability for continuous flow than for pulsatile left ventricular assist devices. Even longer durations of support can be expected if pump durability continues to improve.

Bariatric Surgery for a Patient with a Heartmate II Ventricular Assist Device for Destination Therapy

A patient with a HeartMate II left ventricular assist device who had a body mass index of 52 needed gastric bypass surgery in order to qualify for a heart transplant. Unlike previous experience in which the surgery was performed at the implant hospital, the gastric bypass surgery in this case was performed at a bariatric center of excellence that was a separate facility from the implant hospital. The artificial heart program of the University of Pittsburgh Medical Center worked with the bariatric center of excellence in scheduling the gastric bypass surgery using a multidisciplinary team approach at 2 hospitals to coordinate safe, high-quality patient care in a unique situation.

Muscle-derived stem cell sheets support pump function and prevent cardiac arrhythmias in a model of chronic myocardial infarction

Direct intracardiac cell injection for heart repair is hindered by numerous limitations including: cell death, poor spreading of the injected cells, arrhythmia, needle injury, etc. Tissue-engineered cell sheet implantation has the potential to overcome some of these limitations. We evaluated whether the transplantation of a muscle-derived stem cell (MDSC) sheet could improve the regenerative capacity of MDSCs in a chronic model of myocardial infarction. MDSC sheet-implanted mice displayed a reduction in left ventricle (LV) dilation and sustained LV contraction compared with the other groups. The MDSC sheet formed aligned myotubes and produced a significant increase in capillary density and a reduction of myocardial fibrosis compared with the other groups. Hearts transplanted with the MDSC sheets did not display any significant arrhythmias and the donor MDSC survival rate was higher than the direct myocardial MDSC injection group. MDSC sheet implantation yielded better functional recovery of chronic infarcted myocardium without any significant arrhythmic events compared with direct MDSC injection, suggesting this cell sheet delivery system could significantly improve the myocardial regenerative potential of the MDSCs.

Predictors and outcomes of health-related quality of life in caregivers of cardiothoracic transplant recipients

Cardiothoracic transplant programs generally require that transplant recipients have family caregivers to assist them posttransplant. The burden of caregiving on the family members remains poorly understood. If caregivers' well-being is compromised by caregiving, it may bode poorly for transplant recipients' own health in the long-term posttransplant. We examined caregiver health-related quality of life (HRQOL) during the first year after their family member's transplant, its predictors and its relationship to subsequent patient survival. Adult (aged 18+) caregivers of 242 cardiothoracic transplant recipients (lung = 134; heart = 108) completed assessments of demographics, psychosocial characteristics and caregiver burden at 2 months posttransplant, and HRQOL at 2, 7 and 12 months posttransplant. Recipients' survival time was obtained from medical records. Caregiver HRQOL was generally high across the first-year posttransplant in emotional and social functioning; caregiver physical functioning significantly worsened. There were no differences by type of recipient transplant. Greater caregiver burden predicted poorer caregiver HRQOL in several physical domains at 12 months posttransplant. Transplant recipients whose caregivers had lower perceived general health at 12 months posttransplant showed poorer survival rates during the subsequent 7 years of follow up. Transplant teams should identify those caregivers at risk for poorer general health posttransplant to maximize positive outcomes for the entire family.

Invasive aspergillosis among heart transplant recipients is rare but causes rapid death due to septic shock and multiple organ dysfunction syndrome

Between 2000 and 2011, proven or probable invasive aspergillosis (IA) was diagnosed in 1.7% (8/455) of heart transplant (HTx) recipients at our center, in the absence of antifungal prophylaxis. All patients had invasive pulmonary infections and 75% (6/8) were diagnosed during 2 separate 3-month periods. Cases were notable for their association with septic shock and multiple organ dysfunction syndrome (MODS) (75%, 6/8 each), non-specific clinical and radiographic findings, and rapid mortality despite mould-active antifungal therapy (88%, 7/8; occuring at a median 11 days after diagnosis). All patients had predisposing conditions known to be risk factors for IA. For patients with early IA (within 90 days of HTx), conditions included hemodialysis, thoracic re-operation, and the presence of another case in the institution within the preceding 3 months. For late-onset IA, conditions included hemodialysis and receipt of augmented immunosuppression. Clinicians should suspect IA in HTx recipients with risk factors who present with non-specific and unexplained respiratory syndromes, including those in septic shock and MODS, and institute prompt antifungal therapy without waiting for the results of cultures or other diagnostic tests.

Long-term mechanical circulatory support (destination therapy): on track to compete with heart transplantation?

OBJECTIVES

Average 2-year survival after cardiac transplantation is approximately 80%. The evolution and subsequent approval of larger pulsatile and, more recently, continuous flow mechanical circulatory support (MCS) technology for destination therapy (DT) offers the potential for triage of some patients awaiting cardiac transplantation to DT.

METHODS

The National Heart, Lung, and Blood Institute Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) is a national multi-institutional study of long-term MCS. Between June 2006 and December 2011, 127 pulsatile and 1160 continuous flow pumps (24% of total primary left ventricular assist devices [LVADs]) carried an initial strategy of DT therapy.

RESULTS

By multivariable analysis, risk factors (P < .05) for mortality after DT included older age, larger body mass index, history of cancer, history of cardiac surgery, INTERMACS level I (cardiogenic shock), dialysis, increased blood urea nitrogen, use of a pulsatile flow device, and use of a right ventricular assist device (RVAD). Among patients with a continuous flow LVAD who were not in cardiogenic shock, a particularly favorable survival was associated with no cancer, patients not in cardiogenic shock, and blood urea nitrogen less than 50 mg/dL, resulting in 1- and 2-year survivals of 88% and 80%.

CONCLUSIONS

(1) Evolution from pulsatile to continuous flow technology has dramatically improved 1- and 2-year survivals; (2) DT is not appropriate for patients with rapid hemodynamic deterioration or severe right ventricular failure; (3) important subsets of patients with continuous flow DT now enjoy survival that is competitive with heart transplantation out to about 2 years.

The Fourth INTERMACS Annual Report: 4,000 implants and counting

The Fourth Annual Report of the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) summarizes and analyzes the first 5 years of patient and data collection. With more than 4,000 patients entered into the database, the evolution of pump technology, strategy at implant, and pre-implant patient profiles are chronicled. A risk factor analysis of the entire adult primary implant population is provided, and the recent composition of patient profiles is examined. Current actuarial survival with continuous-flow pumps exceeds 80% at 1 year and 70% at 2 years.

Use of an intrapericardial, continuous-flow, centrifugal pump in patients awaiting heart transplantation

BACKGROUND

Contemporary ventricular assist device therapy results in a high rate of successful heart transplantation but is associated with bleeding, infections, and other complications. Further reductions in pump size, centrifugal design, and intrapericardial positioning may reduce complications and improve outcomes.

METHODS AND RESULTS

We studied a small, intrapericardially positioned, continuous-flow centrifugal pump in patients requiring an implanted ventricular assist device as a bridge to heart transplantation. The course of investigational pump recipients was compared with that of patients implanted contemporaneously with commercially available devices. The primary outcome, success, was defined as survival on the originally implanted device, transplantation, or explantation for ventricular recovery at 180 days and was evaluated for both noninferiority and superiority. Secondary outcomes included a comparison of survival between groups and functional and quality-of-life outcomes and adverse events in the investigational device group. A total of 140 patients received the investigational pump, and 499 patients received a commercially available pump implanted contemporaneously. Success occurred in 90.7% of investigational pump patients and 90.1% of controls, establishing the noninferiority of the investigational pump (P<0.001; 15% noninferiority margin). At 6 months, median 6-minute walk distance improved by 128.5 m, and both disease-specific and global quality-of-life scores improved significantly.

CONCLUSIONS

A small, intrapericardially positioned, continuous-flow, centrifugal pump was noninferior to contemporaneously implanted, commercially available ventricular assist devices. Functional capacity and quality of life improved markedly, and the adverse event profile was favorable.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00751972.

Onset and risk factors for anxiety and depression during the first 2 years after lung transplantation

OBJECTIVE

Anxiety disorders are prominent in chronic lung disease; lung transplant recipients may therefore also be at high risk for these disorders. We sought to provide the first prospective data on rates and risk factors for anxiety disorders as well as depressive disorders during the first 2 years after transplantation.

METHOD

A total of 178 lung recipients and a comparison group (126 heart recipients) received psychosocial and Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition assessments at 2, 7, 12, 18 and 24 months posttransplant. Survival analysis determined onset rates and risk factors.

RESULTS

The panic disorder rate was higher (P<.05) in lung than heart recipients (18% vs. 8%). Lung and heart recipients did not differ on rates of transplant-related posttraumatic stress disorder (15% vs. 14%), generalized anxiety disorder (4% vs. 3%) or major depression (30% vs. 26%). Risk factors for disorders included pretransplant psychiatric history, female gender, longer wait for transplant, and early posttransplant health problems and psychosocial characteristics (e.g., poorer caregiver support and use of avoidant coping).

CONCLUSIONS

Heightened vigilance for panic disorder in lung recipients and major depression in all cardiothoracic recipients is warranted. Strategies to prevent psychiatric disorder should target recipients based not only on pretransplant characteristics but on early posttransplant characteristics as well.

Survival benefit of implantable cardioverter-defibrillators in left ventricular assist device-supported heart failure patients

BACKGROUND

Implantable cardioverter-defibrillators (ICDs) reduce mortality in heart failure (HF). In patients requiring a ventricular assist device (VAD), the benefit from ICD therapy is not well established. The aim of this study was to define the impact of ICD on outcomes in VAD-supported patients.

METHODS AND RESULTS

We reviewed data for consecutive adult HF patients receiving VAD as a bridge to transplantation from 1996 to 2003. The primary outcome was survival to transplantation. A total of 144 VADs were implanted [85 left ventricular (LVAD), 59 biventricular (BIVAD), mean age 50 ± 12 years, 77% male, left ventricular ejection fraction 18 ± 9%, 54% ischemic]. Mean length of support was 119 days (range 1-670); 103 patients (72%) survived to transplantation. Forty-five patients had an ICD (33 LVAD, 12 BIVAD). More LVAD patients had an appropriate ICD shock before implantation than after (16 vs 7; P = .02). There was a trend toward higher shock frequency before LVAD implant than after (3.3 ± 5.2 vs 1.1 ± 3.8 shocks/y; P = .06). Mean time to first shock after VAD implant was 129 ± 109 days. LVAD-supported patients with an ICD were significantly more likely to survive to transplantation [1-y actuarial survival to transplantation: LVAD: 91% with ICD vs 57% without ICD (log-rank P = .01); BIVAD: 54% vs 47% (log-rank P = NS)]. An ICD was associated with significantly increased survival in a multivariate model controlling for confounding variables (odds ratio 2.54, 95% confidence interval 1.04-6.21; P = .04).

CONCLUSIONS

Shock frequency decreases after VAD implantation, likely owing to ventricular unloading, but appropriate ICD shocks still occur in 21% of patients. An ICD is associated with improved survival in LVAD-supported HF patients.

Decision tree for adjuvant right ventricular support in patients receiving a left ventricular assist device

BACKGROUND

Right ventricular (RV) failure is a significant complication after implantation of a left ventricular assist device (LVAD). It is therefore important to identify patients at risk a priori. However, prognostic models derived from multivariate analyses have had limited predictive power.

METHODS

This study retrospectively analyzed the records of 183 LVAD recipients between May 1996 and October 2009; of these, 27 later required a RVAD (RVAD(+)) and 156 remained on LVAD only (RVAD(-)) until transplant or death. A decision tree model was constructed to represent combinatorial non-linear relationships of the pre-operative data that are predictive of the need for RVAD support.

RESULTS

An optimal set of 8 pre-operative variables were identified: transpulmonary gradient, age, right atrial pressure, international normalized ratio, heart rate, white blood cell count, alanine aminotransferase, and the number of inotropic agents. The resultant decision tree, which consisted of 28 branches and 15 leaves, identified RVAD(+) patients with 85% sensitivity, RVAD(-) patients with 83% specificity, and exhibited an area under the receiver operating characteristic curve of 0.87.

CONCLUSIONS

The decision tree model developed in this study exhibited several advantages compared with existing risk scores. Quantitatively, it provided improved prognosis of RV support by encoding the non-linear, synergic interactions among pre-operative variables. Because of its intuitive structure, it more closely mimics clinical reasoning and therefore can be more readily interpreted. Further development with additional multicenter, longitudinal data may provide a valuable prognostic tool for triage of LVAD therapy and, potentially, improve outcomes.

Minimally invasive approach to thoracic effusions in patients with ventricular assist devices

The aim of this study was to compare our experience between open and video-assisted thoracic surgery (VATS) approaches to the management of thoracic effusions in ventricular assist device (VAD) patients. This was a retrospective review of a prospectively collected database of VAD patients at a single institution. Patients who were operated on for pericardial and/or pleural effusions were included. Primary outcomes included operative mortality and morbidity as well as effusion recurrence. From 1993 to 2009, 360 adult patients underwent VAD placement. Twenty-three patients (11.9%) required operative management of pleural (n = 24), pericardial (n = 13) or both pleural and pericardial (n = 6) effusions [open = 20 (47%); VATS = 23 (53%)]. Drainage with decortication was performed in five patients, with the remaining undergoing drainage alone. Open and VATS patients were similar in age, gender and indication for VAD support. Conversion from VATS to open was necessary in four patients (17%). There was no operative mortality and no difference in perioperative complications between approaches. The open and VATS approaches had similar rates of pleural (open = 63%; VATS = 41%; P = 0.42) and pericardial (open = 31%; VATS = 17%; P = 1) effusion recurrences. In spite of apparent challenges, the VATS approach may be as safe and effective as open surgery for the management of pleural and pericardial effusions in VAD patients in centres with significant minimally invasive thoracic experience.

Third INTERMACS Annual Report: the evolution of destination therapy in the United States

The third annual report of the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) provides documentation of the current landscape of durable mechanical circulatory support in the United States. With nearly 3,000 patients entered into the database, the transition to continuous-flow pump technology is evident and dramatic. This report focuses on the rapidly expanding experience with mechanical circulatory support as destination therapy. The current 1-year survival of 75% with continuous-flow destination therapy provides a benchmark for the evolving application of this therapy.

A Classification Approach for Risk Prognosis of Patients on Mechanical Ventricular Assistance

The identification of optimal candidates for ventricular assist device (VAD) therapy is of great importance for future widespread application of this life-saving technology. During recent years, numerous traditional statistical models have been developed for this task. In this study, we compared three different supervised machine learning techniques for risk prognosis of patients on VAD: Decision Tree, Support Vector Machine (SVM) and Bayesian Tree-Augmented Network, to facilitate the candidate identification. A predictive (C4.5) decision tree model was ultimately developed based on 6 features identified by SVM with assistance of recursive feature elimination. This model performed better compared to the popular risk score of Lietz et al. with respect to identification of high-risk patients and earlier survival differentiation between high- and low- risk candidates.

Intra-operative preparation of autologous bone marrow-derived CD34-enriched cellular products for cardiac therapy

BACKGROUND AND AIMS

With the advent of regenerative therapy, there is renewed interest in the use of bone marrow as a source of adult stem and progenitor cells, including cell subsets prepared by immunomagnetic selection. Cell selection must be rapid, efficient and performed according to current good manufacturing practices. In this report we present a methodology for intra-operative preparation of CD34(+) selected autologous bone marrow for autologous use in patients receiving coronary artery bypass grafts or left ventricular assist devices.

METHODS AND RESULTS

We developed a rapid erythrocyte depletion method using hydroxyethyl starch and low-speed centrifugation to prepare large-scale (mean 359 mL) bone marrow aspirates for separation on a Baxter Isolex 300i immunomagnetic cell separation device. CD34 recovery after erythrocyte depletion was 68.3 ± 20.2%, with an average depletion of 91.2 ± 2.8% and an average CD34 content of 0.58 ± 0.27%. After separation, CD34 purity was 64.1 ± 17.2%, with 44.3 ± 26.1% recovery and an average dose of 5.0 ± 2.7 × 10(6) CD34(+) cells/product. In uncomplicated cases CD34-enriched cellular products could be accessioned, prepared, tested for release and administered within 6 h. Further analysis of CD34(+) bone marrow cells revealed a significant proportion of CD45(-) CD34(+) cells.

CONCLUSIONS

Intra-operative immunomagnetic separation of CD34-enriched bone marrow is feasible using rapid low-speed Hetastarch sedimentation for erythrocyte depletion. The resulting CD34-enriched product contains CD45(-) cells that may represent non-hematopoietic or very early hematopoietic stem cells that participate in tissue regeneration.

Myocardial Fas and cytokine expression in end-stage heart failure: impact of LVAD support

Left ventricular assist device (LVAD) support may facilitate myocardial recovery. We evaluated the impact of LVAD support on Fas expression in a cohort with end-stage heart failure. Myocardial gene expression was assessed pre- and post-LVAD by RNase protection assay and compared to control donor hearts. The expression of Fas is markedly elevated at the time of LVAD support and is tightly correlated with TNF expression. While interleukin (IL)-6 was significantly reduced by LVAD support, the impact of support on Fas was highly variable and tightly linked to tumor necrosis factor (TNF). The role of Fas in predicting recovery after LVAD support requires further investigation.

The Joint Commission's Disease-Specific Care Certification for Destination Therapy Ventricular Assist Devices

The Centers for Medicare and Medicaid Services announced that all hospitals implanting ventricular assist devices are required to have certification from the The Joint Commission for disease-specific care destination therapy with a ventricular assist device effective March 27, 2009, in order to receive Medicare reimbursement for services rendered to patients who have devices implanted for destination therapy. On February 23, 2007, The Joint Commission released the certification requirements for ventricular assist devices implanted for destination therapy in an 8-page document so that hospitals could prepare to meet the 2009 certification deadline. The Artificial Heart Program of the University of Pittsburgh Medical Center undertook a multidisciplinary project, under the guidance of the nurse coordinator, to prepare the hospital and program for a precertification survey by The Joint Commission for disease-specific destination therapy ventricular assist device certification. The Presbyterian Hospital Artificial Heart Program was awarded The Joint Commission's device-specific certification for destination therapy with ventricular assist devices in June 2008.

Pulsatile left ventricular assist device support as a bridge to decision in patients with end-stage heart failure complicated by pulmonary hypertension

BACKGROUND

Severe pulmonary hypertension (PH) in heart failure (HF) is a risk factor for adverse outcomes after heart transplantation (HTx). Left ventricular assist devices (LVADs) improve pulmonary hemodynamics, but our understanding of the degree of improvement and the effect on outcomes is still evolving.

METHODS

We reviewed invasive pulmonary hemodynamics from 58 consecutive patients receiving LVAD support as a bridge to HTx from 1996 to 2003. The primary outcome was change in baseline transpulmonary gradient (TPG) during LVAD support and after HTx/recovery. The secondary outcome was post-HTx survival.

RESULTS

All patients (age, 49 +/- 14 years, 79% male, 40% ischemic) received a pulsatile LVAD (median support, 97 days; interquartile range [IQR], 31-222). Hemodynamic measurements were obtained at baseline (median, 1 day; IQR, 1-3), during early (median, 1 day; IQR, 0-4) and late (median, 75 days; IQR, 24-186) LVAD support, and after HTx/recovery (median, 28 days; IQR, 17-40). Improvement in TPG occurred throughout LVAD support and was sustained after HTx/recovery. Levels of TPG reductions in patients with a baseline TPG in the highest quartile (14.1-26.0 mm Hg) were 8.6 +/- 3.5 vs 6.5 +/- 3.1 mm Hg in the lowest quartile (2.0-7.7 mm Hg) during LVAD support (p = 0.102), with 90% vs 100% 30-day post-HTx survival (P = 0.113).

CONCLUSION

Pulmonary hemodynamics and post-HTx survival were similar after pulsatile LVAD support in patients with and without pre-implant PH. LVAD support may be a useful strategy to reverse PH in carefully selected patients, thus improving candidacy for HTx.

Impact of abdominal complications on outcome after mechanical circulatory support

BACKGROUND

Mechanical circulatory support (MCS) is life sustaining for patients with end-stage heart failure. Most devices require abdominal wall transgression, creating a potential for abdominal complications. The incidence and impact of these relatively underreported complications are unknown.

METHODS

A retrospective review was performed on 179 patients who received MCS therapy from 1999 to 2008. Abdominal complications were grouped as abdominal wall, gastrointestinal tract, and solid organ.

RESULTS

Ninety-eight patients (55%) experienced 157 abdominal complications. These involved the abdominal wall in 69 (44%), the gastrointestinal tract in 52 (33%), and the solid organs in 36 (23%). Surgical intervention was required in 36% of patients with abdominal wall complications, 19% of patients with gastrointestinal tract complications, and 14% of patients with solid organ complications. Multivariate analysis identified diabetes mellitus (p < 0.001), emergent device placement (p = 0.019), and preimplant mechanical ventilation (p = 0.045) as independent risk factors for developing an abdominal complication. Kaplan-Meier survival while receiving MCS was significantly reduced for patients with abdominal complications versus those without (p = 0.0142). Multivariate analysis identified only solid organ abdominal complications (p = 0.001) as an independent risk factor for death while receiving device support.

CONCLUSIONS

Abdominal complications are common in patients supported with MCS devices and significantly reduce survival. Surgical intervention is more frequently required for complications related to the abdominal wall compared with other complications. Patients with significant comorbidities (diabetes mellitus, respiratory failure) requiring urgent or emergent device placement are at higher risk for the development of abdominal complications with an attendant reduction in device-related survival.

Alemtuzumab induction prior to cardiac transplantation with lower intensity maintenance immunosuppression: one-year outcomes

Induction therapy with alemtuzumab (C-1H) prior to cardiac transplantation (CTX) may allow for lower intensity maintenance immunosuppression. This is a retrospective study of patients who underwent CTX at a single institution from January 2001 until April 2009 and received no induction versus induction with C-1H on a background of tacrolimus and mycophenolate. Those with C-1H received dose-reduced calcineurin inhibitor and no steroids. A total of 220 patients were included, 110 received C-1H and 110 received no induction. Recipient baseline characteristics, donor age and gender were not different between the two groups. Mean tacrolimus levels (ng/mL) for C-1H versus no induction: months 1-3 (8.5 vs. 12.9), month 4-6 (10.2 vs. 13.0), month 7-9 (10.2 vs. 11.9) and month 10-12 (9.9 vs. 11.3) were all significantly lower for the C-1H group, p < 0.001. There were no differences between the C-1H and no induction groups at 12 months for overall survival 85.1% versus 93.6% p = 0.09, but freedom from significant rejection was significantly higher for the C-1H group, 84.5% versus 51.6%, p < 0.0001. In conclusion, induction therapy after CTX with C-1H results in a similar 12 month survival, but a greater freedom from rejection despite lower calcineurin levels and without the use of steroids.

Left ventricular remodeling and myocardial recovery on mechanical circulatory support

BACKGROUND

Myocardial recovery after ventricular assist devices (VAD) is rare but appears more common in nonischemic cardiomyopathies (NICM). We sought to evaluate left ventricular (LV) end diastolic diameter (LVEDD) for predicting recovery after VAD.

METHODS AND RESULTS

NICM patients receiving long-term mechanical support between 1996 and 2008 were reviewed. Subjects were divided into 3 groups: mild, moderate, and severe dilation (Group A: LVEDD <6.0 cm [n = 22]; Group B: 6.0-7.0 cm [n = 32]; Group C: >7.0 cm [n = 48], respectively). Overall, recovery (successful explant without transplantation) occurred in 14 of 102 subjects (14%). Of these, 2 died and 2 required transplantation within 1 year. Recovery was more common in patients without LV dilation (Groups A/B/C = 32%/22%/0%, P < .001), as was sustained recovery (alive and transplant free 1 year after explant; A/B/C = 27%/10%/0%, P = .001). Of the recovery patients in Group A, 6/7 (86%) had sustained recovery versus 3/6 (50%) in Group B.

CONCLUSIONS

Recovery occurred in 32% of NICM patients without significant LV dilation at time of VAD, the majority of whom experienced significant sustained recovery. Recovery was not evident in those with severe LV dilation. Routine echocardiography at the time of implant may assist in targeting patients for recovery after VAD.

Incidence and patterns of adverse event onset during the first 60 days after ventricular assist device implantation

BACKGROUND

Although ventricular assist devices (VADs) provide effective treatment for end-stage heart failure, VAD support remains associated with significant risk for adverse events (AEs). To date there has been no detailed assessment of the incidence of a full range of AEs using standardized event definitions. We sought to characterize the frequency and timing of AE onset during the first 60 days of VAD support, a period during which clinical observation suggests the risk of incident AEs is high.

METHODS

A retrospective analysis was performed utilizing prospectively collected data from a single-site clinical database including 195 patients aged 18 or greater receiving VADs between 1996 and 2006. Adverse events were coded using standardized criteria. Cumulative incidence rates were determined, controlling for competing risks (death, transplantation, recovery-wean).

RESULTS

During the first 60 days after implantation, the most common AEs were bleeding, infection, and arrhythmias (cumulative incidence rates, 36% to 48%), followed by tamponade, respiratory events, reoperations, and neurologic events (24% to 31%). Other events (eg, hemolysis, renal, hepatic events) were less common (rates <15%). Some events (eg, bleeding, arrhythmias) showed steep onset rates early after implantation. Others (eg, infections, neurologic events) had gradual onsets during the 60-day period. Incidence of most events did not vary by implant era (1996 to 2000 vs 2001 to 2006) or by left ventricular versus biventricular support.

CONCLUSIONS

Understanding differential temporal patterns of AE onset will allow preventive strategies to be targeted to the time periods when specific AE risks are greatest. The AE incidence rates provide benchmarks against which future studies of VAD-related risks may be compared.