Richard Ha

Pulmonary artery pulsatility index predicts right ventricular failure after left ventricular assist device implantation

BACKGROUND Right ventricular failure (RVF) is a major cause of morbidity and mortality after left ventricular assist device (LVAD) implantation. The pulmonary artery pulsatility index (PAPi) is a novel hemodynamic index that predicts RVF in the setting of myocardial infarction, although it has not been shown to predict RVF after LVAD implantation. METHODS We performed a retrospective, single-center analysis to examine the utility of the PAPi in predicting RVF and RV assist device (RVAD) implantation in 85 continuous-flow LVAD recipients. We performed a multivariate logistic regression analysis incorporating previously identified predictors of RVF after LVAD placement, including clinical and echocardiographic variables, to determine the independent effect of PAPi in predicting RVF or RVAD after LVAD placement. RESULTS In this cohort, the mean PAPi was 3.4 with a standard deviation of 2.9. RVF occurred in 33% of patients, and 11% required a RVAD. Multivariate analysis, adjusting for age, blood urea nitrogen (BUN), and Interagency Registry for Mechanically Assisted Circulatory Support profile, revealed that higher PAPi was independently associated with a reduced risk of RVAD placement (odds ratio [OR], 0.30; 95% confidence interval [CI], 0.07-0.89). This relationship did not change significantly when echocardiographic measures were added to the analysis. Stratifying the analysis by the presence of inotropes during catheterization revealed that PAPi was more predictive of RVAD requirement when measured on inotropes (OR, 0.21; 95% CI, 0.02-0.97) than without (OR, 0.49; 95% CI, 0.01-1.94). Furthermore, time from catheterization to LVAD did not significantly affect the predictive value of the PAPi (maximum time, 6 months). Receiver operating characteristic curve analysis revealed that optimal sensitivity and specificity were achieved using a PAPi threshold of 2.0. CONCLUSIONS In LVAD recipients, the PAPi is an independent predictor of RVF and the need for RVAD support after LVAD implantation. This index appears more predictive in patients receiving inotropes and was not affected by time from catheterization to LVAD in our cohort.

Long-term outcomes of septal reduction for obstructive hypertrophic cardiomyopathy.

BACKGROUND Surgical myectomy and alcohol septal ablation (ASA) aim to decrease left ventricular outflow tract (LVOT) gradient in hypertrophic cardiomyopathy (HCM). Outcome of myectomy beyond 10 years has rarely been described. We describe 20 years of follow-up of surgical myectomy and 5 years of follow-up for ASA performed for obstructive HCM. METHODS We studied 171 patients who underwent myectomy for symptomatic LVOT obstruction between 1972 and 2006. In addition, we studied 52 patients who underwent ASA for the same indication and who declined surgery. Follow-up of New York Heart Association (NYHA) functional class, echocardiographic data, and vital status were obtained from patient records. Mortality rates were compared with expected mortality rates of age- and sex-matched populations. RESULTS Surgical myectomy improved NYHA class (2.74±0.65 to 1.54±0.74, p<0.001), reduced resting gradient (67.4±43.4mmHg to 11.2±16.4mmHg, p<0.001), and inducible LVOT gradient (98.1±34.7mmHg to 33.6±34.9mmHg, p<0.001). Similarly, ASA improved functional class (2.99±0.35 to 1.5±0.74, p<0.001), resting gradient (67.1±26.9mmHg to 23.9±29.4mmHg, p<0.001) and provoked gradient (104.4±34.9mmHg to 35.5±38.6mmHg, p<0.001). Survival after myectomy at 5, 10, 15, and 20 years of follow-up was 92.9%, 81.1%, 68.9%, and 47.5%, respectively. Of note, long-term survival after myectomy was lower than for the general population [standardized mortality ratio (SMR)=1.40, p<0.005], but still compared favorably with historical data from non-operated HCM patients. Survival after ASA at 2 and 5 years was 97.8% and 94.7%, respectively. Short-term (5 year) survival after ASA (SMR=0.61, p=0.48) was comparable to that of the general population. CONCLUSION Long-term follow-up of septal reduction strategies in obstructive HCM reveals that surgical myectomy and ASA are effective for symptom relief and LVOT gradient reduction and are associated with favorable survival. While overall prognosis for the community HCM population is similar to the general population, the need for surgical myectomy may identify a sub-group with poorer long-term prognosis. We await long-term outcomes of more extensive myectomy approaches adopted in the past 10 years at major institutions.

Treatment of left ventricular assist device-associated arteriovenous malformations with thalidomide.

Gastrointestinal bleeding because of arteriovenous malformations (AVMs) is an increasingly recognized complication of continuous flow left ventricular assist devices (LVADs). Currently, therapeutic options for LVAD-associated AVMs are limited and often require repeated endoscopic procedures and reduction or cessation of anticoagulation. Thalidomide has been utilized in the treatment of refractory bleeding because of gastrointestinal vascular malformations. Here we describe the case of a 66-year-old man with severe ischemic cardiomyopathy implanted with a continuous flow HeartMate II. His postoperative course was complicated by multiple hospital admissions for gastrointestinal bleeding because of LVAD-associated AVMs refractory to repeated argon plasma laser coagulation. Anticoagulation was discontinued with subsequent pump stoppage because of thrombus requiring urgent surgical pump exchange. Following this, thalidomide was initiated and anticoagulation with warfarin was continued. Since initiation of thalidomide, the patient has not had further gastrointestinal bleeding or evidence of pump thrombus in the subsequent 1 year.

Lung Quality and Utilization in Controlled Donation After Circulatory Determination of Death Within the United States

Although controlled donation after circulatory determination of death (cDCDD) could increase the supply of donor lungs within the United States, the yield of lungs from cDCDD donors remains low compared with donation after neurologic determination of death (DNDD). To explore the reason for low lung yield from cDCDD donors, Scientific Registry of Transplant Recipient data were used to assess the impact of donor lung quality on cDCDD lung utilization by fitting a logistic regression model. The relationship between center volume and cDCDD use was assessed, and the distance between center and donor hospital was calculated by cDCDD status. Recipient survival was compared using a multivariable Cox regression model. Lung utilization was 2.1% for cDCDD donors and 21.4% for DNDD donors. Being a cDCDD donor decreased lung donation (adjusted odds ratio 0.101, 95% confidence interval [CI] 0.085–0.120). A minority of centers have performed cDCDD transplant, with higher volume centers generally performing more cDCDD transplants. There was no difference in center‐to‐donor distance or recipient survival (adjusted hazard ratio 1.03, 95% CI 0.78–1.37) between cDCDD and DNDD transplants. cDCDD lungs are underutilized compared with DNDD lungs after adjusting for lung quality. Increasing transplant center expertise and commitment to cDCDD lung procurement is needed to improve utilization.

Influence of durable mechanical circulatory support and allosensitization on mortality after heart transplantation

BACKGROUND Allosensitization has been shown to negatively affect post-heart transplant (HTx) survival even with a negative crossmatch. Whether allosensitization related to mechanical circulatory support (MCS) is associated with worse post-HTx survival remains controversial. METHODS Adult HTx recipients listed in the United Network for Organ Sharing database (July 2006-December 2012) were identified. Multivariate Cox regression assessed the effect of allosensitization on survival. Propensity matching was performed to compare patients who were and were not allosensitized. Kaplan-Meier survival analysis compared matched and unmatched patients in the MCS and medically managed cohorts. RESULTS We identified 11,840 HTx recipients, of whom 4,167 had MCS. MCS was associated with allosensitization in multivariate logistic regression. Each different MCS device was associated with worse post-HTx survival in multivariate Cox regression. Allosensitization did not predict post-HTx mortality in MCS patients (hazard ratio, 1.07; 95% confidence interval, 0.89-1.28; p = 0.48. Among patients without MCS, allosensitization was associated with post-HTx mortality (hazard ratio, 1.19; 95% confidence interval, 1.03-1.39; p = 0.02). Kaplan-Meier analysis revealed equivalent survival in unmatched and matched cohorts when MCS patients who were allosensitized were compared with non-allosensitized MCS patients. Among non-MCS patients, allosensitization was associated with worse survival in unmatched and matched analysis. CONCLUSIONS MCS was associated with allosensitization. For MCS patients, allosensitization did not independently predict worse post-HTx outcome. Among non-MCS patients, allosensitization was associated with worse post-HTx survival. Allosensitization appears to be a heterogeneous process influenced by presence of MCS.

Elevated pretransplant pulmonary vascular resistance index does not predict mortality after isolated orthotopic heart transplantation in children: A retrospective analysis of the UNOS database

OHT is the definitive therapy in end‐stage heart failure. Elevated PVRI is considered a relative contraindication to isolated OHT; this assumption is re‐evaluated using data from the UNOS database. A retrospective review of de‐identified data from the UNOS dataset was performed. There were 1943 pediatric OHT recipients between 10/87 and 12/11 with sufficient data for analysis. Cox regression was performed to examine the effect of baseline characteristics on post‐transplant survival. Patients were propensity matched, and Kaplan–Meier survival analysis was performed comparing cohorts of patients using thresholds of 6 and 9 WU × m2. PVRI was not a significant predictor of post‐transplant outcomes in either univariate or multivariate Cox regression. Kaplan–Meier analysis revealed no difference in survival between both unmatched and propensity‐matched OHT recipients. In conclusion, elevated PVRI was not associated with post‐transplant mortality in pediatric OHT recipients. A prospective study assessing the current use of PVRI ≥6 as a threshold to contraindicate isolated OHT should be undertaken. Removing this potentially unnecessary restriction on transplant candidacy may make this life‐saving therapy available to a greater number of patients.

Biventricular VAD versus LVAD for right heart failure

Right ventricular failure (RVF) in the era of left ventricular assist device (LVAD) therapy remains a significant problem. Approximately 6% to 10% of patients with an LVAD will require the implantation of a right ventricular assist device (RVAD) (1) with an additional 15% to 20% requiring prolonged inotropic support for RVF (2,3). Several mechanisms may contribute to RVF post LVAD implantation, most importantly the unloading of the left ventricle and resultant loss of septal contribution to right ventricular (RV) function. In addition, perioperative factors such as myocardial ischemia can further compromise a vulnerable right ventricle. As these factors may lead to rescue implantation of an RVAD, which is associated with increased mortality (4), research should focus on identifying patients that would benefit from preemptive implantation of an RVAD. Here we highlight recent advances in the field, focusing on risk stratification scores, the use of pulmonary vasodilators, the use of biventricular assist devices (BIVAD) versus a total artificial heart (TAH), and the use of a temporary RVAD (tRVAD). We also briefly present recent data on right heart recovery post LVAD using tRVAD support.

A Novel, Catheter-Based Approach to Left Ventricular Assist Device Deactivation After Myocardial Recovery

We describe a case of catheter-based embolization and deactivation of a left ventricular assist device using an Amplatzer plug for a patient demonstrating myocardial recovery after diagnosis of nonischemic cardiomyopathy. This procedure can provide a minimally invasive, low morbidity solution for patients wishing to be separated from left ventricular assist device support who want to avoid invasive surgery for device removal.

Intra-aortic balloon pump therapy negatively affects flow through a continuous-flow left ventricular assist device

From the Divisions of Cardiovascular Medicine and Cardiothoracic Surgery, Stanford University School of Medicine, Stanford University Medical Center, Stanford, Calif. Disclosures: Both D.B. and R.H. receive research support fromHeartWare Corporation and Thoratec Corporation. C.C has nothing to disclose with regard to commercial support. Received for publication June 27, 2016; revisions received Aug 10, 2016; accepted for publication Sept 2, 2016. Address for reprints: Dipanjan Banerjee, MD,MS, Falk CVRB 275, 870 Quarry Rd, Stanford, CA 94305 (E-mail: dipanjan@stanford.edu). J Thorac Cardiovasc Surg 2016;-:e1-2 0022-5223/

Imaging in Lung Transplantation: Surgical Considerations of Donor and Recipient

36.00 Copyright 2016 Published by Elsevier Inc. on behalf of The American Association for Thoracic Surgery http://dx.doi.org/10.1016/j.jtcvs.2016.09.012