Salvage of severe primary graft dysfunction following heart transplantation using extracorporeal life support

Primary graft dysfunction (PGD) is the leading cause of early mortality after heart transplantation. Typically, mechanical circulatory support is necessary to provide hemodynamic support and to enable graft recovery. However, both the reported incidence of PGD and the reported salvage rates with extracorporeal membrane oxygenation (ECMO) vary widely. This may partly be due to variations in the definition of PGD and its levels of severity. We analyzed a prospectively maintained database of 255 transplant recipients at our institution to determine the effectiveness of ECMO support in those who develop severe PGD as defined by the International Society for Heart and Lung Transplantation consensus guidelines. Nineteen (7.5%) patients (aged 32-69 years) developed severe PGD and were treated with veno-arterial (VA) ECMO, which was initiated in the operating room at the time of transplant in most patients. The majority received VA ECMO through femoral cannulation. Two patients required veno-venous ECMO for respiratory support after VA ECMO separation. The 30-day in-hospital survival rate following transplantation was 63% (n = 12). In conclusion, ECMO proved to be a viable option for early hemodynamic support in patients with severe PGD and has become our preferred modality for mechanical circulatory support in these patients.

The Impella Microaxial Flow Catheter Is Safe and Effective for Treatment of Myocarditis Complicated by Cardiogenic Shock: An Analysis From the Global cVAD Registry

BACKGROUND

Myocarditis complicated by cardiogenic shock remains a complex problem. The use of acute mechanical circulatory support devices for cardiogenic shock is growing. We explored the utility of Impella transvalvular microaxial flow catheters in the setting of myocarditis with cardiogenic shock.

METHODS AND RESULTS

We retrospectively analyzed data from 21 sites within the cVAD registry, an ongoing multicenter voluntary registry at sites in North America and Europe that have used Impella in patients with myocarditis. Myocarditis was defined by endomyocardial biopsy (n = 11) or by clinical history without angiographic evidence of coronary disease (n = 23). A total of 34 patients received an Impella 2.5, CP, 5.0, or RP device for cardiogenic shock complicating myocarditis. Baseline characteristics included age 42 ± 17 years, left ventricular ejection fraction (LVEF) 18% ± 10%, cardiac index 1.82 ± 0.46 L·min^-1·m^-2, pulmonary capillary wedge pressure 25 ± 7 mm Hg, and lactate 27 ± 31 mg/dL. Before Impella placement, 32% (n = 11) of patients required intra-aortic balloon pump. Mean duration of Impella support was 91 ± 74 hours; 21 of 34 patients (62%) survived the index hospitalization and were discharged with an improved mean LVEF of 37.32% ± 20.31% (P = .001); 15 patients recovered with successful support, 5 patients were transferred to another hospital on initial Impella support, 1 patient underwent orthotopic heart transplantation. Ten patients required transition to another mechanical circulatory support device.

CONCLUSIONS

This is the largest analysis of Impella-supported myocarditis cases to date. The use of Impella appears to be safe and effective in the settings of myocarditis complicated by cardiogenic shock.

Percutaneous temporary circulatory support devices and their use as a bridge to decision during acute decompensation of advanced heart failure

Temporary mechanical cardiac support (TMCS) devices intend to restore systemic perfusion and prevent further end-organ damage in patients with refractory cardiogenic shock until the insult is addressed. TMCS has been associated with reductions in hospital costs and in-hospital mortality. We review the four primary TMCS modalities available: intra-aortic balloon pump, TandemHeart, veno-arterial extracorporeal membrane oxygenation, and Impella pump. All have their own implantation technique and hemodynamic profile, and their use may therefore be tailored to the specific patient's needs. The appropriate TMCS may thus help stabilize the patient, enabling the care team to make decisions about durable support or transplantation.

Repeat Cardiac Transplant Indicated by Severe Cardiac Allograft Vasculopathy in a Patient With Danon Disease

Danon disease is a rare, X-linked dominant, lysosomal storage disorder, presenting with cardiomyopathy mostly in adolescent men. Male patients face a high mortality rate and rarely live to the age of 25 years unless they receive a heart transplant. Because they generally undergo heart transplantation at a young age, many patients ultimately face both short- and long-term complications. We present a 32-year-old man diagnosed with Danon disease; a nonsense mutation in the LAMP-2 gene. Progressive heart failure symptoms resulted in initial heart transplant at age 27 years. He subsequently developed severe cardiac allograft vasculopathy that led to graft failure requiring a redo orthotopic heart transplant. This is one of only two reported Danon disease cases described to date surviving repeat orthotopic heart transplants. We present this case to highlight the importance of heart transplantation in the management of Danon disease, to emphasize the risk of cardiac allograft vasculopathy post-transplant, and to discuss management strategies.

Complications of Radiofrequency Ablation for Supraventricular Tachycardia in the Wolff-Parkinson-White Syndrome Associated With Noncompaction Cardiomyopathy

Described herein is a 52-year-old man with Wolff-Parkinson-White syndrome and noncompaction cardiomyopathy who underwent 4 sternotomies to correct complications of 3 ablation procedures (2 open) for recurring supraventricular tachycardia, mitral valve repair for a damaged mitral valve during the third radiofrequency ablation procedure, and finally orthotopic heart transplantation.

Determinants and Outcomes of Vasoplegia Following Left Ventricular Assist Device Implantation

BACKGROUND

Vasoplegia is associated with adverse outcomes following cardiac surgery; however, its impact following left ventricular assist device implantation is largely unexplored.

METHODS AND RESULTS

In 252 consecutive patients receiving a left ventricular assist device, vasoplegia was defined as the occurrence of normal cardiac function and index but with the need for intravenous vasopressors within 48 hours following surgery for >24 hours to maintain a mean arterial pressure >70 mm Hg. We further categorized vasoplegia as none; mild, requiring 1 vasopressor (vasopressin, norepinephrine, or high-dose epinephrine [>5 μg/min]); or moderate to severe, requiring ≥2 vasopressors. Predictors of vasoplegia severity were determined using a cumulative logit (ordinal logistic regression) model, and 1-year mortality was evaluated using competing-risks survival analysis. In total, 67 (26.6%) patients developed mild vasoplegia and 57 (22.6%) developed moderate to severe vasoplegia. The multivariable model for vasoplegia severity utilized preoperative Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) profile, central venous pressure, systolic blood pressure, and intraoperative cardiopulmonary bypass time, which yielded an area under the curve of 0.76. Although no significant differences were noted in stroke or pump thrombosis rates (P=0.87 and P=0.66, respectively), respiratory failure and major bleeding increased with vasoplegia severity (P<0.01). Those with moderate to severe vasoplegia had a significantly higher risk of mortality than those without vasoplegia (adjusted hazard ratio: 2.12; 95% confidence interval, 1.08-4.18; P=0.03).

CONCLUSIONS

Vasoplegia is predictive of unfavorable outcomes, including mortality. Risk factors for future research include preoperative INTERMACS profile, central venous pressure, systolic blood pressure, and intraoperative cardiopulmonary bypass time.

Patient activation with respect to advanced heart failure therapy in patients over age 65 years

BACKGROUND

Clinical and ethical issues persist in determining candidacy for advanced heart failure (HF) therapies in elderly patients. Selection takes many factors into account, including "activation" (engagement and ability to self-manage).

OBJECTIVE

To investigate effects of age, activation, and depression/anxiety on selection and 6-month survival of participants considered for therapy.

METHODS

Consecutive people referred for advanced HF therapy completed the Patient Activation Measure and Hospital Anxiety and Depression Scale. We analyzed data from participants by age (≥65 vs. <65 years), stratified by approval for therapy.

RESULTS

Among 168 referred, 109 were approved, with no difference in activation between age groups (88% highly activated). Similarly, activation was not associated with age among those not approved. Activation was related to anxiety in older, approved participants, but not to depression.

CONCLUSIONS

Concerns regarding reduced self-management in the elderly may not be valid. Age alone should not disqualify a candidate for advanced HF therapy.

Validation of Peripherally Inserted Central Catheter-Derived Fick Cardiac Outputs in Patients with Heart Failure

The pulmonary artery catheter (PAC) remains the gold standard to calculate Fick cardiac outputs (FCOs) in patients with heart failure admitted to the intensive care unit (ICU). The peripherally inserted central catheter (PICC) provides long-term intravenous access and is used outside the ICU; however, there is scant literature validating venous oxygen saturations (VOSs) from PICC lines. Heart failure patients in the ICU with an existing PAC requiring a PICC line to transition were enrolled. Three blood samples were taken per person (1 at PICC, 1 at central venous pressure [CVP], and 1 at distal PAC). We performed repeated measures analysis of variance, as well as reliability analysis on 31 subjects (77% male, 71% Caucasian, mean ± standard deviation age 60 ± 8 years, 80% on inotropes). The average VOSs were 62 ± 11%, 62 ± 12%, and 61 ± 9% for the PICC line, CVP, and distal port, respectively (p = 0.66); there was excellent reliability (0.79). The median FCOs were 5 [4, 6], 5 [4, 6], and 5 [4, 6] L/min at the PICC, CVP, and distal port, respectively (p = 0.91); there was fair-to-good reliability (0.67). In conclusion, VOS and FCO did not differ by location, on average. Reliable data may be obtained through the PICC line, after evaluation from the PAC. The PICC may provide longer-term hemodynamic assessment while improving patient comfort.

Application of the International Society for Heart and Lung Transplantation (ISHLT) criteria for primary graft dysfunction after cardiac transplantation: outcomes from a high-volume centre†

OBJECTIVES

A standardized definition for primary graft dysfunction (PGD) after cardiac transplantation was recently proposed by the International Society of Heart and Lung Transplantation (ISHLT). We sought to characterize the outcomes associated with and identify risk factors for PGD following cardiac transplantation using these criteria at a high volume centre.

METHODS

Donor and recipient medical records of 201 consecutive adult cardiac transplantations performed between November 2012 and March 2015 were retrospectively reviewed. Patients undergoing isolated heart transplantation were diagnosed with none, mild, moderate, or severe PGD using ISHLT criteria. Cumulative survival was calculated according to the Kaplan–Meier method. Associations of risk factors for combined moderate/severe PGD were assessed with univariate and multivariate analyses.

RESULTS

A total of 191 consecutive patients underwent isolated heart transplantation, and 59 (30%) met ISHLT criteria for PGD: 35 (18%) mild, 8 (4%) moderate and 16 (8%) severe. Thirty-day/in-hospital mortality occurred in six (3%) patients, all of whom were diagnosed with severe PGD. Patients with moderate/severe PGD also had significantly increased intensive care unit length of stay (LOS), total LOS, reoperations for bleeding and postoperative infections. Survival at 1-year was diminished with increasing severity of PGD (none 93%, mild 94%, moderate 75% and severe 44%; log-rank P < 0.001). Elevated preoperative creatinine, pretransplantation hospitalized recipient and undersized donor were independently predictive of moderate/severe PGD.

CONCLUSIONS

A diagnosis of PGD portends worse outcomes including increased 30-day and 1-year mortality. The ISHLT diagnostic criteria for moderate and severe PGD identify and discriminate patients with PGD in a clinically relevant manner.

Bilateral sympathectomy for treatment of refractory ventricular tachycardia

Ventricular tachycardia (VT) commonly occurs in patients with ischemic or nonischemic cardiomyopathy and requires antiarrhythmic drugs, ablation, or advanced circulatory support. However, life-threatening VT may be refractory to these therapies, and may cause frequent implantable cardioverter defibrillator (ICD) discharges. Left cardiac sympathetic denervation reduces the occurrence of these fatal arrhythmias by inhibiting the sympathetic outflow to the cardiac tissue. We present a 69-year-old man with nonischemic cardiomyopathy, life-threatening VT, and hemodynamic instability with numerous ICD discharges, who remained refractory to antiarrhythmic drug therapy and ablation attempts. He was effectively treated with bilateral cardiac sympathectomy. Six months later, he remained free of VT with no ICD discharges.

Rational Heart Transplant From a Hepatitis C Donor: New Antiviral Weapons Conquer the Trojan Horse

BACKGROUND

Donors with hepatitis C (HCV) viremia are rarely used for orthotopic heart transplantation (HT) owing to post-transplantation risks. New highly effective HCV antivirals may alter the landscape.

METHODS

An adult patient unsuitable for bridging mechanical support therapy accepted a heart transplant offer from a donor with HCV viremia. On daily logarithmic rise in HCV viral load and adequate titers to ensure successful genotyping, once daily sofosbuvir (400 mg)-velpatasvir (100 mg) (Epclusa; Gilead) was initiated empirically pending HCV genotype (genotype 3a confirmed after initiation of therapy).

RESULTS

We report the kinetics of acute hepatitis C viremia and therapeutic response to treatment with a new pangenotypic antiviral agent after donor-derived acute HCV infection transmitted incidentally with successful cardiac transplantation to an HCV-negative recipient. Prompt resolution of viremia was noted by the 1st week of a 12 week course of antiviral therapy. Sustained virologic remission continued beyond 12 weeks after completion of HCV therapy (SVR-12).

CONCLUSIONS

The availability of effective pangenotypic therapy for HCV may expand donor availability. The feasibility of early versus late treatment of HCV remains to be determined through formalized protocols. We hypothesize pharmacoeconomics to be the greatest limitation to widespread availability of this promising tool.

Probability of Accurate Heart Failure Diagnosis and the Implications for Hospital Readmissions

Heart failure (HF) is a complex syndrome with inherent diagnostic challenges. We studied the scope of possibly inaccurately documented HF in a large health care system among patients assigned a primary diagnosis of HF at discharge. Through a retrospective record review and a classification schema developed from published guidelines, we assessed the probability of the documented HF diagnosis being accurate and determined factors associated with HF-related and non-HF-related hospital readmissions. An arbitration committee of 3 experts reviewed a subset of records to corroborate the results. We assigned a low probability of accurate diagnosis to 133 (19%) of the 712 patients. A subset of patients were also reviewed by an expert panel, which concluded that 13% to 35% of patients probably did not have HF (inter-rater agreement, kappa = 0.35). Low-probability HF was predictive of being readmitted more frequently for non-HF causes (p = 0.018), as well as documented arrhythmias (p = 0.023), and age >60 years (p = 0.006). Documented sleep apnea (p = 0.035), percutaneous coronary intervention (p = 0.006), non-white race (p = 0.047), and B-type natriuretic peptide >400 pg/ml (p = 0.007) were determined to be predictive of HF readmissions in this cohort. In conclusion, approximately 1 in 5 patients documented to have HF were found to have a low probability of actually having it. Moreover, the determination of low-probability HF was twice as likely to result in readmission for non-HF causes and, thus, should be considered a determinant for all-cause readmissions in this population.

New Drugs for the Treatment of Heart Failure

Angiotensin receptor-neprilysin inhibitor, Entresto® (Novartis), a combination of sacubitril and valsartan, and funny channel inhibitor of the sinoatrial node, Corlanor® (Amgen), are two new drugs that have been Food and Drug Association-approved for treatment of symptomatic heart failure patients. Their mechanisms of action differ from each other and from the heart failure drugs available prior to their approval. Reduction in mortality is the hallmark of Entresto, while reduction in hospitalizations was the common denominator of both Entresto and Corlanor. These drugs are generally well tolerated and are widely used by heart failure cardiologists. Another promising agent, omecamtiv mecarbil, a myosin activator, is currently under trials, while RLX030, a relaxin receptor agonist, did not meet primary endpoints in a study.

HeartMate II Left Ventricular Assist Device Pump Exchange: A Single-Institution Experience

Background Left ventricular assist devices (LVADs) have revolutionized the treatment of patients with end-stage heart failure. These devices are replaced when pump complications arise if heart transplant is not possible. We present our experience with HeartMate II (HMII (Thoratec, Plesanton, California, United States)) LVAD pump exchange. Materials and Methods We retrospectively reviewed all cases that required pump exchange due to LVAD complication from November 2011 until June 2016 at a single high-volume institution. The indications, demographics, and outcome were extracted and analyzed. Results Of 250 total patients with implanted HMII LVADs, 16 (6%) required pump exchange during the study period. The initial indications for LVAD placement in these patients were bridge to transplantation (n = 6 [37.5%]) or destination therapy (n = 10 [62.5%]). Fifteen patients (93.8%) required pump exchange due to pump thrombosis and 1 (6.2%) due to refractory driveline infection. Nine patients (56.2%) underwent repeat median sternotomy while a left subcostal approach was used in the remaining seven patients. Fifteen patients (93.7%) survived until hospital discharge. During the follow-up period (median, 155 days), 11 patients remained alive and 4 of these underwent successful cardiac transplantation. Conclusion HMII LVAD pump exchange can be safely performed for driveline infection or pump thrombosis when heart transplantation is not an option.

Quantifying Interparticle Forces and Heterogeneity in 3D Granular Materials

Interparticle forces in granular materials are intimately linked to mechanical properties and are known to self-organize into heterogeneous structures, or force chains, under external load. Despite progress in understanding the statistics and spatial distribution of interparticle forces in recent decades, a systematic method for measuring forces in opaque, three-dimensional (3D), frictional, stiff granular media has yet to emerge. In this Letter, we present results from an experiment that combines 3D x-ray diffraction, x-ray tomography, and a numerical force inference technique to quantify interparticle forces and their heterogeneity in an assembly of quartz grains undergoing a one-dimensional compression cycle. Forces exhibit an exponential decay above the mean and partition into strong and weak networks. We find a surprising inverse relationship between macroscopic load and the heterogeneity of interparticle forces, despite the clear emergence of two force chains that span the system.

Comparison of Characteristics of Patients Undergoing Heart Transplantation at the Same Hospital in Two Different Time Periods (1997-2012 and 2013-2015)

Heart transplantation (HT) increases at some centers each year and decreases at others. We examined characteristics of patients having HT at the same hospital in 2 different time periods (1997-2012 and 2013-2015) by 2 different surgical groups. We compared certain clinical and morphological finding in 291 patients having HT 1997 to 2012 to finding in 228 other patients having HT from 2013 to 2015. Several significant (p <0.05) differences were found: in the most recent time period (2013-2015) compared to the earlier time period (1997-2012), the mean ages of the men were older (57 years -vs- 55 years); diabetes mellitus was more frequent (37% -vs- 21%); systemic hypertension (by history) was more frequent (59% -vs- 32%); the mean body mass index was higher (29.2 kg/m(2) -vs- 26.5 kg/m(2)), and mean heart weight was lower in both men (509 g -vs- 549 g) and women (422 g -vs- 454 g). There were insignificant (p >0.05) differences in gender, frequency of massive cardiac adiposity, underlying cardiac condition, frequency of coronary heart disease, and frequency of previous insertion of a left ventricular assist device. In conclusion, certain characteristics of patients having HT at one Texas hospital changed in several respects in 2 time periods corresponding to changes in surgeons doing the HTs.

Effectiveness and Safety of the Impella 5.0 as a Bridge to Cardiac Transplantation or Durable Left Ventricular Assist Device

Many patients with end-stage heart failure require mechanical circulatory support as a temporizing measure to enable multidisciplinary assessment for the most suitable therapeutic strategy. Impella 5.0 can be used as a bridge to decision to evaluate patients for potential recovery or bridge to next therapy (bridge to heart transplantation [BTHT] or bridge to durable left ventricular assist device or VAD [BLVAD]. Our goal was to examine single-center outcomes with the Impella 5.0 device as a bridge to next therapy (BTHT or BTLVAD). Forty patients underwent Impella 5.0 support from December 2009 to December 2015 with the intent of BTHT (n = 20) or BTLVAD (n = 20). The primary end point was survival to next therapy. Secondary end points included hemodynamic assessments and in-hospital/30-day complications. All patients were inotrope-dependent, with severely depressed left ventricular ejection fraction (12%) and renal insufficiency (creatinine 2.0 mg/dl). Most were Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) 2 (66%) with biventricular failure (65%). Thirty patients (75%) survived to next therapy, including transplant (n = 13), durable LVAD (n = 15), and recovery of native heart function (n = 2). No strokes or major bleeding events requiring surgery were observed. Acute renal dysfunction, bleeding requiring transfusion, hemolysis, device malfunction, limb ischemia occurred in 13 (33%), 11 (28%), 3 (8%), 4 (10%), and 1 (3%) patients, respectively. Survival rate to discharge and/or 30 days was 68% (27 of 40). Temporary support with the Impella 5.0 allows for an effective bridge to decision strategy for hemodynamic stabilization and multidisciplinary heart team assessment of critically ill patients with heart failure. In conclusion, many of these patients can be subsequently bridged to the next therapy with favorable outcomes.

Frequency of Massive Cardiac Adiposity (Floating Heart) in the Native Hearts of Patients Having Heart Transplantation at a Single Texas Hospital (2013 to 2015) and Comparison of Various Clinical and Morphologic Variables in the Patients With Massive Versus Nonmassive Cardiac Adiposity

Body weight continues to increase worldwide due primarily to the increase in body fat. This study analyzes the frequency of massive adiposity at hearts of patients who underwent heart transplantation (HT) determined by the ability of the heart to float in a container of 10% formaldehyde (because adipose tissue is lighter than myocardium) and compares certain characteristics of those patients with and without floating hearts. The hearts studied at HT during a 3-year period (2013 to 2015) at Baylor University Medical Center were carefully "cleaned" and weighed by the same individual and tested as to their ability to float in a container of formaldehyde, an indication of severe cardiac adiposity. Of the 220 hearts studied, 84 (38%) floated in a container of formaldehyde and 136 (62%) did not. Comparison of the 84 patients with floating hearts to the 136 with nonfloating hearts showed a significant difference in ages, but a nonsignificant difference in gender, body mass index, frequency of systemic hypertension, or diabetes mellitus. The odds of a heart being a floating one was increased in patients with a diagnosis of ischemic cardiomyopathy (unadjusted odds ratio 2.12, 95% CI 1.21 to 3.70). The frequency of massive cardiac adiposity in the native hearts of patients having HT (38%) is striking and appears to have increased in frequency in the recent decades.