Negative Endomyocardial Biopsy Research Articles

(421) - The Enigma of Elevated Donor-Derived Cell-Free DNA with Negative Endomyocardial Biopsy

(421) - The Enigma of Elevated Donor-Derived Cell-Free DNA with Negative Endomyocardial Biopsy

Abnormal Global Longitudinal Strain Correlates with Amyloidogenic Light Chain-Induced Cardiac Dysfunction via Direct Myocardial Toxicity in Patients without Significant Amyloid Fibril Deposition

Introduction: Patients with advanced cardiac AL have high early mortality despite receiving effective plasma cell-directed therapies. Cardiac dysfunction is caused by direct myocardial toxicity from amyloidogenic light chains (LCs) and architectural distortion from amyloid fibril deposition. Diagnosis before significant fibril-induced cardiac dysfunction is critical for improving outcomes. While measuring cardiac biomarkers is standard for risk stratification of patients with newly diagnosed AL, serum concentrations can be impacted by fluid shifts and renal impairment, suggesting a need for complementary biomarkers. Our transcriptomic analysis highlighted dysregulation of myocardial contractility in cardiac cells exposed to amyloidogenic LCs, leading us to hypothesize that there could be clinically measurable differences in cardiac contractility (Ghosh et al., 2023). Global longitudinal strain (GLS) is a sensitive echocardiographic measure of myocardial contractility and may predict survival independent of serum cardiac biomarkers. Since LC-induced cardiac dysfunction via direct myocardial toxic effects is reversible with plasma cell-directed therapy and may represent an early cardiac insult in patients with cardiac AL, we identified and evaluated patients with LC-induced cardiac dysfunction and no clinical or echocardiographic evidence of significant cardiac amyloid fibril deposition to determine clinical features potentially associated with early cardiac AL. Methods: We analyzed the demographic, clinical, and echocardiographic features of patients with non-cardiac biopsy-proven AL amyloidosis and LC-induced cardiac dysfunction seen at the Boston University Amyloidosis Center between January 1, 2011 and March 31, 2023. Direct LC-induced cardiac dysfunction was defined as: (1) elevated cardiac biomarkers (BNP >176 pg/mL or NT-proBNP >899 pg/mL or troponin I >0.033 ng/mL, per institutional reference ranges); (2) normal echocardiographic interventricular septal thickness (<11 mm in males and <10 mm in females); (3) estimated glomerular filtration rate >60 mL/min/1.73m 2; (4) absence of late gadolinium enhancement on cardiac magnetic resonance imaging (if performed); and (5) negative endomyocardial biopsy (if performed). Echocardiographic variables, including left ventricular ejection fraction (LVEF) and GLS, were collected from the electronic health record or post-processed manually using TomTec 2D CPA. All statistical analyses were performed using GraphPad Prism version 8©. Overall survival (OS) was evaluated using the Kaplan-Meier estimator and log rank tests. Results: Twenty-nine patients met our criteria for direct LC-induced cardiac dysfunction. Median age at diagnosis was 65 years (range: 46-83), and 55% of patients (n=16) were male ( Table 1). LC isotype was lambda in 69% (n=20) and kappa in 31% (n=9) of patients. The difference in free light chains (dFLC) was >50 mg/L in 62% (n=18) of patients at diagnosis.Additionally, 76% (n=22) of patients met criteria for Boston University stage II cardiac disease with mildly elevated cardiac biomarkers (median BNP 237 pg/mL, median troponin I 0.053 ng/mL). Among 16 patients for whom a GLS measurement was available, 81% (13/16) had an abnormal GLS (normal < -18%). Median and mean GLS were -15.5% (-7 to -21.7) and -15.3% ± 4.5, respectively ( Figure 1). Median OS was 5.2 years for the entire cohort. Conclusion: We found that a subset of patients with AL amyloidosis demonstrate cardiac dysfunction without substantial clinical or echocardiographic evidence of amyloid deposition; this we postulate to be the result of direct myocardial toxic effects by amyloidogenic LCs. Early cardiac biomarker stage and abnormal GLS were commonly associated with LC-induced cardiac dysfunctionin these patients.

Abstract 17577: Cardiomyopathy With Positive ATTR Mutation but Negative Tc-PYP Scan: A Conundrum

Background: Cardiac amyloidosis (CA) is a Hypertrophic Cardiomyopathy (HCM) mimic. Technetium labeled pyrophosphate (Tc-PYP) scan provides a rapid & non-invasive means for identifying ATTR-type CA with 99% sensitivity and specificity. We present 2 patients who were referred to HCM clinic but were found to have genetic testing positive for hTTR. In both cases, Tc-PYP scan was negative. Case Presentation: Outlined in Figure 1. Discussion: Both cases present a diagnostic and management dilemma. Neither of these two patients can be strictly considered asymptomatic carriers of the ATTR gene as both had phenotypic expression in the form of cardiomyopathy & massive LVH on imaging. Yet, in both Tc-PYP scan was negative. Neither had the ATTR mutations (Phe64Leu and Val30Met) that have reported association with negative Tc-PYP scan. Another possibility is early CA, which maybe rarely associated with negative Tc-PYP scan. Patient 1 refused endomyocardial biopsy, so early CA remains on the differential for her. Patient 2 had a negative endomyocardial biopsy. Her case is unique due to history of liver transplant 20 years prior to presentation making phenotypic CA less likely, but not impossible as there have been prior reports of cardiac disease progressing even after liver transplantation in familial ATTR. She also had tacrolimus exposure, which is known to cause LVH in rare cases. Both patients had hypertension, which could have also contributed to LVH. This case series serves to highlight the importance of maintaining a broad differential diagnosis in patients undergoing evaluation for HFpEF and severe LVH, particularly in cases of positive genetic testing but negative PYP scan for CA. From a management standpoint, it is unclear if early initiation of tafamidis might have a role in preventing cardiomyopathy progression in such patients with diagnostic uncertainty & ongoing concern for early CA.

Donor-Derived Cell-Free DNA Predicts De Novo DSA after Heart Transplantation

PurposeDevelopment of de novo donor-specific HLA antibodies (dnDSA) may contribute to allograft injury and dysfunction, antibody-mediated rejection (ABMR), and potential development of cardiac allograft vasculopathy (CAV). Elevated plasma donor-derived cell-free DNA (dd-cfDNA) levels have been demonstrated during acute cellular rejection (ACR) and ABMR events after heart transplant (HT). The purpose of this study is to investigate the relationship between dd-cfDNA and subsequent DSA development.MethodsFrom the 916 HT patients enrolled in the Surveillance Heart Care Outcome Registry (SHORE), we reviewed 2136 samples of dd-cfDNA surveillance monitoring. Patients with ACR or ABMR on biopsy were excluded from analysis. The dnDSAs included HLA Class I and/or Class II epitopes and were analyzed to development of first dnDSA or last negative test, with censoring at 365 days. There were 613 DSA samples paired with dd-cfDNA levels that were obtained within 30 days of the DSA draw, with prior negative endomyocardial biopsy. Cox proportional hazards model fitting was utilized with dd-cfDNA as a covariate (p<0.05).ResultsFrom analysis of 613 paired samples, 127 (20.7%) demonstrated dnDSA with an associated median dd-cfDNA of 1.20% (IQR: 0.100 - 3.10%). 71 (11.6%) were associated with dnDSA Class I and 93 (15.2%) with Class II. When dichotomized for dd-cfDNA > 0.15%, [FIGURE] the positive likelihood ratio for development of Class I and/or Class II dnDSA (+LR) was 4.47 (p=0.03). When analyzed without censoring at 365 days, using dd-cfDNA at this cutoff, the +LR was 5.68 (p=0.02).ConclusionIn the prospective SHORE cohort, elevated dd-cfDNA levels > 0.15% were associated with increased likelihood for the subsequent development of dnDSA within the first year after heart transplantation. Development of de novo donor-specific HLA antibodies (dnDSA) may contribute to allograft injury and dysfunction, antibody-mediated rejection (ABMR), and potential development of cardiac allograft vasculopathy (CAV). Elevated plasma donor-derived cell-free DNA (dd-cfDNA) levels have been demonstrated during acute cellular rejection (ACR) and ABMR events after heart transplant (HT). The purpose of this study is to investigate the relationship between dd-cfDNA and subsequent DSA development. From the 916 HT patients enrolled in the Surveillance Heart Care Outcome Registry (SHORE), we reviewed 2136 samples of dd-cfDNA surveillance monitoring. Patients with ACR or ABMR on biopsy were excluded from analysis. The dnDSAs included HLA Class I and/or Class II epitopes and were analyzed to development of first dnDSA or last negative test, with censoring at 365 days. There were 613 DSA samples paired with dd-cfDNA levels that were obtained within 30 days of the DSA draw, with prior negative endomyocardial biopsy. Cox proportional hazards model fitting was utilized with dd-cfDNA as a covariate (p<0.05). From analysis of 613 paired samples, 127 (20.7%) demonstrated dnDSA with an associated median dd-cfDNA of 1.20% (IQR: 0.100 - 3.10%). 71 (11.6%) were associated with dnDSA Class I and 93 (15.2%) with Class II. When dichotomized for dd-cfDNA > 0.15%, [FIGURE] the positive likelihood ratio for development of Class I and/or Class II dnDSA (+LR) was 4.47 (p=0.03). When analyzed without censoring at 365 days, using dd-cfDNA at this cutoff, the +LR was 5.68 (p=0.02). In the prospective SHORE cohort, elevated dd-cfDNA levels > 0.15% were associated with increased likelihood for the subsequent development of dnDSA within the first year after heart transplantation.

P2724Diagnosis of transthyretin versus light chain cardiac amyloidosis by apical sparing strain ratio in patients with clinically suspected disease

Abstract Background Apical sparing by longitudinal strain imaging has reported utility for the diagnosis of cardiac amyloidosis. However, potential differences in the apical sparing pattern in light chain (AL) versus transthyretin (ATTR) amyloidosis in patients with high clinical suspicion for cardiac amyloidosis is not clear. Purpose Our objective was to test the hypothesis that echocardiographic strain imaging could determine differences in patients with clinically suspected AL and ATTR cardiac amyloidosis. Methods We studied 206 patients, aged 64±11, with clinically suspected cardiac amyloidosis. Routine longitudinal strain imaging analyses was performed (EchoPAC, GE Healthcare) with bulls-eye plots. After 27 exclusions (8 arrhythmia/frame rate, 19 missing/poor images), there were 179 patients. Included were 129 patients with cardiac amyloid: 42 by endomyocardial biopsy, 4 by technetium pyrophosphate scan, 65 by non-cardiac biopsy with suggestive cardiac imaging (interventricular septal thickness ≥1.2cm by echocardiography or characteristic cardiac MRI findings), 15 with multiple myeloma and suggestive cardiac imaging, and 3 by autopsy; 50 patients had a negative endomyocardial biopsy or autopsy for cardiac amyloid. The apical sparing ratio by strain imaging was calculated as the (average of apical segments) / (average of mid segments + average of basal segments). Results Cardiac amyloidosis patients were 79% with AL and 21% with ATTR. Applying the previously published apical sparing ratio cut-off of 1.0 for longitudinal strain imaging, sensitivity and specificity were 29% and 78%, respectively, for diagnosis of cardiac amyloidosis. Applying a ratio cut-off of 0.81 improved sensitivity to 72% with specificity of 64% and area under the curve (AUC) of 0.66. Positive and negative predictive values were 85% and 46%, respectively, at this ratio cut-off. The apical sparing ratio was significantly higher in AL and ATTR as compared to the biopsy negative group (p&lt;0.001). Furthermore, the apical sparing ratio was significantly higher in ATTR as compared to AL (p&lt;0.05). Apical sparing pattern and ratio Conclusions Among patients with high clinical suspicion for cardiac amyloidosis, the apical sparing ratio by echocardiographic strain imaging can demonstrate differences for AL and ATTR cardiac amyloidosis and has potential for clinical utility.

Acute Myocarditis Following Influenza Vaccine in a Heart Transplant Patient

Introduction Seasonal influenza vaccine is recommended in heart transplant patients. While it is typically well tolerated, there have been reports of low level histologic rejections . The influenza vaccine itself has been linked to inflammatory myopathies and has also been implicated in a case of myocarditis in a previously healthy individual . We present the first suspected case of myocarditis after influenza vaccine in a heart transplant patient. Case Report A 30-year-old African-American male with familial cardiomyopathy status post heart transplantation 18 months ago developed recurrent significant left ventricular dysfunction. Immediately post transplantation, he had acute graft dysfunction without evidence of acute cellular or antibody mediated rejection and negative donor specific antibodies. He received steroids, IVIG and plasmapheresis with restoration of graft function. 16 moths post-transplant, he had acute cellular rejection in the setting of subtherapeutic tacrolimus levels and was treated with pulse dose steroids with resolution. At 18 months, his EF dropped from 55-60% to 30-35% with a low cardiac index of 1.8, felt to be secondary to a non HLA antibodies given a negative endomyocardial biopsy. Pulse dose steroids resulted in recovery of his LV function by cardiac MRI (LVEF 52%). As part of his care he received the seasonal influenza vaccine. 3 weeks later he presented with dyspnea and fatigue. An echocardiogram at that time showed an ejection fraction of 35-40%. EMB was negative for rejection. A repeat cardiac MRI showed acute myocarditis. Although the EMB was negative for myocarditis, the sensitivity would have increased if a sample from the left ventricle was obtained. Summary This is the first case of a heart transplant patient with suspected acute myocarditis after receiving the influenza vaccine. Although alternative diagnoses cannot be excluded, the proximity of the vaccine and imaging evidence supports a direct correlation.

Reversal of Cardiac Allograft Dysfunction with Medical Therapy

Background Acute cellular rejection (ACR) among heart transplant recipients is common with up to 20% to 40% of patients developing an episode in the first year. Yet, stability is the norm after the first year. Late graft dysfunction is less common and can result in the need for re-transplantation. We present a case in which medical therapy was used in lieu and resulted in resolution of graft dysfunction. Case report A 48 year old man who underwent orthotopic heart transplant in July 2014 had an uncomplicated early transplant course with negative endomyocardial biopsy (EMBx) for allograft rejection through 21 months. At that time he presented with dyspnea, lower extremity swelling and excess sinus tachycardia (140 bpm). Given new heart failure symptoms, rejection evaluation was completed, including EMBx. Pathology revealed International Society for Heart and Lunt Transplantation (ISHLT) grade 2R ACR. Staining for antibody mediated rejection was negative. An echocardiogram (TTE) revealed a decline in allograft function from 70% to 40% with restrictive filling pattern. Treatment with anti-thymocyte globulin, high dose prednisone taper, plasmapheresis and bortezomib was given. Despite treatment the patient returned for heart failure hospitalization 3 months later. Right heart catheterization (RHC) showed pulmonary capillary wedge pressure of 24 mmHg, mean right atrial pressure of 12 mmHg and cardiac index of 1.9 L/min/m^2. Due to reluctance on the part of the patient to immediately consider re-transplantation, intravenous milrinone and titration of guideline-directed medical therapy was completed. Fortunately, the graft ejection fraction normalized on subsequent TTE and he was successfully weaned off milrinone over 5 months. Repeat RHC showed normal filling pressures and normal cardiac index. Conclusions Patients who develop graft dysfunction with cellular rejection may continue to experience residual graft dysfunction after treatment. Continued medical therapy with standard heart failure regimen and inotropes helped support this patient during decompensation. This case suggests the possibility of late allograft recovery with medical support and avoidance of re-transplantation. Further research is needed regarding effective medical management of graft dysfunction.

A Phase I Dose-Escalation Study of Carfilzomib in Patients with Previously-Treated Systemic Light-Chain (AL) Amyloidosis

A Phase I Dose-Escalation Study of Carfilzomib in Patients with Previously-Treated Systemic Light-Chain (AL) Amyloidosis

Novel prognostic tissue markers in congestive heart failure.

Heart failure is a relatively common disorder associated with high morbidity, mortality, and economic burden. Better tools to predict outcomes for patients with heart failure could allow for better decision making concerning patient treatment and management and better utilization of health care resources. Endomyocardial biopsy offers a mechanism to pathologically diagnose specific diseases in patients with heart failure, but such biopsies can often be negative, with no specific diagnostic information. Novel tissue markers in endomyocardial biopsies have been identified that may be useful in assessing prognosis in heart failure patients. Such tissue markers include ubiquitin, Gremlin-1, cyclophilin A, and heterogeneous nuclear ribonucleoprotein C. In some cases, tissue markers have been found to be independent of and even superior to clinical indices and serum markers in predicting prognosis for heart failure patients. In some cases, these novel tissue markers appear to offer prognostic information even in the setting of an otherwise negative endomyocardial biopsy.

Diagnosis of systemic amyloidosis and amyloidosis mediated cardiomyopathy by VATS pleural biopsy for chronic pleural effusion.

Amyloidosis is a family of diseases characterized by the extracellular accumulation of amyloid protein, causing altered physiology based on its abnormal deposition in an organ. The etiology of persistent pleural effusions in patients with systemic amyloidosis is unknown. Endomyocardial biopsy is the gold standard of diagnosis for patients with cardiac involvement in systemic amyloidosis. We present the case of a patient with systemic amyloidosis whose diagnosis was made by pleural pathology collected via video-assisted thoracic surgery after a false negative endomyocardial biopsy.

Myocardial Ischemia: Atypical Presentation of an Atrial Septal Defect in Childhood

We describe a 17-year-old male with a secundum atrial septal defect (ASD), who presented with acute myocardial ischemia. The presumptive diagnosis of a paradoxical coronary embolism was based on the demonstration of a large ASD in conjunction with normal coronary arteries, a negative endomyocardial biopsy, and a negative drug screen. After percutaneous closure with an Amplatzer device, there has been no recurrence for 2 years.

Diagnostic accuracy of antimyosin scintigraphy in suspected myocarditis

Background. Radiolabeled antibody specific for cardiac myosin administered intravenously has been used to define noninvasively regions of myocardial necrosis. Inflammatory heart disorders such as myocarditis and heart transplant rejection demonstrate diffuse and often faint myocardial uptake of antimyosin antibody. This study was undertaken to evaluate the reproducibility and diagnostic accuracy of antimyosin antibody imaging for the detection of patients with suspected myocarditis. Methods and Results. Fifty antimyosin scans, performed consecutively in patients with suspected myocarditis, were evaluated by one independent observer and two panels of observers. Antimyosin scan interpretations were compared with endomyocardial biopsy results and also with serial changes in left ventricular function. An independent observer (A) and a panel of five observers (A through E) interpreted the antimyosin scans as positive or negative on the basis of both planar images and tomographic reconstructions. Three of the five observers (A through C) again interpreted the scans but based interpretation only on planar images. Blinded random sequence evaluation of antimyosin scans based on the planar and tomographic interpretations revealed moderate agreement between the independent observer (A) and the group of observers (A through E) (κ = 0.58). There was also moderate agreement between interpretations based on planar images alone and interpretations based on both planar and tomographic images ( κ [A through E] [A through C] = 0.57; κ [A through C] A = 0.48 ). Comparison of antimyosin scan results with histologic evidence of myocarditis in endomyocardial biopsy specimens demonstrated that all scan results obtained from the individual or the panels of observers had a very high sensitivity (91% to 100%) and a high negative predictive value (93% to 100%). The specificity (31% to 44%) and positive predictive value (28% to 33%) were less impressive. We also compared the scan and biopsy results with the composite clinical standard of significant left ventricular functional improvement. Endomyocardial biopsy demonstrated poor sensitivity (35%) compared with antimyosin scans (82% to 94%) but had superior specificity (endomyocardial biopsy, 79%; antimyosin scan, 25% to 42%). The specificity of interpretations based on planar and tomographic interpretations (38% to 42%) was better than the planar images alone (25%). If reversible left ventricular dysfunction is considered clinical evidence of myocarditis, this study suggests that a negative endomyocardial biopsy significantly misses the presence of the disease. On the other hand, a negative antimyosin scan almost invariably excludes myocarditis. Conclusions. This study demonstrates a high degree of interobserver reproducibility of antimyosin interpretation. Comparison of the scintigraphic results with histologic and clinical standards indicates a high sensitivity of antimyosin scans for the detection of myocarditis. The antimyosin scan is also not likely to miss clinically or pathologically diagnosed myocarditis, in contrast to the endomyocardial biopsy, which missed clinically validated myocarditis 65% of time. The combination of high sensitivity and negative predictive value suggests that antimyosin scintigraphy may be an effective screening procedure for obviating biopsies in patients with suspected myocarditis.

Histopathologic and Molecular Profile of Human Cytomegalovirus Infections in Patients with Heart Transplants

From November 1985 to December 1990, 2,552 endomyocardial biopsy specimens from 209 heart transplant patients were studied. Forty-four (21%) patients developed 45 episodes of major human cytomegalovirus infection (HCMV). Human cytomegalovirus infection was primary in 13 of 44 patients. Thirty-one patients developed episodes of recurrent major infection. One patient had both primary and recurrent infections. Conventional histopathologic and immunohistochemical study, in situ hybridization, and polymerase chain reaction were used to diagnose HCMV myocardial involvement on corresponding endomyocardial biopsy specimens performed during infection. Conventional morphologic study showed typical viral inclusion bodies in four biopsy specimens. Two cases had myocyte HCMV localization with necrotizing myocarditis, whereas two had endothelial cell involvement without any inflammatory reaction. In these four biopsy specimens, immunohistochemistry showed a higher number of infected cells than that recognized by conventional histopathologic study. In situ hybridization detected infected cells with no evidence of cytopathic effect. Polymerase chain reaction gave HCMV amplification products in two additional biopsy specimens otherwise interpreted as moderate and mild rejection, respectively. Therefore, 6 biopsies showed HCMV myocardial involvement (6 of 45; 13.3%): all were from patients with primary HCMV infection (6 of 13; 46%). None of 32 major recurrent infections showed any myocardial involvement. In conclusion, our study is the first to demonstrate that myocardial HCMV involvement preferentially occurs in primary infection and HCMV endothelial localization can be free from inflammatory reaction, whereas HCMV myocyte localization leads to necrotizing myocarditis. Polymerase chain reaction has a higher diagnostic sensitivity than in situ hybridization. However, polymerase chain reaction findings of HCMV DNA on otherwise negative endomyocardial biopsy specimens remains of questionable significance because polymerase chain reaction-positive biopsy samples do not necessarily indicate tissue infection. It is impossible to determine whether amplified sequences derive from circulating leukocytes or from tissue cells.