Grogan, Martha

Abstract Aims Cardiac scintigraphy, a non-invasive technique for diagnosing ATTR cardiac amyloidosis, lacks specificity in patients with concomitant monoclonal gammopathy (up to 40% of cases). For these patients, amyloid type is often established by endomyocardial biopsy (EMB), which has clinical risk. This study aimed to investigate the frequency of ATTR in amyloid-positive tendon/synovium, urinary bladder, and prostate biopsies, sites for which prior biopsy specimens might exist for patients suspected of having cardiac amyloidosis, and, when available, determine the amyloid type concordance rate with other anatomic sites and provide clinical data regarding subsequent development of cardiac amyloidosis. Methods and results We queried our reference laboratory database of 19,298 amyloid specimens from myriad anatomic sites typed by mass spectrometry-based proteomics (LC-MS/MS) to investigate the frequency of ATTR amyloid in tendon/synovium, urinary bladder, and prostate. The amyloid type was ATTR in 104/138 (75.4%) tendon/synovium, 173/453 (38.0%) urinary bladder, and 27/81 (33.3%) prostate samples. Of 62 patients with available clinical data, 12 (19%) had bona fide ATTR cardiac amyloidosis prior to/concomitant with the non-cardiac site biopsy. Of the remaining 14 with follow-up, 8 developed bona fide and 2 probable cardiac amyloidosis; at last follow-up 4 had no evidence of cardiac amyloidosis. Fourteen of 16 patients (87.5%) for whom we typed both non-cardiac and cardiac sites had concordant amyloid types. There were 2 discordant cases (prostate = ASem1/heart = AL and urinary bladder = AL/heart = ATTR); only the latter is potentially clinically consequential. Conclusions In patients suspected of having cardiac amyloidosis based on cardiac scintigraphy, LC-MS/MS typing of Congophilic deposits in pre-existing biopsy specimens from non-cardiac sites may help establish the cardiac amyloid type, obviating the need for EMB. However, if the amyloid type identified in the non-cardiac site is not in keeping with other clinical features, then EMB for typing the cardiac amyloid might be indicated.

Introduction: Tafamidis meglumine, available as 20 mg capsules, is approved in >40 countries for use in early stage, symptomatic transthyretin amyloidosis with polyneuropathy. It is also approved in a growing number of countries as an 80 mg daily dose (4 x 20 mg capsules) and as tafamidis free acid 61 mg (a single dose bioequivalent to tafamidis meglumine 80 mg) for the treatment of transthyretin amyloid cardiomyopathy (ATTR-CM). As some patients receiving tafamidis meglumine 20 mg may benefit from transition to tafamidis free acid 61 mg, we assessed the hypothesis that this transition is not associated with any new safety concerns. Methods: In the Tafamidis in Transthyretin Cardiomyopathy Clinical Trial (ATTR-ACT) patients with ATTR-CM were treated with tafamidis meglumine 20 mg, 80 mg, or placebo for up to 30 months. Patients completing the trial could enroll in a long-term extension study (LTE) with placebo-treated patients randomized to tafamidis meglumine 20 mg or 80 mg. All patients in the LTE were later transitioned to tafamidis free acid 61 mg. Adverse events (AEs) emerging during the LTE were assessed in patients treated with tafamidis meglumine 20 mg in the LTE who transitioned to tafamidis free acid 61 mg (median exposure 19.8 months). AEs were compared with those emerging during ATTR-ACT in patients treated with tafamidis meglumine 20 mg (median exposure 29.7 months). Results: The 87 patients treated with tafamidis meglumine 20 mg in the LTE who transitioned to tafamidis free acid 61 mg had a similar incidence of the most common AEs by system organ class, and of specific AEs, as those treated with tafamidis meglumine 20 mg in ATTR-ACT (see Table ). The safety profile of tafamidis meglumine 20 mg was previously shown to be similar to placebo. Conclusions: While the duration of exposure to tafamidis free acid 61 mg was shorter than for tafamidis meglumine 20 mg, these data demonstrate that the transition to tafamidis free acid 61 mg is not associated with any new safety concerns.

Background: The extent of cardiac involvement has a major impact on clinical outcomes in patients with newly diagnosed light chain (AL) amyloidosis. Here, we present the hematologic responses, major organ deterioration progression-free survival (MOD-PFS) and event-free survival (MOD-EFS), and organ responses by cardiac stage in patients with newly diagnosed AL amyloidosis treated with cyclophosphamide, bortezomib, and dexamethasone (VCd) with or without daratumumab subcutaneous (DARA SC) in the ANDROMEDA trial (NCT03201965). Methods: Key eligibility criteria included newly diagnosed AL amyloidosis with measurable hematologic disease, ≥1 involved organ, cardiac stage I-IIIA (based on the European Modification of the Mayo staging system), eGFR ≥20 mL/min, and absence of symptomatic multiple myeloma. Patients were randomized (1:1) to receive DARA-VCd or VCd alone. All patients received bortezomib (1.3 mg/m2 SC weekly), cyclophosphamide (300 mg/m2 oral [PO] or intravenous [IV] weekly [500 mg maximum]), and dexamethasone (20-40 mg PO or IV weekly) for six 28-day cycles. DARA SC (1800 mg, co-formulated with recombinant human hyaluronidase PH20 in 15 mL) was administered by injection weekly in Cycles 1-2, every 2 weeks in Cycles 3-6, and every 4 weeks thereafter for up to 24 cycles. Disease evaluations occurred every 4 weeks (Cycles 1-6) and every 8 weeks (after Cycle 7) until major organ deterioration, hematologic progression, death, end of study, or withdrawal. The primary endpoint was overall (ie, at any time) hematologic complete response (CR) rate. Secondary endpoints included MOD-PFS, MOD-EFS, organ response rate, time to hematologic response, survival, and safety. Analyses of hematologic CR and MOD-PFS were performed on the intent-to-treat analysis set; cardiac response analyses were based on patients who were evaluable for cardiac response, defined as patients with baseline NT-ProNBP value ≥650 ng/L or baseline NYHA class 3 or 4 and received at least 1 administration of study treatment. Patients without a baseline assessment or post-baseline assessment were censored at randomization for the MOD-PFS analysis. Descriptive statistics were used to summarize overall CR rate and organ response rate. Hazard ratios and corresponding 95% confidence intervals were estimated based on Cox proportional hazard model. Results: A total of 388 patients were randomized to receive DARA-VCd (n=195) or VCd alone (n=193). Baseline characteristics were well balanced between treatment groups. The median age was 64 years and the proportions of patients with cardiac stage I, II, and III were 23%, 40%, and 37%, respectively. The median duration of treatment was 9.6 months for DARA-VCd and 5.3 months for VCd. Median follow-up was 11.4 months (range, 0.03-21.3+). Baseline characteristics were generally balanced across cardiac stages, except increasing cardiac stage was associated with older age (≥65 years), worse Eastern Cooperative Oncology Group performance status, more advanced renal failure (CrCl ≤30), and functionally worse heart failure (NYHA IIIA). Hematologic CR rates were higher in the DARA-VCd group than in the VCd group in patients with cardiac stages I, II, and III at baseline (Table). Cardiac and renal response rates at 6 months were also higher in the DARA-VCd group regardless of cardiac stage at baseline (Table). The hazard ratios (HRs) for MOD-PFS were 0.33, 0.55 and 0.66 for cardiac stages I, II and III, respectively, favoring DARA-VCd. Corresponding HRs for MOD-EFS were 0.24, 0.39, and 0.48, respectively. Rates of any grade adverse events (AEs) were similar in patients with and without cardiac involvement at baseline. Across both treatment arms, rates of serious treatment-emergent AEs were higher in patients with cardiac involvement at baseline than in those without. Conclusions: The benefit of DARA-VCd was retained over VCd alone across cardiac stages for hematologic CR, MOD-PFS, MOD-EFS, and organ responses. Disclosures Minnema: Kite, a Gilead Company: Speakers Bureau; Celgene: Other: travel support, Research Funding; Amgen: Consultancy; Servier: Consultancy. Dispenzieri:Alnylam: Research Funding; Intellia: Research Funding; Janssen: Research Funding; Pfizer: Research Funding; Takeda: Research Funding; Celgene: Research Funding. Comenzo:Unum: Consultancy; Prothena: Consultancy, Research Funding; Amgen: Consultancy; Sanofi: Consultancy; Caleum: Consultancy; Janssen: Consultancy, Research Funding; Karyopharm: Consultancy, Research Funding; Takeda: Consultancy, Research Funding. Kastritis:Janssen: Consultancy, Honoraria, Research Funding; Genesis Pharma: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria; Amgen: Consultancy, Honoraria, Research Funding. Wechalekar:Takeda: Honoraria, Other: Travel; Celgene: Honoraria; Janssen: Honoraria, Other: Advisory; Caelum: Other: Advisory. Witteles:Pfizer: Membership on an entity's Board of Directors or advisory committees; Alnylam Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees. Maurer:Pfizer: Membership on an entity's Board of Directors or advisory committees, Research Funding; Alnylam: Membership on an entity's Board of Directors or advisory committees, Research Funding; Ionis: Research Funding; Eidos: Research Funding; Akcea: Research Funding. Tran:Janssen: Current Employment, Current equity holder in publicly-traded company. Qin:Janssen: Current Employment. Vasey:Janssen Research & Development: Current Employment, Current equity holder in publicly-traded company. Tromp:Janssen: Current Employment, Current equity holder in publicly-traded company. Weiss:Janssen: Current Employment, Current equity holder in publicly-traded company. Vermeulen:Janssen: Current Employment, Current equity holder in publicly-traded company. Jaccard:Janssen: Consultancy, Honoraria, Other: A.J. has served in a consulting or advisory role for Janssen and has received honoraria from, received research funding from, and had travel, accommodations, or other expenses paid for or reimbursed by Janssen., Research Funding; Celgene: Honoraria, Other: A.J. has served in a consulting or advisory role for Janssen and has received honoraria from, received research funding from, and had travel, accommodations, or other expenses paid for or reimbursed by Celgene., Research Funding.

Abstract Systemic amyloidosis is a rare protein misfolding and deposition disorder leading to progressive organ failure. There are over 15 types of systemic amyloidosis, each caused by a different precursor protein which promotes amyloid formation and tissue deposition. Amyloidosis can be acquired or hereditary and can affect various organs, including the heart, kidneys, liver, nerves, gastrointestinal tract, lungs, muscles, skin and soft tissues. Symptoms are usually insidious and nonspecific resulting in diagnostic delay. The field of amyloidosis has seen significant improvements over the past decade in diagnostic accuracy, prognosis prediction and management. The advent of mass spectrometry‐based shotgun proteomics has revolutionized amyloid typing and has led to the discovery of new amyloid types. Accurate typing of the precursor protein is of paramount importance as the type dictates a specific management approach. In this article, we review each type of systemic amyloidosis to provide the practitioner with practical tools to improve diagnosis and management of these rare disorders.

The transthyretin (TTR) and immunoglobulin light chain proteins do not exist in isolation in cardiac amyloid (CA) plaques. Laser microdissection followed by mass spectrometry-based proteomic (LMD-MS) typing techniques can identify hundreds of co-deposited proteins in the "nano-environment" of amyloid deposits. Some, such as the "amyloid signature" proteins (SAP, APOE, APOA4, vitronectin, clusterin), are specific for amyloid plaques across different tissues and amyloid types. However, many of the remaining proteins are also abundant in the serum or normal tissues making it difficult to discern if they are unique to the amyloid plaque or part of the normal tissue background. We included 288 patients/samples with TTR CA (of which 53 were mutated) diagnosed by endomyocardial biopsy and 5 normal control samples obtained from 3 patients during autopsy. At the time of the meeting updated analyses including 168 cardiac light chain amyloid patients and 15 controls from patients with restrictive and hypertensive cardiomyopathy will be presented. Normalized spectral counts were used as a semi-quantitative measure of abundance. Proteins were considered part of the proteome if their abundance in the amyloid plaque was increased by 1.5-fold compared to normal controls (FDR p<0.05). Of 2240 unique proteins identified across all samples, 42 were differentially expressed in amyloid plaques. These included a) signature proteins: SAP, APOE, APOA4, vitronectin, clusterin; b) serum proteins: albumin, b2-glycoprotein, 7 complement pathway proteins; c) matrix proteins: 2 collagen isoforms, fibulin 1, decorin, PCOLCE2, TIMP3; d) cytosketal and contractile proteins: 2 actin isoforms, MYL2, 8 myosin isoforms, 3 ankyrin isofroms, desmin; and "other" proteins: serpine2, MAGE-like protein-2, pleiotrophin, AMBP, SRPX and QSOX1). The signature and cytoskeletal proteins were the most abundant overall, however, proteins that were most increased compared to normal included (log2 fold change in parentheses): fibulin (24.5), PCOLCE2 (23.5), b2-glycoprotein (23.5), factor H related peptide-2 (24.2), serpine2 (24.7), mage-like protein-2 (22.8), pleiotrophin (23.8), QSOX1 (22.9), SRPX (23.5). B2 glycoprotein was more abundant in wild type TTR samples(p=0.003). APOE (p=0.002), fibulin (p=0.008) and serpine2 (p<0.0001) were more abundant in UK stage (Gilmore JD et al, Eur Heart J 2018) 2/3 patients. Unsupervised hierarchical clustering of patients by normalized protein abundance revealed two major distinct patterns of co-deposited proteins (figure). Patients with high levels of contractility proteins (myosin isoforms, desmin, actins) were characterized by low levels of most other proteins (clusters on the left). Most complement proteins co-deposited along with higher levels of signature proteins (clusters on the right). When comparing clinical and laboratory characteristics between those 2 groups of patients only cardiac strain was found to be significantly higher (worse) in patients with lower levels of contractility proteins (p=0.01). Our data shows that the TTR CA proteome includes signature, serum and cardiac tissue proteins with variable expression according to TTR mutation status and cardiac functional status, which could inform mechanisms of disease pathogenesis. Comparison with diseased controls may further clarify if this proteomic pattern is specific to CA. Figure Disclosures Dasari: The Binding Site: Patents & Royalties: US Patent Rights on Mass Spectroscopy Licensing agreement with The Binding Site, Research Funding. Dispenzieri:Akcea: Consultancy; Intellia: Consultancy; Janssen: Consultancy; Pfizer: Research Funding; Takeda: Research Funding; Celgene: Research Funding; Alnylam: Research Funding.

Abstract Introduction Transthyretin amyloidosis (ATTR amyloidosis) is a rare, life-threatening disorder caused by the deposition of amyloid fibrils composed of misfolded transthyretin (TTR). ATTR amyloidosis may arise from mutations in TTR or from aggregation of wild-type TTR (ATTRwt). ATTR amyloidosis with predominantly symptoms of cardiomyopathy (ATTR-CM) includes both hereditary and wild-type forms of the disease. Purpose To describe clinical history and disease presentation in a large population of patients with wild-type ATTR-CM from the Transthyretin Amyloidosis Outcomes Survey (THAOS). THAOS is an ongoing, global, longitudinal, observational survey of patients with ATTR amyloidosis, including both inherited and wild-type disease, and asymptomatic patients with TTR mutations. Methods Data from ATTRwt patients were extracted from THAOS (cut-off date: January 16, 2019) and demographic and clinical characteristics reported using descriptive statistics. Results There were 758 ATTRwt patients in THAOS (95% male). The majority of patients (69.3%) were in the United States, with the remainder in Italy (11.1%), Germany (7.3%), Spain (5.3%), and other countries (7.1%). Most patients (86.3%) were Caucasian, with 3.3% being of African Descent and 3.1% being of other races/ethnicities (7.4% missing data). The median (10–90th percentile) age at symptom onset was 69.7 (54.0–81.3) years and the median (10–90th percentile) time from symptom onset to diagnosis was 3.9 (0.1–17.8) years. Median (10–90th percentile) age at enrollment in THAOS was 76.4 (67.2–85.2) years. Nearly all subjects had either a cardiac (59.6%) or mixed cardiac and neurologic (36.5%) phenotype. At enrollment, 97.1% (577 of 594 patients assessed) had an abnormal ECG, with the prevalence of low voltage being 20.8% (115 of 552) and prevalence of left-ventricular hypertrophy being 2.1% (16 of 758). Atrial fibrillation was documented in 55% of patients (208 of 378). The mean (standard deviation [SD]) left-ventricular septum thickness was 17.5 (3.5) mm (n=505; 94.9% with thickness >12 mm) and mean (SD) left-ventricular ejection fraction (LVEF) was 48.3% (13.2) (n=511; 48.0% with LVEF <50.0%). Other signs and symptoms at enrollment were compatible with a sensory neuropathy in 54.2% of patients, autonomic neuropathy in 33.5% of patients, and motor neuropathy in 29.1% of patients. Gastrointestinal symptoms related to ATTR amyloidosis were present in 10.4% of patients. Conclusions Although patients with wild-type ATTR-CM tend to be older Caucasian men with a mostly cardiac disease phenotype, the clinical spectrum of ATTRwt is heterogeneous and differs from the classic phenotype. Our findings show that ATTRwt should not be considered an exclusively cardiac disease and there is a need for both cardiologic and neurologic assessment of these patients. Further study is needed to determine if the non-cardiac manifestations are due to amyloidosis or more common causes in this older population. Acknowledgement/Funding This study was sponsored by Pfizer.

Abstract Introduction: Prognosis of AL amyloidosis has improved in recent years; however for many patients prognosis remains poor. We aimed to define patient-, disease- and treatment characteristics which are associated with long-term survival. Method: A retrospective chart review of all patients with biopsy-proven systemic AL amyloidosis, who were seen within 90 days of the confirmed diagnosis. Long-term survival was defined as 5-year and 10-year survival from the time of diagnosis. For 5-year survival we selected patients seen between January 1, 2000 and December 31, 2012 (allowing a minimum of 5-year follow-up, n=1331) and for 10-year survival we screened patients seen between January 1, 2000 and December 31, 2007 (allowing a minimum of 10-year follow-up; n=779). Treatment allocation was defined as the first regimen given, irrespective of subsequent treatment modifications. Results: Of the screening population, 498 patients survived ≥5 years from diagnosis (37% of the 5-year screening cohort) and 168 patients survived 10 years or more (22% of the 10-year screening cohort). Five-year survivors and 10-year survivors as compared to their counterparts were (Table): younger, higher proportion of women, more likely to have single organ involvement, less heart/liver/nerve involvement and more kidney involvement. Long-term survivors also had lower bone marrow plasma cell percentage at the time of diagnosis and lower tumor burden measured by the difference between involved to uninvolved light chain (dFLC). Similarly, long-term survivors had lower Mayo stages and higher systolic blood pressure. No difference in light chain isotype was observed between long-term survivors to long term non-survivors. Long-term survivors were less likely to be seen within 30 days of diagnosis compared to their counterparts (52% among 5-year survivors vs 67% among 5-year non-survivor; P<0.001). FISH abnormalities (data available for 555/1331 patients, 42%) were comparable between groups with regard to t(11;14) (50% among 5-year survival compared to 50% among 5-year non-survivors; P=0.93) and 13q abnormalities (34% vs 36%, respectively; P=0.53). However, trisomies were less frequently encountered in the 5-year survivor group (20% vs 29%, respectively; P=0.01), and far less common among 10-year survivors (11% vs 26%, respectively; P=0.04). Autologous stem cell transplantation (ASCT) was more likely to be associated with long-term survival. Of all patients who underwent ASCT, 74% survived more than 5 years and 49% survived more than 10 years. In comparison, among the standard-intensity therapies, 5-year survival rates for melphalan-dexamethasone, bortezomib-based regimens, immunomodulatory drug-based regimens and single agent dexamethasone/ melphalan-prednisone were 29%, 28%, 30% and 10%, respectively. The corresponding 10-year survival rates were 15%, 20%, 20% and 5%, respectively. Conclusions: Long-term AL survivors have distinct favorable baseline characteristics (including those introduced by referral bias) and ASCT as their initial therapy. Identification of these patients, especially the Mayo 2004 stage III and the Mayo 2012 stage III-IV patients who unexpectedly survived 10 years, will allow for further study and insights. Disclosures Gertz: Teva: Consultancy; Prothena: Honoraria; Alnylam: Honoraria; celgene: Consultancy; Ionis: Honoraria; Physicians Education Resource: Consultancy; Research to Practice: Consultancy; Amgen: Consultancy; janssen: Consultancy; Apellis: Consultancy; Medscape: Consultancy; Abbvie: Consultancy; spectrum: Consultancy, Honoraria; annexon: Consultancy. Lacy:Celgene: Research Funding. Dingli:Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.; Millennium Takeda: Research Funding; Millennium Takeda: Research Funding; Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.. Kapoor:Takeda: Research Funding; Celgene: Research Funding. Russell:Vyriad: Equity Ownership. Kumar:KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; Merck: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees; Roche: Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Oncopeptides: Membership on an entity's Board of Directors or advisory committees. Dispenzieri:Celgene, Takeda, Prothena, Jannsen, Pfizer, Alnylam, GSK: Research Funding.

Abstract Abstract 2887 Introduction: Cardiac involvement is the major cause of death in patients with immunoglobulin light chain amyloidosis (AL). Detection of cardiac involvement and risk stratification has been facilitated by cardiac biomarkers like troponin T (cTnT) and N-terminal brain natriuretic peptide (NT-proBNP). A novel high sensitivity cTnT (hs-cTnT) assay has been developed, and we evaluated its diagnostic use with three questions in mind: 1) How do the cTnT and hs-cTnT perform in the AL amyloid staging system? 2) Does higher sensitivity add significant additional value in terms of prognosticating outcomes for patients with AL amyloidosis? 3) Can the current AL amyloidosis staging system be further improved upon? Methods: Stored serum samples (-20°C) from 224 pts with AL were analyzed for concentrations of hsTnT, TnT, and NT-proBNP on the E170 Modular analyzer (Roche Diagnostics, Penzberg, Germany). 99th percentile reference limits were <0.014 and <0.010 mcg/L for hsTnT and TnT, respectively. Results: Median values for hsTnT, TnT, and NT-proBNP were 38 ng/L (range 0–075.4), 0.017 mcg/L (<0.0–0.904), and 1230 ng/L (0–32, 226), respectively. The correlation coefficient between hsTnT and TnT was 0.972. Those classified by echocardiographic parameters as having (n=143) or not having (n=81) cardiac involvement had TnT concentrations of 0.04 and 0.01 mcg/L and hsTnT levels of 52.2 and 15.6 ng/L, respectively. The direct numeric result from the hs-cTnT result CANNOT merely be substituted for a cTnT result in the Mayo AL staging system since 14% of patients would be misclassified. The performance of the receiver operation curve derived hs-cTnT cut-point of 54 ng/L is a slight improvement over the direct substitution of 35 ng/L if replacement of one assay for another is required. An alternate staging option using hs-cTnT alone—using the two thresholds14 ng/L and 54 ng/L (figure)—performs as well as either the original Mayo AL staging system or a derivative system incorporating hs-cTnT with respective relative risks of death (95%CI) of 3.6 (2.3, 5.7), 3.8 (2.5, 5.9), and 3.3 (2.2, .50). On multivariate analysis, our newly described alternate 3 level, hs-cTnT alone staging system is independent of other factors including period of diagnosis, type of therapy, and NT-proBNP value, the last of which dropped out of the model. Alternate models using NT-proBNP and cTnT were explored, but none performed better than the original staging system or the new hs-cTnT system. Conclusion: The direct numeric result from the hs-cTnT result cannot merely be substituted for a cTnT result in the Mayo amyloid staging system. Consideration could be made for AL staging systems using hs-cTnT alone and relegating the NT-proBNP for measuring cardiac response. Disclosures: Jaffe: Roche: Consultancy.

Abstract Background: Amyloidosis is a multisystem disease with extracellular deposition of pathological insoluble beta-fibrillar proteins. Involvement of the heart is seen in more than one-half of the patients with systemic AL amyloidosis and it is the most important determinant of clinical outcome. Cardiac amyloidosis is a restrictive infiltrative cardiomyopathy in which, despite declines in stroke volume that accompany disease progression, the ejection fraction (EF) often remains preserved even in advanced stages of the disease. King et al. proposed a novel index of myocardial function, the myocardial contraction fraction (MCF), defined as the ratio of stroke volume (SV) to myocardial volume (MV). MCF is a measure of myocardial shortening, which differentiated myocardial performance in patients with similar degrees of hypertrophy and in a recent small cohort of AL amyloidosis patients appeared superior to left ventricular ejection fraction (EF) in predicting overall survival (OS). It was our goal to assess the prognostic role of MCF in a large cohort of patients with AL amyloidosis in the context of other prognostic variables. Methods: Patients seen between 4/1/1999 and 2/1/2015 were eligible for this retrospective study if they had an ECHO at the Mayo Clinic, Rochester, MN within 30 days of their AL amyloidosis diagnosis with measurements of left ventricular chamber size and wall thickness needed to calculate MCF, EF, and the presence or absence of pericardial effusion. To capture the full cohort, modeling was done first excluding Mayo (2012) staging and global averaged left ventricular longitudinal peak systolic strain (LV strain) since limited numbers of patients had these studies, 342 and 294, respectively. Thresholds of continuous variables were chosen based on receiver operator curves targeting death at 1-year. Cox proportional hazards analysis was used to identify factors that were prognostic for OS. Statistical analyses were done using JMP 9.0 (SAS, Cary, NC). Results: Among the 722 patients satisfying entry criteria,median age was 64 years (range 32-94) and 66% were male. The best cutoff for MCF was 21% (sensitivity: 74%, specificity: 60%; AUC=0.699) and distinguished two groups with different OS (median 53 vs. 9 months, P<0.0001; Figure). On univariate analysis the baseline ECHO variables predicting OS were interventricular septum thickness (IVS) >12 mm (RR 1.8, P=0.0002), EF <60% (RR 1.7), MCF ≤21% (RR 2.1), and presence of pericardial effusion (RR 2.0), all with P<0.0001. On multivariate MCF ≤21% (RR 1.6, P <0.0001), EF <60% (RR 1.4, P=0.0007) and the presence of pericardial effusion (RR 1.3, P=0.002) were independent predictors of OS. Additional modeling was done with the subset of 342 patients who were assessable for Mayo (2012) staging, (i.e. measurements of immunoglobulin free light chain, NT-proBNP, and troponin T). On univariate analysis, patients with a Mayo (2012) stage ≥ 3 had a RR 2.1, p<0.0001. On multivariate, only MCF ≤21% (RR 1.5, P =0.01), Mayo (2012) stage ≥ 3 (RR 1.5, P=0.01) and EF<60% (RR 1.7, P=0.0006) were independent prognostic determinants. Finally, we addressed LV-strain among the 294 patients in whom the study was performed. There was a significant correlation between MCF and LV strain (rho =-0.86, P<0.0001). On univariate, LV-strain less negative than -13 generated a RR of 2.3, p<0.0001. In contrast to the model containing MCF, on LV-strain multivariate, EF was no longer significant, but LV-strain less negative than -13 (RR 2.0, P=0.008) and Mayo (2012) stage ≥ 3 (RR 2.0, P=0.008) predicted independently OS. Conclusions: MCF ≤21% identified a subgroup of patients with a high mortality risk, and it was independent of the Mayo (2012) staging but highly correlated with LV strain. An advantage of MCF, which is a novel volumetric measurement of the left ventricular chamber, is that, unlike LV-strain, MCF is simple to calculate from routine ECHO measures. Figure 1. Overall survival of 722 patients according to MCF<21%. Figure 1. Overall survival of 722 patients according to MCF<21%. Disclosures Kumar: AbbVie: Research Funding; Celgene: Research Funding; Janssen: Research Funding; Skyline, Noxxon: Honoraria; Celgene, Millenium, Sanofi, Skyline, BMS, Onyx, Noxxon,: Other: Consultant, no compensation,; Sanofi: Research Funding; Millenium/Takeda: Research Funding; Onyx: Research Funding.

Abstract Introduction Although peripheral neuropathy and cardiomyopathy are well‐recognized manifestations of transthyretin (ATTR) amyloidosis, myopathy has been rarely reported. Methods In this study we reviewed our muscle biopsy database (January 1998 to June 2018) to identify patients with ATTR amyloid myopathy confirmed by molecular or proteomic analysis. Clinical and laboratory findings were reviewed. Results We identified eight ATTR amyloid myopathy patients (5 hereditary ATTR [ATTRv] and 3 wild‐type ATTR [ATTRwt]). Myopathy was the initial manifestation in all ATTRwt patients and followed peripheral neuropathy (4 patients) or cardiomyopathy (1 patient) in ATTRv patients. One ATTRv patient developed myopathy after liver transplant. Peripheral neuropathy and cardiac amyloidosis occurred in seven and six patients, respectively. Muscle biopsy showed interstitial amyloid deposition in all patients, rare necrotic/regenerating fibers in six, and vacuoles in four. Discussion Myopathy can be the initial manifestation of ATTRwt amyloidosis and can precede the peripheral neuropathy or occur after liver transplant in ATTRv amyloidosis.