Cardiac amyloidosis: a practical approach to diagnosis and management

Cardiac amyloidosis, the primary determinant of prognosis in systemic amyloidoses, is characterized by infiltration of myocardium by amyloid protein resulting in cardiomyopathy and conduction disturbances. Cardiac involvement is primarily encountered in immunoglobulin (AL) and transthyretin-associated (hereditary/familial and senile) amyloidoses. Although the latter variants could be indolent, untreated AL amyloidosis with clinical cardiac involvement is a rapidly fatal disease. The management decisions of cardiac amyloidosis are based on the underlying cause. Although treatment of senile systemic amyloidosis is largely supportive, the therapeutic approaches for AL amyloidosis include chemotherapy, autologous stem cell transplantation, and, rarely, cardiac transplantation. The familial variant is potentially curable with a liver ± cardiac transplantation. This narrative review outlines a practical approach to these challenging diagnoses in the face of rapidly evolving management strategies.     

Reduced intensity allogeneic stem cell transplantation for systemic primary amyloidosis refractory to high-dose melphalan

Complete elimination of the plasma cell dyscrasia is a rational therapeutic goal, as intercepting supply of precursor protein is a necessary condition for a major regression of amyloid deposits. High-dose melphalan with autologous stem cell transplantation has shown the ability to induce complete hematological response (HR) along with recovery of organ dysfunction. However, the rate of HR with this treatment rarely exceeds 40%. We describe here the first known case of successful reduced intensity allogeneic stem cell transplantation (RIST) for a patient with primary amyloidosis complicated with nephrotic syndrome but without cardiac disease, who had obtained only partial HR by high-dose melphalan with autologous stem cell transplantation. RIST may be feasible and be capable of achieving complete HR along with recovery from nephrotic syndrome with acceptable toxicity.     

Orthotopic Heart Transplant Facilitated Autologous Hematopoietic Stem Cell Transplantation in Light-Chain Amyloidosis

Initial manifestations of light-chain amyloidosis (AL) are variable and often result in missed or delayed diagnosis. Survival in AL patients depends mainly on the severity of cardiac involvement. Dominant stage-III cardiac involvement due to primary systemic amyloidosis precludes effective AL treatment and is associated with an average survival of only 3–4 months. The following paper discusses the benefits of orthotopic heart transplantation and autologous hematopoietic stem cell transplantation to improve survival in patients with progressive cardiac AL.     

Sequential heart and autologous stem cell transplantation for systemic AL amyloidosis

Extensive cardiac amyloid deposition in systemic AL amyloidosis is associated with a grave prognosis. Heart transplantation is rarely performed because of the systemic and progressive nature of the disease. Patients with severe cardiac amyloid infiltration are ineligible for the preferred treatment of melphalan chemotherapy with stem cell transplantation (SCT) rescue because of the high risk for treatment-related mortality. Heart transplantation followed by SCT was performed in 5 patients with AL amyloidosis and predominant cardiomyopathy. Patients were followed up for a median of 95 months (range, 37-118 months) from diagnosis. At censor, 3 of 5 patients were well without evidence of intracardiac or extracardiac amyloid accumulation, and median overall survival by Kaplan-Meier estimate was not reached. Two patients died of progressive amyloidosis 33 and 90 months after heart transplantation after relapse of their underlying plasma cell dyscrasia. Heart transplantation followed by SCT is feasible in selected patients with cardiac AL amyloidosis and may confer substantial survival benefit.     

Heart Transplantation and End-Stage Cardiac Amyloidosis: A Review and Approach to Evaluation and Management

Cardiac amyloidosis is one of the most common of the infiltrative cardiomyopathies and is associated with a poor prognosis. The extent of cardiac involvement with amyloid deposition is an important determinant of treatment options and is the major determinant of outcome in patients with amyloidosis. Several small case series with sequential orthotopic heart transplantation and autologous stem cell transplant have demonstrated an improvement in post-transplant outcome and have revived enthusiasm about heart transplantation for patients with end-stage heart failure due to AL amyloidosis. The purpose of this review is to summarize the evaluation and management of cardiac amyloidosis and to provide our single-center experience with end-stage heart failure due to AL amyloidosis treated with heart transplantation followed by an autologous stem cell transplant.     

An overview of high-dose melphalan and stem cell transplantation in the treatment of AL amyloidosis.

AL amyloidosis is the most common form of systemic amyloidosis and is associated with an underlying plasma cell dyscrasia. This review outlines an overview of high-dose intravenous melphalan and stem cell transplantation in the treatment of AL amyloidosis. An algorithm of our recommendations for the treatment of AL amyloidosis is also outlined.     

An overview of high-dose melphalan and stem cell transplantation in the treatment of AL amyloidosis

AL amyloidosis is the most common form of systemic amyloidosis and is associated with an underlying plasma cell dyscrasia. This review outlines an overview of high-dose intravenous melphalan and stem cell transplantation in the treatment of AL amyloidosis. An algorithm of our recommendations for the treatment of AL amyloidosis is also outlined.     

Improvement of cardiac diastolic function and prognosis after autologous peripheral blood stem cell transplantation in AL cardiac amyloidosis

AL amyloidosis is a disease in which immunoglobulin L chain is deposited in multiple organs, and the prognosis of cardiac amyloidosis is extremely poor. Although several treatments based on that for multiple myeloma, have been performed, there is no clear evidence that cardiac function is improved. We report a case of AL cardiac amyloidosis with moderate cardiac dysfunction for which we performed autologous peripheral blood stem cell transplantation (auto-PBSCT) in combination with high-dose melphalan therapy. This treatment resulted in significant improvement in cardiac function and good prognosis for about 3.5 years after the diagnosis. Therefore, auto-PBSCT is a possible option as up-front therapy for AL cardiac amyloidosis.     

Cardiac Amyloidosis: Evolving Approach to Diagnosis and Management

The systemic amyloidoses are a group of heterogeneous disorders characterized by extracellular deposition of misfolded fibrillar protein that results in organ dysfunction. Involvement of the heart (cardiac amyloidosis) is manifest by increased cardiac wall thickness and impairment of myocardial diastolic and systolic properties, changes that result in heart failure, dysrhythmia, and death. Amyloidosis is classified by precursor protein, with light-chain (AL) and transthyretin (TTR) disease being most common in the United States. TTR amyloid can result from misfolding of variant TTR, a genetically inherited disease, or wild-type TTR, an acquired form of disease (termed senile systemic amyloidosis). In recent years, advances in the diagnosis and treatment of cardiac amyloidosis include identification and validation of disease biomarkers, new imaging techniques, and consensus treatment guidelines. Elevations of B-type natriuretic peptide and cardiac troponins can identify cardiac amyloidosis with a high degree of precision and confer important prognostic information. Non-invasive cardiac imaging techniques, such as cardiac magnetic resonance imaging and echocardiography with strain quantification, afford the ability to diagnose cardiac amyloidosis most often without the need for a confirmatory heart biopsy. Treatment of heart failure resulting from cardiac amyloidosis differs in many respects from most other etiologies of cardiomyopathy. The mainstay of treatment involves volume control with diuretics, low dose β-adrenergic antagonists or amiodarone for dysrhythmia, and warfarin to prevent thromboembolism. Although widely held to have a dismal prognosis, modern treatments such as high-dose melphalan with stem cell transplantation (HDM/SCT) for AL disease achieve a complete hematologic response in nearly half of eligible patients and yield long-term survival. For patients with advanced AL cardiac amyloidosis, cardiac transplantation followed by HDM/SCT is also an option that has proven highly effective. For familial amyloid derived from variant TTR, liver transplantation is the one validated treatment; however, small molecule therapeutic agents now in clinical trials appear capable of slowing or halting TTR amyloid deposition.     

Successful heart transplantation following melphalan plus dexamethasone therapy in systemic AL amyloidosis

Recurrence in the allograft and progression in other organs increase mortality after cardiac transplantation in AL amyloidosis. Survival may be improved after suppression of monoclonal light chain (LC) production following high dose melphalan and autologous stem cell transplantation (HDM/ASCT). However, because of high treatment related mortality, this tandem approach is restricted to few patients without significant extra-cardiac involvement. A diagnosis of systemic AL amyloidosis was established in a 45-year old patient with congestive heart failure related to restrictive cardiomyopathy, nephrotic syndrome, peripheral neuropathy, postural hypotension, macroglossia, and lambda LC monoclonal gammopathy. After melphalan and dexamethasone (M-Dex) therapy, which resulted in 80% reduction of serum free lambda LC, he underwent orthotopic cardiac transplantation. Two years later, he remains in a sustained hematologic remission, with no evidence of allograft or extra-cardiac amyloid accumulation. M-Dex should be considered as an alternative therapy in AL amyloid heart transplant recipients ineligible for HDM/ASCT.     

Immune reconstitution following reduced-intensity transplantation with cladribine,busulfan, and antithymocyte globulin: serial comparison with conventional myeloablative transplantation

The primary object of the conditioning regimen for allogeneic reduced-intensity stem cell transplantation (RIST) is immunosuppression to achieve stable engraftment of donor cells, rather than bone marrow ablation. Therefore, immune reconstitution after RIST might be different from that after conventional stem cell transplantation (CST). In this study, 22 patients underwent RIST and 28 underwent CST. The RIST regimen consisted of cladribine (2-CdA; 0.11 mg/kg/day for 6 days), BU (4 mg/kg/day for 2 days), and rabbit anti-thymocyte globulin (ATG; 2.5 mg/kg/day for 2-4 days). The CST group received either the BU (4 mg/kg/day x 4 days)/CY (60 mg/kg/day x 2 days) (n=13) or CY (60 mg/kg/day x 2 days)/TBI (4 Gy/day x 3 days) regimen (n=15). All patients underwent transplantation with G-CSF-mobilized blood stem cells. Engraftment speed after RIST was fast and seven of 22 patients did not require platelet transfusion. We noted that the numbers of CD4+, CD4+CD45RA+, and CD4+CD45RO+ T cells after transplant in the RIST group were significantly lower than those in the CST group (P=0.0001 for both the comparisons). However, the reconstitution of CD20+ B cells was faster in the RIST group (P=0.0001). The response of T cells to PHA stimulation was lower in the RIST group (P=0.0001 on day 30 and P=0.02 on day 90). Nevertheless, there were no significant differences in the incidence of bacterial, fungal, or viral infections between the two groups. We concluded that our RIST regimen might delay laboratory-evaluated T-cell immune reconstitution compared to CST; however, the observed setbacks did not directly translate into clinically significant increases in infectious episodes.     

Allogeneic and autologous transplantation for haematological diseases,solid tumours and immune disorders: definitions and current practice in Europe

The Accreditation Sub-Committee of the EBMT regularly publishes special reports on current practice of haemopoietic stem cell transplantation for haematological diseases, solid tumours and immune disorders. Major changes have occurred since the last report in 1998. Haemopoietic stem cell transplantation today includes allogeneic and autologous stem cells derived from bone marrow, peripheral blood and cord blood. With reduced intensity conditioning regimens in allogeneic transplantation, the age limit has increased, permitting the inclusion of older patients. New indications have emerged, such as autoimmune disorders and AL amyloidosis for autologous, and solid tumours for allogeneic transplants. Other indications, such as autologous transplantation for breast cancer have been challenged. An updated report with revised tables and operating definitions is presented here.     

Suspected delayed immune recovery against cytomegalovirus after reduced-intensity stem cell transplantation using anti-thymocyte globulin

A reduced-intensity hematopoietic stem cell transplantation (RIST) regimen was developed to induce immunosuppression to facilitate the engraftment of donor cells. However, there have been concerns that the incidence of opportunistic infection may increase after this procedure. To address this problem, we retrospectively analyzed the medical records of 24 RIST recipients who were treated over a recent 16-month period for comparison with 31 recipients of conventional allogeneic transplantation (CST). The RIST regimen consisted of cladribine (0.66 mg/kg), busulfan (8 mg/kg), and rabbit anti-thymocyte globulin (ATG; 5-10 mg/kg). All of the patients received allogeneic peripheral blood stem cells from an HLA-identical or one-locus mismatched related donor. Although the incidence of positive CMV antigenemia was comparable between the two groups (58% vs 68%), RIST patients developed positive antigenemia significantly sooner than did CST patients (P = 0.01) and showed higher initial and maximum antigenemia values (P = 0.026 and P = 0.003, respectively). These findings may suggest that immune recovery against CMV was delayed after our RIST procedure, but this did not directly translate into an increase in clinically significant CMV disease. Early therapeutic intervention with ganciclovir might play a role in preventing the progression of early CMV infection to CMV disease.     

Cyclophosphamide-bortezomib-dexamethasone (CyBorD) produces rapid and complete hematologic response in patients with AL amyloidosis

Cyclophosphamide, bortezomib, and dexamethasone (CyBorD) is highly effective in multiple myeloma. We treated patients with light chain amyloidosis (AL) before stem cell transplantation (ASCT), instead of ASCT in ineligible patients or as salvage. Treatment was a combination of bortezomib (1.5 mg/m2 weekly), cyclophosphamide (300 mg/m2 orally weekly), and dexamethasone (40 mg weekly). Seventeen patients received 2 to 6 cycles of CyBorD. Ten (58%) had symptomatic cardiac involvement, and 14 (82%) had 2 or more organs involved. Response occurred in 16 (94%), with 71% achieving complete hematologic response and 24% a partial response. Time to response was 2 months. Three patients originally not eligible for ASCT became eligible. CyBorD produces rapid and complete hematologic responses in the majority of patients with AL regardless of previous treatment or ASCT candidacy. It is well tolerated with few side effects. CyBorD warrants continued investigation as treatment for AL.     

Allogeneic stem-cell transplantation with reduced conditioning intensity as a novel immunotherapy and antiviral therapy for adult T-cell leukemia/lymphoma

Sixteen patients with adult T-cell leukemia/lymphoma (ATL) who were all over 50 years of age underwent allogeneic stem cell transplantation with reduced-conditioning intensity (RIST) from HLA-matched sibling donors after a conditioning regimen consisting of fludarabine (180 mg/m2), busulfan (8 mg/kg), and rabbit antithymocyte globulin (5 mg/kg). The observed regimen-related toxicities and nonhematologic toxicities were all found to be acceptable. Disease relapse was the main cause of treatment failure. Three patients who had a relapse subsequently responded to a rapid discontinuation of the immunosuppressive agent and thereafter achieved another remission. After RIST, the human T-cell leukemia virus type 1 (HTLV-1) proviral load became undetectable in 8 patients. RIST is thus considered to be a feasible treatment for ATL. Our data also suggest the presence of a possible graft-versus-ATL effect; an anti-HTLV-1 activity was also found to be associated with this procedure.     

Newer Therapies for Amyloid Cardiomyopathy

The heart and the kidneys are the most commonly involved organs in systemic amyloidosis. Cardiac involvement is associated with an increased morbidity, treatment intolerance, and poorer overall survival. The most common types of amyloidosis that are associated with cardiac involvement include light chain (AL) amyloidosis and transthyretin (TTR) amyloidosis (both mutant and wild type). The traditional first-line treatment for AL amyloidosis includes alkylator-based chemotherapy or high-dose melphalan followed by autologous stem cell transplantation (ASCT). Novel agents, including proteasome inhibitors, immunomodulators, and monoclonal antibodies, have shown promising activity in both frontline and relapsed settings. Orthotopic heart transplantation (OHT) followed by ASCT has led to superior outcomes compared to OHT alone. Orthotopic liver transplantation (OLT) is the first-line treatment for TTR amyloidosis. However, progression of cardiac amyloidosis after OLT is often noted due to deposition of wild TTR. Combined OLT and OHT also has a role in treatment and leads to superior outcomes in carefully selected candidates. Pharmacologic agents, including diflunisal, tafamidis, small interfering ribonucleic acid, and doxycycline, have shown promising activity in stabilizing TTR from misfolding into fibrils and are being actively investigated. Best supportive care and management of heart failure symptoms with diuretics are a mainstay of treatment in all cardiac amyloidosis subtypes. Robust data on the benefit of angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, or beta blockers in amyloid cardiomyopathy is lacking.     

Allogeneic and autologous transplantation for haematological diseases, solid tumours and immune disorders: definitions and current practice in Europe

The Accreditation Subcommittee of the EBMT regularly publishes special reports on current practice of haemopoietic stem cell transplantation for haematological diseases, solid tumours and immune disorders in Europe. Major changes have occurred since the first report was published in 1996. Haemopoietic stem cell transplantation today includes grafting with allogeneic and autologous stem cells derived from bone marrow, peripheral blood and cord blood. With reduced intensity conditioning regimens in allogeneic transplantation, the age limit has increased, permitting the inclusion of older patients. New indications have emerged such as autoimmune disorders and AL amyloidosis for autologous, and solid tumours for allogeneic transplants. The introduction of alternative therapies has challenged well-established indications such as imatinib for chronic myeloid leukaemia. An updated report with revised tables and operating definitions is presented here.     

Autologous transplantation for primary systemic AL amyloidosis is feasible outside a major amyloidosis referral centre: the Calgary BMT Program experience

Recent reports from large amyloidosis referral centers suggest that primary systemic AL amyloidosis patients treated with high-dose melphalan (HDM) and autologous stem cell transplantation (ASCT) survive longer than historical controls treated with less intensive chemotherapy, despite high transplant-related mortality (TRM) rates of >10%. A retrospective review was conducted to determine if the outcome of ASCT for AL amyloidosis at our institution was similar to that reported at major amyloidosis referral centers. Over a 7 year period, we treated a total of 15 AL amyloidosis patients with ASCT, including four with poor prognosis cardiac or multisystem involvement. No TRM was observed. Overall, 10 patients (67%) achieved a complete hematological response and four patients (27%) achieved a complete organ response. The 4-year event-free and overall survival rates were 60% (95% CI 32-89%) and 75% (95% CI 50-100%), respectively. One patient, who presented with cardiac failure and multiorgan involvement with colonic bleeding currently remains in complete remission 62 months post-ASCT. In conclusion, ASCT for primary AL amyloidosis can safely be performed at experienced transplant centers that are not associated with major amyloidosis referral centers, and is feasible for patients who have multisystem involvement, particularly for motivated patients with good performance status.     

Autologous stem cell transplantation for primary systemic amyloidosis

High-dose melphalan with autologous blood stem cell transplantation (SCT) can reverse the disease process in selected patients with primary systemic amyloidosis (AL); however, SCT for AL remains controversial because of the treatment-related mortality in patients with cardiac and multisystem organ involvement. In this review, we briefly discuss recent advances in AL, such as the free light-chain assay and the role of immunoglobulin light-chain variable region germline genes in the disease, and then we discuss the current status of SCT for AL with emphases on patient selection, approaches to stem cell mobilization, and peri-SCT management. It is clear that patients with AL who have advanced amyloid cardiomyopathy or more than 2 major viscera involved with disease are poor candidates for SCT. Therefore, the importance of patient selection cannot be overemphasized, and patients with 1 or 2 involved organs or with early cardiac involvement are usually appropriate candidates for SCT. Because the toxicity of melphalan is dose-related and survival with AL may be age-related, patient age and the extent of organ involvement can provide a basis for patient stratification. We discuss such a risk-adapted approach to melphalan dosing in detail and conclude with a brief overview of current research using SCT to treat patients with AL.     

Clinical analysis of autologous stem cell transplantation for nine cases of cardiac amyloidosis

Long-term survival remains poor for patients with cardiac amyloidosis. High-dose melphalan (MEL) with stem cell transplantation (HDM/SCT) is an effective treatment for AL amyloidosis, but patients with cardiac involvement are ineligible because of high therapy-related mortality. Here we report detailed HDM/SCT outcomes of 9 patients with cardiac failure. Their median age was 56 years (range, 45～66). After a median follow-up of 15 months (range 9～32), three died of multiorgan failure within the early phase after HDM/SCT, and the other six including poor risk patients are alive at present. Their symptoms of cardiac decompensation have improved. Decreases in interventricular septum thickness were confirmed in 4 patients 6～12 months after HDM/SCT by echocardiography. One-year overall survival rate was 67%, longer than previously reported rates. HDM/SCT may lead to improvements in quality of life and extended survival in cardiac amyloidosis patients. Meanwhile, the median dosage of MEL in our procedure was 103 mg/m(2) (range 68～180), less than the recommended dose, and patients were maintained on miscellaneous therapies. Further studies are required to clarify an effective MEL dose and to refine selection criteria for patients undergoing HDM/SCT.