Clinical implications of gastrointestinal symptoms in systemic amyloidosis

BACKGROUND

Gastrointestinal (GI) symptoms in systemic amyloidosis patients are poorly characterized. This purpose of this study is to define the epidemiology and clinical implications of such symptoms.

METHODS

This was a retrospective cohort study of 583 amyloid patients seen at a tertiary referral center. Of 96 symptomatic patients, 82 received endoscopic biopsies, subsequently grouped into those with histologic evidence of GI amyloid (biopsy proven) vs without (biopsy absent).

KEY RESULTS

16.8% of patients had GI symptoms, and had more abnormal NT-proBNP, cardiac ejection fraction, serum albumin, and alkaline phosphatase (P < .01). Of those who received endoscopy, the sites of highest diagnostic yield were stomach, duodenum and colon. The most common symptom was abdominal pain, nausea, or vomiting (50.0%). Of the symptomatic patients, only 37 (45%) had biopsy proven GI amyloid. Biopsy proven patients more often had cardiac involvement (P < .005), and more often received hematologic therapy or transplant (P = .01). Biopsy absent patients had more frequent neurologic involvement (P = .17). Biopsy status had no significant correlation with other indicators of amyloid burden, GI symptoms or management.

CONCLUSIONS & INFERENCES

Nearly one in six amyloid patients have GI symptoms, and half do not have GI amyloid. The type of symptom does not predict endoscopic findings. Most biopsy absent patients are not managed as a functional disorder despite no alternative etiology. Gastroenterologists may have an increased role to play in the care of systemic amyloidosis beyond performing endoscopies, such as evaluating cardiac amyloid patients for concurrent GI amyloid.

Outcomes after heart transplantation for amyloid cardiomyopathy in the modern era

We conducted a review of patients undergoing heart transplantation (HT) at our institution for amyloid cardiomyopathy (ACM) between 2008 and 2013. Complete follow-up was available for all patients. Nineteen patients with ACM underwent HT during the study period, accounting for 9.4% of all HT performed at our institution during this period. Amyloid subtype was light chain (AL) in 9 patients and transthyretin (ATTR) in 10 (2 wild-type, 7 familial, 1 unknown). Eight of nine patients with AL amyloidosis began chemotherapy prior to HT, six have resumed chemotherapy since HT, and five have undergone autologous stem cell transplantation. Most recent free light chain levels in AL patients decreased by a median of 85% from peak values. Only one patient developed recurrent graft amyloidosis, occurring at 3.5 years post-HT and asymptomatic. After a median follow-up of 380 days, 17 (89.5%) patients are alive. To our knowledge, this is the largest single-center series reported of ACM patients undergoing HT in the modern era. Our results suggest that acceptable outcomes following HT can be achieved in the short-to-intermediate term and that this is a feasible option for end-stage ACM with careful patient selection and aggressive control of amyloidogenic light chains in AL patients.

Prospective cardiotoxicity screening during tyrosine kinase inhibitor therapy for renal cell carcinoma: An institutional experience

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Background: Tyrosine kinase inhibitors (TKI) can lead to cardiotoxicity either directly by causing left ventricular dysfunction, or indirectly by increasing blood pressure. In light of prior studies at our institution documenting a high rate of symptomatic heart failure in patients with renal cell carcinoma undergoing treatment with sunitinib, we instituted a prospective screening protocol to characterize the incidence and natural history of TKI-associated cardiotoxicity. Methods: From March-December 2008, patients receiving TKI therapy for renal cell carcinoma received cardiac biomarker screening (NT- BNP and Troponin I at baseline and after week 4 of each cycle) and transthoracic echocardiography (baseline, 1 month, 3 months, and every 3 months thereafter). If biomarkers were elevated or a decline in ejection fraction was observed, patients were referred for cardiology evaluation. Results: Twenty-six patients have been included since the protocol's initiation. No elevations in cardiac troponin I have been observed to date. Eight patients (31%) had elevations in NT-BNP (a sensitive marker for heart failure). The TKIs involved included sunitinib (5 patients), sorafenib (2 patients), and bevacizumab (1 patient). One patient who was treated with sunitinib had frank left ventricular systolic dysfunction. Seven of the eight patients with elevated NT-BNP values had baseline hypertension, and five patients had significant increases in blood pressure during TKI treatment. In all patients with follow-up biomarkers, NT-BNP levels fell after initiation of heart failure therapy. TKI treatment appeared to ‘unmask’ previously subclinical cardiac injury, including prior silent myocardial infarction (one patient), left ventricular hypertrophy (four patients), and valvular disease (three patients). Updated data from the ongoing screening protocol will be presented. Conclusions: The Stanford TKI screening protocol identified a high rate of subclinical cardiotoxicity and allowed for early initiation of heart failure therapy. Further studies are needed to determine if this approach can decrease cardiac morbidity and improve oncologic outcomes by preventing discontinuation or dose interruption of TKI therapy.

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Left ventricular dysfunction in patients receiving cardiotoxic cancer therapies: Are clinicians responding appropriately?

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Background: Cancer survivors treated with anthracyclines and/or trastuzumab are at risk for cardiotoxicity. Left ventricular (LV) systolic dysfunction (symptomatic or asymptomatic) represents a Class I indication for therapy with beta-blockers and angiotensin-converting enzyme inhibitors (ACE-I) or angiotensin receptor blockers (ARB) according to American College of Cardiology/American Heart Association heart failure guidelines. We designed this study to examine treatment practices for patients with cancer therapy-associated LV dysfunction, and the real-world adoption of treatment guidelines. Methods: After IRB approval, we identified all patients who received anthracycline and/or trastuzumab cancer therapy at Stanford University from October 1, 2005 to October 31, 2007 using an institutional pharmacy database. Out of 6,530 total cycles of chemotherapy administered, we identified all unique patients who had at least one echocardiogram performed before and after the start of chemotherapy using an institutional echocardiography database. Details of the chemotherapy regimen, cardiac risk factors, cardiac imaging results, concomitant medications, and referrals/consultations were examined for these patients. Results: A total of 88 patients met inclusion criteria. Ninety-two percent were treated with anthracyclines, 25% with trastuzumab in combination with anthracyclines, and 8% with trastuzumab alone. Mean baseline ejection fraction (EF) was 60%, with 13% of patients having a baseline EF below normal. A total of 41% had LV dysfunction (EF less than 55%) during or after cancer therapy. Of these patients, 56% received beta-blocker therapy, 47% received ACE-I or ARB therapy, and 50% were referred for cardiology consultation. Of the patients with asymptomatic LV dysfunction (75% of the LV dysfunction cohort), 41% received beta-blocker therapy, 33% received ACE-I or ARB therapy, and 37% received cardiology consultation. Conclusions: In real-world clinical practice, many cancer survivors with cardiotoxicity are not adequately evaluated and treated from a cardiovascular standpoint. Multidisciplinary collaboration between oncologists and cardiologists is needed to improve the quality of care for these patients.

No significant financial relationships to disclose.

Cardiotoxicity associated with the cancer therapeutic agent sunitinib malate

BACKGROUND

In the pivotal phase III metastatic renal cell carcinoma trial, updated data indicates that 21% of sunitinib-treated patients experienced a decline in left ventricular ejection fraction to below normal. This cardiotoxicity was reported to be reversible and without clinical sequelae. We conducted a retrospective analysis of our institutional experience of cardiotoxicity with sunitinib after observing a high incidence of symptomatic heart failure.

PATIENTS AND METHODS

Patients receiving sunitinib at Stanford University from 1 July 2004 to 1 July 2007 were identified. Medical records were reviewed and those patients experiencing symptomatic grade 3/4 left ventricular systolic dysfunction were identified. Potential cardiac risk factors were analyzed.

RESULTS

Forty-eight patients treated with sunitinib were assessable. Seven patients experienced symptomatic grade 3/4 left ventricular dysfunction 22-435 days after initiation of sunitinib. Three patients had persistent cardiac dysfunction after discontinuation of sunitinib and initiation of heart failure therapy. A history of congestive heart failure, coronary artery disease and lower body mass index were factors associated with increased risk.

CONCLUSIONS

Among patients treated with sunitinib at our institution, 15% developed symptomatic grade 3/4 heart failure. Future studies of sunitinib-related cardiotoxicity are urgently needed, particularly as the oncologic indications for this drug continue to expand.

Adult-onset nesidioblastosis causing hypoglycemia: an important clinical entity and continuing treatment dilemma

HYPOTHESIS

Nesidioblastosis is an important cause of adult hyperinsulinemic hypoglycemia, and control of this disorder can often be obtained with a 70% distal pancreatectomy.

DESIGN

The records of all adult patients operated on for hypoglycemia between 1974 and 1999 were reviewed retrospectively. Patients with the pathologic diagnosis of nesidioblastosis were contacted for follow-up (1.5-21 years) and are presented. Patients' results were compared with those of 36 other individuals with this disorder who were previously reported in the literature.

SETTING

The University of Chicago Medical Center (Chicago, Ill), a tertiary care facility.

PATIENTS

A consecutive sample of all patients operated on for hypoglycemia.

INTERVENTIONS

Seventy percent distal pancreatectomy for all patients with nesidioblastosis, and maintenance therapy with verapamil hydrochloride for 2 patients.

MAIN OUTCOME MEASURES

Achievement of normoglycemia with and without medication, development of insulin-dependent diabetes mellitus, pancreatic exocrine insufficiency, and need for reoperation.

RESULTS

Of 32 adult patients who underwent surgical exploration for hyperinsulinemic hypoglycemia at our institution, 27 (84%) were found to have 1 or more insulinomas, and 5 (16%) were diagnosed with nesidioblastosis. Each patient with nesidioblastosis underwent a 70% distal pancreatectomy. Follow-up duration for the 5 patients ranged from 1.5 to 21 years, with 3 patients (60%) asymptomatic and taking no medications, and 2 patients (40%) experiencing some recurrences of hypoglycemia. The 2 patients with recurrences are now successfully treated with a calcium channel blocker, an approach, to our knowledge, never before reported for adult-onset nesidioblastosis.

CONCLUSIONS

Nesidioblastosis is an uncommon but clinically important cause of hypoglycemia in the adult population, and must always be considered in a patient with a presumptive preoperative diagnosis of insulinoma. This study indicates that a 70% distal pancreatectomy is often successful in controlling hypoglycemia, and rarely results in diabetes mellitus. However, the optimal treatment of this disorder remains to be determined.

Sensitivity of diagnostic and localization tests for pheochromocytoma in clinical practice

BACKGROUND

Although pheochromocytomas are believed to account for fewer than 0.3% of all cases of hypertension, aggressive diagnostic and surgical intervention is recommended whenever a pheochromocytoma is suspected because uncontrolled catecholamine release from the tumors can lead to catastrophic consequences. Many biochemical diagnostic and imaging localization tests exist for detecting pheochromocytomas. We sought to evaluate the sensitivity of these tests used over a 35-year period at a single institution.

METHODS

Thirty-five patients with complete medical records who had pathologically confirmed pheochromocytomas between 1962 and 1997 at the University of Chicago Hospitals were identified. Sensitivity and 95% confidence intervals were calculated for 12 laboratory diagnostic tests and 5 imaging studies.

RESULTS

The most sensitive laboratory diagnostic tests in our study were plasma total catecholamines (95%) and urine total metanephrines (100%). Testing for urine vanillylmandelic acid, while less expensive and easier to perform than many other tests, had a slightly lower sensitivity (89%). The most sensitive imaging tests in the study were magnetic resonance imaging (100%) and iodine I-131 metaiodobenzylguanidine scintigraphy (100%). The more often used computed tomography had only 88% sensitivity. Localization was safely and successfully performed on two pregnant patients using magnetic resonance imaging and ultrasound.

CONCLUSIONS

By properly choosing from the wide array of laboratory diagnostic and imaging tests, pheochromocytomas can be identified and localized with nearly 100% sensitivity. These tests should be performed in any patient for whom the diagnosis of pheochromocytoma is being considered.

Safe and cost-effective preoperative preparation of patients with pheochromocytoma

This study examines the management of patients diagnosed with pheochromocytoma at a major academic teaching hospital. The findings indicate that most patients can be safely managed as outpatients preoperatively, resulting in significantly shorter hospitalizations and no adverse sequelae.