Risk Stratification in Transthyretin Cardiac Amyloidosis: The Added Value of Lung Spirometry.

Transthyretin cardiac amyloidosis (ATTR-CA) is an increasingly recognized disease that often results in heart failure and death. Traditionally, biological staging systems are used to stratify disease severity. Reduced aerobic capacity has recently been described as useful in identifying higher risk of cardiovascular events and death. Assessment of lung volume via simple spirometry might also hold prognostic relevance. We aimed to assess the combined prognostic value of spirometry, cardiopulmonary exercise testing (CPET) and biomarker staging in ATTR-CA patients in a multi-parametric approach. We retrospectively reviewed patient records with pulmonary function and CPET testing. Patients were followed until study endpoint (MACE: composite of heart-failure-related hospitalization and all-cause death) or censure (1 April 2022). In total, 82 patients were enrolled. Median follow-up was 9 months with 31 (38%) MACE. Impaired peak VO2 and forced vital capacity (FVC) were independent predictors of MACE-free survival, with peak VO2 < 50% and FVC < 70% defining the highest risk group (HR 26, 95% CI: 5-142, mean survival: 15 months) compared to patients with the lowest risk (peak VO2 ≥ 50% and FVC ≥ 70%). Combined peak VO2, FVC and ATTR biomarker staging significantly improved MACE prediction by 35% compared to ATTR staging alone, with 67% patients reassigned a higher risk category (p < 0.01). In conclusion, combining functional and biological markers might synergistically improve risk stratification in ATTR-CA. Integrating simple, non-invasive and easily applicable CPET and spirometry in the routine management of ATTR-CA patients might prove useful for improved risk prediction, optimized monitoring and timely introduction of newer-generation therapies.

Clinical Outcomes With and Without Plasma Exchange in the Treatment of Rapidly Progressive Interstitial Lung Disease Associated With Idiopathic Inflammatory Myopathy.

BACKGROUND/OBJECTIVE: A subset of patients with idiopathic inflammatory myopathy (IIM) develops highly fatal, rapidly progressive interstitial lung disease (RP-ILD). Treatment strategies consist of glucocorticoid and adjunctive immunosuppressive therapies. Plasma exchange (PE) is an alternative therapy, but its benefit is unclear. In this study, we aimed to determine whether PE benefited outcomes for patients with RP-ILD. METHODS: In this medical records review study, we compared baseline characteristics and clinical outcomes for 2 groups of patients with IIM-related RP-ILD: those who received and did not receive PE. RESULTS: Our cohort consisted of 15 patients, 9 of whom received PE. Baseline demographic characteristics and severity of lung, skin, and musculoskeletal disease between the 2 groups of patients were not significantly different. Five patients required mechanical ventilation (2, PE; 3, no PE). Plasma exchange was generally a third-line adjunctive treatment option. The PE group had a longer median (interquartile range) hospitalization (27.0 [23.0-36.0] days) than the non-PE group (12.0 [8.0-14.0] days) ( p = 0.02). There was a potential benefit in 30-day mortality improvement in those receiving PE (0% vs 33%, p = 0.14), with a statistically significant improvement in 2 important composite end points including 30-day mortality or need for lung transplant (0% vs 50%, p = 0.04) and 1-year mortality or need for lung transplant or hospital readmission for RP-ILD in those receiving PE (22% vs 83%, p = 0.04). CONCLUSIONS: Plasma exchange may be an underutilized, safe salvage therapy for patients with IIM-related RP-ILD when other immunosuppressive therapies fail.

Clinical, radiologic, and pathologic features and outcomes of pulmonary transthyretin amyloidosis.

INTRODUCTION: Amyloid transthyretin amyloidosis (ATTR) is characterized by deposition of a misfolded conformation of the transport protein TTR, most commonly in cardiac and nerve tissue, causing clinical disease. Pulmonary amyloidosis, or deposition of ATTR in lung tissue, is a poorly characterized manifestation of this disease. We present the clinical course, imaging characteristics, pathology results, and outcomes of a patient cohort diagnosed with pulmonary ATTR. METHODS: We retrospectively reviewed records of 28 patients with pulmonary ATTR seen at Mayo Clinic from September 30, 2005, through December 31, 2020. Data collected included information on demographics, subjective symptoms, tissue biopsy results, pulmonary function testing, imaging findings, and treatment. RESULTS: Of the patients, 89% were men; the median age was 74.5 years (range, 50-99 years). Patients were typically diagnosed after persistent dyspnea and abnormal chest imaging resulted in lung biopsy, which yielded the ATTR diagnosis. Most patients had a preexisting diagnosis of cardiac ATTR. The disease was wild-type in 62% and hereditary in 38%. Normal pulmonary function tests followed by a restrictive pattern were the most common presentation. Of the patients, 93% had chest computed tomography, with common findings of diffuse nodularity, calcified granulomas, interlobular septal thickening, and pleural effusions. Almost all patients had pulmonary vascular involvement, and half had interstitial involvement on tissue biopsy. One-third received either anti-amyloid pharmacotherapy or a heart transplant. Half of patients had died before the time of study inclusion. CONCLUSION: Pulmonary disease is a less common but clinically important manifestation of ATTR.