Tan, Tow-Shung

Abstract Background Wild type transthyretin cardiac amyloidosis (wtATTR-CA) is increasingly recognized as a cause of heart failure with preserved ejection fraction (HFpEF) but prognosis is often limited due to late or misdiagnosis.Longitudinal left ventricular strain and biomarkers are established as markers of disease severity, but the role of RV free wall strain, reflecting RV contractility, is less well understood. Purpose We sought to determine whether RV free wall strain might add incremental prognostic value in wtATTR-CA. Methods Consecutive patients diagnosed with wtATTR-CA with tissue confirmation at Mayo clinic between 2013 and 2015 were included. Patients with TTR gene mutations were excluded. Baseline characteristics and transthoracic echocardiography measurements were obtained from the medical records. Speckle tracking RV free wall longitudinal 2D strain and peak LA longitudinal 2D strain were measured using Tom Tec Imaging System. Survival was determined using Kaplan Meier estimates and using the cox proportional hazard ratio, univariate and multivariable analysis were performed to identify predictors of mortality in patients with wtATTR. Results The study group comprised 139 patients (mean age 74.9±8.6, 92.8% male), of which 102 had adequate image quality for RV strain, and 99 for LA strain. Amongst these, 102 (73.3%) had AF and 118 patients (84.8%) had HF. During 3.23±2.0 years of follow up, 66 patients died. Both mean RV and LA strain were impaired at baseline: RV free wall strain was −14.7±4.9, and peak atrial longitudinal strain (PALS) was 13.2±8.8%. Using ROC analysis, RV strain of −16.8% was an independent predictor of all-cause mortality. In univariate modeling, higher levels of NT-proBNP (HR: 1.1 per 1000 pg.ml; 95%, CI 1.05–1.15, p<0.001) and Troponin T (HR: 2.0 per 0.1ng/ml; 95% CI 1.49–2.61, p<0.001) were associated with increased all-cause mortality. In addition, LV GLS (HR: 1.13 per 1%; 95% CI1.04–1.24, p=0.003), RV free wall LS (HR: 2.16 per 5%; 95%, CI 1.57–3.03, p<0.0001), and PALS (HR: 0.91 per1%; 95% CI 0.85–0.96, p<0.0001) were univariate predictors of all-cause mortality. In multivariate analysis using a stepwise regression model, RV free wall longitudinal strain (HR: 1.81; 95% CI 1.29–2.62, p<0.001) and Troponin T (HR: 1.7; 95% CI 1.25–2.26, p=0.001) remained independent predictors. Kaplan-Meier survival analysis demonstrated a higher mortality rate above −16.8 RV strain cut-off (Wilcoxon <0.0001). All stages were divided into two groups by −16.8% RV strain, and survival in individual stages analyzed. Stage 1 and 2 with <−16.8 RV free wall strain value had higher mortality than ≤-16.8% RV strain (Stage 1: Wilcoxon = 0.0041 and Stage 2: Wilcoxon = 0.023). However, there was not a survival difference between two RV strain groups in stage3 (Wilcoxon = 0.34) Conclusion RV free wall strain is an independent predictor of survival in wtATTR patients and may add incremental prognostic value to NT-proBNP and Troponin. Funding Acknowledgement Type of funding sources: None. Kaplan-Meier curve of all patientsKaplan-Meier curve of stages

Abstract Background: Primary systemic amyloidosis (AL) is an incurable plasma cell disorder with a poor survival, especially in patients (pts) with multiple organ involvement. For pts with limited organ involvement, high dose chemotherapy with autologous stem cell (SCT) support is an effective approach. However, the toxicity of SCT limits its widespread use. Melphalan and dexamethasone has been previously shown to be effective in pts ineligible for SCT. Methods: We reviewed our experience with melphalan and dexamethasone for treatment of AL. Eighty one pts were treated between 2001 and 2003; median age at start of therapy was 63 years (range, 38–80) and 56 pts (69%) were males. Among these, 46 pts (57%) had 2 or more major organs (cardiac, renal, hepatic) involved. Intravenous melphalan (IV) was used in 45 pts (56%), 32 (40%) received oral melphalan (PO) and the rest received cycles of both. The most common doses were 16 mg/m2 for IV administration (every 4–6 weeks) and 0.22 mg/kg for PO administration (every 4 weeks). Dexamethasone was usually given at a dose of 40 mg for the first 4 days of each cycle. Results: Patients received a median of 5 cycles (range; 1–17). At the time of analysis, 53 (65%) pts were alive with a median follow up of 10.8 months (range, 1.4–47.1).The estimated median overall survival (OS) was 25.6 months for the entire group, with the number or type of organs involved not impacting survival. Hematological response (HR) was defined by a 50% reduction in either serum M-spike, urine M-spike, or the absolute difference between the involved and uninvolved immunoglobulin free light chains. A HR was observed in 43 pts (67%) of the 64 pts measurable for HR by conventional criteria. Achievement of HR was associated with a superior OS with a median post-therapy OS that was not reached, while non-responders had a median OS of 11.1 months (p<0.0001) (Figure 1). Among these pts, an organ response as defined by conventional criteria, was seen in 14 pts (22%), which was significantly correlated with obtaining a hematological response (33% vs. 5%, p=0.01). A 25% reduction in the difference between the involved and uninvolved FLC strongly predicted prolonged OS, with a median post-therapy OS that was not reached for responders vs. 11.3 months for non-responders (p<0.0001) (Figure 2). A decrease in post-therapy brain natriuretic peptide (BNP) also predicted for a survival improvement, with the median OS not reached for responders vs. a median OS of 17 months for non-responders (p<0.016). Conclusion: Treatment with melphalan and dexamethasone is effective and a significant survival advantage is achieved in patients with a hematological response. FLC and BNP response can help identify patients that are likely to benefit from this therapy. Figure Figure Figure Figure