Table 4.

Clinical Use of cTn in the Management of Patients With AL Amyloidosis

	Prognosisa		Response to Therapy
	Prognostic Variables and Staging Systems	Estimated Survival
Diagnostic score to define cardiac involvement in AL amyloidosis67 •hs-cTnT >35 ng/L (1 point) •GLS ≥−17% (1 point) •RELAPS ≥0.9 (1 point)	Mayo Clinic 200473 •cTnT ≥ 0.035 μg/L or cTnI (Stratus CS) ≥0.1 μg/L or hs-cTnT ≥50 ng/L •NT-proBNP ≥332 ng/L	Stage 1: 26.4 mo Stage 2: 10.5 mo Stage 3: 3.5 mo	Cardiac disease progression89 •cTn increase >33% or •NT-proBNP increase >30% and >300 ng/L or •LV ejection fraction reduction ≥10%
CA very likely in patients with suspected CA65 •hs-cTnT ≥86 ng/L	Mayo Clinic 201233 •cTnT ≥0.025 μg/L or hs-cTnT ≥40 ng/L •NT-proBNP ≥1,800 ng/L •dFLC ≥180 mg/L	Stage 1: 94.1 mo Stage 2: 40.3 mo Stage 3: 14 mo Stage 4: 5.8 mo	Cardiac disease response89 •NT-proBNP reduction >30% and >300 ng/L (if baseline ≥650 ng/L) or •≥2-class reduction in NYHA functional class (if baseline III or IV)
CA unlikely in patients with suspected CA65 •hs-cTnT <14 ng/L and •NT-proBNP <180 ng/L	European 2015 modification of Mayo 200474,75 •cTnT ≥0.035 μg/L or cTnI (Stratus CS) ≥0.1 μg/L or hs-cTnT ≥50 ng/L •NT-proBNP ≥332 ng/L and >8500 ng/L	Stage 1: NR Stage 2: 55% 3 y Stage 3a: 52% 3 y Stage 3b: 7 mo	Graded cardiac response91 •CarCR: nadir NT-proBNP ≤350 pg/mL or BNP ≤80 pg/mL •CarVGPR: >60% reduction in NT-proBNP/BNP from baseline level not meeting CarCR •CarPR: 31%-60% reduction in NT-proBNP from baseline level not meeting CarCR •CarNR: ≤30% reduction in NT-proBNP from baseline level
	Boston University staging system76 •cTnI (assay not specified) >0.1 ng/mL •BNP >81 ng/L and >700 ng/L	Stage 1: NR Stage 2: 9.4 y Stage 3: 4.3 y Stage 3b: 1 y	Restaging with Mayo 2004 and 2012 systems94,95
	Palladini et al80 •hs-cTnT >77 ng/L at baseline •cTnI (Advia Centaur CP, Siemens) ≥100 ng/L (integrated in staging system with NT-proBNP ≥332 ng/L) •Progression of NT-proBNP and increase >75% of hs-cTnT after therapy	10.6 mo
	ASCT candidates70,82 •cTnT >0.06 μg/L or hs-cTnT >75 ng/L •NT-proBNP >5,000 ng/L	Cutoffs for identification of patients at risk of early mortality after ASCT

A summary of different thresholds for specific biomarkers (particularly cTn evaluated with different assays) for diagnosis, prognosis, and response to therapy in patients with AL amyloidosis is shown. For diagnosis, thresholds of specific markers, potentially useful to predict the likelihood of a final diagnosis of AL cardiac amyloidosis, are reported.

AL = amyloid light chain; ASCT = autologous stem cell transplantation; BNP = brain natriuretic peptide; CA = cardiac amyloidosis; CarCR = complete cardiac response; CarNR = cardiac nonresponse; CarPR = cardiac partial response; CarVGPR = cardiac very good partial response; cTnI = cardiac troponin I; cTnT = cardiac troponin T; dFLC = difference between involved and uninvolved free light chains; GLS = global longitudinal strain; hs-cTnT = high sensitivity cardiac troponin T; LV = left ventricular; NR = not reached; NT-proBNP = N-terminal pro–brain natriuretic peptide; RELAPS = relative apical sparing; mo = months; y = years.

^aIn prognostic staging systems, the stage for each patient is defined on the basis of the number of variables above the specified thresholds tabulated in the table. For some staging system, alternative cutoffs for BNP (instead of NT-proBNP) are available. Criteria for response to therapy in AL amyloidosis are reported for completion, even if they do not include cTn or high-sensitivity cTn. Criteria for hematological response are not reported.