Evolution over time of cardiac biomarkers, electrocardiographic and echocardiographic features in a large cohort of patients with wild-type transthyretin cardiac amyloidosis treated with tafamidis

Abstract Introduction Data on evolution of transthyretin wild-type cardiac amyloidosis (ATTRwt) during treatment with tafamidis is scarce. This hinders the quest for parameters of response and a priori treatment eligibility. Purpose To study the evolution of biomarkers, ECG, and echocardiographic features during early tafamidis treatment. Methods We prospectively collected data after 12-18 months of treatment in a single-centre database. Changes of NT-proBNP and high-sensitivity Troponin I (hs-cTnI) between baseline and follow-up evaluations (at 12 and 18 months) were tested for significance. For ECG and echocardiographic features, we considered baseline and the last available follow-up (median interval 11.1 months). Results We included 253 patients (median age 77[71-82]years; 90% males). Median (IQR) baseline NT-proBNP was 2472(1355-4749)ng/L, hs-cTnI 47(30-82)ng/L. Furosemide was administered in 58% of cases (median dose 25[25-50]mg/day). Compared to baseline, NT-proBNP was 2342(1316-4148)ng/L at 12 (p=0.886), and 2633(1393-6063)ng/L at 18 months (p=0.285), with 4% and 30% of patients showing ≥30% and ≥300ng/L increase at 12 and 18 months, respectively; hs-cTnI was 46(29-70)ng/L at 12 (p=0.947), and 44(25-68)ng/L at 18 months (p=0.866), with 35% and 7% showing a ≥20% increase at 12 and 18 months, respectively, and 21 (11.5% over 183 analyzable) with increase at 12 and reduction at 18 months. Patients on furosemide were 69% and 70% at 12 and 18 months, respectively; the dose increased to 37.5(25-75)mg/day at 18 months (p=0.009). At baseline, 117(47%) patients had history/permanent atrial fibrillation (AF). Forty-one(16%) had an implantable electronic device, 16(6%) underwent subsequent implantation. Median PR interval was 210(185-240)msec, trending toward prolongation (p=0.054). QRS duration increased (100[86-130]vs120[90-140]msec, p=0.004), together with conduction disturbances (left anterior fascicular block 30[21%]vs43[29%], p=0.036; right bundle branch block 14[10%]vs27[18%], p=0.002). AF prevalence raised from 19% to 25%. There were no significant changes in left ventricular (LV) geometry (septum thickness 18[16-20]vs18[16-20]mm, p=0.666; end-diastolic diameter 45±7vs45±8mm, p=0.434), systolic function (ejection fraction 51±10%vs49±11%, p=0.070), filling pressures (E/e’ 17[11-20]vs14.9[13-19], p=0.086) and left atrial size (mean volume 46±15vs48±13ml/m2, p=0.649). Tricuspid annular plane systolic excursion (18±4vs17±4mm) and pulmonary artery systolic pressure (40[33-45]vs36[30-45]mmHg) remained stable. Conclusions We did not observe neither improvement nor worsening of laboratory/instrumental variables within the first 12-18 months of tafamidis. There was a progression of electrical disorders. After initial progression hs-cTnI tended to improve. Extended follow-up and a matched case-control series will help identify possible later changes useful to monitor treatment response and effects of supporting heart failure treatments.