Clinical characteristics, patient selection and clinical outcomes of tafamidis treatment in transthyretin amyloidosis cardiomyopathy

Background

Tafamidis is a stabilizer of transthyretin, specifically designed to decrease or prevent amyloidogenesis, and improves prognosis in patients with transthyretin amyloid cardiomyopathy (ATTR-CM). However, clinical coarse, selection of appropriate patients and monitoring therapeutic effect of tafamidis remained unclear.

Purpose

The aim of this study was to clarify the patients' characteristics, clinical coarse, and clinical outcomes of tafamidis in patients with ATTR-CM and to evaluate prognostic factors and changes in clinical data over time.

Methods

We evaluated consecutive 180 patients with ATTR-CM considering tafamids treatment. A total of 107 patients had tafamidis treatment (tafamidis treatment group) and 65 patients did not treat with tafamidis (treatment naïve group). The remaining 8 patients were preclinical. Clinical data were obtained at the consideration of tafamidis treatment. We divided the following the cut-off values of high-sensitivity cardiac troponin T (hs-cTnT); >0.05 ng/mL, B-type natriuretic peptide (BNP); >250 pg/ml, and estimated glomerular filtration rate (eGFR); <45 mL/min/1.73 m2 and calculated the score by adding 1 point if increased or decreased by more than the cut-off value. We divided patients into a low score group (0–1 point) and high score group (2–3 points).

Results

All of study patients in the tafamidis treatment group were wild-type ATTR-CM. Compared to tafamidis treatment group, tafamidis naïve group were significantly older (75.6±5.3 vs. 82.8±4.6 years; p<0.01), female dominant (8% vs. 28%; p<0.01), increased BNP levels (median 209 vs 306 pg/ml; p<0.01), and lower haemoglobin levels (14.1±1.8 vs. 12.4±1.8 g/dl; p<0.01). Tafamidis treatment group was significantly favourable clinical outcomes competed to treatment naïve group (p<0.05; log rank test). According to multivariate logistic regression analysis, prior heart failure hospitalization (hazard ratio [HR]: 5.93, 95% confidence interval [CI]: 1.25–28.03, p=0.03) and high score group (HR: 1.56, 95% CI: 0.37–7.25; <0.01) were the significant poor prognostic factors in tafamids treatment group. Among tafamidis treatment group, Hs-cTnT levels were significantly decreased after 12 months tafamidis treatment (0.055 [0.037–0.082] vs. 0.044 [0.033–0.077]; p<0.01) instead of no significant differences in BNP and significant decline of eGFR levels. There were no significant changes over time in the echocardiographic parameters after 12 months, and native T1 and extracellular volume fraction obtained by cardiac magnetic resonance in a limited number of patients.

Conclusion

The prognosis of ATTR-CM patients treated with tafamidis was favorable compared to tafamidis naïve group. Patient stratification combined with biomarkers predicted favorable prognosis in patients with tafamidis treatment. Hs-cTnT may be a useful maker for evaluating the therapeutic effect by tafamidis.

Funding Acknowledgement

Type of funding sources: None.

Change in echocardiography in patients with transthyretin amyloid cardiomyopathy with tafamidis treatment

Background

Transthyretin amyloid cardiomyopathy (ATTR-CM) is a progressive and infiltrative disease caused by the deposition of insoluble transthyretin (TTR) amyloid fibrils in the myocardium, which leads to cardiomyopathy characterized by increased ventricular wall thickness and diastolic dysfunction. TTR amyloid fibrils are performed by dissociation of the tetrameric TTR into monomers and misfolding and misassemble into insoluble fibrils. Tafamidis stabilizes the tetramers and inhibits the TTR monomerization, leads to inhibit the formation and deposition of TTR fibril. Clinical trials suggested tafamidis could improve prognosis by slowing the progression of amyloidosis. Evaluation of serial measurement echocardiographic findings by tafamidis treatment is important, but these data has not been fully revealed.

Purpose

The aim of study was to evaluate the change of echocardiographic parameter in patients with ATTR-CM received tafamidis for 12 months. Especially in strain echocardiogram, global longitudinal strain (GLS) has reported to be associated with prognosis, and apical sparing pattern, which longitudinal strain (LS) in the basal and middle segments is more severely impaired than the apical segments, is specific finding in ATTR-CM.

Method

Echocardiographic findings before and 12 months were compared in 68 patients with ATTR-CM who started a new prescription of tafamidis and 18 tafamidis naïve patients with ATTR-CM patients who underwent echocardiography annually prior to the approval of tafamidis.

Result

Among tafamidis treatment group, echocardiographic parameters were not significant changes before and after 12 months tafamidis treatment [left ventricular ejection fraction (LVEF): 49.6±10.6% vs. LVEF: 49.9±10.7% (p=0.767), interventricular septum diameter (IVSd):16.0±2.3mm vs 15.7±2.1mm (p=0.241), left ventricular posterior wall diameter (LVPWd):16.1±2.5mm vs 16.1±2.5mm (p=0.964), GLS: −8.4±2.7% vs −8.2±2.8% (p=0.419), LS at base: −4.6±2.6% vs −4.2±2.4% (p=0.291), LS at middle: −6.9±3.6% vs −6.9±2.8% (p=0.922), LS at apical:-12.7±4.2% vs −12.4±4.4% (p=0.615). Among tafamidis naïve group, these parameters remained almost unchanged in 12 months as well, except for GLS and LS at apical. LS at apical showed a significant impairment. [LVEF: 53.8±9.2% vs 51.7±9.3% (p=0.244), IVSd: 15.5±2.3mm vs 16.0±1.8mm (p=0.321), LVPWd: 15.4±2.3mm vs 15.9±2.3mm (p=0.267), GLS: −10.4±2.4% vs −9.0±2.9% (p=0.065), LS at base: −5.0±2.7% vs −5.1±2.9% (p=0.865), LS at middle: −8.9±3.1% vs −8.5±3.5% (p=0.565), LS at apical: −15.4±4.0% vs −12.6±4.4% (p=0.02); Table 1]

Conclusion

We evaluated changes in echocardiographic findings with tafamidis treatment for 12 months. The echocardiographic parameters did not change over the course of 12 months, but the decrease in LS at apex observed in the tafamidis naïve group.Segmental LS could reflect a slight progression of cardiac amyloidosis and the short-term effects of tafamidis.

Funding Acknowledgement

Type of funding sources: None.

Correlations between pathological deposition and non-invasive diagnostic modalities like 99mTc-PYP scintigraphy, cardiac magnetic resonance, GLS in patients with transthyretin cardiac amyloidosis

Background

Although wild-type transthyretin amyloid cardiomyopathy (ATTRwt-CM) was previously considered a rare disease, recent diagnostic imaging modalities have revealed that it is considerably underdiagnosed among elderly patients with heart failure. The severity of CM is thought to be related to the extent of amyloid deposition in heart.

99mTc-labeled pyrophosphate (99mTc-PYP) scintigraphy, cardiovascular magnetic resonance (CMR), global longitudinal strain (GLS) provide diagnostic and prognostic information in ATTRwt-CM. However, the relevance of these imaging modalities and their association with cardiac amyloid load has not been fully evaluated.

Purpose

The aim of study was to elucidate the associations between pathological amyloid load and cardiac retention evaluated by 99mTc-PYP scintigraphy, CMR, GLS in patients with ATTRwt-CM.

Method

Cardiac amyloid load was calculated as (amyloid deposition area/ total myocardium area)×100 using endomyocardial biopsy specimen. Cardiac retention was quantified by heart to contralateral (H/CL) ratio by 99mTc-PYP scintigraphy. Native T1 and extracellular volume (ECV) were obtained by CMR. GLS was analyzed using the 2D echo at the time of diagnosis.

Result

The mean cardiac amyloid load was 23.0±15.2% (n=57) and correlation with H/CL ratio (1.94±0.36 n=57), native T1 (1426.7±52.5 n=57), ECV (57.9±12.9 n=54), GLS (−9.1±2.4 n=57) were positive (r=0.375 p=0.004, r=0.496 r=0.304 p<0.001, r=0.304 p=0.025, r=0.473 p<0.001).

Conclusion

Increased cardiac amyloid load correlated with an increased 99mTc-PYP positivity, native T1, ECV, and an impaired GLS. These results suggest that imaging parameters may reflect histological and functional changes due to amyloid deposition in the myocardium.

Funding Acknowledgement

Type of funding sources: None.

Gender differences in clinical characteristics in wild-type transthyretin amyloidosis cardiomyopathy

Aims

A significant male predominance has been reported in wild-type transthyretin amyloid cardiomyopathy (ATTRwt-CM). In other words, the female ATTRwt-CM may be overlooked and gender differences in ATTRwt-CM remain unclear. This study aims to examine gender differences in clinical characteristics and diagnostic approaches in ATTRwt-CM.

Methods and results

We retrospectively evaluated 171 consecutive ATTRwt-CM patients diagnosed at our university hospital between December 2002 and December 2020. Twenty-two patients (12%) were women. Women were significantly older at diagnosis (77.3 years vs. 83.3 years; P<0.001) and had a higher advanced New York Health Association functional class (2.23±0.70 vs. 2.57±0.81; P=0.04) than men. In echocardiography, mean interventricular septum diameter was less thick (15.8 mm vs. 14.5 mm; P=0.03) and ejection fraction was preserved (51.7% vs. 57.7%; P=0.08) in women. The mean heart-to-contralateral ratio obtained using 99mTc-labeled pyrophosphate (99mTc-PYP) was significantly lower in women than in men (1.89 vs. 1.64; P=0.001). There was no significant gender difference in high-sensitivity median cardiac troponin T levels at diagnosis (0.055 ng/mL vs. 0.069 ng/mL; P=0.30) or history of carpal tunnel syndrome (57% vs. 55%; P=0.93) and electrocardiograms findings. However, the median B-type natriuretic peptide level was significantly higher (254 pg/mL vs. 434 pg/mL; P=0.02) in women. Moderate to severe aortic stenosis was more frequently observed in women (5% vs. 50%; P<0.001). Histological (78% vs. 59%; P=0.07) and genetic confirmation (78% vs. 59%; P=0.003) of ATTRwt-CM were not performed in women.

Conclusion

Women with ATTRwt-CM were predominantly octogenarians, less hypertrophic, and had weaker cardiac uptake of the 99mTc-PYP tracer than men with ATTRwt-CM. These characteristics contribute to the underdiagnosis of ATTRwt-CM in women. The diagnosis of ATTRwt-CM in women is challenging. Therefore, we must be familiar with the clinical characteristics of women with ATTRwt-CM.

Funding Acknowledgement

Type of funding sources: None.

Present status of titanium removable dentures--a review of the literature

Although porcelain and zirconium oxide might be used for fixed partial dental prostheses instead of conventional dental metals in the near future, removable partial denture (RPD) frameworks will probably continue to be cast with biocompatible metals. Commercially pure (CP) titanium has appropriate mechanical properties, it is lightweight (low density) compared with conventional dental alloys, and has outstanding biocompatibility that prevents metal allergic reactions. This literature review describes the laboratory conditions needed for fabricating titanium frameworks and the present status of titanium removable prostheses. The use of titanium for the production of cast RPD frameworks has gradually increased. There are no reports about metallic allergy apparently caused by CP titanium dentures. The laboratory drawbacks still remain, such as the lengthy burn-out, inferior castability and machinability, reaction layer formed on the cast surface, difficulty of polishing, and high initial costs. However, the clinical problems, such as discoloration of the titanium surfaces, unpleasant metal taste, decrease of clasp retention, tendency for plaque to adhere to the surface, detachment of the denture base resin, and severe wear of titanium teeth, have gradually been resolved. Titanium RPD frameworks have never been reported to fail catastrophically. Thus, titanium is recommended as protection against metal allergy, particularly for large-sized prostheses such as RPDs or complete dentures.

Wear resistance of experimental Ti-Cu alloys

After using cast titanium prostheses in clinical dental practice, severe wear of titanium teeth has been observed. This in vitro study evaluated the wear behavior of teeth made with several cast titanium alloys containing copper (CP Ti+3.0 wt% Cu; CP Ti+5.0 wt% Cu; Ti-6Al-4V +1.0 wt% Cu; Ti-6Al-4V+4.0 wt% Cu) and compared the results with those for commercially pure (CP) titanium, Ti-6Al-4V, and gold alloy. Wear testing was performed by repeatedly grinding upper and lower teeth under flowing water in an experimental testing apparatus. Wear resistance was assessed as volume loss (mm(3)) at 5kgf (grinding force) after 50,000 strokes. Greater wear was found for the six types of titanium than for the gold alloy. The wear resistance of the experimental CP Ti+Cu and Ti-6Al-4V+Cu alloys was better than that of CP titanium and Ti-6Al-4V, respectively. Although the gold alloy had the best wear property, the 4% Cu in Ti-6Al-4V alloy exhibited the best results among the titanium metals. Alloying with copper, which introduced the alpha Ti/Ti(2)Cu eutectoid, seemed to improve the wear resistance.

Comparative study of maxillary complete dentures constructed of metal base and metal structure framework

A removable denture designed using a three-dimensional cast metal framework (hereafter referred to as the 'structurally designed' denture) could extend denture longevity because it is unbreakable and easy to adjust. The aim of the present clinical study was to compare two types of maxillary removable dentures: conventional dentures and structurally designed denture. One edentulous and five partially dentate patients were fitted with two maxillary dentures made from the same impression and same occlusal relationship. About 20 days after delivery of the denture, masticatory analysis was conducted chewing phase (open, closed, and occluded); coefficients of variation and average variation were calculated. Denture vibration during tapping was then measured using an accelerometer. The patients were also interviewed about comfort, ease of chewing, speech, stability, aesthetics and preference for regular use. For both masticatory movements and denture vibration, there were no significant differences (P>0.1) between the conventional denture and the structural design denture. In evaluating the dentures according to each criteria, the significant superiority of one denture over the other could not be determined. However, all patients subjectively preferred the structurally designed dentures for regular use. According to these findings, structurally designed dentures do not appear to have any particular physiological problems as compared with the conventional dentures.

Neutral zone approach for denture fabrication for a partial glossectomy patient: a clinical report

According to the neutral zone concept, an appropriate denture form can be molded into a physiologic tooth arrangement by using a narrow rim bar occlusion, tissue conditioner, and a direct relining technique for both intaglio and cameo surfaces by using VLC reline resin. Denture stability can be obtained with this "border molding" technique, not only for edentulous patients but also for those with oral deformities.

[A dynamic fitness test and a new method to measure the thickness of film using the digital subtraction system of X-ray photographic density]

It is impossible to show the dynamic fitness conditions of a denture base using White Silicone or other fitness test materials. In the present paper, materials and the measuring method for the dynamic fitness test were investigated. In order to choose the suitable materials for the dynamic fitness test, various kinds of ready made materials, such as wax or dynamic impression materials, were examined by load test and investigated the change on standing of flow character. EXPERIMENTAL WAX was made for dynamic fitness test, and was examined by load test and clinical test. EXPERIMENTAL WAX consists of DISCLOSING WAX (KERR), as a basic material, and the contrast medium. Extending the system of the conventional measuring method for White Silicone, DIGITAL SUBTRACTION SYSTEM (DSS) was developed as a new method of quantitative analysis for the thickness of wax film. In this system, thickness of wax film is measured from the X-ray photographic density and it's digital subtraction management. Accuracy of this system was also investigated. The summary of results is shown below. 1. It became evident that ready made materials had no useful characters for the dynamic fitness test. 2. EXPERIMENTAL WAX showed similar load effects with White Silicone when the load was 5 or 10kg. 3. Dynamic fitness and the mobility of the denture base during function were able to be shown by EXPERIMENTAL WAX, but it's operation was more complicated than White Silicone. 4. DIGITAL SUBTRACTION SYSTEM (DSS), a new method of quantitative analysis for the thickness of wax film, was developed. 5. Resolving power and measuring range of DSS were effected by quantity of subtraction. 6. DSS is not only useful to measure the thickness of EXPERIMENTAL WAX, but also has wide applications.