Impact of tafamidis on myocardial function and CMR tissue characteristics in transthyretin amyloid cardiomyopathy.

AIMS: Tafamidis improves clinical outcomes in transthyretin amyloid cardiomyopathy (ATTR-CM), yet how tafamidis affects cardiac structure and function remains poorly described. This study prospectively analysed the effect of tafamidis on 12-month longitudinal changes in cardiac structure and function by cardiac magnetic resonance (CMR) compared with the natural course of disease in an untreated historic control cohort. METHODS AND RESULTS: ATTR-CM patients underwent CMR at tafamidis initiation and at 12 months. Untreated patients with serial CMRs served as reference to compare biventricular function, global longitudinal strain (GLS), LV mass and extracellular volume fraction (ECV). Thirty-six tafamidis-treated (n = 35; 97.1% male) and 15 untreated patients (n = 14; 93.3% male) with a mean age of 78.3 ± 6.5 and 76.9 ± 6.5, respectively, and comparable baseline characteristics were included. Tafamidis was associated with preserving biventricular function (LVEF (%): 50.5 ± 12 to 50.7 ± 11.5, P = 0.87; RVEF (%): 48.2 ± 10.4 to 48.2 ± 9.4, P = 0.99) and LV-GLS (-9.6 ± 3.2 to -9.9 ± 2.4%; P = 0.595) at 12 months, while a significantly reduced RV-function (50.8 ± 7.3 to 44.2 ± 11.6%, P = 0.028; P (change over time between groups) = 0.032) and numerically worsening LVGLS (-10.9 ± 3.3 to -9.1 ± 2.9%, P = 0.097; P (change over time between groups) = 0.048) was observed without treatment. LV mass significantly declined with tafamidis (184.7 ± 47.7 to 176.5 ± 44.3 g; P = 0.011), yet remained unchanged in untreated patients (163.8 ± 47.5 to 171.2 ± 39.7 g P = 0.356, P (change over time between groups) = 0.027). Irrespective of tafamidis, ECV and native T1-mapping did not change significantly from baseline to 12-month follow-up (P > 0.05). CONCLUSIONS: Compared with untreated ATTR-CM patients, initiation of tafamidis preserved CMR-measured biventricular function and reduced LV mass at 12 months. ECV and native T1-mapping did not change significantly comparable to baseline in both groups.

Routine 4D Cardiac CT to Identify Concomitant Transthyretin Amyloid Cardiomyopathy in Older Adults with Severe Aortic Stenosis.

Background Transthyretin amyloid cardiomyopathy (ATTR-CM) often coexists with severe aortic stenosis (AS). Although strain analysis from cardiac MRI and echocardiography was demonstrated to predict coexisting ATTR-CM, comparable data from four-dimensional (4D) cardiac CT are lacking despite wide availability. Purpose To evaluate the diagnostic performance of 4D cardiac CT-derived parameters in identifying ATTR-CM in older adults considered for transcatheter aortic valve implantation (TAVI). Materials and Methods This prospective single-center screening study for ATTR-CM included consecutive patients with severe AS considered for TAVI who underwent 4D cardiac CT between August 2019 and August 2021 approximately 1 day before technetium 99m (99mTc) 3,3-diphosphono-1,2-propanodicarboxylic-acid (DPD) scintigraphy. The diagnostic performance of CT-based left ventricular (LV), right ventricular, and left atrial dimensions, ejection fraction (EF), and myocardial strain were evaluated against 99mTc-DPD scintigraphy as the reference standard to identify ATTR-CM. Predictors and an unweighted cardiac CT score were validated with internal bootstrapping. The assignment of variables to the score was based on cutoff values achieving the highest Youden index J. Results Among 263 participants (mean age, 83 years ± 4.6 [SD]; 149 male and 114 female participants), 99mTc-DPD scintigraphy (Perugini grade 2 or 3) confirmed coexisting ATTR-CM in 27 (10.3%). CT-derived LV mass index, LV and LA global longitudinal strain (GLS), and relative apical longitudinal strain each predicted the presence of ATTR-CM with an area under the curve (AUC) of at least 0.70. Implementing these parameters with cutoff values of 81 g/m2 or higher, -14.9% or higher, less than 11.5%, and 1.7 or higher in the CT score, respectively, yielded high diagnostic performance (AUC = 0.89; 95% CI: 0.81, 0.94; P < .001) robust to internal bootstrapping validation (AUC = 0.88; 95% CI: 0.82, 0.94). If two criteria were fulfilled, the sensitivity and specificity in the detection of ATTR-CM were 96.3% (95% CI: 81.0, 99.9) and 58.9% (95% CI: 52.3, 65.2), respectively. Conclusion When compared against 99mTc-DPD scintigraphy as the reference standard, routine 4D cardiac CT in older adults considered for TAVI provided high diagnostic performance in the detection of concomitant ATTR-CM by assessing LV and left atrial GLS, relative apical longitudinal strain, and LV mass index. ClinicalTrials.gov registration no.: NCT04061213 © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Tavakoli and Onder in this issue.

Diagnostic performance of quantitative coronary artery disease assessment using computed tomography in patients with aortic stenosis undergoing transcatheter aortic-valve implantation.

BACKGROUND: Computed tomography angiography (CTA) is a cornerstone in the pre- transcatheter aortic valve replacement (TAVI) assessment. We evaluated the diagnostic performance of CTA and coronary artery calcium score (CACS) for CAD evaluation compared to invasive coronary angiography in a cohort of TAVI patients. METHODS: In consecutive TAVI patients without prior coronary revascularization and device implants, CAD was assessment by quantitative analysis in CTA. (a) Patients with non-evaluable segments were classified as obstructive CAD. (b) In patients with non-evaluable segments a CACS cut-off of 100 was applied for obstructive CAD. The reference standard was quantitative invasive coronary angiography (QCA, i.e. ≥ 50% stenosis). RESULTS: 100 consecutive patients were retrospectively included, age was 82.3 ± 6.5 years and 30% of patients had CAD. In 16% of the patients, adequate visualization of the entire coronary tree (all 16 segments) was possible with CTA, while 84% had at least one segment which was not evaluable for CAD analysis due to impaired image quality. On a per-patient analysis, where patients with low image quality were classified as CAD, CTA showed a sensitivity of 100% (95% CI 88.4-100.0), specificity of 11.4% (95% CI 5.1-21.3), PPV of 32.6% (95% CI 30.8-34.5), NPV of 100% and diagnostic accuracy of 38% (95% CI 28.5-48.3) for obstructive CAD. When applying a combined approach of CTA (in patients with good image quality) and CACS (in patients with low image quality), the sensitivity and NPV remained at 100% and obstructive CAD could be ruled out in 20% of the TAVI patients, versus 8% using CTA alone. CONCLUSION: In routinely acquired pre-TAVI CTA, the image quality was insufficient in a high proportion of patients for the assessment of the entire coronary artery tree. However, when adding CACS in patients with low image quality to quantitative CTA assessment in patients with good image quality, obstructive CAD could be ruled-out in 1/5 of the patients and may therefore constitute a strategy to streamline pre-procedural workup, and reduce risk, radiation and costs in selected TAVI patients without prior coronary revascularization or device implants.

Is it safe to irradiate the newest generation of ventricular assist devices? A case report and systematic literature review.

An increasing number of mechanical assist devices, especially left ventricular assist devices (VADs), are being implanted for prolonged periods and as destination therapy. Some VAD patients require radiotherapy due to concomitant oncologic morbidities, including thoracic malignancies. This raises the potential of VAD malfunction via radiation-induced damage. So far, only case reports and small case series on radiotherapy have been published, most of them on HeartMate II (HMII, Abbott, North Chicago, IL, USA). Significantly, the effects of irradiation on the HeartMate 3 (HM3, Abbott) remain undefined, despite the presence of controller components engineered within the pump itself. We report the first case of a patient with a HM3 who successfully underwent stereotactic hypofractionated radiotherapy due to an early-stage non-small-cell lung cancer. The patient did not suffer from any complications, including toxicity or VAD malfunction. Based on this case report and on published literature, we think that performing radiotherapy after VAD implantation with the aid of a multidisciplinary team could be performed, but more in vitro studies and cases series are needed to reinforce this statement.