June 2026 Research Update

Studies this month added context at two very different ends of treatment: what happens after heart transplant in amyloidosis, and what lab models predict about how ATTR drugs could work. The transplant study gives a real-world picture of outcomes and complications after transplantation in ATTR, while the modeling and lab work focus on biologic effects that may help explain differences between therapies. Together, these studies do not settle which treatment is best, but they sharpen what researchers are measuring: survival and complications for advanced disease, and drug effects on amyloid-related biology in earlier or more controlled settings. [1] [2] [3]

In a multicenter group of 113 people who received a heart transplant for cardiac amyloidosis, 57 had ATTR (including 22 wild-type) and 56 had AL. Five-year survival was reported as similar between ATTR and AL (83% vs 77%), with infections occurring in about 4 in 10 people in both groups during follow-up. Nerve problems were also part of the longer-term course: new neuropathy occurred in 11%, and worsening neuropathy was reported more often in ATTR than AL (23% vs 7.1%). [1]

Two exploratory studies looked at how ATTR medicines might change amyloid-related processes rather than reporting typical patient outcomes. A mathematical model that used "monomer efflux" (a stand-in for amyloid building-block release) predicted larger reductions with acoramidis than with tafamidis, and also larger reductions with acoramidis than with vutrisiran in the model scenarios for both wild-type and hereditary ATTR-CM. Separately, a lab study found that blood serum from people with ATTR caused stress and reduced function in endothelial cells (cells that line blood vessels), and these effects were lessened when tafamidis was present or when serum was collected after tafamidis; the same study reported lower arterial stiffness (pulse wave velocity) after tafamidis in ATTRwt-CM patients. [2] [3]

For patients, the transplant report helps set expectations about outcomes that have been observed after heart transplantation in specialized centers, including survival over several years and the possibility of infections and nerve symptom changes during follow-up. The modeling and lab studies are earlier-stage evidence: they help explain how drugs might differ biologically (for example, in predicted reductions of amyloid building blocks, or effects on blood vessel cell stress), but they are not the same as proving how a person will feel or function on a given medicine. What remains uncertain is how closely these modeled and lab signals match real-world symptom changes across different patient groups, since the studies did not compare treatments head-to-head in patients. [1] [2] [3]

This month, studies on diagnosis pointed in the same direction: ATTRwt-CM can leave recognizable clues, but the diagnostic path in routine care is often uneven. Large health-record analyses described which warning signs tend to appear before ATTRwt is formally diagnosed and showed that many people did not have a complete documented workup. At the same time, two test-focused studies clarified that some tools can be very good at separating ATTRwt-CM from look-alike heart conditions, while other commonly used screening tests can miss ATTRwt. [4] [5] [6] [7] [8]

A large US electronic health record study comparing people later diagnosed with AL versus ATTRwt found different pre-diagnosis patterns. Before ATTRwt diagnosis, cardiac-related codes such as heart failure and atrial fibrillation were more common, and carpal tunnel syndrome appeared more often than in AL. In a separate health-service evaluation from one UK hospital, common triggers for investigation included carpal tunnel syndrome and atrial fibrillation, and many patients had echocardiogram findings such as thickened heart walls and enlarged left atrium recorded along the pathway to diagnosis. [4] [8]

Two studies emphasized that test choice matters because different tests answer different questions and have different "miss rates" in ATTRwt. In a large series of 2830 fat tissue aspiration samples used to screen for systemic amyloidosis, the test was very specific (few false positives) but sensitivity depended strongly on amyloid type, and it detected ATTRwt only 18.8% of the time. In contrast, a heart ultrasound study using right-sided heart measurements reported that right-ventricle strain and wall thickness separated ATTR-CM from hypertrophic cardiomyopathy and Fabry cardiomyopathy with high accuracy in that dataset, suggesting these heart measurements can carry useful diagnostic signal when ATTR-CM is suspected. [7] [6]

A separate US database study focused on what testing was actually recorded before diagnosis codes for AL or ATTRwt-CM. Only about 15% of the ATTRwt-CM cohort had complete monoclonal protein testing documented, and many had no relevant workups recorded in the measured window. The study also reported that some people had bone-tracer heart scans recorded without a complete documented blood test workup around the scan date, highlighting gaps between idealized pathways and what is captured in routine data. [5]

For patients and caregivers, these studies help clarify why ATTRwt can be hard to confirm even when symptoms seem to fit. The health-record studies suggest that heart rhythm problems, heart failure, and carpal tunnel syndrome are common pieces of the story before an ATTRwt diagnosis is made, which may help explain why ATTRwt is sometimes first suspected in cardiology or after orthopedic issues. The diagnostic accuracy study of fat aspiration adds an important caution for ATTRwt specifically: a negative fat test cannot reliably rule out ATTRwt because the study found the test missed many ATTRwt cases. What remains uncertain is how to best combine these different tools for every person, since the studies describe patterns and test performance rather than a single proven step-by-step approach. [4] [8] [7] [6] [5]

This month’s case reports show how ATTRwt can present outside the classic starting point of heart symptoms, and how diagnosis can require more than one type of evaluation. Across cases, musculoskeletal clues (like carpal tunnel history or wrist findings) appeared alongside or before heart involvement, and imaging did not always give a clear answer on the first try. These reports cannot predict what will happen to most people, but they illustrate real diagnostic situations that can lead to delays or extra testing. [9] [10] [11]

One case described a man with recurrent bilateral carpal tunnel syndrome who developed bilateral wrist masses; surgery and pathology confirmed amyloid deposits from wild-type ATTR, and he was symptom-free at 4 years. Another case described an older woman with heart failure symptoms and prior carpal tunnel surgery where a 99mTc-PYP scan was inconclusive because of blood-pool signal, but a different bone-tracer scan (99mTc-HMDP) showed heart uptake, with heart biopsy confirming TTR-positive amyloid and testing consistent with wild-type ATTR-CM. [9] [10]

A third case described a woman with progressive heart failure and conduction disease requiring pacing, where multimodality imaging supported ATTRwt and monoclonal protein studies were negative. After upgrading her pacing system and starting tafamidis, the report noted symptom stabilization with a modest rise in ejection fraction at 3 months and fewer heart-failure admissions. This case mainly highlights the complexity of ATTRwt when heart rhythm devices and heart failure progress together, rather than proving a typical response to any one intervention. [11]

For patients, these case reports add concrete examples of how ATTRwt may show up in everyday medical situations, including repeat carpal tunnel problems, wrist masses, and heart failure with conduction disease. They also show that one scan can be unclear, and that confirmation sometimes required a different scan or a biopsy in the reported patient. What remains uncertain is how often these exact situations occur, because each report describes only 1 person and outcomes can vary widely. [9] [10] [11]