Medical Affairs Pfizer Vaudreuil-Dorion, Quebec, Canada
Background: Transthyretin amyloid cardiomyopathy (ATTR-CM) is a rare, progressive, and fatal disease caused by the extracellular deposition of misfolded transthyretin (TTR) protein in the myocardium. Despite advances in cardiac imaging and a non-invasive diagnosis, many patients remain undiagnosed until advanced disease stages. Treatment options are available to slow the disease progression, but the benefits are greater when initiated early.
METHODS AND RESULTS: CAN-TACTICS is a two-phase survey study of healthcare providers (HCPs) aimed at describing approaches to cardiovascular imaging for diagnosing ATTR-CM in Canada. This abstract reports the findings from phase one, which involved semi-structured qualitative interviews on clinical experiences. This abstract summarizes responses from HCPs who primarily manage ATTR-CM and echocardiography specialists.
Nineteen (19) HCPs were interviewed from July to November 2024. Participants’ clinical specialty and province are described in Table-1. The areas of specialty were cardiac amyloidosis clinic (n=6), Nuclear imaging (n=6), echocardiography (n=4) and cardiac MRI (n=3). Access rates to diagnostic testing in participants’ region were echocardiography (100%), nuclear imaging (84.2%), cardiac MRI (78.9%), genetic testing (42.1%), cardiac biopsy (31.6%), and salivary/fat pad biopsies (5.3%). Wait times for testing from the shortest to the longest were as follows: electrocardiography, troponin and NT-proBNP/BNP (1 to 14 days) < SPEP/UPEP (1 to 6 weeks) < genetic testing 4 to 6 weeks < PYP scintigraphy and cardiac biopsy (1 to 3 months) < echocardiography (0.25 to 7 months < cardiac MRI 1.5 to 5 months. Eight HCPs attending cardiac amyloidosis clinics described their approach to diagnosing ATTR-CM (Figure-1). Echocardiography and troponins and NT-proBNP were used for baseline evaluation and monitoring treatment response by 25%. All echocardiography specialists (n=5) reported that they routinely commented on infiltrative cardiomyopathy or suspected amyloidosis on the echocardiogram report. Approach to global longitudinal strain assessment varied: applied to all patients (40.0%), only if increased wall thickness (40.0%) or only when explicitly requested in the referral (20.0%). While all acknowledged that a 12 mm wall thickness was an established trigger for further ATTR-CM evaluation, most HCPs (80.0%) did not use this threshold due to multiple reasons.
Conclusion: The study sheds light on the current diagnostic and management approaches for ATTR-CM in Canada, highlighting a lack of standardization in imaging approaches. A limitation is the small sample size, but the larger CAN-TACTICS phase 2 survey will increase the sample size and scope of this analysis.
