Emboli are a common complication of amyloid transthyretin cardiomyopathy (ATTR-CM). This study found that the CHA2DS2-VASc score is not useful in predicting embolic events in ATTR-CM patients with or without AF, and that VKAs and DOACs are equally effective in preventing embolism, in this scenario.
Transthyretin amyloid cardiomyopathy (ATTR-CM) is an infiltrative illness with a poor prognosis, and a high cost of treatment. ATTR-CM is characterized by extracellular myocardial deposits of amyloid fibrils leading to heart failure and mortality. Systemic embolism is a possible side effect of transthyretin ATTR-CM.
In this research, published in the European Journal of Heart Failure, the incidence, prevalence, and risk factors related to embolic events in ATTR-CM were discussed. In addition, the performance of the CHA2DS2-VASc score was tested.
A retrospective collection of clinical features, atrial fibrillation (AF) history, and embolic occurrences from ATTR-CM patients was examined at four international amyloid centers. Evaluations were conducted on 1191 ATTR-CM patients with a median age of 77.1 years, over a median of 19.9 months of follow-up.
Ultimately, the researchers discovered that 41 (3.44%) patients experienced embolic events, of which, 24 (57.1%) had AF at initial evaluation, 10 (26%) had AF during follow-up, and seven (16.7%) neither had AF at initial nor follow-up evaluations. In the study population, the combined prevalence of embolic events before initial evaluation and throughout follow-up was 16.2%. Moreover, 566 patients had no history of AF at the initial evaluation, but 173 (30.6%) acquired AF during follow-up.
Additionally, during follow-up 17 of the 566 ATTR-CM patients who did not have AF at first evaluation experienced an embolic episode. Four people were diagnosed with AF prior to the embolic incident. Interestingly, 26 individuals (4.6%) without AF were receiving treatment. A total of 625 patients had a history of AF at the time of their initial examination. Of these, 558 (89.3%) received OAC without interruption during follow-up, 40 (6.4%) received OAC for a portion of follow-up, and 27 (4.3%) did not receive OAC at any point during follow-up.
Non-anticoagulated patients with AF had a higher incidence of embolic events than anticoagulated patients with AF (4.8 embolic events per 100 patients-year [95% CI 2–11.6] vs. 1.7 embolic events per 100 patients-year [95% CI 1.1–2.6]).
Patients with and without AF experienced embolic events, with incidence rates increasing across the clinical range, from sinus rhythm patients not receiving OAC to AF patients with OAC and AF patients not anticoagulated. In addition, this study demonstrated that the CHA2DS2-VASc score was of minimal use in predicting embolic events in ATTR-CM patients with and without AF and that VKAs and DOACs were equally helpful in preventing embolism in this specific context.
The study concluded that embolic events are a prevalent complication of ATTR-CM. The study also provides embolic and bleeding rates based on the presence of AF and use of OAC treatment. OAC medication lowers systemic embolism risk, while VKAs and DOACs have similar rates. The CHA2DS2-VASc score doesn’t correspond well with clinical outcomes in ATTR-CM patients and shouldn’t be used to assess thromboembolic risk. These insights will help plan future field studies.
Vilches, S., Fontana, M., Gonzalez-Lopez, E., Mitrani, L., Saturi, G., Renju, M., . . . Garcia-Pavia, P. (2022). Systemic embolism in amyloid transthyretin cardiomyopathy. European Journal of Heart Failure, 24(8), 1387-1396. doi:10.1002/ejhf.2566