Undergraduate Student St. Paul's Hospital Vancouver, British Columbia, Canada
Background: Transthyretin amyloid cardiomyopathy (ATTR-CM) is a progressive infiltrative cardiomyopathy that is increasingly recognized as an important cause of heart failure (HF). With multiple treatment options becoming available, we aimed to describe the clinical outcomes of patients with ATTR-CM in a real-world cohort.
METHODS AND RESULTS: Patients who underwent pyrophosphate scintigraphy for suspected ATTR-CM were enrolled in a prospective observational registry initiated in 2018 and followed for 3 years. Participants were analysed based on the presence or absence of ATTR-CM. Outcomes of interest included all-cause mortality, cardiovascular mortality, all-cause, HF, and arrythmia hospitalizations, non-cardiac hospitalizations, myocardial infarction (MI), and stroke. P-values for outcomes were calculated using the Log-Rank (Mantel-Cox) test.
Of 200 participants enrolled in our registry, 46 (23.0%) were diagnosed with ATTR-CM. Patients with ATTR-CM were more likely to be male (37 (80.4%) vs. 92 (59.7%); p = 0.013), older (mean age 82.6 ± 7.2 vs. 77.2 ± 8.2 years; p < 0.001), and have a history of HF (45 (97.8%) vs. 121 (78.6%); p = 0.001), compared to the non-ATTR-CM group. At 3 years, the cumulative incidence of all-cause mortality was significantly higher in the ATTR-CM group (21 (45.7%) vs. 28 (18.2%); p < 0.001), driven predominantly by cardiovascular death (14 (30.4%) vs. 10 (6.5%); p < 0.001). HF hospitalization was also more frequent among ATTR-CM patients (15 (32.6%) vs. 22 (14.3%); p = 0.005), contributing to a higher cumulative incidence of all-cause hospitalization (30 (65.2%) vs. 71 (46.1%); p = 0.018). There were no significant differences in MI (1 (2.2%) vs. 4 (2.6%); p = 0.089), stroke or transient ischemic attack (2 (4.3%) vs. 7 (4.5%); p = 0.957), hospitalization for arrhythmia (6 (13%) vs. 12 (7.8%); p = 0.242), or non-cardiac hospitalizations (13 (28.3%) vs. 49 (31.8%); p = 0.581). At 3-year follow-up, 77.8% of patients with ATTR-CM were receiving transthyretin stabilizer therapy.
Conclusion: This registry highlights the significant disease burden of ATTR-CM, a systemic and progressive condition marked by high rates of HF, hospitalization, and mortality. Emerging treatments have the potential to meaningfully improve outcomes in this high-risk population.
