Impaired left atrial (LA) function, particularly atrial electromechanical dissociation (AEMD), appears to increase the risk of cerebrovascular events in patients with transthyretin amyloid cardiomyopathy (ATTR-CM), suggests a study.
“Because patients with ATTR-CM not in atrial fibrillation (AF) rarely receive anticoagulation, these data suggest that they are at substantial increased risk for stroke and transient ischaemic attack (TIA), and thus might benefit from anticoagulation,” the investigators said.
A total of 2,310 patients with ATTC-CM were included in the analysis. Of these, 873 (mean age 77 years, 82 percent male, 61 percent wild type, CHA2DS2-VASc 4) were in sinus rhythm (SR) and not receiving anticoagulation. Some 115 (13.2 percent) patients had AEMD. [J Am Coll Cardiol 2026;88:1371-1383]
Among patients in SR, 269 (30.8 percent) developed incident AF, and 85 (9.7 percent) had a stroke/TIA. Those with baseline AF being treated with anticoagulants had a stroke/TIA rate of 0.7 per 100 person-years (PY).
Patients with AEMD showed a 2.4-fold higher incident AF and threefold greater risk of stroke or TIA than those with SR with LA mechanical contraction (8.7 vs 2.5 per 100 PY, respectively for stroke/TIA), independent of CHA2DS2-based scores and markers of disease severity.
Among patients in SR with no AEMD (n=748), left atrial strain contraction (LASc) tertiles (<4 percent, 4 percent to 7 percent, and >7 percent) independently correlated with a 1-year stroke/TIA risk. Specifically, LASc <4 percent was associated with a tenfold higher risk of stroke/TIA than >7 percent. This association persisted after adjusting for National Amyloidosis Centre stage and prior cerebrovascular events.
Improved stratification
Notably, the addition of LASc tertiles to CHA2DS2-VASc or CHA2DS2-VA resulted in significant improvements in model fit and risk stratification at 1 year.
“Guideline thresholds for anticoagulation are defined using the CHA2DS2-VASc score rather than a fixed absolute risk,” the investigators said. [J Am Coll Cardiol 2024;83:1:109-279; Stroke 2024;55:e344-e424; Eur Heart J 2024;45:3314-3414]
The original derivation study showed that the anticoagulation threshold based on CHA2DS2-VASc indicated a nearly 2.9 percent risk for stroke, TIA, or systemic embolism at 1 year, providing a basis for comparison. [Chest 2010;137:263-272]
“In our study, patients in SR with LASc <4.0 percent had a 1-year cerebrovascular event rate exceeding 2.9-percent 1-year absolute risk of cerebrovascular events,” the investigators said. [J Am Coll Cardiol 2015;66:488-490; Stroke 2016;47:1831-1836]
“This rate rose dramatically to over ∼9.0 percent per year in patients with AEMD, despite these individuals remaining in SR and not receiving anticoagulation therapy,” they added.
Among patients with AF on anticoagulation therapy, the event rate was 0.7 per 100 PY. Those on anticoagulation usually have higher comorbidity burden and baseline thromboembolic risk. However, their crude rate event was lower than that observed among patients with AEMD of LASc <4 percent, according to the investigators.
“These findings confirm that impairment in atrial mechanics is a powerful and potentially clinically actionable marker of thromboembolic risk in ATTR-CM, with potential implications, moving beyond a purely rhythm-guided framework toward a function-informed approach to risk stratification,” the investigators said.
This study involved patients diagnosed with ATTR-CM between January 2003 and December 2023 at the UK National Amyloidosis Centre. LA function was assessed using speckle-tracking strain echocardiography. AEMD was defined as SR on electrocardiogram with absent LASc.
The investigators stratified patients in SR according to LASC tertiles. They assessed cerebrovascular events (stroke/TIA) and AF development. Death was treated as a competing event.