Prognostic Value of Left Atrial Strain for Systemic Embolism in Rheumatic Mitral Stenosis with Sinus Rhythm: Implications for Anticoagulation Strategy

Abstract

Aims: Stroke and systemic embolism are important complications of rheumatic mitral stenosis (MS) even if sinus rhythm (SR) is maintained. We sought to identify the risk factors for these events and to assess the predictive potential of left atrial (LA) mechanics using LA strain in patients with rheumatic MS in SR.

Methods and results: We analyzed 875 patients with rheumatic MS and SR. The primary outcome was defined as a composite of stroke, transient ischemic attack, and noncentral nervous system embolism. Systemic embolic events developed in 124 (14.1%) of 875 patients at a rate of 4.0 per 100 patient-years (95% CI, 2.5-5.5), during a mean follow-up period of 96.4 ± 61.1 months. Patients with systemic embolic events had a higher prevalence of hypertension and old age than those who did not experience such events, without significant differences in LA size. Left atrial reservoir strain (LASr) was impaired in patients with systemic embolic events (18.8 ± 6.8 vs 14.4 ± 5.3; P < .001). Left atrial reservoir strain was an independent predictor of systemic embolic events (hazard ratio, 0.84; 95% CI, 0.80-0.88; P = .001), after adjusting for confounding factors. The optimal LASr cutoff of 16.6%, derived from receiver operating characteristic analysis, identified subgroups with markedly different risks: patients with LASr ≤16.6% showed a 9.5%/year incidence rate (95% CI, 5.9-12.4) of events, while those with LASr >16.6% had a 2.5%/year (95% CI, 1.6-4.1; P < .001).

Conclusions: Impaired LA strain is associated with systemic embolism in patients with rheumatic MS and SR. A targeted anticoagulation approach may be warranted for those with impaired LA strain.

Keywords: Left atrial strain; Rheumatic mitral stenosis; Sinus rhythm; Stroke and systemic embolism.