Atrial mechanics and their prognostic impact in Takotsubo syndrome: A cardiovascular magnetic resonance imaging study

Abstract

Aims: The exact pathophysiology of Takotsubo syndrome (TTS) remains not fully understood with most studies focussing on ventricular pathology. Since atrial involvement may have a significant role, we assessed the diagnostic and prognostic potential of atrial cardiovascular magnetic resonance feature tracking (CMR-FT) in TTS. Methods and results: This multicentre study recruited 152 TTS patients who underwent CMR on average within 3 days after hospitalization. Reservoir [total strain ϵs and peak positive strain rate (SR) SRs], conduit (passive strain ϵe and peak early negative SRe), and booster pump function (active strain ϵa and peak late negative SRa) were assessed in a core laboratory. Results were compared with 21 control patients with normal biventricular function. A total of 20 patients underwent follow-up CMR (median 3.5 months, interquartile range 3-5). All patients were approached for general follow-up. Left atrial (LA) but not right atrial (RA) reservoir and conduit function were impaired during the acute phase (ϵs: P = 0.043, ϵe: P < 0.001, SRe: P = 0.047 vs. controls) and recovered until follow-up (ϵs: P < 0.001, SRs: P = 0.04, ϵe: P = 0.001, SRe: P = 0.04). LA and RA booster pump function were increased in the acute setting (LA-ϵa: P = 0.045, SRa: P = 0.002 and RA-ϵa: P = 0.004, SRa: P = 0.002 vs. controls). LA-ϵs predicted mortality [hazard ratio 1.10, 95% confidence interval (CI) 1.01-1.20; P = 0.037] irrespectively of established cardiovascular risk factors (P = 0.019, multivariate analysis) including left ventricular ejection fraction (LVEF) (area under the curve 0.71, 95% CI 0.55-0.86, P = 0.048). Conclusion: TTS pathophysiology comprises transient impairments in LA reservoir and conduit functions and enhanced bi-atrial active booster pump functions. Atrial CMR-FT may evolve as a superior marker of adverse events over and above established parameters such as LVEF and atrial volume.