Interaction between secondary mitral regurgitation and left atrial function and their prognostic implications after cardiac resynchronization therapy

Eur Heart J Cardiovasc Imaging. 2023 Mar 21;24(4):532-541. doi: 10.1093/ehjci/jeac149.

Abstract

Aims: Left atrial (LA) function is a strong prognostic marker in patients with heart failure and functional mitral regurgitation (MR). Although cardiac resynchronization therapy (CRT) has shown to improve MR severity, the interaction between a reduction in MR severity and an increase in LA function, as well as its association with outcomes, has not been investigated.

Methods and results: LA reservoir strain (RS) was evaluated with speckle tracking echocardiography in patients with at least moderate functional MR undergoing CRT implantation. MR improvement was defined as at least 1 grade improvement in MR severity at 6 months after CRT implantation. The primary endpoint was all-cause mortality. A total of 340 patients (mean age 66 ± 10 years, 73% male) were included, of whom 200 (59%) showed MR improvement at 6 months follow-up. On multivariable analysis, an improvement in MR severity was independently associated with an increase in LARS (odds ratio 1.008; 95% confidence interval 1.003-1.013; P = 0.002). After multivariable adjustment, including baseline and follow-up variables, an increase in LARS was significantly associated with lower mortality. MR improvers showing LARS increasement had the lowest mortality rate, whereas outcomes were not significantly different between MR non-improvers and MR improvers showing no LARS increasement (P = 0.236).

Conclusion: A significant reduction in MR severity at 6 months after CRT implantation is independently associated with an increase in LARS. In addition, an increase in LARS is independently associated with lower all-cause mortality in patients with heart failure and significant functional MR.

Keywords: cardiac resynchronization therapy; functional mitral regurgitation; heart failure; left atrial reservoir strain; mortality.

MeSH terms

  • Aged
  • Atrial Function, Left
  • Cardiac Resynchronization Therapy* / methods
  • Female
  • Heart Failure* / complications
  • Heart Failure* / diagnostic imaging
  • Heart Failure* / therapy
  • Humans
  • Male
  • Middle Aged
  • Mitral Valve Insufficiency* / diagnostic imaging
  • Mitral Valve Insufficiency* / etiology
  • Mitral Valve Insufficiency* / therapy
  • Prognosis
  • Treatment Outcome