Left atrial deformation analysis in patients with non-ischaemic dilated cardiomyopathy in atrial fibrillation

Aims

Atrial fibrillation (AF) is a common comorbidity in non-ischaemic dilated cardiomyopathy (NIDCM) affecting conventional measures of left atrial (LA) function. We aimed to determine whether LA function analysis could identify patients at higher risk of major cardiovascular events (MACEs).

Methods and results

A retrospective study of patients with NIDCM in AF referred to a single centre for transthoracic echocardiography (TTE) between 2015 and 2019. Peak atrial longitudinal strain (PALS) was measured along with LA emptying fraction and LA filling index (LAFI = E wave/PALS). Cox regression analysis was conducted. A total of 153 patients were included [median age 74 years, left ventricular ejection fraction (LVEF) 35%], and 57 (37.3%) had MACE after a median follow-up of 3.2 years. LAFI was the only independent TTE parameter associated with MACE after adjustment for age, diabetes, LVEF, left ventricular global longitudinal strain (LV-GLS), and LA volume index [adjusted hazard ratio (HR) = 1.02 per point increase, P = 0.024], with the best cut-off at ≥15. LAFI ≥15 predicted each of MACE components when separately analysed: MACE HR = 1.95, 95% confidence interval (CI) 1.16-3.30; cardiovascular death HR = 3.68, 95% CI 1.41-9.56, heart failure admission HR = 2.13, 95% CI 1.19-3.80, and ventricular arrhythmia HR = 4.72, 95% CI 1.52-14.67. Higher LAFI was associated with worsening LV-GLS, E/e', systolic pulmonary artery (PA) pressure, tricuspid annular plane systolic excursion, and right ventricular to PA coupling.

Conclusion

LA deformation analysis is feasible in patients with NIDCM presenting with AF. LAFI may identify patients at higher risk of MACE and correlates with higher pulmonary pressures and worse right ventricular function, suggesting an elevation of left-sided ventricular pressures in patients with higher LAFI.

Risk of Stroke and Incident Atrial Fibrillation in Patients in Sinus Rhythm With Nonischemic Dilated Cardiomyopathy

Nonischemic dilated cardiomyopathy (NIDCM) is associated with an increased risk of atrial fibrillation (AF) and stroke, especially in patients with high CHA2DS2-VASc. We aimed to identify variables associated with incident AF or stroke using left atrial deformation analysis and its prognostic value added to CHA2DS2-VASc score. Patients with NIDCM and left ventricular ejection fraction <50% in sinus rhythm were included between January 2015 and December 2019. Left atrial volume index (LAVI) and atrial strain were used in combination with the CHA2DS2-VAS score to predict ischemic stroke or incident AF. Proportional hazards Cox regression was used to provide hazard ratios (HRs). There were 338 patients included. After a median follow-up of 3.6 years, the end point occurred in 41 patients (12.1%). LAVI outperformed other echocardiographic parameters, with a significant improvement in risk reclassification compared with CHA2DS2-VASc alone (net reclassification index 0.6, increase in Harrell's C from 0.63 to 0.73, p = 0.003), and remained significant after multivariate adjustment. LAVI was associated with both components of the end point separately. The best cutoff for LAVI was 44 ml/m2. LAVI ≥44 ml/m2 increased the risk of the end point among those with CHA2DS2-VASc ≥3 (HR 6.0, 95% confidence interval 2.6 to 13.5) but not in those with CHA2DS2-VASc <3 (HR 1.2, 95% confidence interval 0.3 to 4.5). Competing risk analysis did not alter the results. In conclusion, LAVI might be used to assess the risk of incident AF or stroke in NIDCM. Patients with LAVI ≥44 ml/m2 and CHA2DS2-VASc ≥3 could be at high risk of AF and stroke and may benefit from more intensive surveillance.

Left atrial strain in non-ischemic dilated cardiomyopathy in sinus rhythm: Prognostic implications and interrelationship with left ventricular deformation

BACKGROUND

Left atrial deformation analysis may identify patients at higher risk of adverse events in the setting of non-ischemic dilated cardiomyopathy (NIDCM). The purpose was to determine the association between peak longitudinal (PALS) and contraction (PACS) LA strain in NIDCM, accounting for left ventricular global longitudinal strain (LV-GLS).

METHODS

Consecutive patients with NIDCM, sinus rhythm and LV ejection fraction (LVEF)<50 % were included. PALS, PACS and LV-GLS were obtained from echocardiography images. The composite outcome was a combination of hospitalization for heart failure, cardiovascular death, or ventricular arrhythmia. The association with the composite outcome was assessed using Cox regression and a classification and regression tree (CART) analysis was performed.

RESULTS

Among 347 patients included (median age 66 years old, median LVEF 35 %), median PALS and PACS values of 16 % and 9 %. After a median follow-up of 3.6 years, the composite outcome occurred in 70 (20.2 %) patients. PACS ≤8 % was associated with the composite outcome (adjusted HR = 2.73, 95 %CI 1.33-5.60), mostly by increasing the risk of heart failure admission. LV-GLS increased the risk of the composite outcome among patients with PACS>8 % (HR = 1.20, 95 %CI 1.07-1.35). PALS more strongly correlated with LV-GLS (Spearmans' rho = -0.71) than PACS (rho = -0.5). A decreased PALS/LV-GLS ratio was associated with higher rates of the composite outcome.

CONCLUSION

LA dysfunction is a major determinant of the composite outcome in NIDCM with LVEF <50 % and should be routinely assessed. PACS may perform better than PALS when combined with LV-GLS, probably due to lesser dependency from mitral annular motion.