Results
Out of the 274 patients, LA strain analysis was not evaluable in 39
because of the presence of atrial fibrillation with irregular rhythm and
in 7 because of poor quality of imaging. The clinical and
echocardiographic characteristics of the remaining 228 are shown in
Table 1. Among the patients enrolled, 17 presented atrial fibrillation
with regular ventricular paced rhythm; 31 (13.6%) were in KDOQI Class
1, 111 (48.7%) in Class 2, 43 (18.9%) in Class 3a, 34 (14.9%) in
Class 3b, 8 (3.5%) in Class 4, and 1 in Class 5.
Left atrial strain measures’ reproducibility. A high degree of
intra-observer and intra-observer reproducibility was observed for LAr
(average ICC = 0.93; 95% CI: 0.84–0.97 and ICC: 0.87; 95% CI:
0.71–0.95, respectively) as well as for LAcd (ICC: 0.93; 95% CI:
0.84–0.97 and ICC: 0.86; 95% CI: 0.68–0.94, respectively) and LAct
(ICC: 0.89; 95% CI: 0.76–0.96 and ICC: 0.80; 95% CI: 0.56–0.91,
respectively).
Clinical and echocardiographic correlates of left atrial strain
measures. As shown in Supplementary Table 1, LAr was significantly and
positively correlated with GFR-EPI, LVEF, TAPSE, e’s, e’l, and e’m and
significantly and negatively correlated with age, NYHA class, heart
rate, LVEDV, LVESV, LAVi, MR, TR, E/e’s, E/e’m, LV-GLS, RV-GLS, and
RVfwLS. LAcd was significantly and positively correlated with age, NYHA
class, heart rate, LVEDV, LVESV, LAVi, TR, E/e’s, E/e’m, LV-GLS, RV-GLS,
and RVfwLS and significantly and negatively correlated with GFR-EPI,
LVEF, TAPSE, e’s, e’l, and e’m. LAct was significantly and positively
correlated with NYHA class, heart rate, LVEDV, LVESV, LAVi, MR, TR,
E/e’s, E/e’m, LV-GLS, RV-GLS, and RVfwLS and significantly and
negatively correlated with GFR-EPI, LVEF, and TAPSE. LAr/Eel, LAr/Ees,
and LAr/Eem were significantly and positively correlated with SAP,
GFR-EPI, LVEF, TAPSE, e’s, e’l, and e’m and significantly and negatively
correlated with age, NYHA class, heart rate, LVESV, LAVi, MR, TR, E/e’s,
E/e’m, LV-GLS, RV-GLS, and RVfwLS.
Left atrial strain measures and heart failure worsening. During a
mean follow-up of 14±7 months, at least one event related to heart
failure worsening (40 hospitalisations caused by acute decompensated
heart failure, 5 heart transplantations, and 19 cardiovascular deaths)
occurred in 47 patients. As shown in Table 2, during univariate Cox
regression analysis, LAr, LAcd, and LAct were all associated with events
related to heart failure worsening. In forward stepwise Cox regression
analysis, LAr (HR: 0.94; 95% CI: 0.91–0.98; p: 0.006) and LAct (HR:
1.05; 95% CI: 1.00–1.10; p: 0.043) but not LAcd remained associated
with events after correction for NYHA class, heart rate, age, MR, TR,
LVEF, GFR-EPI, and TAPSE.
Analogously, LAr/Eel, LAr/Rrs, and LAr/Eem were associated with events
during univariate analysis, but only LAr/Ees and LAr/Eem remained
significantly associated with them during multivariate analysis (HR:
0.49; 95% CI: 0.30–0.78; p: 0.002 and HR: 0.65; 95% CI: 0.47–0.89;
p: 0.008, respectively) after correction for NYHA class, heart rate,
age, MR, TR, LVEF, GFR-EPI, and TAPSE. As shown in Figure 2, the
presence of a reduced or mildly reduced/preserved LVEF did not influence
the prognostic value of all the LA strain measures as well as of those
derived by the combination with Doppler measures.
ROC curves. As shown in Supplementary Figure 1, among the LA
measures derived by strain analysis, LASr/Ees (AUC 0.76; 95% CI:
0.67–0.85) showed the greater ROC AUC, followed by LASr/Eem (AUC 0.75;
95% CI: 0.65–0.84), LASr (AUC 0.71; 95% CI: 0.63–0.80), LASct (AUC
0.70; 95% CI: 0.61–0.78), and LAScd (AUC 0.60; 95% CI: 0.52–0.69).
For LASr, the best cut-off was 17% (sensitivity of 72% and specificity
of 60%), for LASr/Ees 1.28 (sensitivity of 80% and specificity of
64%), and for LASr/Eem 1.60 (sensitivity of 77% and specificity of
59%). Figure 3 shows the Kaplan–Meier curves of the patients
dichotomised according to the best cut-off of LASr (Panel A) and
LASr/Ees (Panel B).