Relationship between the strain measures of left atrial function and heart failure worsening

BACKGROUND

Two-dimensional speckle tracking evaluation (2D-STE) is a useful tool to evaluate the complexity of atrial function by the analysis of the different phases of atrial deformation and by the combination with Doppler measurements of diastolic function.

AIM OF THE STUDY

To evaluate the role of the left atrial (LA) strain parameters to predict worsening chronic heart failure (CHF).

METHODS

We enrolled outpatients affected by CHF referred to our heart failure unit. Each patient underwent a medical visit, an electrocardiogram (ECG), and an echocardiographic examination. LA function was assessed by 2D-STE. The three phases of LA strain, that is, the reservoir (LAr), the conduit (LAcd), and the contraction (LAct)-were evaluated. Moreover, the ratio between E and LAr (E/LAr) and those between LAr and septal (LAr/Ees), lateral (LAr/Eel), and septal-lateral (LAr/Eem) E/e' were measured. During follow-up, the events related to worsening of heart failure were evaluated.

RESULTS

Two hundred eleven patients were enrolled. During a mean follow-up of 14 ± 7 months, 37 patients showed at least one event related to heart failure worsening. At univariate Cox regression analysis, LAr, LAcd, LAct, E/LAr, LAr/Ees, LAr/Eel, and LAr/Eem were all associated with events related to heart failure worsening, but at multivariate regression analyses, only LAr (Hazard Ratio, HR: .95; 95% Confidence Interval, CI: .92-.99; p: .031), LAct (HR: 1.06; 95% CI: 1.01-1.12; p: .027), E/LAr (HR: 1.10; 95%CI: 1.0-1.16; p < .001), LAr/Ees (HR: .57; 95% CI: .37-.87; p: .010), and LAr/Eem (HR: .71; 95% CI: .53-.96; p: .026) remained significantly associated with the events. Finally, in a predictive model including the other relevant echocardiographic parameters LAr < 18%, LAct > -10.0%, LAr/Ees < 1.28, and E/LAr > 3.70 were associated with a statistically significant overall net reclassification improvement.

CONCLUSIONS

In CHF patients, the measure of the LA reservoir and contraction by 2D-STE is independently associated with heart failure worsening, but the accuracy in predicting the events is even greater when the reservoir is combined with the Doppler measures of diastolic function.

P235 CLINICAL AND INSTRUMENTAL CORRELATES OF LEFT AND RIGHT ATRIAL TWO–DIMENSIONAL STRAIN MEASUREMENTS IN PATIENTS WITH HEART FAILURE

Background

The two–dimensional strain obtained through Speckle Tracking Imaging (STI) represents an innovative, rapid and semi–automatic echocardiographic method to study systolic and diastolic function. By analyzing the deformation of cardiac segments, it provides an indirect index of myocardial contractility and relaxation of left and right ventricles, but also of both left and right atria.

Purpose of the Study

The aim of this study was to evaluate the clinical and instrumental correlates of the different measures of right and left atrial strain in a group of patients with chronic heart failure (CHF). Method. We enrolled 165 out patients with CHF (63 ± 14 years, 76% male, 39 ± 11% ejection fraction). All patients underwent a cardiological examination, ECG and echocardiogram. The echocardiographic images were analyzed using an innovative software (TomTec, Philips) able to semi–automatically analyze both the ventricular and atrial strain. For each patient, both for the left atrium (LA) and the right atrium (RA), the measures related to all atrial functional phases were calculated: reservoir (r), conduit (cd) and contraction (ct).

Results

At univariate and multivariate logistic regression models, the main determinants of atrial strain measurements were evaluated. As shown in the Table, both for the RA and LA the reservoir and conduit were more closely associated with ventricular systolic function and age. LA contraction was associated only with E/e‘ and heart rate, whereas for the RA one there was no independent statistical association with the parameters studied.

Conclusions

The Strain parameters that evaluate right and left atrial function have an independent association with different clinical and instrumental variables. These results support the hypothesis that the reservoir and conduit measurements express a different physiological and pathophysiological substrate than the contraction measures.

P233 ASSOCIATIONS BETWEEN LEFT AND RIGHT ATRIAL BIDIMENSIONAL STRAIN AND HEART FAILURE PROGRESSION

Background

Two dimensional speckle tracking is an innovative echocardiographic method which analyses myocardial deformation thus allowing the evaluation of both atrial and ventricular function. Recently, new software are available to measure it by semiautomatic analyses.

Aim of the Study

To evaluate the association between left and right atrial Strain and the occurrence of clinical events related to the heart failure (HF) progression. Method. We enrolled 165 outpatients with chronic HF (76% males, NYHA 2.2 ± 0.69, ejection fraction 39±11%). All underwent a clinical and echocardiographic evaluation. An innovative software (TomTec, Philips) was used to analyse the images in order to semi–automatically calculate of atrial Strain. For each patient all the measures relative to the different phases of atrial deformation were considered both for the left atrium (LA) and the right one (RA), i.e. reservoir (r), conduit (cd) and contraction (ct). During the follow–up, we defined the HF progression as hospitalization due to HF worsening and/or heart transplantation and/or cardiovascular death.

Results

During a median follow–up of 5 months, at least one event related to HF progression occurred in 22 patients: all underwent at least one hospitalization, 7 patients died because of cardiovascular reasons and 2 underwent heart transplantation. At Cox univariate analysis, LASr (HR: 0,93; 95%CI: 0,88–0,97, p: 0.004; C–index 0,7), LAScd (HR: 1,09; 95%CI: 1,01–1,19; p: 0,023; C–index: 0,64), RASr (HR: 0,95; 95%CI: 0,90–0,99; p: 0,031; C–index: 0,68), RAScd (HR: 1,08; 95%CI: 1,01–1,15; p: 0,021; C–index: 0,67), but not LASct (HR: 1,04; 95%CI: 0,99–1,09; p 0,094; C–index 0,62) and RASct (HR: 1,02; 95%CI: 0,96–1,09; p: 0,61; C–index: 0,55), were significantly associated to HF progression. LASr and RASr showed the higher accuracy in predicting the events by the estimation of C index. At ROC curve analysis, for LASr the best cut–off was 16.1% (Sensitivity 83%, Specificity 56%) and for RASr 17.3% (Sensitivity 79%, Specificity 60%). Figure shows Kaplan–Meier curves for the considered end–point according with these cut–offs.

Conclusions

The preliminary results of this study have showed the association between LA and RA Strain variables and the HF progression. The prosecution of this study will be finalised to demonstrate the prognostic independent and incremental significance.