Impact of left atrial volume in prediction of outcome after cardiac resynchronization therapy

Left atrial volume index (LAVI) as a predictor of mortality has not been well investigated in patients with cardiac resynchronization therapy (CRT). The purpose of this study is to evaluate the impact of LAVI in predicting mortality in CRT patients.

We studied 100 consecutive patients who received CRT (male 73, age 69.9 ± 9.6 years). The follow-up duration of all echocardiographic measurements was 14.4 ± 10.5 months after CRT. LAVI was measured from apical views on two-dimensional echocardiography by bi-plane rule. A decrease of left ventricular end systolic volume ≥ 15% after CRT was defined as a positive response to CRT.

The mean LAVI at baseline was 59.9 ± 22.7 ml/m(2). LAVI in patients who died (78.2 ± 27.5 ml/m(2)) was significantly greater than those who survived (55.9 ± 19.5 ml/m(2), p<0.0001) during follow-up of 17 ± 10.6 months. The area under ROC curve (AUC) for LAVI predicting death was 0.77 (p=0.0001). The cutoff point for LAVI predicting death was LAVI>59.4 ml/m(2). LAVI>59.4 ml/m(2) was related to mortality by Cox proportional univariate regression [hazard ratio (HR)=5.15, 95% CI=1.48-17.93, p=0.01]. After adjustment for the variables with significant difference by univariate regression, LAVI>59.4 ml/m(2) was continuously related to mortality by multivariate regression (HR=4.56, 95% CI, 1.30-15.97, p=0.02). LAVI>59.4 ml/m(2) was associated with a near 5-fold increase in mortality during follow-up of 17 ± 10.6 months.

Patients who have LAVI>59.4 ml/m(2) continue to have increased mortality despite CRT.