Abstract 12531: High Left Atrial Volume Impairs Survival in End Stage Renal Disease: Results From a Prospective Cohort of 575 Patients

Abstract

Background: Left atrial volume index (LAVI) is a predictor of poor prognosis in a variety of cardiovascular disorders. Patients with end stage renal disease (ESRD) have high rates of cardiovascular events and mortality. These patients often have enlarged left atrium secondary to uncontrolled hypertension, volume overload and impaired left ventricular diastolic function. There is limited prospective prognostic data on LAVI in this high risk population.

Methods: We prospectively studied 575 ESRD patients undergoing kidney transplant evaluation at our dedicated cardiology clinic from July 2008 to October 2010. All patients had an echocardiogram on pre or post dialysis days. Demographic, clinical, laboratory and pharmacological data were collected prospectively. Biplane LAVI was calculated at endsystole using Simpson’s method and classified as normal (< 28 ml/m2), mildly enalrged (29-33 ml/m2), moderately enlarged (34-39 ml/m2) and severely enalrged (>40 ml/m2) based on ASE guidelines. Survival was analyzed using the Cox regression method.

Results: Baseline characteristics were as follows: age 57±12 years, males 62%, hypertension 96%, diabetes mellitus 65%, CAD 22%, baseline LVEF 62±12%, 77% on hemodialysis,10% on peritoneal dialysis. The LAVI was normal in 30%, and was increased mildly in 16%, moderately in 17% and severely in 37%. The correlates of increased LAVI included older age (p<0.0001), diabetes mellitus (p=0.009), lower EF (p<0.0001), LV hypertrophy (p=0.0004), mitral regurgitation (p<0.0001), higher left atrial pressure (p<0.0001), higher right atrial pressure (p=0.02) and pulmonary hypertension (p<0.0001). Over a period of 2 years, there were 46 deaths. High LAVI was a predictor of poor survival (HR 1.02 per ml, 95% CI 1.00-1.06, p=0.05) after adjusting for age, gender, hypertension, diabetes, LV hypertrophy, LVEF, high filling and pulmonary artery pressures and treatment with antihypertensive medications.

Conclusions: 1) Left atrial enalrgement is common in ESRD patients and correlates with age diabetes, lower EF, LV hypertrophy, mitral regurgitation and higher filling and pulmonary pressures. 2) It is independently predictive of higher mortality. 3) These mechanistic insights we may help in reducing this risk.