TORONTO — Increased left-atrial volume and abnormal left-ventricular geometry were each independent predictors of death among elderly patients with preserved systolic heart function in a study with more than 11,000 subjects.
The findings suggest a potential role for left-atrial volume index and assessment of left-ventricular geometry in evaluating elderly patients, Dr. Dharmendrakumar A. Patel said at the 14th World Congress on Heart Disease. Both parameters are measured by echocardiography.
A high left-atrial volume index may be an indicator of diastolic dysfunction, said Dr. Patel, a researcher at the Ochsner Clinic in New Orleans. But as of today, no interventions have proved to reduce left-atrial volume and thereby improve prognosis.
His study used echo results from 11,039 patients aged older than 70 years (average age 78 years) who were referred for an echocardiographic examination at the Ochsner Clinic during 2004-2006. All of the patients had a left-ventricular ejection fraction of at least 50%, and their average ejection fraction was about 60%. None of the patients had severe valve disease.
During an average follow-up of 1.6 years, 1,531 of the patients (14%) died.
Analysis of mortality by left-atrial volume index showed that the patients in the quartile with the largest left atria had a 19% mortality rate, significantly higher than the 11% death rate among the patients in the quartile with the smallest left atria. (See box.) The average left-atrial volume index was 32.5 mL/m
Patients with abnormal left-ventricular geometry also had worse survival, compared with those with normal geometry. The mortality rate during follow-up was 12% among those with normal left-ventricular geometry at baseline (about 50% of all people in the study), compared with 19% mortality among the 5% of patients with concentric, left-ventricular hypertrophy at baseline, the geometry that carried the highest mortality risk. Patients with concentric remodeling and those with eccentric hypertrophy also had significantly increased death rates, about 15%-16%, during follow-up.
A multivariate analysis showed that left-atrial volume index and abnormal left-ventricular geometry were significant, independent factors that contributed to mortality in these patients. Other significant mortality determinants were age, gender, body mass index, and left-ventricular ejection fraction.
An additional analysis further documented the additive risk posed by the two echo parameters that Dr. Patel studied. Among the quartile of patients with the highest left-atrial volume index, those who also had a left ventricle with a concentric, hypertrophic shape had a strikingly high, 50% mortality rate during follow-up, he reported.
A limitation of this study was that it included only people who had been referred for an echocardiography examination. Also, Dr. Patel did not have information on the causes of death nor on the prevalence of comorbidities.
Left-atrial volume index and abnormal left-ventricular geometry contributed to mortality. DR. PATEL
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