Left Atrial Volume as a Biomarker of Target Organ Damage in Cardio-Nephrology: A Study in a Wide Range of Renal Function

Rabeeh Fares 1 Zach Rozenbaum 2 Yitzhak Hadad 1 Moshe Iluz 1 Tomer Ziv-Baran 3 Galit Aviram 1
1Department of Radiology, Tel Aviv Medical Center, Tel Aviv, Affiliated to the Sackler faculty of Medicine, Tel Aviv University, Israel
2Department of Cardiology, Tel Aviv Medical Center, Tel Aviv. Affiliated to the Sackler faculty of Medicine, Tel Aviv University, Israel
3Department of Epidemiology and Preventive Medicine, School of Public Health, Sackler Faculty of Medicine, Tel Aviv University, Israel

PURPOSE: Cardiac chambers` sizes were previously studied by echocardiography, among patients with progressive kidney disease only. We aimed to explore the relations between all heart chambers` volumes as assessed by CT pulmonary angiography and renal function – throughout all ranges.

METHODS: Using a novel technology of automatic four chamber volumetric analysis, we analyzed CT pulmonary angiographies of 744 consecutive patients (between January 1st and December 31st, 2014) without pulmonary embolism, and correlated the chambers` volumes indexed to body surface area, to the estimated glomerular filtration rates.

RESULTS: After adjustment for age, all cardiac chambers` volumes aside from the left ventricle inversely correlated to estimated glomerular filtration rate. For every 10 units decrease in estimated glomerular filtration rate, the volume indices of the left atrium (LA), right atrium and right ventricle were larger by 3.1%, 2.3% and 1.5%, p<0.001, p=0.003, p=0.007, respectively. There was a significant correlation between LA volume index (LAVI) and eGFR (r=-0.43; p<0.001). In a categorical comparison, patients with even minimal renal dysfunction (estimated glomerular filtration rate 60-90 ml/min/1.73m2) had a 10.3% larger LAVI (95%CI 3.1-17.9; p=0.004) compared to patients with an estimated glomerular filtration rate >90 ml/min/1.73m2.

CONCLUSION: A simple concomitant volumetric analysis of all four cardiac chambers of CT pulmonary angiography demonstrated that differences in volumes correlate to renal function even within the normal range spectrum. The difference was most evident in the left atria. This finding may be the first clue to an evolving cardio-renal syndrome and may serve as a target for early therapeutic interventions.