Renal function decline predicted by left atrial expansion index in non-diabetic cohort with preserved systolic heart function

Aims: Since natriuretic peptide and troponin are associated with renal prognosis and left atrial (LA) parameters are indicators of subclinical cardiovascular abnormalities, this study investigated whether LA expansion index can predict renal decline. Methods and Results: This study analysed 733 (69% male) non-diabetic patients with sinus rhythm, preserved systolic function, and estimated glomerular filtration rate (eGFR) higher than 60 mL/min/1.73 m2. In all patients, echocardiograms were performed and LA expansion index was calculated. Renal function was evaluated annually. The endpoint was a downhill trend in renal function with a final eGFR of <60 mL/min/1.73 m2. Rapid renal decline was defined as an annual decline in eGFR >3 mL/min/1.73 m2. The median follow-up time was 5.2 years, and 57 patients (7.8%) had renal function declines (19 had rapid renal declines, and 38 had incidental renal dysfunction). Events were associated with left ventricular mass index, LA expansion index, and heart failure during the follow-up period. The hazard ratio was 1.426 (95% confidence interval, 1.276-1.671; P < 0.0001) per 10% decrease in LA expansion index and was independently associated with an increased event rate. Compared with the highest quartile for the LA expansion index, the lowest quartile had a 9.7-fold risk of renal function decline in the unadjusted model and a 6.9-fold risk after adjusting for left ventricular mass index and heart failure during the follow-up period. Conclusions: Left atrial expansion index is a useful early indicator of renal function decline and may enable the possibility of early intervention to prevent renal function from worsening.