Cardiac Mechanics and Kidney Function Decline in the Cardiovascular Health Study.

KEY POINTS: Two-dimensional speckle-tracking echocardiography (2D-STE) can detect early changes in cardiac mechanics and may be able to identify individuals at risk for kidney disease progression. Novel indices of cardiac mechanics on 2D-STE may identify a population that may benefit from early diagnosis, monitoring, and treatment. Novel pharmacologic therapies may be beneficial in patients with subclinical myocardial dysfunction at risk for kidney function decline.

BACKGROUND

Clinical heart failure frequently coexists with CKD and may precipitate kidney function decline. However, whether earlier-stage myocardial dysfunction assessable by speckle-tracking echocardiography (STE) is a contributor to kidney function decline remains unknown.

METHODS

We studied 2135 Cardiovascular Health Study participants who were free of clinical heart failure and had year 2 baseline 2D-STE and two measurements of eGFR (year 2 and year 9). “Archival” speckle tracking of digitized echocardiogram videotapes was used to measure left ventricular longitudinal strain (LVLS), LV early diastolic strain rate (EDSR), left atrial reservoir strain (LARS), right ventricular free wall strain (RVFWS), and mitral annular velocity (e′). Multivariable Poisson regression models that adjusted for demographics and cardiovascular risk factors (RFs) were used to investigate the independent associations of cardiac mechanics indices and decline in kidney function defined as a 30% decline in eGFR over 7 years.

RESULTS

In RF models, LVLS, EDSR, RVFWS, and e′ were all significantly associated with the prevalence of kidney disease. After multivariable adjustment, left atrial dysfunction (relative risk [RR], 1.18; 95% confidence interval [CI], 1.01 to 1.38 per SD lower LARS) and left ventricular diastolic dysfunction (RR, 1.21; 95% CI, 1.04 to 1.41 per SD lower EDSR) were each significantly associated with 30% decline in eGFR.

CONCLUSIONS

Subclinical myocardial dysfunction suggesting abnormal diastolic function detected by 2D-STE was independently associated with decline in kidney function over time. Further studies are needed to understand the mechanisms of these associations and to test whether interventions that may improve subclinical myocardial dysfunction can prevent decline of kidney function.