Abstract 12905: Association Between Renal Function and Myocardial Contractile Function following Myocardial Infarction-The VALIANT Echo Substudy
Background: Chronic kidney disease has been associated with alterations in left ventricular geometry and with worse cardiovascular outcomes following infarction. We assessed the association of renal function on myocardial contractile function in high risk myocardial infarction.
Methods: We explored the relationship between eGFR, and contractile function using myocardial deformation imaging in 603 patients with LV systolic dysfunction, HF or both after acute myocardial infarction enrolled in the Valsartan in Acute Myocardial Infarction Trial echo study. Patients were divided into eGFR categories (<60, 60-75, 75-90, > 90 ml/min/1.73 m²). Baseline systolic LV longitudinal (n=380) and circumferential (n=420) deformation (strain and strain rate) imaging were assessed by 2D speckle tracking (Velocity Vector Imaging, Siemens, Inc.) from apical- and short-axis views and related to cardiac structure, MDRD equation-determined renal function (eGFR) and outcomes.
Results: Lower eGFR was associated with smaller left ventricular end-diastolic volumes (trend p=0.01), increased left ventricular mass index (trend p<0.01), but was not related to left ventricular ejection fraction (p = 0.18). As eGFR declined, both systolic longitudinal and circumferential myocardial strain rate (SR) worsened (both trend p<0.01). For each 10 units decline of eGFR, longitudinal strain rate decreased by 0.08 (1/100ms) (p = 0.044), even after adjustment for clinical covariates, systolic blood pressure, LV mass, body mass index and LV ejection fraction. In a multivariable model, both circumferential strain rate and renal function (p<0.001 & 0.045 for circumferential SR & eGFR) were independently associated with all cause death and heart failure incidence.
Conclusions: Impaired renal function may affect systolic contractile function independently of ejection fraction, and may in part account for the increased risk of death or heart failure in patients with impaired renal function.
- © 2011 by American Heart Association, Inc.