Abstract 6245: Evidence for Increased Left Ventricular Chamber Stiffness in Type 2 Diabetes: The Strong Heart Study
Introduction: We have shown that diabetes-dependent heart failure (HF), not related to coronary heart disease (CHD), is associated with normal initial left ventricular (LV) systolic function and delayed mitral E wave velocity deceleration. Lack of more evident abnormalities of LV relaxation could be due to concomitant increase in late diastolic LV stiffness.
Hypothesis: Diabetes is associated with increased LV chamber stiffness.
Methods: We analyzed 2136 Strong Heart Study members, in sinus rhythm and without prevalent HF or CHD or valve disease (1355 women, 1038 diabetic). Left atrial systolic force (LASF) was calculated as previously reported. LV volume change due to atrial contraction (LVAC) was generated by multiplying LV stroke volume by atrial filling fraction. LASF was divided by LVAC, providing a raw estimate of LV chamber stiffness.
Results: LVAC was independently correlated to age, gender, BMI, heart rate, Doppler E/A ratio and systolic blood pressure (BP, p<0.0001, multiple R=0.64). Residuals of this regression were positively correlated with LASF (r=0.25, p<0.0001), supporting normalization of LASF for LVAC. After adjusting for age, gender, BMI, heart rate, Doppler E/A ratio class, BP and hypertension status, although LV end-diastolic volume (EDV) and stroke volume were similar, LASF was greater in diabetic than in non diabetic participants, and so was LASF/LVAC (both p<0.0001). During follow-up, 155 incident HF events were adjudicated (113 in diabetic participants, p<0.0001 vs. non-diabetic participants). For comparable EDV, diabetes with follow-up HF was associated with increased LASF (14.54± 5.22 vs. 12.79± 4.53 kdynes, p<0.007) and increased LASF/LVAC (0.24± 0.14 vs. 0.21± 0.10 kdynes/mL, p<0.0001), independent of covariates.
Conclusions: In the absence of prevalent cardiovascular disease, diabetes is associated with increased LV chamber stiffness, detectable by the ratio of LASF to LVAC. This alteration is also independently related to follow-up incident HF and coexists with the previously demonstrated prolonged LV relaxation.