Abstract 17175: Coronary Vascular Dysfunction in the Absence of Overt Coronary Atherosclerosis is Independently Associated with Left Ventricular Diastolic and Subclinical Systolic Dysfunction

Abstract

Background: The relationship between coronary vascular dysfunction and myocardial diastolic and systolic dysfunction has not been well described. We evaluated the hypothesis that myocardial blood flow (MBF) during vasodilator stress is independently associated with diastolic dysfunction and subclinical systolic dysfunction.

Methods: We studied 138 consecutive patients without overt cardiovascular disease or atrial fibrillation undergoing cardiac PET imaging for evaluation of exertional dyspnea and/or chest pain with normal regional myocardial perfusion and resting left ventricular (LV) ejection fraction (EF), who also underwent rest echocardiography within 14 days. MBF was quantified using ⁸²Rb PET at rest and at peak vasodilator stress. Diastolic function and subclinical systolic dysfunction were assessed with echocardiography of mitral inflow Doppler (E, A wave velocities), tissue Doppler (TDI) early diastolic mitral annular velocity (E’), E/E’ ratio, a marker of LV diastolic filling pressure, and TDI peak systolic mitral annual velocity (S’). The independent relationship between stress MBF and echo parameters was investigated using linear regression to adjust for age, sex, body mass index, hypertension, diabetes, rest blood pressure, rest EF and LV mass.

Results: Median age was 64 years (IQR 55-76). Patients were predominantly female (75%) with high rates of hypertension (75%), dyslipidemia (54%) and diabetes (28%). Stress MBF significantly correlated with E’, E/E’, and S’ (Figure). These correlations remained significant after adjustment for other factors associated with diastolic and subclinical systolic dysfunction.

Conclusions: Stress MBF is independently associated with echocardiographic markers of diastolic function, elevated LV diastolic filling pressure and subclinical systolic dysfunction, suggesting a relationship between impaired microvascular tissue perfusion and LV diastolic and systolic dysfunction.