Abstract 529: Subclinical Left Ventricular Systolic Dysfunction Identifies Patients With Obstructive Coronary Artery Disease
Background. Left ventricular (LV) diastolic dysfunction and subclinical systolic dysfunction may be markers of coronary artery disease (CAD). The present study determined whether LV diastolic dysfunction and subclinical systolic dysfunction are useful for prediction of obstructive CAD, being of incremental value over pre-test likelihood of CAD.
Methods. A total of 182 consecutive outpatients (54±10 years, 59% males) without known CAD and overt LV systolic dysfunction underwent 64-slice MSCT coronary angiography and echocardiography. MSCT angiograms showing atherosclerosis were classified as showing obstructive (≥50% luminal narrowing) CAD or not. Conventional echocardiographic parameters of LV systolic and diastolic function were obtained; in addition,
global longitudinal strain (GLS) and strain rate (indices of systolic function) and
global strain rate during the isovolumic relaxation period and during early diastolic filling (indices of diastolic function) were assessed using speckle-tracking echocardiography.
Results. Based on MSCT, 32% of patients were classified as having no CAD, whereas 33% showed non-obstructive CAD and the remaining 35% had obstructive CAD. At multivariate analysis, only high pre-test likelihood of CAD (OR 3.21, 95% 1.02–10.09, p=0.046), diastolic dysfunction (OR 3.72, 95% CI 1.44 –9.57, p=0.006) and GLS (OR 1.97, 95% CI 1.43–2.71, p<0.001) were associated with obstructive CAD. A value of GLS ≥−17.4 yielded high sensitivity and specificity in identifying patients with obstructive CAD (83% and 77%, respectively). GLS provided significant incremental value over pre-test likelihood of CAD and diastolic dysfunction for the detection of obstructive CAD (p<0.001 for comparison between ROC curves).
Conclusions. GLS impairment aids detection of patients without overt LV systolic dysfunction having obstructive CAD.