Importance and inter-relationship of tissue Doppler variables for predicting adverse outcomes in high-risk patients: an analysis of 388 diabetic patients referred for coronary angiography

AIMS: To investigate the relative importance of individual tissue Doppler imaging variables to predict adverse events in a high-risk population with diabetes, ischaemic heart disease, and/or systolic dysfunction. METHODS AND RESULTS: Transthoracic echocardiograms were analysed in 388 diabetic patients without significant valve disease, bundle branch block, and atrial fibrillation who underwent coronary angiography. Multivariable Cox's regression analyses were used to establish the association between peak systolic (s'), early diastolic (e'), and late diastolic (a') tissue velocities and outcomes (hospitalization for heart failure or death). The mean age and left ventricular ejection fraction (LVEF) was 66±10 years and 45±12%, respectively. During 2.3 (±1.0) years of follow-up, 91 patients (24%) met the combined endpoint. After adjustment for LVEF, coronary artery pathology, heart failure at baseline, age, and gender, each 1 cm/s decrease in s', e', and a' was associated with a hazard ratio (HR) of 1.18 (0.89-1.57), 1.03 (0.86-1.22), and 1.20 (1.05-1.37), respectively. A significant interaction was found between s' and a', P<0.01. In patients with lower than mean s', 1 cm/s decrease in a' was associated with HR 1.31 (1.10-1.55, P<0.01), whereas a' was without prognostic importance in patients with higher than mean s' [HR 0.99 (0.78-1.25, P=0.6)]. Patients having lower than mean values of both s' and a' had a poorer prognosis than patients having at least one of s' and a' high. CONCLUSION: Peak systolic and late diastolic tissue velocities add prognostic information beyond LVEF in high-risk patients. Variables should be considered together as they interact on prognosis.