Role of global longitudinal strain diastolic index in assessment of patients with suspected obstructive coronary artery disease and normal or mildly reduced ejection fraction
Objective – To examine the utility of global longitudinal strain imaging diastolic index (SI-DI) in the assessment of patients with suspected obstructive coronary artery disease (CAD). Methods – We performed rest 2D standard echocardiography and strain imaging in 30 healthy subjects and in 148 patients with normal or mildly reduced ejection fraction and indication for coronarography for suspected obstructive CAD. Standard echocardiographic and strain parameters were analysed. Results – Global SI-DI was signifi cantly lower in the selected vs control group (p <0.001). After coronarography patients were divided in three subgroups: 74 patients with more than 50% obstruction in any major artery, 26 patients with previous revascularisation but no significant obstructive lesions at present and 48 patients without obstructive artery disease. Average global SI-DI was significantly lower in the subgroup with obstructive CAD vs the other two subgroups (p<0.05). Global SI-DI lower than 0.5 had a good sensitivity (84%) and a reasonable positive predictive value (52%) for detection of obstructive CAD. Conclusions – Global SI-DI is significantly lower in patients with obstructive CAD and normal or mildly reduced ejection fraction compared with normal subjects. A cut off value lower than 0.5 selects patients with a higher probability of obstructive CAD.