Relationship between the ischemic threshold at the onset of wall-motion abnormality on semisupine exercise echocardiography and the extent of coronary artery disease

Prognostic Implications of Left Ventricular Filling Pressure With Exercise

Background— The estimation of left ventricular (LV) filling pressure from the ratio of transmitral and annular velocities (E/e′) after exercise echocardiography may identify diastolic dysfunction in patients who complain of exertional dyspnea. This study sought to determine the relative contributions of exercise E/e′ and ischemia to outcomes in patients referred for exercise echocardiography.

Methods and Results— Rest and exercise E/e′ were obtained in 522 patients referred for exercise echocardiography, who were followed for cardiovascular death and hospitalization over a median of 13.2 months. Exercise E/e′ >2 SD from normal was used to denote raised LV filling pressure with stress (n=75), and ischemia (n=250) was identified by inducible wall motion abnormalities. There were 65 cardiovascular hospitalizations during the follow-up period. Survival analysis showed patients without ischemia and with normal exercise E/e′ to have a better prognosis than those with ischemia, with or without raised exercise E/e′ ( P =0.003) and the outcomes of patients with isolated raised exercise E/e′ and isolated ischemia to be similar. Exercise E/e′ was most valuable in patients with normal resting E/e′; those with elevation with exercise had a worse outcome than those with normal exercise E/e′ ( P =0.014). Exercise capacity (hazard ratio, 0.893; P =0.008), exercise wall motion score index (hazard ratio, 1.507; P <0.001), and exercise E/e′ >14.5 (hazard ratio, 2.988; P =0.002) were independent predictors of outcome. The addition of exercise E/e′ to exercise capacity and wall motion score index resulted in an increment in model power to predict adverse outcome ( P =0.006).

Conclusions— Exercise E/e′ is associated with cardiovascular hospitalization, independent of and incremental to inducible ischemia.