Relation between Contractile Reserve and Prognosis in Patients with Coronary Artery Disease

Postextrasystolic potentiation (PESP) and l-epinephrine infusion have previously been shown by the ventriculographic technique to augment left ventricular wall motion in patients with coronary artery disease. The present study relates the magnitude of this augmentation to short-term prognosis in 56 patients with coronary artery disease and a factor already identified with reduced life expectancy, i.e., an abnormal ejection fraction (EF < .50). Forty-two patients received PESP and 14 l-epinephrine infusion. Based on severity of symptoms and technical suitability, 37 were treated surgically and 19 medically. Mean follow-up times were 11.7 and 14.3 months, respectively. The mean increase in EF induced by PESP or l-epinephrine infusion was significantly greater in patients who subsequently had good results from either surgical or medical therapy than in those who died or had progressive cardiac deterioration. In addition, those patients with an increase in EF of .10 or greater had a statistically greater chance of doing well than patients with less augmentation. Evaluation of change in ejection fraction after inotropic stimulation in patients with depressed ejection fractions is helpful in identifying those patients with greatest contractile reserve and hence better short-term prognosis with either medical or surgical therapy. Because of its ease of performance and greater enhancement of contractility, PESP is preferred to l-epinephrine infusion as the inotropic stimulus of choice.