IMPROVEMENT OF LEFT-VENTRICULAR EJECTION FRACTION DIRECTLY AFTER TRANSLUMINAL CORONARY ANGIOPLASTY

The purpose of this study was to evaluate if left ventricular ejection fraction (EF) at rest can improve already during the first 4 h after successful transluminal coronary angioplasty (PTCA). Measurements were carried out with the CardioScint LV Function Monitor Version 1.3. Comparison of ejection fraction values evaluated by the CardioScint Monitor revealed a good correlation with usual equilibrium radionuclide ventriculography (n = 28; r = 0.89). Also, intra- and interobserver variability was low (n = 26; r = 0.94 and n = 21; r = 0.92 respectively). Two hundred follow-up-measurements in eight patients over a time period of 4 h revealed a significant decrease of EF from 45 +/- 12 % to 39 +/- 18 % (p = 0.037) (reference group). This decrease was due to a continuous increase of background activity. The study population consisted of 14 patients with successful PTCA (dilatation from 85 +/- 7 to 34 +/- 9 % linear vessel diameter). To evaluate the hemodynamic significance of the coronary lesion, left ventricular ejection fraction was registered during the balloon occlusion of the vessel. After dilatation, 25 EF measurements were carried out in each patient over the following 4 h (350 values). During PTCA, EF decreased from 52 +/- 16 to 37 +/- 9 % (p = 0.0027). During the 4-h follow-up EF slightly decreased from 50 +/- 8 to 46 +/- 9 % (p = 0.07). For further analysis patients were divided into two subgroups: seven patients with a decrease of left ventricular ejection fraction during PTCA of more than 8 % as indicator for the hemodynamic significance of the lesion (subgroup 1) and seven patients with only mild EF reduction during PTCA (subgroup 2). In subgroup 1, ejection fraction remained unchanged at 52 +/- 8% (relative increase); the time-course over 4 h was horizontal (175 measurements) in contrast to the decrease in the untreated reference group (p < 0.0001); and exercise-induced myocardial ischemia significantly improved (ischemia score: from 2.3 +/- 2.6 to 0.3 +/- 0.5, p = 0.04). In subgroup 2, EF decreased similar to the untreated reference group from 48 +/- 8 to 40 +/- 6 % (p = 0.003); the time-course of EF over 4 h (175 measurements) resembled the course in the reference group, and exercise stress test did not reveal a reduction of myocardial ischemia (1.3 +/- 1.7 vs 0.2 +/- 0.4, p = 0.11). It is concluded that left ventricular ejection fraction at rest can improve already during the first 4 h after successful transluminal coronary angioplasty. This can be expected in patients with hemodynamic and electrocardiographic evidence for significant coronary lesions.