The changes of left ventricular ejection fraction after elective surgical coronary revascularization

The aim – to study the clinical characteristics of patients with stable coronary artery disease (CAD) in groups with different dynamics of left ventricular (LV) ejection fraction (EF) after coronary artery bypass grafting (CABG).Materials and methods. We conducted a prospective single-center study and enrolled 384 patients with stable CAD, selected for CABG (328 [85.4 %] males and 56 [14.6 %] females, age 39–92; average age [61 ± 8] years). We analyzed demographic, clinical, laboratory, echocardiographic, coronary angiographic, intra- and postoperative data. The changes of LV EF were evaluated at periods 1 (between 6 and 12 months after CABG) and 2 (24 months after CABG). The total sample of enrolled patients were subdivided retrospectively into three groups according to the LV EF change: 1) 1st – LV EF relative change of ≥ 10 % towards its improvement (n = 110 [28.7 %]); 2) 2nd – «without change» (LVEF relative change less than 10 % in both directions; n = 207 (53.9 %); 3) 3rd – LV EF relative change of ≥ 10 % towards its decline (n = 67 [17.4 %]). LV EF at both follow-up periods was assessed in 128 (33.3 %) patients. The sample of 128 patients was used for LV EF change evaluation depending on baseline LV EF grade: LV EF ≥ 50 % (n = 35; 27.3 %); LV EF 41–49 % (n = 27; 21.1 %) and LV EF ≤ 40 % (n = 66; 51.6 %). Numeric data were presented as median with interquartile range.Results. Group 3, compared to the pooled group 1 and 2, was characterized by the higher frequency of patients with heart failure (HF) NYHA class III: 20/67 (18.2 %) vs. 10/274 (3.6 %), respectively (р ˂ 0.001). The baseline LV EF in group 1 was significantly lower compared to that in groups 2 and 3: 37 % (32 –47 %), 55 % (45–62 %) and 52 % (38–59 %), respectively (р ˂ 0.001 for both comparisons). The frequency of patients with preserved LV EF (≥ 50 %) was lower in group 1, as opposed to groups 2 and 3. Group 3, in contrast to groups 1 and 2, was characterized by the higher value of end-systolic LV volume (and its index), as well as the higher frequency of patients with mitral and tricuspidal regurgitation. At period 1, the structure of the sample of 128 patients by LV EF grades was as follows: LV EF ≥ 50 %, 41–49 % and ≤ 40 %, respectively, 54 (42.2 %) patients, 38 (29.7 %) and 36 (28.1 %). At period 2 we observed the shift towards increased frequency of patients with LV EF ≤ 40 % (55 [43.0 %] patients).Conclusions. The LV EF improvement at different follow-up periods after elective surgical coronary revascularization was associated with worse baseline LV EF and more prevalent HF NYHA class III cases. The LV EF dynamics in patients with baseline LV EF < 50 % was «biphasic»: the initial LV EF improvement or recovery was subsequently shifted to its decline in a proportion of patients. The determination of predictors of different LV EF dynamics patterns is crucially important for individualized management of post-CABG patients.