Changes of Left Ventricular Systolic Function in Patients Undergoing Coronary Artery Bypass Grafting

Abstract

AIM: This prospective study was designed to evaluate the changes in left ventricular (LV) systolic function after coronary artery bypass grafting (CABG) in patients with both normal and abnormal pre-operative systolic function.
 METHODS: During the period from October 2017 to October 2018, forty-seven consecutive patients undergoing CABG were enrolled in this prospective study. Transthoracic echocardiography was performed within 1 week before CABG as well as 4 to 6 months after surgery. All measurements were made by a single experienced investigator.
 RESULTS: While the mean LV ejection fraction (LVEF) showed neither improvement nor significant reduction in the whole group of patients following CABG (from 54.21 ± 15.36 to 53.66 ± 11.56%, p = 0.677), significant improvement in LVEF was detected in the subgroup of patients with pre-operative LV dysfunction (from 40.05 ± 8.65 to 45.85 ± 9.04%, p = 0.008). On the other hand, there was a significant decline in LEFT in the subgroup of patients with normal pre-operative LEFT (from 64.70 ± 9.72 to 59.44 ± 9.75%, p = 0.008). As for the other parameters of systolic function, significant decrease in LV end-diastolic volume index (LVEDVI) (p = 0.001), LV end-systolic volume index (LVESVI) (p = 0.0001), wall motion score index (WMSI) (p = 0.013) and LVmass index in male patients (p = 0.011) was shown only in patients with decreased LVEF after CABG. Patients with improved postoperative LVEF (53.2% of all patients) had significantly lower baseline LVEF (p = 0.0001), higher LVESVI (0.009) and higher WMSI (p = 0.006) vs patients with worsened postoperative LVEF (38.3% of all patients). Postoperative improvement of LVEF was correlated with stabile angina, lack of preoperative myocardial infarction and smoking, higher baseline WMSI, higher LV internal diameters and indexed volumes in diastole and systole and lower baseline LVEF. In stepwise linear regression analysis the value of baseline LVEF appeared as independent predictor of improved LVEF after CABG (B = 0,836%; 95% CI 0.655-1.017; p = 0.0001).
 CONCLUSION: Our study showed that LVEF, internal baseline diameters and indexed volumes of LV in diastole and systole are important determinants of postoperative change in LVEF. In patients with preoperative depressed myocardial function, there is an improvement in systolic function, whereas in patients with preserved preoperative myocardial function, the decline in postoperative LVEF was detected.

Perioperative changes in left ventricular systolic function following surgical revascularization

“…Papestiev et al, prospectively evaluated 47 patients (27 with preoperative LVEF >50%) and found that ΔLVEF >5% occurred in 53.2% of patients. LVEF improvement of >5% was significantly more likely if LVEF <50%, and preoperative LVEF was inversely associated with perioperative LVEF improvement [6]. Similarly, in two cohort studies limited to preoperative LVEF <35%, CABG was associated with increases in LVEF [18,19].…”

“…Finally, within a cohort with LVEF <50% (mean LVEF = 32%), Cornel et al observed a ΔLVEF >5% in 19% of patients at 3 months, which increased to 31% at twelve months [20]. Cumulatively, these prior works have shown LVEF improvement in patients who had preoperative LV systolic dysfunction but a higher risk of LVEF decline in individuals with a preoperatively normal LVEF [4][5][6][18][19][20].…”

“…Although there is reason to expect that reduction of myocardial ischemia and recovery of hibernating myocardium through coronary revascularization would result in improvement of LV systolic function, there is relatively little data to support this assertion [3]. Prior single-center, retrospective studies in this area were limited by patient selection bias and imaging studies that were not performed systematically at pre-determined time points after CABG [4][5][6]. Since left ventricular ejection fraction (LVEF) is an important clinical variable guiding therapeutic decisions, and offering prognostic information, it is important to characterize the extent, direction and implications of LVEF changes following CABG [7][8][9].…”

Coronary Artery Bypass Graft Surgery Brings Better Benefits to Heart Failure Hospitalization for Patients with Severe Coronary Artery Disease and Reduced Ejection Fraction

“…Therefore, the underlying pathology needs to be further investigated in such population. LV remodeling improved the outcomes of HF hospitalization and the value of baseline LVEF appeared as independent predictor of improved LVEF after CABG [ 34 ].…”

Ninety-seven cases of experiences with the left thoracotomy approach for off-pump conventional revascularization: a retrospective cohort study

“…Meanwhile, for patients with a preserved baseline LVEF, research on the changes of LVEF after CABG is scarce. Papestiev et al reported that in patients with preoperative LV dysfunction, there is an improvement in systolic function, whereas, in patients with preserved preoperative myocardial function, a decline in postoperative LVEF was observed ( 22 ). This is consistent with our findings, which showed statistical differences in the non-single graft group and no statistical differences in the single graft group (not illustrated in table).…”