Myocardial Function after Coronary Artery Bypass Grafting in Patients with Preoperative Preserved Left Ventricular Ejection Fraction-The Role of the Left Ventricular Longitudinal Strain.

Background and Objectives: The role of coronary artery bypass grafting (CABG) on postoperative left ventricular (LV) function in patients with preoperatively preserved left ventricular ejection fraction (LVEF) is still being discussed and only a few studies address this question. This study aimed to assess LV function after CABG in patients with preoperatively preserved LVEF using left ventricular longitudinal strain assessed by 2D speckle tracking imaging (STI). Materials and Methods: Fifty-nine consecutive adult patients with coronary artery disease (CAD) referred for a first-time elective CABG surgery were enrolled in the final analysis of this prospective single-center clinical study. Transthoracic echocardiography (TTE), with conventional measures and STI measures, was performed within 1 week before CABG as well as 4 months after surgery. Patients were divided into groups based on their preoperative global longitudinal strain (GLS) value. Differences in systolic and diastolic parameters between groups were analyzed. Results: Preoperative GLS was reduced (GLS < -17%) in 39% of the patients. Parameters of systolic LV function were significantly reduced in this group of patients compared to the patient group with GLS% ≥ -17%. In both groups, 4 months after CABG there was a decline in LVEF but statistically significant only in the group with GLS% ≥ -17% (p = 0.035). In patients with reduced GLS, there was a statistically significant postoperative improvement (p = 0.004). In patients with preoperative normal GLS, there was not a significant change in any strain parameters after CABG. There was an improvement in diastolic function parameters measured by Tissue Doppler Imaging (TDI) in both groups. Conclusions: There is improvement in LV systolic and diastolic function after CABG in patients with preserved preoperative LVEF measured by STI and TDI. GLS might be more sensitive and effective than LVEF for monitoring improvements in myocardial function after CABG surgery in patients with preserved LVEF.

Frequency of Left Atrial Enlargement According to Different Modes of Indexing in Overweight and Obese Individuals.

Background: Current guidelines recommend indexing left atrial volume (LAV) by body surface area (BSA). However, in overweight and obese individuals this may result in the underestimation of left atrial enlargement (LAE). The aim of our study was to assess whether alternative LAV indexing to height and/or height-squared better identifies individuals with LAE among those who are overweight and/or obese. Methods: LAV was indexed to BSA (LAVI), height (LAVh), and height-squared (LAVh2) in 127 individuals with a mean age of 45.7 years and a mean body mass index (BMI) of 34.9 kg/m2 who underwent outpatient echocardiography at the University clinic of cardiology in Skopje. Results: LAVI, LAVh, and LAVh2 showed a progressive increase of respective values with the extent of BMI showing the most enlarged LA size in individuals with Class III obesity. There was a progressive significant increase in the prevalence of LAEh and LAEh2 in obese groups with the highest prevalence among those with class III obesity (p=0.002, p=0.002, respectively), on the contrary of LAEBSA where we could not find any significance in its distribution among obese classes. The greatest degree of reclassification occurred when indexing for height-squared, having relatively less reclassification when indexing for height (p=0.0001). The degree of reclassification varied depending on BMI with the greatest impact among the Class III obese patients, where as many as 76.5% and 88.2% of individuals were reclassified according to height or height-squared, respectively. Conclusions: The use of height, and especially height-squared, in comparison to BSA-based indexing methods are more successful in identifying the LAE prevalence in each class of obesity. Using allometric indexation leads to the significant reclassification of LA size from normal to dilated, especially in women and those with severe obesity, thereby providing an opportunity to identify more individuals at increased risk of adverse events.

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

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.

Does the Presence of Diabetes Mellitus Make a Difference in Pharmacological Stress Echocardiography Outcome Results?

BACKGROUND: Coronary artery disease (CAD) is the leading cause of mortality and morbidity in patients with diabetes (DM). AIM: The aim of our study was to analyse the ability of pharmacological SE to risk stratify patients with DM using qualitative and quantitative assessment of LV function. METHODS: We prospectively assessed 105 consecutive patients (58.7 ± 9.5 y, 39 male) with known or suspected CAD who underwent dipyridamole or dobutamine SE. RESULTS: Change of systolic LV function at maximal SE was less pronounced in patients with DM, while parameters of the diastolic function and its change with stress were almost insignificant. WMSI in comparison to GLS% didn't make a difference in SE outcome regarding DM presence. WMSI was almost unchanged at maximal stress in diabetic patients. Conversely, GLS% showed significant worsening at maximal stress in diabetic patients. However, only WMSI at maximal stress along with DM presence appeared as independent predictors of the presence of new and worsening CAD during SE. Longitudinal strain assessed using speckle tracking during pharmacological stress echocardiography was superior to conventional echocardiography expressed by wall motion analysis in making a difference regarding DM presence. CONCLUSION: We confirmed the usefulness of stress echocardiography using qualitative and/or quantitative parameters in the detection of CAD in patients with DM.