Heart failure

LV changes and CABG contribute to higher mortality risk from heart failure

In this new study from China, the link between structural changes in the left ventricle (LV) and mortality after coronary artery bypass graft (CABG) surgery was investigated among a cohort of heart failure patients with reduced ejection fraction.

Heart failure with reduced ejection fraction (HFrEF) may predispose individuals to a higher risk of death after coronary artery bypass surgery, due to left ventricular (LV) changes that include left ventricular hypertrophy (LVH) and l left ventricular enlargement (LVE), according to new study results Posted in International Journal of General Medicine.

“The relationship between abnormal LV structure and adverse outcomes has been confirmed in various patient groups in previous studies,” the authors wrote. “However, it remains unclear whether LV structure has predictive implications in HFrEF patients with CABG. [coronary artery bypass grafting].”

Coronary artery disease, they added, is responsible for up to 60% of heart failure cases.

Data on their 435 consecutive patients show a mean (SD) age of 59.4 (9.6) years, all of whom had HFrEF (New York Heart Association Class II-IV disease) and underwent CABG between January 2013 and July 2019 at Beijing Anzhen Hospital, Capital Medical University, China. Transthoracic echocardiography assessed LVH and LVE, finding the conditions in 102 and 95 patients, respectively. The entire study cohort was then classified into these 4 groups:

  • –LVH/–LVE (n=288; 66.2%)
  • +LVH/–EVG (n = 52; 12.0%)
  • –HVG/+EVG (n = 45; 10.3%)
  • +HVG/+EVG (n = 50; 11.5%)

Overall, an independent association was found between LVH or EVG (both P

  • +LVH/–LVE: odds ratio (OR), 7.525 (95% CI, 1.827-30.679; P = .004)
  • –LVH/+EVG: OR, 7.253 (95% CI, 1.950-27.185; P = .003)
  • +LVH/+EVG: OR, 9.547 (95% CI, 2.726-34.805; P

Translated into percentages, the mortality rates were 3.1%, 9.6%, 15.6%, and 16.0%, respectively.

These results were observed after adjustment for the baseline model including age, critical condition, stroke, recent myocardial infarction, LV ejection fraction, and aneurysm intervention. ventricular, the authors wrote.

Twenty-nine patients died following coronary bypass surgery: 10 each from low cardiac output and severe infection, 7 from cardiac arrest due to malignant arrhythmia, and 2 from stroke. Of this group, 13 had LVH and 15 had LVE. On their own, LVH was associated with a more than 2.5 times greater risk of mortality than no LVH, at 12.7% versus 4.8% (P = 0.01), and LVE with a mortality risk almost 4 times higher than no LVE, at 15.8% versus 4.1% (P

For this study, death was defined as “any death occurring after surgery during the hospital stay”.

“Adding LV structural types to the base model had an additional effect on the predictive value of postoperative mortality (AUC: 0.838 [baseline model] versus 0.901 [baseline model + LV structural types]; P for comparison = 0.010; net improvement of reclassification out of category: 0.764; P P = 0.007),” the authors pointed out.

Categorizing patients according to their LV remodeling patterns, they concluded, allows for more detailed risk stratification and provides additional risk predictability. For this reason, routine clinical practice should incorporate the assessment of LVH and EVG by echocardiography.

The references

Yan P, Zhang K, Cao J, Dong R. Left ventricular structure is associated with postoperative death after coronary artery bypass grafting in heart failure patients with reduced ejection fraction. Int J Gen Med. 2022;15:53-62. doi:10.2147/IJGM.S341145