Late outcomes of off-pump versus on-pump coronary bypass in patients with diabetes: A nationwide study from Taiwan

Off-pump Versus On-pump Coronary Artery Bypass Grafting in Diabetic patients: A Meta-analysis of Observational Studies with a Propensity-Score Analysis

PURPOSE

The debate between off-pump coronary artery bypass grafting (OPCAB) and on-pump coronary artery bypass grafting (ONCAB) in diabetic patients remains. This meta-analysis aimed to investigate outcomes after OPCAB versus ONCAB for patients with diabetes.

METHODS

Literature research was conducted up to December 2023 using Ovid Medline, EMBASE, and the Cochrane Library. Eligible studies were observational studies with a propensity-score analysis of OPCAB versus ONCAB. The primary outcomes were early mortality and mid-term survival. The secondary outcomes were cerebrovascular accidents, reoperation for bleeding, incomplete revascularization, myocardial infarction, low cardiac output, and renal replacement therapy.

RESULTS

Our research identified seven observational studies with a propensity-score analysis enrolling 13,085 patients. There was no significant difference between OPCAB and ONCAB for early mortality, mid-term survival, myocardial infarction, low cardiac output, and renal replacement therapy. OPCAB was associated with a lower risk of cerebrovascular accidents (OR 0.43; 95% CI, 0.24-0.76, P = 0.004) and reoperation for bleeding (OR 0.60; 95% CI, 0.41-0.88, P = 0.009). However, OPCAB was associated with a higher risk of incomplete revascularization (OR 2.07; 95% CI, 1.60-2.68, P < 0.00001).

CONCLUSION

Among patients with diabetes, no difference in early mortality and mid-term survival was observed. However, OPCAB was associated with a lower incidence of morbidity, including cerebrovascular accidents and reoperation for bleeding.

Clinical outcomes of off-pump coronary artery bypass graft in patients with diabetes and non-diabetics: A systematic review and meta-analysis

BACKGROUND AND AIM

Diabetes mellitus is a prevalent risk factor for developing coronary artery disease which worsens the clinical outcomes of patients undergoing coronary artery bypass grafting (CABG). This study aimed to determine the clinical outcomes of patients with diabetes and non-diabetic patients who underwent off-pump CABG surgery.

METHOD

Medline, Scopus, Proquest, Embase, Web of Science, and Google scholar were searched until September 10, 2021. The effect sizes including unstandardized mean difference and odds ratio with 95% confidence interval were calculated using "Metan" package. The Cochran's Q-test and I² statistic were used to assess heterogeneity, a random-effects model was applied to estimate the pooled effect sizes, and meta-regression was used to investigate the factors affecting heterogeneity between studies.

RESULTS

10 studies with 6200 sample sizes were included in the study. In groups with diabetes, Summary odds ratio (SOR) and 95% confidence interval of infection was 2.18 more than non-diabetic groups. Also, odds renal complication was 1.74 more than non-diabetic groups, and the odds cardiovascular complication in groups with diabetes was 1.30 more than non-diabetics. There were no differences in mortality, neurologic, respiratory and surgical complications between groups with diabetes and non-diabetics. Based on meta-regression results, age (Coefficient: 0.942; p = 0.009) had a significant direct relationship and sample size (Coefficient: 0.001; p = 0.009) had an indirect significant relationship with heterogeneity of neurologic outcomes. There was no significant publication bias in our results.

CONCLUSION

Our study revealed that off-pump CABG led to some significant outcomes in patients with diabetes compared to non-diabetics. Renal and infection complications were higher in patients with diabetes but no significant differences were seen in most of other postoperative outcomes between the two groups.

Real-World Outcomes of On- vs Off-Pump Coronary Bypass Surgery: Result from Korean Nationwide Cohort

BACKGROUND

While several randomized trials have shown conflicting results regarding the comparative effectiveness of on- and off-pump coronary arterial bypass grafting (CABG), research on long-term outcomes in large-scale, real-world clinical settings are limited. We sought to examine the comparative effectiveness of on- and off-pump CABG in a real-world clinical setting.

METHODS

Using the nationwide claims database of the Korean National Health Insurance Service, we identified patients who underwent isolated CABG from 2004 to 2013. Propensity-score matching with multivariable adjustment was used to assemble a cohort of patients with similar baseline characteristics.

RESULTS

Among 23,828 patients, 12,639 in the off-pump (53.0%) and 11,189 in the on-pump (47.0%) groups were enrolled. After matching, 6,483 pairs were included in the final analysis. At 30 days, there was no significant difference in adjusted mortality between the off- and on-pump groups (hazard ratio [HR], 1.00; 95% confidence interval [CI], 0.87-1.16). During long-term follow-up (100% complete; median 5.3yrs, maximum 13.2yrs), however, off-pump CABG was associated with a higher risk of mortality than on-pump CABG (HR, 1.09; 95% CI, 1.03-1.15). The risks of myocardial infarction (MI) (HR, 1.3; 95% CI, 1.16-1.45) and repeat revascularization (HR, 1.50; 95% CI, 1.37-1.63) were also significantly higher in the off-pump CABG group than in the on-pump CABG group, while the stroke risk was similar inter-groups (HR, 0.99; 95% CI, 0.87-1.13).

CONCLUSIONS

In this contemporary, nationwide, clinical practice claim registry, off-pump CABG was associated with higher long-term risks of mortality, MI, and repeat revascularization than on-pump CABG.

MicroRNA-92a -mediated endothelial to mesenchymal transition controls vein graft neointimal lesion formation

PURPOSE

Long-term failure of vein grafts due to neointimal hyperplasia remains an important problem in coronary artery bypass graft surgery. Endothelial to mesenchymal transition (EndMT) contributes to vein graft vascular remodeling. However, there is little study on microRNA-mediated EndMT contributions to neointimal formation in vein graft. We hypothesized that microRNA-92a (miR-92a) might play an important role in determining EndMT contributions to neointimal formation.

METHODS

miR-92a and EndMT-related proteins detected by qRT-PCR and Western blot in vitro and in vivo. Adeno-associated virus 6 (AAV6) delivery gene therapy was used to inhibit neointimal formation in vivo. The intimal hyperplasia of vein grafts was measured by HE staining, the expression of EndMT-related protein in vein grafts was measured by immunofluorescence. Immunohistochemistry and luciferase assay were used to detect potential targets of miR-92a.

RESULTS

The expression of miR-92a was found to be upregulated in neointimal hyperplasic lesions after vein grafting. Using cultured human umbilical vein endothelial cells (HUVECs), we show that TGF-β1 treatment of HUVECs significantly increased miR-92a expression and induced EndMT, characterized by suppression of endothelial-specific markers (CD31 and VE-cadherin) and an increase in mesenchymal-specific markers (a-SMA and vimentin), while inhibition of miR-92a expression blunted EndMT in cultured HUVECs. Furthermore, AAV6 mediated miR-92a suppression gene therapy effectively resulted in decreased EndMT and less neointimal formation in vein grafts in vivo. We further identified that integrin alpha 5 (ITGA5) is a potential target gene involved in the development of neointima formation in these vein grafts.

CONCLUSION

This data suggests that neointimal formation does not solely rely on vascular smooth muscle cell phenotypic switching but is also related to EndMT, and miR-92a-mediated EndMT is an important mechanism underlying neointimal formation in vein grafts.