The Effects of Melatonin on the Oxidative Stress and Duration of Atrial Fibrillation after Coronary Artery Bypass Graft Surgery: A Randomized Controlled Trial

BACKGROUND

Atrial Fibrillation (AF) is a common complication following Coronary artery bypass graft (CABG) Surgery, which may be due to oxidative stress, necrosis and inflammation during CABG and can lead to increases the length of hospital stay and the risk of morbidity and mortality. Melatonin is a hormone with anti-oxidant and anti-inflammatory properties in the cardiovascular system. This study assessed the efficacy of sublingual consumption of melatonin in reducing necrosis and inflammation, in patients undergoing CABG with respect to C-reactive protein (hs-CRP), Creatine Kinase-Muscle-Brain subunits (CK-MB) and cardiac Troponin T (cTnT) levels.

METHODS

One hundred and two patients were enrolled and twenty-six patients were excluded during the study process and finally seventy-six patients undergoing CABG surgery randomly assigned to melatonin group (n = 38, 12 mg sublingual melatonin the evening before and 1 hour before surgery, or the control group which did not receive Melatonin, n = 38). Three patients in the melatonin group and three patients in the control group were excluded from the study because of discontinued intervention and lost to follow up. The samples were collected before and 24 hours after surgery. hs-CRP, CK-MB, and cTnT levels were measured in all patients with the Elisa method.

RESULTS

There was no significant difference in influencing variables among the groups at the baseline. The incidence of AF following CABG surgery was not statistically significant between the two groups, (p-value = 0.71). However, the duration of AF (p-value = 0.01), the levels of hs-CRP (p-value = 0.001) and CK-MB (p-value = 0.004) measured, 24 hours after surgery were significantly lower in the melatonin group. cTnT levels measured 24 hours post-CABG did not show any significant difference in both groups (p-value = 0.52).

CONCLUSION

Our findings suggest that the administration of melatonin may help modulate oxidative stress, based on the reduction of the levels of hs-CRP, CK-MB, and the duration of AF following CABG surgery.

Results of bypass graft surgery after prior angioplasty in critical limb ischaemia treatment

BACKGROUND

The aim of this study was to determine the outcomes of primary bypass graft surgery (BGS) compared to BGS after failed angioplasty (PTA).

PATIENTS AND METHODS

Between January 2007 and January 2014, we performed 136 BGSs exclusively for the treatment of critical limb ischaemia. Two cohorts were identified: 1) primary BGS (n = 102; group I), and 2) BGS after prior PTA (n = 34; group II). Data were analysed retrospectively and the primary endpoints were the rates of secondary patency, amputation-free survival, freedom from major adverse outcomes (graft occlusion, amputation, or death), and overall survival, which were assessed with the Kaplan-Meier method.

RESULTS

Both groups were comparable with a predominance of Rutherford's category 5 ischaemic lesions (73.3 %). Most patients had extensive TASC D athe-rosclerotic disease (83.6 %), and the main conduit was the greater saphenous vein (58.1 %). The mean follow-up time was 36.2 months. The 3-year secondary patency rates were better for group I (64.3 % vs 49.6 %; P = 0.04). During the same period, the amputation-free survival rates were similar between the groups (77.4 % vs 74.5 %; P = 0.59). For multivariate Cox regression analysis, BGS after prior PTA was the only factor associated with re-intervention for limb salvage (hazard ratio = 2.39; CI 95 % = 1.19 - 4.80; P = 0.02). At the 3-year point, there were no differences in the overall survival rates (72.6 % vs 70 %; P = 0.97), but the proportion of patients without adverse outcomes was higher in group I (37.3 % vs 13.4 %; P = 0.007).

CONCLUSIONS

Although secondary patency was better after primary BGS, the amputation-free and overall survival rates support the use of BGS after prior PTA.