New-onset postoperative atrial fibrillation: A riddle wrapped in a mystery inside an enigma

The Impact of New-Onset Atrial Fibrillation on In-hospital Mortality Following Cardiac Surgery

BACKGROUND

The impact of new-onset postoperative atrial fibrillation (NAF) on in-hospital mortality (IHM) following cardiac surgery is unknown.

METHODS

All patients without preoperative atrial fibrillation undergoing isolated coronary artery bypass graft surgery (CABG) and concomitant CABG and valve surgery were identified (n = 7,347). The association between NAF and IHM was determined using logistic regression modeling. Also, propensity score analysis was used to create two matched subgroups of patients with and without NAF (n = 2,015 in each group). The secondary outcomes examined were stroke, myocardial infarction (MI), intra-aortic balloon pump use, GI complications, deep sternal wound infection (DSWI), septicemia, renal failure, and length of stay.

RESULTS

NAF developed in 2,047 patients (27.9%). NAF was not an independent predictor of IHM (odds ratio, 0.8; 95% confidence interval, 0.6 to 1.2; p = 0.3). In multivariate analysis, NAF was associated with age >/= 60 years, combined procedures, preoperative MI within 7 days of surgery, COPD, cerebrovascular disease, and male gender. Propensity-adjusted results revealed no difference in IHM between NAF vs no-NAF patients (2.9% vs 3.5%, respectively; Bonferroni-corrected p = 0.99). However, GI complications (4.2% vs 2.1%), DSWI (1.3% vs 0.4%), septicemia (4.0% vs 1.1%), renal failure (7.6% vs 4.3%), and length of stay (8 days vs 6 days) were significantly increased in patients with NAF.

CONCLUSION

NAF following cardiac surgery is not associated with increased IHM.

Ventral cardiac denervation increased right coronary arterial blood flow

BACKGROUND

Cardiac denervation accompanied with coronary artery bypass surgery has been widely performed for the treatment of vasospastic angina associated with atherosclerotic coronary artery disease. However, the effect of cardiac denervation on phasic coronary blood flow patterns of the left anterior descending coronary artery (LAD), left circumflex coronary artery (LCX) and right coronary artery (RCA) remains unknown. This study aimed to investigate the effect of cardiac denervation on phasic coronary blood flow patterns of the LAD, LCX and RCA.

METHODS

Phasic coronary blood flow patterns were analyzed using three flow probes placed around the LAD, LCX and RCA with and without LAD stenosis. Ventral cardiac denervation (VCD) was performed in 8 pigs, and 16 pigs were used as control subjects. Autonomic activities before and after the VCD were quantified by wavelet analysis of heart rate variability.

RESULTS

The mean LAD flow (34.4+/-9.4 to 32.6+/-7.1 ml/min, p=0.638) and mean LCX flow (26.3+/-10.2 to 27.2+/-6.0 ml/min, p=0.825) showed no significant change after VCD, while the mean RCA flow (31.3+/-9.0 to 38.2+/-11.2 ml/min, p=0.003) significantly increased. The hemodynamic variables in the VCD group were well maintained after creation of LAD stenosis, while they deteriorated in the control group. The low-frequency components, high-frequency components and their ratio did not change after VCD.

CONCLUSIONS

VCD prevented the deterioration of cardiac function after creation of an LAD stenosis and resulted in an increase of the mean RCA flow. VCD did not affect autonomic nervous system activity.