[New-onset postoperative atrial fibrillation following coronary artery bypass grafting: Incidence, clinical course and short-term outcomes].

INTRODUCTION: The aims of this retrospective study were to investigate the incidence, clinical course and short term outcomes of new-onset postoperative atrial fibrillation (POAF) following coronary artery bypass surgery (CABG). MATERIALS AND METHODS: A nation-wide study on 1622 patients who underwent CABG from 2006-2020 at Landspitali University Hospital. Clinical data were extracted from registries and 121 patients with pre-existing AF excluded, leaving 1501 patients for further analysis. Patient charts and postoperative ECGs were manually reviewed for determining details of POAF, which was defined as a postoperative episode of AF before discharge lasting at least 5 minutes. Patients with POAF (n=483) were compared to non-POAF patients (n=1018). RESULTS: Altogether 483 (32.2%) patients developed POAF; the annual incidence decreasing over time (tau= -0,45, p=0.023). Most patients were diagnosed on the second day postoperatively (43.5%) and over 90% were diagnosed within 4 days. The median number of POAF episodes was 3 (IQR: 1-5), the first episode lasting 1-6 hours in half of the cases and the total POAF-duration being 12 hours median (IQR: 5-30). Over 94% of cases converted to sinus rythm before discharge, with 25 (5.3%) patients being discharged in AF. Most patients were treated with beta-blockers (98.8%), amiodarone (95%) and 14.9% with electric cardioversion. POAF-patients were older, had higher EuroSCORE II and a longer hospital stay, however, they had similar rates of early postoperative stroke and 30 day mortality. CONCLUSION: The incidence of POAF remains high and was associated with prolonged hospital stay, but not significantly higher 30 day mortality or early postoperative stroke compared to patients in sinus rhythm. POAF-episodes were predominantly transient and almost 95% of patients were discharged in sinus rythm.

[Impact of renal dysfunction on early outcomes of coronary artery bypass grafting surgery].

INTRODUCTION: Impaired renal function as seen in chronic kidney disease (CKD) is a known risk factor for coronary artery diseases and has been linked to inferior outcome after myocardial revascularization. Studies on the outcome of coronary bypass grafting (CABG) in CKD-patients are scarce. We aimed to study this subgroup of patients following CABG in a well defined whole-nation cohort, focusing on short term complications and 30 day mortality. MATERIALS AND METHODS: A retrospective study on 2300 consecutive patients that underwent CABG at Landspítali University Hospital 2001-2020. Patients were divided into four groups according to preoperative estimated glomerular filtration rate (GFR), and the groups compared. GFR 45-59 mL/mín/1.73m2, GFR 30-44 mL/mín/1.73m2, GFR <30 mL/mín/1.73m2 and controls with normal GFR (≥60 mL/mín/1.73m2). Clinical information was gathered from medical records and logistic regression used to estimate risk factors of 30-day mortality. RESULTS: Altogether 429 (18.7%) patients had impaired kidney function; these patients being more than six years older, having more cardiac symptoms and a higher mean EuroSCORE II (5.0 vs. 1.9, p<0.001) compared to controls. Furthermore, their left ventricular ejection fraction was also lower, their median hospital stay extended by two days and major short-term complications more common, as was 30 day mortality (24.4% vs. 1.4%, p<0.001). In multivariate analysis advanced age, ejection fraction <30% and GFR <30 mL/min/1.73m2 were independent predictors of higher 30-day mortality (OR=10.4; 95% CI: 3.98-25.46). CONCLUSIONS: Patients with impaired renal function are older and more often have severe coronary artery disease. Early complications and 30-day mortality were much higher in these patients compared to controls and advanced renal failure and the strongest predictor of 30-day mortality.

Non-infectious sternal dehiscence after coronary artery bypass surgery.

INTRODUCTION: Non-infectious sternal dehiscence (NISD) is a known complication following coronary artery bypass grafting (CABG), with previous studies estimating an incidence of 0.4-1% of surgeries. We aimed to study the incidence of NISD together with short- and long-term outcomes in a whole-nation cohort of patients. MATERIALS AND METHODS: A retrospective study on consecutive CABG patients diagnosed with NISD at Landspitali from 2001 to 2020. Patients diagnosed with infectious mediastinitis (n = 20) were excluded. NISD patients were compared to patients with an intact sternum regarding patient demographics, cardiovascular risk factors, intra- and postoperative data, and estimated overall survival. The median follow-up was 9.5 years. RESULTS: Twenty out of 2280 eligible patients (0.88%) developed NISD, and the incidence did not change over the study period (p = 0.98). The median time of diagnosis was 12 days postoperatively (range, 4-240). All patients were re-operated using a Robicsek-rewiring technique, with two cases requiring a titanium plate for fixation. Patients with NISD were older, had a higher BMI and EuroSCORE II, lower LVEF, and more often had a history of COPD, MI, and diabetes compared to those without NISD. Length of stay was extended by 15 days for NISD patients, but short and long-term survival was not statistically different between the groups. CONCLUSIONS: The incidence of NISD was low and in line with previous studies. Although the length of hospital stay was extended, both short- and long-term survival of NISD patients was not significantly different from patients with an intact sternum.