[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.

Reoperation for bleeding following coronary artery bypass surgery with special focus on long-term outcomes.

Objectives: We studied the incidence and risk factors of reoperation for bleeding following CABG in a nationwide cohort with focus on long-term complications and survival. Design: A retrospective study on 2060 consecutive, isolated CABG patients operated 2001-2016. Outcome of reoperated patients (n = 130) were compared to non-reoperated ones (n = 1930), including major adverse cardiac and cerebrovascular events (MACCE) and overall survival. Risk factors for reoperation were determined using multivariate logistic regression and a Cox proportional hazards model to assess prognostic factors of long-term survival. Median follow-up was 7.6 years. Results: One hundred thirty patients (6.3%) were reoperated with an annual decrease of 4.1% per year over the study period (p=.04). Major complications (18.5 vs. 9.6%) and 30-day mortality (8.5 vs. 1.9%,) were higher in the reoperation group (p<.001). The use of clopidogrel preoperatively (OR 3.62, 95% CI: 1.90-6.57) and reduced left ventricular ejection fraction (OR 2.23, 95% CI: 1.25-3.77) were the strongest predictors of reoperation, whereas off-pump surgery was associated with a lower reoperation risk (OR 0.44, 95% CI: 0.22-0.85). After exluding patients that died within 30 days postoperatively, no difference in long-term survival or freedom from MACCE was found between groups, and reoperation was not an independent risk factor for long-term mortality in multivariate analysis. Conclusions: The reoperation rate in this study was relatively high but decreased significantly over time. Reoperation was associated with twofold increased risk for major complications and fourfold 30-day mortality, but comparable long-term MACCE and survival rates. This implies that if patients survive the first 30 days following reoperation, their long-term outcome is comparable to non-reoperated patients.

ABO blood group does not impact incidence or outcomes of surgery for acute type A aortic dissection.

Objectives. To evaluate the distribution and impact of ABO blood groups on postoperative outcomes in patients undergoing surgery for acute type A aortic dissection (ATAAD). Design. A total of 1144 surgical ATAAD patients from eight Nordic centres constituting the Nordic consortium for acute type A aortic dissection (NORCAAD) were analysed. Blood group O patients were compared to non-O subjects. The relative frequency of blood groups was assessed with t-distribution, modified for weighted proportions. Multivariable logistic regression was performed to identify independent predictors of 30-day mortality. Cox regression analyses were performed for assessing independent predictors of late mortality. Results. There was no significant difference in the proportions of blood group O between the study populations in the NORCAAD registry and the background population (40.6 (95% CI 37.7-43.4)% vs 39.0 (95% CI 39.0-39.0)%). ABO blood group was not associated with any significant change in risk of 30-day or late mortality, with the exception of blood group A being an independent predictor of late mortality. Prevalence of postoperative complications was similar between the ABO blood groups. Conclusions. In this large cohort of Nordic ATAAD patients, there were no associations between ABO blood group and surgical incidence or outcomes, including postoperative complications and survival.

[Incidence and predictors of prolonged intensive care unit stay after coronary artery bypass in Iceland].

INTRODUCTION: To maximize the use of intensive care unit (ICU) re--sources, it is important to estimate the prevalence and risk factors for prolonged ICU unit stay after coronary artery bypass grafting (CABG) surgery. MATERIAL AND METHODS: This retrospective cohort study included all patients who underwent primary isolated CABG at Landspitali between 2001 and 2018. Patient information was collected from hospital charts and death registries. Patients who stayed in the ICU for the conventional one night postoperatively were compared with those who needed longer stays in the ICU. Survival rate was estimated with the Kaplan-Meier method. Predictors for prolonged ICU stay were calculated with logistic regression and the outcome used to create a calculator that estimates the probability of prolonged ICU stay. RESULTS: Out of 2177 patients, 20% required prolonged ICU stay. Patients with prolonged stay were more frequently female (23% vs 16%, p=0.001), had a higher rate of cardiovascular risk factors and higher EuroSCORE II (4.7 vs. 1.9, p<0.001). They also had a higher rate of impaired renal function before surgery (14% vs. 4%, p<0.001) and emergent surgery (18% vs. 2%, p<0.001). Furthermore, these patients had higher rates of both short-term and long-term complications, and lower long-term survival (85% vs 68% five-year survival rate, p<0.0001). Independent risk factors for prolonged ICU stay were advanced age, female gender, EuroSCORE II, history of heart diseases, impaired renal function and emergent surgery.  Conclusions: Every fifth patient had a prolonged ICU stay after CABG. Several risk factors predicted prolonged ICU stay after CABG, in particular patients' medical condition before surgery, EuroSCORE II and emergent surgery. A better understanding of the risk factors for prolonged ICU stay will hopefully aid in scheduling CABG surgeries at Landspitali.

[The use of Intra Aortic Balloon Pump in Coronary Artery Bypass Graft Surgery].

INTRODUCTION: Intra-aortic balloon pump (IABP) is a mechanical device that increases cardiac output by increasing diastolic blood flow to the coronary arteries and lowers the afterload of the left ventricle in systole. IABP is primarily used in acute heart failure, that includes patients that have to undergo coronary artery bypass grafting (CABG). Its usage, however, in cardiac surgery has been declining with ongoing controversy regarding its benefits. The aim of this study was to assess the use and indications and outcome of IABP related to CABG surgery. MATERIAL AND METHODS: The study was retrospective and included 2177 patients that underwent CABG at Landspítali during 2001-2018. We compared those who received an IABP with controls, using uni- and multivariate analysis. Long term survival and complications (major adverse cardiovascular and cerebral events, MACCE) was estimated with Kaplan-Meier method. RESULTS: A total of 99 (4.5%) patients received an IABP. The incidence was highest in 2006 (8.9%) and lowest in 2001 (1.7%), but the incidence did not change during the study period (p=0.90). Most patients received the pump before (58.6%) or during (34.3%) CABG, but only 6.1% after surgery. Complication rate was 14.1%, with bleeding from the insertion site in the groin being the most common complication. Thirty day mortality was higher in the IABP group compared with controls (22.2% vs 1.3%, p<0.001) and both 5-year survival (56.4% vs 91.5%, 95% CI: 0.47-0.67) and 5-year MACCE-free survival (46.9% vs 83.0%, 95% CI: 0.38-0.58) were inferior. CONCLUSIONS: Less than 5% of patients received IABP in relation to CABG in Iceland and the rate hasn't changed much for the last 18 years. Both the complication rate and 30-day mortality was higher in patients in IABP group and both the long term and MACCE-free survival was much worse, probably mostly related to worse overall clinical condition of the patient that received IABP.

[No significant association between obesity and long-term outcome of coronary artery bypass grafting].

OBJECTIVES:  Our objective was to investigate long-term outcomes of obese patients undergoing coronary artery bypass grafting (CABG) in Iceland. MATERIALS AND METHODS:  A retrospective analysis on 1698 patients that underwent isolated CABG in Iceland between 2001-2013. Patients were divided into four groups according to body mass index (BMI); Normal=18.5-24.9kg/m2 (n=393), ii) overweight=25-29.9 kg/m2 (n=811), iii) obese=30-34.9 kg/m2 (n=388) and iv) severely obese ≥35kg/m2 (n=113). Thirty-day mortality and short-term complications were documented as well as long-term complications that were pooled into major adverse cardiac and cerebrovascular events (MACCE) and included myocardial infarction, stroke, repeated CABG, percutaneous coronary intervention with or without stenting, and death. After pooling the study groups, survival and freedom from MACCE plots (Kaplan- Meier) were generated and Cox regression analysis used to identify predictive factors of survival. Average follow-up time was 5.6 years. RESULTS:  Severely obese and obese patients were significantly younger than those with a normal BMI, more often males with identifiable risk factors of coronary artery disease (CAD) and a lower EuroSCORE II (1.6 vs. 2.7, p=0.002). The incidence of major early complications, 30-day mortality (2%), long-term survival (90% at 5 years, log-rank test p=0.088) and MACCE-free survival (81% at 5 years, log-rank test p=0.7) was similar for obese and non-obese patients. BMI was neither an independent predictor for long-term (OR: 0.98 95%-CI: 0.95-1.01) nor MACCE-free survival (OR: 1.0 95%-CI: 0.98-1.02).  Conclusions: Obese patients that undergo CABG in Iceland are younger and have an increased number of risk factors for coronary disease when compared to non-obese patients. However, BMI neither predicted long-term survival or long-term complications. The outcomes following CABG in obese patients are good in Iceland.

Long-term outcome of patients undergoing re-exploration for bleeding following cardiac surgery: a SWEDEHEART study.

OBJECTIVES: Excessive bleeding leading to re-exploration is a severe complication of cardiac surgical procedures, associated with early postoperative morbidity and mortality. Less is known about the long-term outcome of these patients. We evaluated the impact of re-exploration after cardiac surgery on peri- and postoperative morbidity and mortality, as well long-term mortality, in a well-defined nationwide population. METHODS: In this retrospective study, 48 060 consecutive patients undergoing coronary artery bypass grafting (CABG) and/or valve surgery from 2006 to 2015 were analysed. Multivariable logistic regression was used to identify factors associated with re-exploration, morbidity and mortality. Cox regression analysis was implemented to explore the association between re-exploration and long-term mortality. The mean follow-up time was 4.6 years (range 0-10 years) with follow-up time set at 31 December 2015. RESULTS: Overall, 2371 patients (4.9%) underwent re-exploration. Factors associated with re-exploration included advanced age, procedures other than isolated CABG and acute surgery. Re-explored patients had an increased risk of unadjusted mortality at 30, 90 and beyond 90 days (all P < 0.001). Significance was maintained after adjustment at 30 days [odds ratio: 3.94, 95% confidence interval (CI): 3.19-4.85, P < 0.001] and 90 days (odds ratio: 3.79, 95% CI: 3.14-4.55, P < 0.001), but not with long-term mortality (hazard ratio: 1.02, 95% CI: 0.91-1.15, P = 0.712). Furthermore, re-exploration was independently associated with other postoperative complications, e.g. prolonged hospital stay, stroke and renal injury. CONCLUSIONS: Patients who are re-explored for bleeding within 24 h have almost four-fold higher odds of mortality within 3 months post-procedure. However, the increased risk of death following re-exploration is not maintained in the long term.

Long-term outcome of surgical revascularization in patients with reduced left ventricular ejection fraction-a population-based cohort study.

OBJECTIVES: Surgical revascularization is an established indication for patients with advanced coronary artery disease and reduced left ventricular ejection fraction (LVEF). Long-term outcomes for these patients are not well-defined. We studied the long-term outcomes of patients with ischaemic cardiomyopathy who underwent surgical revascularization in a well-defined nationwide cohort. MATERIALS AND METHODS: A retrospective study on 2005 patients that underwent isolated coronary artery bypass grafting in Iceland between 2000 and 2016. Patients were categorized into two groups based on their preoperative LVEF; LVEF ≤35% (n = 146, median LVEF 30%) and LVEF >35% (n = 1859, median LVEF 60%). Demographics and major adverse cardiac and cerebrovascular events were compared between groups along with cardiac-specific and overall survival. The median follow-up was 7.6 years. RESULTS: Demographics were similar in both groups regarding age, gender and most cardiovascular risk factors. However, patients with LVEF ≤35% more often had diabetes, renal insufficiency, chronic obstructive pulmonary disease and a previous history of myocardial infarction. Thirty-day mortality was 4 times higher (8% vs 2%, P < 0.001) in the LVEF ≤35%-group compared to controls. Overall survival was significantly lower in the LVEF ≤35%-group compared to controls, at 1 year (87% vs. 98%, P < 0.001) and 5 years (69% vs. 91%, P < 0.001). In multivariable analysis LVEF ≤35% was linked to inferior survival with an adjusted hazard ratio of 2.0 (95%-CI 1.5 - 2.6, p<0.001). CONCLUSIONS: A good long-term outcome after coronary artery bypass grafting can be expected for patients with reduced LVEF, however, their survival is still significantly inferior to patients with normal ventricular function.

Use of serotonin reuptake inhibitors is not associated with increased bleeding after CABG.

OBJECTIVES: Selective serotonin reuptake inhibitors (SSRIs) and serotonin noradrenaline reuptake inhibitors (SNRIs) are the most commonly prescribed antidepressants worldwide. Studies suggest that SSRI/SNRIs can increase bleeding following different surgical procedures, including open heart surgery, but results are conflicting. The objective of this study was to analyse their effects on bleeding after coronary artery bypass grafting (CABG). METHODS: Of 1237 patients that underwent CABG in Iceland in 2007-2016, 97 (7.8%) used SSRIs/SNRIs preoperatively and were compared to a reference group (n = 1140). Bleeding was assessed using 24-h chest-tube output, number of RBC units transfused and reoperation for bleeding. Thirty-day mortality rates and incidence of complications were also compared. RESULTS: The two groups were comparable with respect to preoperative and operative variables, with the exception of BMI being significantly higher in the SSRI/SNRI group (30.2 vs. 28.3 kg/m2, p < 0.001). No significant differences were observed between groups in 24-h chest-tube output [815 (SSRI/SNRI) vs. 877 ml (reference), p = 0.26], number of RBC units transfused (2.2 vs. 2.2, p = 0.99) or the rate of reoperation for bleeding (4.1% vs. 6.0%, p = 0.61). The incidences of complications and 30-day mortality rate were also similar. CONCLUSIONS: Using three different criteria, preoperative use of SSRIs/SNRIs was not shown to increase bleeding after CABG. Furthermore, short-term complications as well as 30-day mortality rates did not differ from those of controls. Thus, temporary cessation of SSRI/SNRI treatment prior to CABG to decrease the risk of bleeding is unwarranted.

Penetrating stab injuries in Iceland: a whole-nation study on incidence and outcome in patients hospitalized for penetrating stab injuries.

BACKGROUND: Studies on penetrating injuries in Europe are scarce and often represent data from single institutions. The aim of this study was to describe the incidence and demographic features of patients hospitalized for stab injury in a whole nation. MATERIALS AND METHODS: This was a retrospective nationwide population-based study on all consecutive adult patients who were hospitalized in Iceland following knife and machete-related injuries, 2000-2015. Age-standardized incidence was calculated and Injury Severity Score (ISS) was used to assess severity of injury. RESULTS: Altogether, 73 patients (mean age 32.6 years, 90.4% males) were admitted during the 16-year study period, giving an age-standardized incidence of 1.54/100,000 inhabitants. The incidence did not vary significantly during the study period (P = 0.826). Most cases were assaults (95.9%) occurring at home or in public streets, and involved the chest (n = 32), abdomen (n = 26), upper limbs (n = 26), head/neck/face (n = 21), lower limbs (n = 10), and the back (n = 6). Median ISS was 9, with 14 patients (19.2%) having severe injuries (defined as ISS > 15). The median length of hospital stay was 2 days (range 0-53). Forty-seven patients (64.4%) underwent surgery and 26 of them (35.6%) required admission to an intensive care unit (ICU), all with ISS scores above 15. Three patients did not survive for 30 days (4.1%); all of them had severe injuries (ISS 17, 25, and 75). CONCLUSION: Stab injuries that require hospital admission are rare in Iceland, and their incidence has remained relatively stable. One in every five patients sustained severe injuries, two-thirds of whom were treated with surgical interventions, and roughly one-third required ICU care. Although some patients were severely injured with high injury scores, their 30-day mortality was still low in comparison to other studies.