Impact of minimal invasive extracorporeal circulation on atrial fibrillation after coronary artery bypass surgery.

Postoperative atrial fibrillation (POAF) is the most common arrhythmia after cardiac surgery with an incidence between 15% and 50% and pathophysiology not fully known. By choosing the method of extracorporeal circulation with focus on the reduction of systemic inflammatory response, one can potentially decrease the risk of POAF. In this prospective, randomized trial, we compared minimal invasive extracorporeal circulation (MiECC) with conventional extracorporeal circulation (CECC) in the prevention of POAF after coronary artery bypass surgery (CABG). A total of 240 patients who were scheduled for their first on-pump CABG, were randomized to MiECC or CECC. The primary outcome measure was the incidence of first POAF during the first 84 hours after surgery. POAF occurred in 42/120 (35.0%) MiECC patients and 43/120 (35.8%) CECC patients with nonsignificant difference between the groups (OR 1.043, 95% CI 0.591-1.843, P = .884). The first postoperative creatine kinase-MB mass (CK-MBm) value was lower in the MiECC group, 13.95 [10.5-16.7] (median [IQR]) than in the CECC group, 15.30 [11.4-18.9] (P = .036), whereas the use of perioperative dobutamine was higher in the MiECC group, 18/120 (15.0%), than in the CECC group 8/120 (6.7%) (P = .038). The incidence of a stroke, perioperative myocardial infarction, and resternotomy caused by bleeding did not differ in the MiECC and CECC groups. Age (OR 1.08, 95% CI 1.04-1.13, P = .000) and peak postoperative CK-MBm (OR 1.57, 95% CI 1.06-2.37, P = .026) were independent predictors of POAF. MiECC compared to CECC was not effective in reducing the incidence of POAF in patients undergoing CABG.

Impact of minimal invasive extracorporeal circulation on the need of red blood cell transfusion.

OBJECTIVE: Minimal invasive extracorporeal circulation may decrease the need of packed red blood cell transfusions and reduce hemodilution during cardiopulmonary bypass. However, more data are needed on the effects of minimal invasive extracorporeal circulation in more complex cardiac procedures. We compared minimal invasive extracorporeal circulation and conventional extracorporeal circulation methods of cardiopulmonary bypass. METHODS: A total of 424 patients in the minimal invasive extracorporeal circulation group and 844 patients in the conventional extracorporeal circulation group undergoing coronary artery bypass grafting and more complex cardiac surgery were evaluated. Age, sex, type of surgery, and duration of perfusion were used as matching criteria. Hemoglobin <80 g/L was used as red blood cell transfusion trigger. The primary endpoint was the use of red blood cells during the day of operation and the five postoperative days. Secondary endpoints were hemodilution (hemoglobin drop after the onset of perfusion) and postoperative bleeding from the chest tubes during the first 12 hours after the operation. RESULTS: Red blood cell transfusions were needed less often in the minimal invasive extracorporeal circulation group compared to the conventional extracorporeal circulation group (26.4% vs. 33.4%, p = 0.011, odds ratio 0.72, 95% confidence interval 0.55-0.93), especially in coronary artery bypass grafting subgroup (21.3% vs. 35.1%, p < 0.001, odds ratio 0.50, 95% confidence interval 0.35-0.73). Hemoglobin drop after onset of perfusion was also lower in the minimal invasive extracorporeal circulation group than in the conventional extracorporeal circulation group (24.2 ± 8.5% vs. 32.6 ± 12.6%, p < 0.001). Postoperative bleeding from the chest tube did not differ between the groups (p = 0.808). CONCLUSION: Minimal invasive extracorporeal circulation reduced the need of red blood cell transfusions and hemoglobin drop when compared to the conventional extracorporeal circulation group. This may have implications when choosing the perfusion method in cardiac surgery.

New-onset atrial fibrillation at discharge in patients after coronary artery bypass surgery: short- and long-term morbidity and mortality.

OBJECTIVES: Atrial fibrillation (AF) after coronary artery bypass surgery is often considered a non-harmful and self-terminating condition. We studied the mortality and morbidity in patients with new-onset AF (NOAF) present at the time of hospital discharge. METHODS: We conducted a retrospective follow-up study of 138 patients discharged in NOAF (NOAF group) and a propensity score-matched control group of 138 patients who were in sinus rhythm (SR) at the time of discharge (SR group). Follow-up data were obtained from the hospitals' records, from the national registry of hospital discharge diagnoses and death records from the Finnish Statistical Bureau. RESULTS: At 3 and 12 months after surgery, AF was present in 20.3 and 23.2% of patients in the NOAF group, respectively, but in none of the patients in the SR group (P < 0.001). At the end of follow-up (8.5 ± 2.8 years), 28.3 and 5.1% of the patients who survived in the NOAF and SR groups, respectively, were in chronic AF (P < 0.001). All-cause mortality (33.3 vs 18.8%, P = 0.002) and cardiac mortality (15.2 vs 4.3%, P = 0.001) were higher in the NOAF group when compared with the SR group. The incidence of cerebrovascular disorders in the NOAF and SR groups did not differ from each other (13.8 vs 10.9%, P = NS). Independent risk factors for all-cause death were NOAF [P = 0.024, hazard ratio (HR) 1.828, 95% CI 0.547-3.09], age (P = 0.0025, HR 1.074, 95% CI 1.026-1.13), diabetes (P = 0.015, HR 1.965, 95% CI 1.142-3.38) and prolonged respiratory support (P = 0.00024, HR 3.394, 95% CI 1.767-6.52). In addition, patients in the NOAF group had more hospitalizations due to heart failure (7.2 vs 0.7%, P < 0.001) and had a higher rate of implantation of permanent pacemakers (6.5 vs 0.4%, P < 0.001). CONCLUSIONS: A majority of NOAF patients revert to SR during the first months after surgery. On the other hand, 20-25% of NOAF patients develop chronic AF during long-term follow-up. Almost half of the NOAF patients were hospitalized during follow-up due to cardiovascular causes. Similarly, NOAF was associated with increased mortality due to cardiac causes, but not increased risk of stroke. This highlights the need for proper oral anticoagulation therapy in these patients.

Levosimendan increases bleeding risk after heart valve surgery: a retrospective analysis of a randomized trial.

OBJECTIVE: To investigate whether levosimendan, an inotrope with cardioprotective properties, increases postoperative bleeding after cardiac surgery. DESIGN: Retrospective analysis of a randomized, prospective clinical study. SETTING: Post-anesthesia care unit (PACU) and surgical ward in a university hospital. PARTICIPANTS: Two hundred heart valve surgery patients. INTERVENTIONS: The patients were randomized to receive either a 24-hour intravenous infusion of levosimendan or placebo. Infusion was administered as a 24 µg/kg bolus over 30 minutes and then continued at a dose of 0.2 µg/kg/min. MEASUREMENTS AND MAIN RESULTS: Postoperative bleeding was approximately 31% greater in the levosimendan group (1050 mL) compared to the placebo group (880 mL, p = 0.008). Serious bleeding exceeding 1000 mL was more common in the levosimendan group than the placebo group (51 v 38 patients, p = 0.044, risk ratio (RR) 1.37, 95% CI 1.00-1.87). However, the risk of reoperation for bleeding did not increase if patients received levosimendan (RR 1.52, 95% CI 0.77-2.97, p = 0.309). This result did not change after excluding patients who received clopidogrel preoperatively (RR 2.13, 95% CI 0.98-4.65, p = 0.145). The groups did not differ regarding transfused blood products. Eight patients, including seven from the levosimendan group, had delayed (diagnosed>48 hours after the surgery) cardiac tamponade and underwent re-exploration (7 v 1, p = 0.031). CONCLUSIONS: Levosimendan increased the risk of postoperative bleeding after cardiac valve surgery. In addition, the risk of postoperative cardiac tamponade was increased in patients who received levosimendan compared to placebo.

Levosimendan reduces heart failure after cardiac surgery: a prospective, randomized, placebo-controlled trial.

OBJECTIVE: To investigate whether levosimendan diminishes the incidence of heart failure after cardiac surgery. DESIGN: Prospective, randomized, placebo-controlled clinical study. SETTING: Cardiac surgery operating room and postanesthesia care unit in a university hospital. PATIENTS: Two hundred patients assigned to undergo heart valve or combined heart valve and coronary artery bypass grafting surgery. INTERVENTIONS: Patients were randomized to receive a 24-hr infusion of placebo or levosimendan administered as a 24 µg/kg bolus over 30-mins and thereafter at a dose of 0.2 µg/kg/min. MEASUREMENTS AND MAIN RESULTS: Heart failure was defined as cardiac index<2.0 L/min/m or failure to wean from cardiopulmonary bypass necessitating inotrope administration for at least 2 hrs postoperatively. Heart failure was less frequent in the levosimendan compared to the placebo group: 15 patients (15%) in the levosimendan and 59 patients (58%) in the placebo group experienced heart failure postoperatively (risk ratio 0.26; 95% confidence interval 0.16-0.43; p<.001). Accordingly, a rescue inotrope (adrenaline) was needed less frequently in the levosimendan compared to the placebo group (risk ratio 0.11; 95% confidence interval 0.01-0.89), p=.005. Intra-aortic balloon pump was utilized in one patient (1%) in the levosimendan and in nine patients (9%) in the placebo group (risk ratio 0.11; 95% confidence interval 0.01-0.87), p=.018. The hospital and the 6-month mortality were comparable between groups. There were no significant differences in major organ failures postoperatively. Eighty-three patients were hypotensive and needed noradrenaline in the levosimendan compared to 52 patients in the placebo group, p<.001. The cardiac enzymes (creatine kinase MB isoenzyme mass) indicating myocardial damage were lower in the levosimendan group on the first postoperative day, p=.011. CONCLUSIONS: In the present study, levosimendan infusion reduced the incidence of heart failure in cardiac surgery patients but was associated with arterial hypotension and increased requirement of vasopressor agents postoperatively. Improved mortality or morbidity was not demonstrated.

Comparison of spectral entropy and BIS VISTA™ monitor during general anesthesia for cardiac surgery.

OBJECTIVES: We compared the primary metrics of the Spectral entropy M-ENTROPY™ module and BIS VISTA™ monitor-i.e., bispectral index (BIS), state entropy (SE), and response entropy (RE) in terms of agreement and correlation during general anesthesia for cardiac surgery. We also evaluated responsiveness of electroencephalogram (EEG)-based and hemodynamic parameters to surgical noxious stimulation, skin incision, and sternotomy, hypothesizing that RE would be a better responsiveness predictor. METHODS: BIS and entropy sensors were applied before anesthesia induction in 32 patients having elective cardiac surgery. Total intravenous anesthesia was standardized and guided by the BIS index with neuromuscular blockade tested with train-of-four monitoring. Parameters included SE, RE, BIS, forehead electromyography (EMG), and hemodynamic variables. Time points for analyzing BIS, entropy, and hemodynamic values were 1 min before and after: anesthesia induction, intubation, skin incision, sternotomy, cannulation of the aorta, cardiopulmonary bypass (CPB), cross-clamping the aorta, de-clamping the aorta, and end of CPB; also after starting the re-warming phase and at 10, 20, 30, and 40 min following. RESULTS: The mean difference between BIS and SE (Bland-Altman) was 2.14 (+16/- 11; 95% CI 1.59-2.67), and between BIS and RE it was 0.02 (+14/- 14; 95% CI 0.01-0.06). BIS and SE (r(2) = 0.66; P = 0.001) and BIS and RE (r(2) = 0.7; P = 0.001) were closely correlated (Pearson's). EEG parameters, EMG values, and systolic blood pressure significantly increased after skin incision, and sternotomy. The effect of surgical stimulation (Cohen's d) was highest for RE after skin incision (-0.71; P = 0.0001) and sternotomy (-0.94; P = 0.0001). CONCLUSION: Agreement was poor between the BIS index measured by BIS VISTA™ and SE values at critical anesthesia time points in patients undergoing cardiac surgery. RE was a good predictor of arousal after surgical stimulation regardless of the surgical level of muscle relaxation. Index differences most likely resulted from different algorithms for calculating consciousness level.

Health-related quality of life after coronary artery bypass grafting: a review of randomized controlled trials.

Objective outcome measures (i.e., survival, mortality, morbidity, complication rate, symptom recurrence, and need for re-interventions) have long been used as benchmarks for successful cardiac surgery, including coronary artery bypass grafting (CABG). Along with these objectively measurable outcome indicators, acquired improvement by cardiac surgery in subjectively experienced health-related quality of life (HRQoL) has gained importance during the last decade in cardiac surgical research. If an increasing proportion of adult patients referred for CABG are elderly, octogenarians or even nonagenarians, the acquired HRQoL benefit from bypass surgery should be considered to be at least as important an outcome measure as potentially marginal improvement in life expectancy or longevity alone. To achieve the maximal HRQoL benefit and to optimize patient selection, a comprehensive analysis and understanding of contributors that affect pre- and postoperative self-perceived HRQoL is essential. These include patient-related characteristics (e.g., demographics and underlying comorbidities), surgical technique-related factors, and healthcare-related attributes. In this paper we review the randomized controlled trials published during the last ten years to analyze the effect of CABG on HRQoL. Specifically, we focus on the differences between the on-pump and off-pump (OPCAB) bypass techniques, investigate the factors that contribute to post-CABG HRQoL, and study post-CABG HRQoL in elderly patients.

Pacemaker therapy after tricuspid valve operations: implications on mortality, morbidity, and quality of life.

BACKGROUND: We studied the incidence and predictors of permanent pacemaker implantation after tricuspid valve operation and its implications on patient outcome in terms of survival, morbidity, and quality of life. METHODS: Between 1992 and 2007, 136 consecutive patients underwent tricuspid valve repair or valve replacement with a biologic valve at Kuopio University Hospital. Comprehensive clinical data were recorded prospectively. Data for the Nottingham Health Profile quality of life analysis were collected cross-sectionally. RESULTS: The mean follow-up time was 7.9 +/- 4.1 years (range, 0.8 to 15.7 years). A pacemaker was implanted in 28 patients (21%); 54% were implanted before hospital discharge. The 10-year survival of patients with a pacemaker was higher (94%) than of patients without a pacemaker (59%; p = 0.050). The need of a pacemaker was related to a significantly higher rate of transient ischemic attacks (30% vs 6%, p = 0.004), strokes (9% vs 4%; p = 0.008), and impaired physical capacity in terms of higher New York Heart Association functional class (p = 0.03) and the quality of life scores describing energy (31 vs 17; p = 0.01) and mobility (32 vs 17; p = 0.005). CONCLUSIONS: The need for pacemaker implantation after tricuspid valve operations was high. Unexpectedly, the life expectancy of the patients who needed a pacemaker postoperatively was higher compared with those who did not. This beneficial effect on mortality was offset by impaired morbidity: patients with a pacemaker experienced a significantly higher rate of thromboembolic complications and impaired quality of life.

Veno-venous extracorporeal membrane oxygenation in surgery for bronchial repair.

Single-lung ventilation using a double-lumen endobronchial tube is often performed for surgical procedures involving the thorax. Tracheobronchial rupture during use of an endobronchial tube is an uncommon and serious complication. We present the case of a patient undergoing a right pneumonectomy who experienced a bronchial rupture due to a double-lumen endobronchial tube. Institution of veno-venous extracorporeal membrane oxygenation allowed removal of the endobronchial tube, and the repair was successfully performed. We hope that this information can provide further insight into the management of such a complication.

Mitral valve replacement versus repair: propensity-adjusted survival and quality-of-life analysis.

BACKGROUND: We investigated whether mitral valve repair (MVP) is superior to mitral valve replacement (MVR) in terms of survival and quality of life during the long-term follow-up. METHODS: One hundred eighty-four consecutive patients underwent MVP or MVR for mitral regurgitation with or without concomitant coronary artery bypass grafting. Clinical data were recorded prospectively, and the data for the Nottingham Health Profile quality-of-life analysis was collected cross-sectionally. Propensity score analysis was used for the study group matching. RESULTS: The mean follow-up time was 7.3 +/- 1.4 years. After adjustment for baseline characteristics by the propensity score method, there was a statistically significant survival benefit for the patients who underwent MVP (p = 0.02). Risk factors for death were preoperative unstable angina pectoris (relative risk ratio, 4.4; 95% confidence interval, 2.2 to 8.8), age older than 60 years (relative risk ratio, 1.1; 95% confidence interval, 1.0 to 1.1), use of mitral prosthesis (relative risk ratio, 2.7; 95% confidence interval, 1.4 to 5.3), preoperative renal insufficiency (relative risk ratio, 1.0; 95% confidence interval, 1.0 to 1.007), and preoperative cerebrovascular disorder (relative risk ratio, 2.7; 95% confidence interval, 1.0 to 5.3). The quality of life of the MVP and MVR groups did not differ from each other, but the MVP and the MVR patients had lower energy and mobility scores than an age- and sex-matched reference population. CONCLUSIONS: Survival is longer after MVP than after MVR. The quality of life of MVP and MVR patients does not differ from each other. In terms of most quality-of-life variables, patients who undergo mitral valve operations cope similarly to an age- and sex-matched reference population. Only the scores reflecting energy and mobility were lower in the patients who were operated on than in the reference population.

Population-based audit of fresh-frozen plasma transfusion practices.

BACKGROUND: In contrast to decreasing red blood cell (RBC) consumption in Finland, the use of fresh-frozen plasma (FFP) has been increasing since the 1990s, suggesting that FFP use may not always be optimal. To improve transfusion practices, knowledge of current FFP use and regional, national, and international comparison is necessary. STUDY DESIGN AND METHODS: Nine (of 21) Finnish hospital districts participated. Data concerning FFP-transfused patients in the years 2002 and 2003 were collected from existing computerized medical records into a yearly updated database as part of a Finnish benchmarking project on blood component use. RESULTS: Data included 11,590 FFP-transfused patients and 60,240 FFP units (71.2% of Finnish FFP use) delivered to Finnish hospitals during the study period. FFP was transfused most often to surgery patients (62.8% of FFP transfusion hospital visits) with blood circulatory system problems (32.3% of surgically treated and FFP-transfused patients). In only 65.9 percent of FFP-transfused patients were coagulation variables measured at any point in the hospital episode, and FFP was usually transfused in paired doses. Mean FFP use in Finland is comparable to other countries. CONCLUSION: Although overall FFP use in Finland is similar to that of international figures, it does not ensure best practice. Perioperative staff, being the largest FFP user, should be encouraged to dose FFP based on coagulation variables and body weight. Improvement efforts should be directed to patient groups transfused with large amounts of FFP.

Early and late outcome after coronary artery bypass surgery in diabetic patients.

OBJECTIVE: To determine the impact of diabetes on outcome after coronary artery bypass surgery. DESIGN: We matched 866 diabetic patients with non-diabetic controls in regards to gender, age, left ventricular ejection fraction, body mass index, presence of unstable angina and history of myocardial infarction, and day of surgery. The 30-d mortality and morbidity were evaluated with univariate analysis and survival and freedom from cardiac death were assessed with the Kaplan-Meier method. RESULTS: Follow-up time was 69+/-37 months. The 30-d mortality was 2.0% in the diabetic group and 1.0% in the non-diabetic group (p=0.15). Postoperative morbidity did not differ between groups. Cumulative 5- and 10-year survival rates were 89 and 71% in diabetics and 94 and 84% in non-diabetics (p=0.001). During follow-up, there was no difference between groups in regards to repeat revascularization. CONCLUSIONS: The 30-d mortality was equally low in diabetic and non-diabetic patients with severe coronary artery disease. However, long-term survival was significantly lower in the diabetic group than in the non-diabetic group.

Cardioplegic arrest does not increase the risk of atrial fibrillation after coronary artery bypass surgery.

OBJECTIVE: Atrial fibrillation (AF) is the most common arrhythmia after coronary artery bypass grafting (CABG). It is a considerable source of morbidity, prolongs hospital stay and increases costs of treatment. Atrial cannulation, cardiopulmonary bypass and cardioplegic arrest have been suggested to play a role in the development of AF after CABG. The aim of this case-control study was to evaluate the role of cardiopulmonary bypass and cardioplegic arrest in the development of postoperative AF. METHODS: Data from 114 patients undergoing CABG without cardiopulmonary bypass and cardioplegic arrest (off-pump) between October, 1998 and December, 2002 were evaluated for the occurrence of postoperative AF. Each patient was individually matched by gender, age (+/-3 years), left ventricle ejection fraction (+/-5%), history of myocardial infarction, unstable angina, and beta-blocker medication with patients undergoing CABG with cardiopulmonary bypass and cardioplegic arrest (on-pump) during the same period. The data from off-pump and on-pump groups were compared. RESULTS: Off-pump and on-pump groups had similar preoperative characteristics. The number of distal anastomoses was lower in the off-pump (2.3+/-0.9) than in the on-pump (3.9+/-1.1, (P<0.001) group. However, the incidence of postoperative AF in the off-pump (36.8%) and the on-pump groups (36.0%) did not differ from each other. Old age was the only independent predictor of AF after CABG. CONCLUSIONS: Neither cardiopulmonary bypass nor cardioplegic arrest increases the risk of postoperative AF after CABG.