Pharmacologic prophylaxis for postoperative atrial tachyarrhythmia in general thoracic surgery: Evidence from randomized clinical trials

Utility of magnesium sulfate in the treatment of rapid atrial fibrillation in the emergency department: a systematic review and meta-analysis

Atrial fibrillation with rapid ventricular response (Afib/RVR) is a frequent reason for emergency department (ED) visits and can be treated with a variety of pharmacological agents. Magnesium sulfate has been used to prevent and treat postoperative Afib/RVR. We performed a systematic review and meta-analysis to assess the effectiveness of magnesium for treatment of Afib/RVR in the ED. PubMed and Scopus databases were searched up to June 2021 to identify any relevant randomized trials or observational studies. We used Cochrane's Risk-of-Bias tools to assess study qualities and random-effects meta-analysis for the difference of heart rate (HR) before and after treatment. Our search identified 395 studies; after reviewing 11 full texts, we included five randomized trials in our analysis. There were 815 patients with Afib/RVR; 487 patients (60%) received magnesium treatment, whereas 328 (40%) patients received control treatment. Magnesium treatment was associated with significant reduction in HR [standardized mean difference (SMD), 0.34; 95% CI, 0.21-0.47; P < 0.001; I2 = 4%), but not associated with higher rates of sinus conversion (OR, 1.46; 95% CI, 0.726-2.94; P = 0.29), nor higher rates of hypotension and bradycardia (OR, 2.2; 95% CI, 0.62-8.09; P = 0.22). Meta-regressions demonstrated that higher maintenance dose (corr. coeff, 0.17; P = 0.01) was positively correlated with HR reductions, respectively. We observed that magnesium infusion can be an effective rate control treatment for patients who presented to the ED with Afib/RVR. Further studies with more standardized forms of control and magnesium dosages are necessary to assess the benefit/risk ratio of magnesium treatment, besides to confirm our observations.

Calcium Channel Blockers in Acute Care: The Links and Missing Links Between Hemodynamic Effects and Outcome Evidence

Calcium channel blockers (CCBs) exert profound hemodynamic effects via blockage of calcium flux through voltage-gated calcium channels. CCBs are widely used in acute care to treat concerning, debilitating, or life-threatening hemodynamic changes in many patients. The overall literature suggests that, for systemic hemodynamics, although CCBs decrease blood pressure, they normally increase cardiac output; for regional hemodynamics, although they impair pressure autoregulation, they normally increase organ blood flow and tissue oxygenation. In acute care, CCBs exert therapeutic efficacy or improve outcomes in patients with aneurysmal subarachnoid hemorrhage, acute myocardial infarction and unstable angina, hypertensive crisis, perioperative hypertension, and atrial tachyarrhythmia. However, despite the clear links, there are missing links between the known hemodynamic effects and the reported outcome evidence, suggesting that further studies are needed for clarification. In this narrative review, we aim to discuss the hemodynamic effects and outcome evidence for CCBs, the links and missing links between these two domains, and the directions that merit future investigations.

Diltiazem Prophylaxis for the Prevention of Atrial Fibrillation in Patients Undergoing Thoracoabdominal Esophagectomy: A Retrospective Cohort Study

Background

Atrial fibrillation (AF) represents the most frequent arrhythmic disorder after thoracoabdominal esophageal resection and is associated with a significant increase in perioperative morbidity and mortality.

Methods

In this retrospective cohort study, 167 patients who underwent thoracoabdominal esophagectomy at a large university hospital were assessed. We compared patients who received a 14-day postoperative course of diltiazem with a control group of patients who did not undergo diltiazem prophylaxis. Diltiazem therapy started immediately upon admission to the intensive care unit (ICU) with a loading dose of 0.25 mg/kg bodyweight (i.v.) followed by continuous infusion (0.1 mg/kg bodyweight/h) for 40–48 h. Oral administration (Dilzem^® 180 mg uno retard, once a day) was started on postoperative day 3.

Results

A total of 117 patients were assessed. Twelve (10.3%) of all patients developed postoperative new-onset atrial fibrillation in the first 30 days after surgical intervention. Prevalence of new-onset AF showed no significant differences between the diltiazem group and control group (p = 0.74). The prevalence of bradycardia (14.7% vs. 3.6%; p = 0.03) and dose of norepinephrine required (0.09 vs. 0.04 µg/kg bodyweight/min; p = 0.04) were higher in the diltiazem group. There were no significant differences between the groups for the median postoperative duration of hospital/ICU stay or mortality.

Conclusions

A prophylactic 14-day postoperative course of diltiazem was not associated with a reduction in new-onset AF or 30-day mortality following thoracoabdominal esophagectomy. Prophylactic diltiazem therapy was associated with drug-related adverse effects such as bradycardia and increased requirement of norepinephrine.

German Clinical Trial Registration Number: DKRS00016631.

Incidence, Management, Prevention and Outcome of Post-Operative Atrial Fibrillation in Thoracic Surgical Oncology

Atrial fibrillation (AF) is a common supraventricular arrhythmia, a recognized risk factor for ischemic stroke, as a potential driver for heart failure (HF). Cancer patients have an increased risk for AF, even not including any cancer-specific treatment, as surgery or chemotherapy. The mechanism is multifactorial, with inflammation and changes in autonomic tone as critical actors. Commonly, AF is a recurrent complication of the post-operative period in cancer surgery (especially thoracic). Recent papers confirmed a significant incidence of post-operative (non-cardiac surgery) AF (PAF), partially mitigated by the use of prophylactic (rate o rhythm control) treatments. A relevant difference, in terms of mean hospitalization time, emerges between patients developing PAF and those who do not, while long term impact remains a matter of debate, due to several potential confounding factors. Besides clinical predictors, structural (i.e., echocardiographic) and bio-humoral findings may help in risk prediction tasks. In this respect, pre-operative natriuretic peptides (NPs) concentrations are nowadays recognized as significant independent predictors of perioperative cardiovascular complications (including PAF), while elevated post-operative levels may further enhance risk stratification. The aim of the present paper is to trace the state of the art in terms of incidence, management, prevention, and outcome of PAF in the field of thoracic surgical oncology.

The suppressive effects of landiolol administration on the occurrence of postoperative atrial fibrillation and tachycardia, and plasma IL-6 elevation in patients undergoing esophageal surgery: A randomized controlled clinical trial

STUDY OBJECTIVE

To determine whether perioperative landiolol administration suppresses postoperative atrial fibrillation (AF) and the plasma cytokines elevation in patients undergoing esophageal cancer surgery.

DESIGN

A prospective, randomized controlled trial.

SETTING

Akita University Hospital, Akita, Japan, from April 2012 to January 2015.

PATIENTS

Forty American Society of Anesthesiologists grade I-II patients undergoing elective esophagectomy.

INTERVENTIONS

Patients were randomly divided into two groups, landiolol group (landiolol: 5μg/kg/min) and control group (the same volume of covered saline). Landiolol or saline was infused continuously from the induction of anesthesia until next morning.

MEASUREMENTS

We examined the new onset of AF and sinus tachycardia, and measured plasma concentrations of cytokines (IL-1β, IL-6, IL-8, IL-10, and TNF-α) just before surgery, at the end of surgery, the next day, and 2days after surgery. Data (mean±SD) were analyzed using two-way ANOVA followed by the Bonferroni"s test for post hoc comparison; a P<0.05 was considered statistically significant.

MAIN RESULTS

Demographic data were similar between the landiolol and the control groups. The incidence of AF was significantly lower in the landiolol group (1/19=5.3%) compared with the control group (7/20=35%) as well as sinus tachycardia (landiolol group, 0/19=0% vs. control group, 5/20=25%). Plasma IL-6 level at the end of surgery was significantly lower in the landiolol group compared with the control group, but the other plasma cytokines levels were similar between the two groups during the entire study period.

CONCLUSIONS

Perioperative landiolol administration suppressed the incidence of new-onset of AF as well as sinus tachycardia, and the plasma IL-6 elevation in patients undergoing esophageal cancer surgery.

Prophylaxis Against Atrial Fibrillation After General Thoracic Surgery: Trial Sequential Analysis and Network Meta-Analysis

BACKGROUND

Postoperative atrial fibrillation/flutter (POAF) is associated with significant morbidity and mortality after general thoracic surgery, but the need for and the best agent for prophylaxis remains obscure.

METHODS

A systematic literature search was performed to identify randomized controlled trials that compared regimens for POAF prophylaxis after general thoracic surgery. Random-effects meta-analyses with trial sequential analyses were performed to compare the effects of medical prophylaxis vs placebo/usual care. The risk of POAF among patients receiving various prophylactic regimens was subjected to Bayesian network meta-analysis.

RESULTS

Twenty-two trials (2,891 patients and 11 regimens) were included. Overall, medical prophylaxis reduced the incidence of POAF (OR, 0.33; 95% CI, 0.22-0.49) but not short-term mortality (OR, 0.85; 95% CI, 0.41-1.73). There was no significant difference in patient withdrawal due to adverse events (OR, 1.67; 95% CI, 0.67-4.16). Trial sequential analysis showed that as of 2012, sufficient evidence had accrued in support of the effectiveness of medical prophylaxis in reducing POAF after general thoracic surgery. In network meta-analysis, β-blockers, angiotensin-converting enzyme inhibitors, amiodarone, magnesium, and calcium channel blockers significantly reduced the risk of POAF compared with placebo/usual care. β-Blockers had the highest probability of being the most effective agents (OR, 0.12; 95% credible interval [CrI], 0.05-0.27; probability of being best, 77.7%; number needed to treat, 5.2).

CONCLUSIONS

The current literature supports the effectiveness and tolerability of medical prophylaxis and the superiority of β-blockers in preventing POAF after general thoracic surgery. β-Blockers are recommended, taking into consideration the status of the bronchopulmonary system.

Post-thoracotomy dysrhythmia

PURPOSE OF REVIEW

This article reviews and summarizes the pathophysiology, risk factors, and the management of arrhythmias in patients undergoing noncardiac thoracic surgery.

RECENT FINDINGS

Cardiac arrhythmias are common findings in the perioperative period, particularly with increasing age. They often complicate the course of the patient's recovery after operation. The most common postoperative arrhythmia is atrial fibrillation. It requires either a rate or rhythm control strategy, and the need for anticoagulation has to be assessed depending on the duration of the arrhythmia and risk factors. Fortunately, malign sustained ventricular tachyarrhythmias (ventricular tachycardia, ventricular fibrillation) are rare. Acute treatment and, in the absence of a reversible cause, a long-term preventive strategy may be warranted. Transient bradyarrhythmias can be managed by atropine or with temporary pacing.

SUMMARY

Arrhythmias are common after thoracotomy. Physicians treating patients with postoperative arrhythmias should bear in mind that arrhythmia management does not only comprise a specific therapy for the arrhythmia itself, but also includes the correction of transient and correctable predisposing and causative factors.

Atrial arrhythmias after lung transplantation: Incidence and risk factors in 652 lung transplant recipients

OBJECTIVES

Atrial arrhythmia (AA) after lung transplantation (LTx) is a potentially morbid event often associated with increased length of hospital stay. Predictors of postsurgical AA, however, are incompletely understood. We characterized the incidence and predisposing risk factors for AA in patients undergoing LTx.

METHODS

A retrospective analysis of prospectively collected data was conducted to identify LTx recipients between January 2008 and October 2013. Patients were divided into 2 groups on the basis of postoperative AA development. Univariable and multivariable analyses were performed to define differences between groups and identify factors associated with AA. Survival differences were assessed by the use of competing risks methodology.

RESULTS

A total of 198 of 652 (30.4%) patients developed AA at a median onset of 5 days after transplant. Increasing age (hazard ratio [HR] 1.03 per additional year, P < .001) and previous coronary artery bypass grafting (HR 2.77, P = .002) were found to be independent risk factors. Counterintuitively, patients with a medical history of AA before LTx had a lower incidence of postoperative AA. Preoperative beta-blocker usage was not a significant predictor of postoperative AA. Postoperative AA was a significant predictor of long-term mortality (HR 1.63, P = .007) when we adjusted for other risk factors.

CONCLUSIONS

AA is a common occurrence after LTx, occurring with greatest frequency in the first postoperative week, and results in a significant reduction in long-term survival. Increasing age and before coronary artery bypass grafting were identified as independent risk factors for AA development. Better understanding of these risk factors may improve identification of patients at heightened risk after transplantation.

Postlobectomy Early Complications

Immediate postoperative complications are common after lobectomy. The most effective management of postoperative crises is prevention, which starts with preoperative preparation and patient screening. There are many factors that can be controlled and improved by the patient. Equally important is patient selection, which is influenced by pulmonary function tests, cardiopulmonary reserve, and preexisting comorbidities. After the operation, the care team can also greatly improve outcomes with aggressive cardiopulmonary therapies, ambulation, vigilant monitoring, and frequent assessments of the patient. Prevention strategies can minimize risks; however, when they occur, a proactive approach may minimize the long-term sequelae.

Anesthesia for esophagectomy

Esophagectomy is a high-risk operation with significant perioperative morbidity and mortality. Attention to detail in many areas of perioperative management should lead to an aggregation of marginal gains and improvement in postoperative outcome. This review addresses preoperative assessment and patient selection, perioperative care (focusing on pulmonary prehabilitation, ventilation strategies, goal-directed fluid therapy, analgesia, and cardiovascular complications), minimally invasive surgery, and current evidence for enhanced recovery in esophagectomy.

Postoperative atrial fibrillation in patients undergoing non-cardiac non-thoracic surgery: A practical approach for the hospitalist

New postoperative atrial fibrillation (POAF) is the most common perioperative arrhythmia and its reported incidence ranges from 0.4 to 26% in patients undergoing non-cardiac non-thoracic surgery. The incidence varies according to patient characteristics such as age, presence of structural heart disease and other co-morbidities, as well as the type of surgery performed. POAF occurs as a consequence of adrenergic stimulation, systemic inflammation, or autonomic activation in the intra or postoperative period (e.g. due to pain, hypotension, infection) in the setting of a susceptible myocardium and other predisposing factors (e.g. electrolyte abnormalities). POAF develops between day 1 and day 4 post-surgery and it is often considered a self-limited entity. Its acute management involves many of the same strategies used in non-surgical patients but the optimal long-term management is challenging because of the limited available evidence. Several studies have shown an association between occurrence of POAF and in-hospital morbidity, mortality, and length of stay. Although, traditionally, POAF was considered to have a generally favorable long-term prognosis, recent data have shown an association with an increased risk of stroke at 1 year after hospitalization. It is unknown, however, whether strategies to prevent POAF or for rate/rhythm control when it does occur, lead to a reduction in morbidity or mortality. This suggests the need for future studies to better understand the risks associated with POAF and to determine optimal strategies to minimize long-term thromboembolic risks. In this article, we summarize the current knowledge on epidemiology, pathophysiology, and short- and long-term management of POAF after non-cardiac non-thoracic surgery with the goal of providing a practical approach to managing these patients for the non-cardiologist clinician.

Supraventricular arrhythmias after thoracotomy: is there a role for autonomic imbalance?

Supraventricular arrhythmias are common rhythm disturbances following pulmonary surgery. The overall incidence varies between 3.2% and 30% in the literature, while atrial fibrillation is the most common form. These arrhythmias usually have an uneventful clinical course and revert to normal sinus rhythm, usually before patent's discharge from hospital. Their importance lies in the immediate hemodynamic consequences, the potential for systemic embolization and the consequent long-term need for prophylactic drug administration, and the increased cost of hospitalization. Their incidence is probably related to the magnitude of the performed operative procedure, occurring more frequently after pneumonectomy than after lobectomy. Investigators believe that surgical factors (irritation of the atria per se or on the ground of chronic inflammation of aged atria), direct injury to the anatomic structure of the autonomic nervous system in the thoracic cavity, and postthoracotomy pain may contribute independently or in association with each other to the development of these arrhythmias. This review discusses currently available information about the potential mechanisms and risk factors for these rhythm disturbances. The discussion is in particular focused on the role of postoperative pain and its relation to the autonomic imbalance, in an attempt to avoid or minimize discomfort with proper analgesia utilization.

Does the prophylactic administration of magnesium sulphate to patients undergoing thoracotomy prevent postoperative supraventricular arrhythmias? A randomized controlled trial

BACKGROUND

Supraventricular arrhythmias (SVA) are common after thoracic surgery and are associated with increased morbidity and mortality. This prospective, randomized, double-blind, placebo-controlled trial examined the effects of perioperative magnesium on the development of postoperative SVA.

METHODS

Two hundred patients undergoing thoracotomy for lobectomy, bi-lobectomy, pneumonectomy, or oesophagectomy were recruited and randomly allocated into two groups. The treatment group received magnesium (5 g daily) intraoperatively, and on days 1 and 2 after operation, the control group received placebo. The primary outcome of the study was the development of SVA within the first 5 days after operation.

RESULTS

There were 100 patients in each arm of the study, with one withdrawal and three lost to follow-up in the treatment group and four withdrawals in the control group. Ninety-six patients received magnesium and 96 received placebo. There was no difference in the incidence of SVA between the treatment and control groups, 16.7% (16/96) vs 25% (24/96), P=0.16. In the predefined subgroup analysis, patients at highest risk of arrhythmias (those undergoing pneumonectomy) had a significant reduction in the frequency of SVA, 11.1% (2/18) vs 52.9% (9/17), P=0.008. There were no differences in hospital length of stay or mortality. Patients receiving i.v. magnesium experienced a higher frequency of minor side-effects (stinging at injection site). The treatment was otherwise well tolerated.

CONCLUSIONS

Overall, prophylactic magnesium did not reduce the incidence of SVA in patients undergoing thoracotomy. However, it reduced the incidence of SVA in the high-risk cohort of patients undergoing pneumonectomy. (ISRCTN22028180.).

Perioperative anesthetic management for esophagectomy

Esophageal resection is a formidable operation associated with high morbidity and mortality. Anesthetic management may contribute to the containment of respiratory failure and anastomotic leakage by the use of thoracic epidural analgesia, protective ventilation strategies, prevention of tracheal aspiration, and judicious fluid management.

Physiologic evaluation of the patient with lung cancer being considered for resectional surgery: ACCP evidenced-based clinical practice guidelines (2nd edition)

BACKGROUND

This section of the guidelines is intended to provide an evidence-based approach to the preoperative physiologic assessment of a patient being considered for surgical resection of lung cancer.

METHODS

Current guidelines and medical literature applicable to this issue were identified by computerized search and evaluated using standardized methods. Recommendations were framed using the approach described by the Health and Science Policy Committee.

RESULTS

The preoperative physiologic assessment should begin with a cardiovascular evaluation and spirometry to measure the FEV(1). If diffuse parenchymal lung disease is evident on radiographic studies or if there is dyspnea on exertion that is clinically out of proportion to the FEV(1), the diffusing capacity of the lung for carbon monoxide (Dlco) should also be measured. In patients with either an FEV(1) or Dlco < 80% predicted, the likely postoperative pulmonary reserve should be estimated by either the perfusion scan method for pneumonectomy or the anatomic method, based on counting the number of segments to be removed, for lobectomy. An estimated postoperative FEV(1) or Dlco < 40% predicted indicates an increased risk for perioperative complications, including death, from a standard lung cancer resection (lobectomy or greater removal of lung tissue). Cardiopulmonary exercise testing (CPET) to measure maximal oxygen consumption (Vo(2)max) should be performed to further define the perioperative risk of surgery; a Vo(2)max of < 15 mL/kg/min indicates an increased risk of perioperative complications. Alternative types of exercise testing, such as stair climbing, the shuttle walk, and the 6-min walk, should be considered if CPET is not available. Although often not performed in a standardized manner, patients who cannot climb one flight of stairs are expected to have a Vo(2)max of < 10 mL/kg/min. Data on the shuttle walk and 6-min walk are limited, but patients who cannot complete 25 shuttles on two occasions will likely have a Vo(2)max of < 10 mL/kg/min. Desaturation during an exercise test has not clearly been associated with an increased risk for perioperative complications. Lung volume reduction surgery (LVRS) improves survival in selected patients with severe emphysema. Accumulating experience suggests that patients with extremely poor lung function who are deemed inoperable by conventional criteria might tolerate combined LVRS and curative-intent resection of lung cancer with an acceptable mortality rate and good postoperative outcomes. Combining LVRS and lung cancer resection should be considered in patients with a cancer in an area of upper lobe emphysema, an FEV(1) of > 20% predicted, and a Dlco of > 20% predicted.

CONCLUSIONS

A careful preoperative physiologic assessment will be useful to identify those patients who are at increased risk with standard lung cancer resection and to enable an informed decision by the patient about the appropriate therapeutic approach to treating their lung cancer. This preoperative risk assessment must be placed in the context that surgery for early-stage lung cancer is the most effective currently available treatment for this disease.

The Changing Face of Postoperative Atrial Fibrillation Prevention

Atrial fibrillation is the most common postoperative arrhythmia with significant consequences on patient health. Postoperative atrial fibrillation (POAF) complicates up to 8% of all noncardiac surgeries, between 3% and 30% of noncardiac thoracic surgeries, and between 16% and 46% of cardiac surgeries. POAF has been associated with increased morbidity, mortality, and longer, more costly hospital stays. The risk of POAF after cardiac and noncardiac surgery may be affected by several epidemiologic and intraoperative factors, as well as by the presence of preexisting cardiovascular and pulmonary disorders. POAF is typically a transient, reversible phenomenon that may develop in patients who possess an electrophysiologic substrate for the arrhythmia that is present before or as a result of surgery. Numerous studies support the efficacy of beta-blockers in POAF prevention; they are currently the most common medication used in POAF prophylaxis. Perioperative amiodarone, sotalol, nondihydropyridine calcium channel blockers, and magnesium sulfate have been associated with a reduction in the occurrence of POAF. Biatrial pacing is a nonpharmacologic method that has been associated with a reduced risk of POAF. Additionally, recent studies have demonstrated that hydroxymethylglutaryl-CoA reductase inhibitors may decrease the risk of POAF. Finally, based on recent evidence that angiotensin converting enzyme inhibitors and angiotensin receptor blockers reduce the risk of permanent atrial fibrillation, these medications may also hold promise in POAF prophylaxis. However, there is a need for further large-scale investigations that incorporate standard methodologies and diagnostic criteria, which have been lacking in past trials.

Comparative study of methods for ventricular activity cancellation in atrial electrograms of atrial fibrillation

Atrial fibrillation is a very common cardiovascular disease in clinical practice. One relevant issue to understand its pathophysiological mechanisms is the analysis and interpretation of atrial electrograms (AEG). To study these signals properly, ventricular activity has to be removed from the AEG. In this work, a new application of independent component analysis (ICA) to the AEG is presented, where ventricular activity is removed from atrial epicardial recordings making use of only one reference lead. Therefore the technique is suitable when multi-lead recordings are unavailable as in atrial implantable cardioverter defibrilators. In addition to the proposed new methodology this work also presents the first comparative study, making use of unipolar epicardial AEGs, among the ICA-based technique, template matching and subtraction (TMS), and adaptive ventricular cancellation (AVC) on a database of 20 patients. A performance comparative analysis was carried out by evaluating epicardial atrial waveform similarity (S) and ventricular depolarization reduction (VDR) as a function of atrial rhythm regularity on a beat-by-beat basis. Results indicate that, when the epicardial atrial rhythm is quite organized, ICA is able to preserve the atrial waveform very precisely and better than the other methods (median S = 99.64% +/- 0.31% in contrast to 95.18% +/- 2.71% for TMS and 94.76% +/- 4.12% for AVC). Moreover, ventricular reduction is the best for ICA (median VDR = 6.32 +/- 4.41 dB in contrast to 4.98 +/- 4.48 dB for TMS and 4.12 +/- 2.72 dB for AVC). On the other hand, when the atrial activity is disorganized, TMS notably improves performance (S = 97.72% +/- 1.87%), but ICA still is the best in waveform preservation (S = 98.22% +/- 1.53%) whereas AVC remains similar (S = 93.74% +/- 4.38%). In conclusion, ICA can be considered as notably the best approach to reduce ventricular activity from unipolar atrial electrograms in organized atrial arrhythmias. On the other hand, both TMS and ICA give quite similar results when the atrial arrhythmia is disorganized.

Critical care issues in the patient after major joint replacement

Admission rates of orthopedic patients to intensive care units are increasing. Thus, an intensivist's familiarity with specific problems associated with major joint replacement surgery is of utmost importance in order to meet the needs of this particular patient population. In this article, the authors review the most commonly encountered complications after major hip and knee arthroplasty. Perioperative risk factors for morbidity and mortality and the epidemiology, diagnosis, and treatment of cardiopulmonary complications in this patient population are discussed. Procedure-specific complications such as fat embolism and acrylic bone cement-related issues are reviewed.

Postoperative outcome of patients undergoing lung resection presenting with new-onset atrial fibrillation managed by amiodarone or diltiazem

OBJECTIVE

Atrial fibrillation (AF) is a common complication after thoracic surgery. The objective of the study was to prospectively evaluate the postoperative outcome of patients undergoing lung resection and presenting with new onset of AF. The postoperative course of AF was also evaluated in relation to either amiodarone or diltiazem employed as anti-arrhythmic agents.

METHODS

A prospective observational study during a 3-year period was designed to evaluate all patients presenting AF as a complication of anatomic lung resections. The absence of a history of heart rhythm disease was an inclusion criterion. Amiodarone was employed as the anti-arrhythmic drug during the first 18 months, and diltiazem in the second half of the study. Anti-arrhythmic drugs were started intravenously; when rhythm was restored or after 48h of treatment, they were administered orally. AF duration, recurrences and the postoperative outcome of patients were recorded.

RESULTS

Thirty patients fulfilled inclusion criteria. No deaths occurred; median hospital stay was 10 days (range 6-37). AF presented as a solitary complication in 17 patients; in 10 patients it was associated with a respiratory complication and in the last three patients in one case each with pulmonary embolism, acute renal failure and chylothorax respectively. AF occurred on median post-operative day 2 (range: 1-9). Sinus rhythm restoration within the first 24h was observed in 11 (70%) out of the 15 patients receiving diltiazem and in 10 (67%) out of the 15 receiving amiodarone. After 48h, in 80% of patients in both groups cardioversion was achieved. AF recurrence occurred in 11 patients (37%). In 10 out of these 11 patients iterative intravenous treatment was attempted and in all a permanent cardioversion was achieved. Fisher's exact test indicated AF recurrence as being significantly correlated to the presence of a respiratory complication (p=0.02).

CONCLUSION

Postoperative outcome of patients undergoing lung surgery with new onset of AF resulted as being significantly complicated by AF recurrence in the case of an associated respiratory complication. The pharmacological strategies tested during this pilot study led to no differences in the postoperative course of AF.

Health related quality of life after mitral valve repairs and replacements

BACKGROUND

The decision to replace or repair mitral valves is often a difficult decision, and outcomes from the patients' perspective should guide decision-making. We investigated whether the change in health related quality of life (HRQOL) after mitral valve surgery is different after valve repairs compared with replacements.

METHODS

We prospectively studied 25 patients with mitral valve replacement and 45 patients with valve repairs performed in 1998-99. We measured HRQOL at baseline and at 18 months using the Medical Outcomes Trust Short Form 36-item Health Survey (SF-36) questionnaire. We compared mean HRQOL scores of the groups with age-adjusted U.S. population scores. We used analysis of covariance to determine a change in HRQOL within groups (repair or replacement) and if the change in HRQOL was different between the groups.

RESULTS

We found few differences between the groups, with more men and simultaneous coronary artery bypass graft surgery in the valve repair group and more prior operation in the valve replacement group. HRQOL improved after surgery in most domains, and was comparable to age-adjusted U.S. norms in the valve repair group. In the multivariable analysis, mitral valve repair recipients reported higher social functioning compared with patients who received valve replacement (p = 0.04). We did not find other statistically significant differences. However, the adjusted improvements in the component scales of physical functioning (PCS) and mental functioning (MCS) were substantial in the valve repair group (mean changes: PCS = 6.8, p = 0.003; MCS = 8.1, p = 0.014) and less pronounced in the replacement group (mean changes: PCS = 3.6, p = 0.09; MCS = 4.3, fsp = 0.16).

CONCLUSIONS

While many considerations influence the decision to repair or replace mitral valves, these findings suggest that repair may be better from the health status perspective. Further studies are necessary to validate this finding.

Leukocytosis and Increased Risk of Atrial Fibrillation After General Thoracic Surgery

BACKGROUND

In older patients who are known to be at greater risk for atrial fibrillation, we aimed to determine whether patients who develop atrial fibrillation-flutter (AF) after major thoracic surgery have an exaggerated white blood cell (WBC) count in response to surgical stress compared with those who do not develop AF.

METHODS

Using a prospective database, 272 patients 60 years or older who were in sinus rhythm before surgery and had elective lobectomy, pneumonectomy, or esophagectomy were studied. Patients did not receive perioperative medications to prevent AF. Clinical characteristics and preoperative 12-lead electrocardiogram were examined and WBC counts were recorded for patients prior to and for up to five days after surgery.

RESULTS

Atrial fibrillation-flutter was observed in 74 of 272 (27%) patients a median of 3 days after surgery. The increase in WBC count from preoperative to postoperative day 1 and age were jointly significant predictors of AF by multiple logistic regression (area under the receiver operating characteristic curve = 0.69). Using this model, a twofold increase in WBC from presurgery to postoperative day 1 corresponded to a 3.3-fold increase in the odds of developing AF (95% confidence interval [CI] 2.0 to 8.3) and for each 10 year increase in age, a 1.8-fold increase in risk of AF (95% CI 1.1 to 2.8) was seen.

CONCLUSIONS

Increments in WBC were greater in patients with AF and coincided with the peak onset of AF. These prospective data support an important role for stress-mediated autonomic mechanisms in the pathogenesis of AF after major thoracic surgery. We aim to examine further whether WBC elevations on postoperative day one can help further risk stratify patients younger than 60 years or those with the highest risk who could benefit from one or more AF prevention strategies.

Perioperative β-blocker therapy in vascular surgery: Clinical update

Patients undergoing vascular surgery comprise a group at elevated risk of fatal and nonfatal perioperative cardiovascular events. In four recent longitudinal studies, the 30-day incidence of death in such patients was 3% to 6%, and the incidence of myocardial infarction was 5% to 14%. Growing evidence suggests that beta-adrenergic receptor antagonists prevent cardiovascular morbidity and mortality in high-risk patients undergoing noncardiac surgery, including those undergoing vascular surgery. This article reviews the available evidence concerning beta-blockers and provides guidance for their use in the perioperative setting.