Clinical and echocardiographic correlates of symptomatic tachydysrhythmias after noncardiac thoracic surgery

Sleeve lobectomy versus pneumonectomy following neoadjuvant therapy in patients with non-small cell lung cancer

OBJECTIVES

Neoadjuvant therapy has gained widespread acceptance as the standard modality for locally advanced non-small cell lung cancer. However, the clinical benefit of sleeve lobectomy (SL) or pneumonectomy (PN) following neoadjuvant therapy remains controversial.

METHODS

The clinical and pathological characteristics of non-small cell lung cancer patients who underwent SL or PN after neoadjuvant therapy at a high-volume single centre between December 2019 and March 2023 were retrospectively collected. The SL group was matched 4:1 with the PN group by propensity score matching. The surgical outcomes were systematically collected and analysed.

RESULTS

During a 5-year study period, the majority of patients (175 of 215, 81.4%) underwent the SL procedure, while 40 patients (18.6%) underwent PN. Following propensity score matching, the SL group exhibited lower postoperative arrythmia (4.8% vs 26.9%, P < 0.001), lower 30-day mortality (1.0% vs 7.7%, P = 0.046) and a shorter length of postoperative hospital stay (6.0 days vs 10.0 days, P < 0.001), compared with the PN group. In addition, no significant difference was observed between the two groups in terms of disease-free survival or overall survival (P = 0.977 and P = 0.913, respectively).

CONCLUSIONS

SL stands as a safe and feasible option for patients with centrally located non-small-cell lung cancer who have undergone neoadjuvant therapy, in comparison to PN. This finding suggests that SL remains the preferable choice when feasible in the context of the widespread utilization of neoadjuvant therapy.

Risk factors associated with atrial fibrillation following lung cancer surgery: A multi-center case-control study

BACKGROUND

Postoperative atrial fibrillation (POAF) is a common complication after major thoracic operations. The objective of this case-control study was to identify the risk factors for POAF following lung cancer surgery.

METHODS

In total, 216 patients with lung cancer who were selected from three different hospitals were followed up between May 2020 and May 2022. They were divided into two groups: case group, patients with POAF and control group, patients without POAF (case-control). Risk factors associated with POAF were investigated using univariate and multivariate logistic regression analyses.

RESULTS

Risk factors that were significantly associated with POAF were preoperative brain-type natriuretic peptide (BNP) levels [odds ratio (OR): 4.46; 95% confidence interval (CI): 1.52-13.06; P = 0.0064], sex (OR: 0.07; 95%CI: 0.02-0.28; P = 0.0001), preoperative white blood cell (WBC) count (OR: 3.00; 95%CI: 1.89-4.77; P < 0.0001), lymph node dissection (OR: 11.49; 95%CI: 2.81-47.01; P = 0.0007), and cardiovascular disease (OR: 4.93; 95%CI: 1.14-21.31; P = 0.0326).

CONCLUSION

In summary, data from the three hospitals suggested that preoperative BNP levels, sex, preoperative WBC count, lymph node dissection, and hypertension/coronary heart disease/myocardial infarction were associated with a significantly high risk of POAF following lung cancer surgery.

Relationship between postoperative atrial fibrillation and its recurrence after lung resection

PURPOSE

Atrial fibrillation (AF) frequently occurs after pulmonary resection and is commonly referred to as postoperative atrial fibrillation (POAF). This study explored whether or not POAF is related to the recurrence of AF in the chronic phase.

METHODS

A total of 1311 consecutive patients without a history of AF who underwent lung resection based on a diagnosis of lung tumor were retrospectively analyzed.

RESULTS

POAF occurred in 46 patients (3.5%), and a logistic regression analysis revealed that the age (p < 0.05), history of hyperthyroidism (p < 0.05), and major lung resection (p < 0.05) were independent predictors of POAF. AF events in the chronic phase were observed in 15 (32.6%) and 45 (3.6%) patients with and without POAF, respectively. A Cox regression analysis revealed that POAF was the only independent predictor of AF development in the chronic phase (p < 0.01). The Kaplan-Meier curve and log-rank test revealed that the cumulative incidence of AF in the chronic phase was significantly higher in patients with POAF than in those without POAF (p < 0.01).

CONCLUSION

POAF was an independent predictor for AF in the chronic phase after lung resection. Further investigations including cases of catheter ablation and optimal medical therapy for patients with POAF after lung resection are needed.

Genetic risk factors for postoperative atrial fibrillation-a nationwide genome-wide association study (GWAS)

Background

Atrial fibrillation (AF) is a major cause of morbidity with a high prevalence among the elderly and has an established genetic disposition. Surgery is a well-known risk factor for AF; however, it is currently not recognized how much common genetic variants influence the postoperative risk. The purpose of this study was to identify Single Nucleotide Polymorphisms associated with postoperative AF.

Methods

The UK Biobank was utilized to conduct a Genome-Wide Association Study (GWAS) to identify variants associated with AF after surgery. An initial discovery GWAS was performed in patients that had undergone surgery with subsequent replication in a unique non-surgical cohort. In the surgical cohort, cases were defined as newly diagnosed AF within 30 days after surgery. The threshold for significance was set at 5 × 10^-8.

Results

After quality control, 144,196 surgical patients with 254,068 SNPs were left for analysis. Two variants (rs17042171 (p = 4.86 × 10^-15) and rs17042081 (p = 7.12 × 10^-15)) near the PITX2-gene reached statistical significance. These variants were replicated in the non-surgical cohort (1.39 × 10^-101 and 1.27 × 10^-93, respectively). Several other loci were significantly associated with AF in the non-surgical cohort.

Conclusion

In this GWAS-analysis of a large national biobank, we identified 2 variants that were significantly associated with postoperative AF. These variants were subsequently replicated in a unique non-surgical cohort. These findings bring new insight in the genetics of postoperative AF and may help identify at-risk patients and guide management.

Perioperative cardiovascular pathophysiology in patients undergoing lung resection surgery: a narrative review

Although thoracic surgery is understood to confer a high risk of postoperative respiratory complications, the substantial haemodynamic challenges posed are less well appreciated. This review highlights the influence of cardiovascular comorbidity on outcome, reviews the complex pathophysiological changes inherent in one-lung ventilation and lung resection, and examines their influence on cardiovascular complications and postoperative functional limitation. There is now good evidence for the presence of right ventricular dysfunction postoperatively, a finding that persists to at least 3 months. This dysfunction results from increased right ventricular afterload occurring both intraoperatively and persisting postoperatively. Although many patients adapt well, those with reduced right ventricular contractile reserve and reduced pulmonary vascular flow reserve might struggle. Postoperative right ventricular dysfunction has been implicated in the aetiology of postoperative atrial fibrillation and perioperative myocardial injury, both common cardiovascular complications which are increasingly being appreciated to have impact long into the postoperative period. In response to the physiological demands of critical illness or exercise, contractile reserve, flow reserve, or both can be overwhelmed resulting in acute decompensation or impaired long-term functional capacity. Aiding adaptation to the unique perioperative physiology seen in patients undergoing thoracic surgery could provide a novel therapeutic avenue to prevent cardiovascular complications and improve long-term functional capacity after surgery.

Pharmacological interventions for preventing atrial fibrillation after lung surgery: systematic review and meta-analysis

BACKGROUND

Postoperative atrial fibrillation/flutter (POAF) is one of the most common cardiac complications after lung surgery. We aimed to assess the safety and efficacy of pharmacological interventions for new-onset POAF prophylaxis in patients with lung cancer after lung surgery.

METHODS

PubMed, Embase, Web of Science, Scopus, and the Cochrane Library were searched to identify randomized controlled trials comparing the effects of pharmacological interventions to prevent POAF following lung surgery.

RESULTS

A total number of 19 studies with 2,922 participants were included. Pharmacological interventions significantly reduced the incidence of POAF (odds ratio [OR] 0.36, 95% confidence interval [95% CI] 0.26-0.52) while did not increase the incidence of severe pulmonary complications (OR 1.17, 95% CI 0.57-2.41) after lung surgery compared with placebo/usual care. Among different trials, beta-blockers appeared to be the most effective with an OR of 0.13 (95% CI, 0.07-0.27) and a number needed-to-treat (NNT) of 3.63 and was considered safe with no serious adverse events recorded. The risk of POAF decreased from 25.6 to 11.4% (P < 0.001) overall and from 34.2 to 6.7% (P < 0.001) with beta-blockers as monotherapy. Pharmacological interventions did not reduce the 30-day mortality (OR 0.89, 95% CI 0.43-1.84, I² = 0%), but showed a trend toward reducing major cardiovascular complications including myocardial ischemia/infarction, cardiac arrest, heart failure, and stroke (OR 0.41, 95% CI 0.13-1.29, I² = 0%).

CONCLUSION

Current clinical evidence supports the effectiveness of pharmacological intervention with beta-blockers, amiodarone, magnesium sulfate, or calcium-channel blockers to reduce the incidence of POAF after lung surgery in patients with lung cancer. In the absence of contraindications, prophylaxis with beta-blockers seems to be the most effective of the treatments studied.

Endovascular recanalization of acute ischemic stroke patients exhibiting large vessel occlusion after pulmonary lobectomy: case series

Objective

We analyzed the outcomes of patients suffering acute ischemic stroke (AIS) with large vessel occlusion (LVO) soon after pulmonary lobectomy.

Methods

We retrospectively reviewed the clinical records of patients who underwent pulmonary lobectomy to treat primary lung cancer. We retrieved clinical characteristics and the incidence of AIS with LVO. The clinical courses of patients who experienced AIS were reviewed.

Results

In 10 (0.3%) of 3406 patients, AIS with LVO developed soon (within 3 days) after pulmonary lobectomy. The lung resection site was on the left in eight patients (80%). All patients underwent thrombectomy and achieved complete recanalization (Thrombolysis in Cerebral Infarction [TICI] 3). The average time between symptom onset and recanalization was 165.5 min. Nine (90%) patients exhibited favorable outcomes (modified Rankin scale [mRS] score ≤ 2) at the 3-month follow-up.

Conclusion

Endovascular therapy effectively treats AIS with LVO that develops after lung surgery, and direct aspiration is a promising strategy. A large, multicenter study is warranted to further confirm these findings.

Incidence and predictors of perioperative atrial fibrillation in burn intensive care unit patients following burn surgery

BACKGROUND

Atrial fibrillation is a well-documented complication following cardiac surgery. It is associated with increased inpatient and long-term mortality. There have been few prior studies on perioperative atrial fibrillation following burn surgery in severely burned patients. The purpose of this study was to identify the incidence, predictors, and prognosis of perioperative atrial fibrillation after burn surgery in severely burned patients.

METHODS

Patients aged older than 18 years with 30% burned total body surface area (TBSA) were enrolled in this study. Patients who had a previous history of atrial fibrillation or atrial fibrillation on the preoperative electrocardiogram were excluded. We reviewed medical records retrospectively, and the data of 214 patients were studied.

RESULTS

A total of 214 critically ill burned patients and 1132 operations were available for analysis during the 5-year study period; 12 (1.1%) patients were diagnosed with newly developed atrial fibrillation after a burn operation, of whom 4 patients showed paroxysmal atrial fibrillation (all related to surgical stimulation) and none changed to persistent atrial fibrillation. The incidence of perioperative atrial fibrillation was associated with TBSA%, full-thickness TBSA%, and hypertension. Multiple logistic regression analysis indicated that TBSA% (OR=13.851, P < 0.001) and full-thickness TBSA% (OR=15.223, P = 0.018) were independent predictors for developing perioperative atrial fibrillation. All of our patients had at least one risk factor, with blood volume variation or burn sepsis occurring most commonly. Perioperative atrial fibrillation developed after a median of 0 days after burn surgery. Three patients died, and the causes of death were noncardiovascular events such as sepsis and multiple organ failure.

CONCLUSION

Atrial fibrillation was a relatively rare complication among severely burned patients admitted to surgery and was associated with TBSA% and full thickness TBSA%. All of our patients exhibited at least one of the modifiable risk factors for atrial fibrillation, confirming the importance of optimization of electrolytes and fluid status and limitation of sympathetic activation.

Beta-Blocker Landiolol Hydrochloride in Preventing Atrial Fibrillation Following Cardiothoracic Surgery: A Systematic Review and Meta-Analysis

OBJECTIVE

The purpose of this article was to assess the benefit of perioperative administration of the intravenous beta-blocker landiolol hydrochloride in preventing atrial fibrillation (AF) after cardiothoracic surgery.

METHODS

We performed a systematic search in PubMed, Web of Science, CNKI, and OVID to identify randomized controlled trials (RCTs) and cohorts up to January 2021. Data regarding postoperative atrial fibrillation (POAF) and safety outcomes were extracted. Odds ratios (ORs) with 95% confidence intervals (CIs) were determined using the Mantel-Haenszel method. Meanwhile, subgroup analyses were conducted according to surgery type including lung cancer surgery, esophageal cancer surgery, and cardiac surgery.

RESULTS

Seventeen eligible articles involving 1349 patients within 13 RCTs and four cohorts were included in our meta-analysis. Compared with control group, landiolol administration was associated with a significant reduction of the occurrence of AF after cardiothoracic surgery (OR = 0.32, 95% CI 0.23-0.43, P <0.00001). In addition, the results demonstrated that perioperative administration of landiolol hydrochloride minimized the occurrence of postoperative complications (OR = 0.48, 95% CI 0.33-0.70, P = 0.0002). Funnel plots indicated no obvious publication bias.

CONCLUSIONS

Considering this analysis, landiolol was effective in the prevention of AF after cardiothoracic surgery and did not increase the risk of major postoperative complications.

Pulmonary hypertension after pneumonectomy: a preclinical model in rats and human pulmonary endothelial cells

OBJECTIVES

Pulmonary hypertension and heart disease contribute to the high morbidity rate following pneumonectomy (PN). The pathophysiology is still poorly understood. The objective was to investigate the consequences of PN on cardiopulmonary function in rats and to explore in vitro the involved mechanisms.

METHODS

Sixty Sprague-Dawley male rats randomly underwent either a right PN (PN group) or sham surgery. Ten rats per group were sacrificed on postoperative days 3, 7 and 28. Cardiopulmonary alterations were investigated by echocardiographic, haemodynamic and histological analyses. In vitro, the shear stress was reproduced using a Flexcell Tension™ cyclic stretch on cultured human pulmonary endothelial cells (P-ECs) to investigate the impact on pulmonary artery smooth muscle cell (PA-SMC) growth. Data are expressed as mean ± SD.

RESULTS

Mean pulmonary arterial pressure gradually increased in the PN group to reach 35 ± 7 mmHg on postoperative day 28 vs 18 ± 4 in sham (P = 0.001), likewise the proportion of muscularized distal pulmonary arteries, 83 ± 1% vs 5 ± 1%, respectively (P < 0.001), related to in situ PA-SMC proliferation. The right ventricle area and lateral wall thickness were doubled in the PN group on postoperative day 28. The left ventricle ejection fraction decreased on postoperative days 7 and 28 while the right ventricle function was maintained. In vitro, the human PA-SMC growth was significantly greater when seeded with stretched vs non-stretched P-EC media, highlighting the role of shear stress on the P-EC paracrine function.

CONCLUSIONS

Right PN led to pulmonary hypertension and proportional right heart remodelling in rats. The shear stress related to high blood flow alters the pulmonary endothelial paracrine control of SMC growth.

Association Between Perioperative Atrial Fibrillation and Long-term Risks of Stroke and Death in Noncardiac Surgery: Systematic Review and Meta-analysis

BACKGROUND

Atrial fibrillation (AF) is frequently reported as a complication of noncardiac surgery. It is unknown whether new-onset perioperative AF is associated with an increased risk of stroke and death beyond the perioperative period. We performed a systematic review and meta-analysis to assess the long-term risks of stroke and mortality associated with new-onset perioperative AF after noncardiac surgery.

METHODS

MEDLINE and EMBASE were searched from inception to March 2020 for studies reporting on the association between perioperative AF and the risk of stroke and death occurring beyond 30 days after noncardiac surgery. Reference screening, study selection, data extraction, and quality assessment were performed in duplicate. Data were pooled using inverse variance-weighted random-effects models and presented as risk ratios (RRs).

RESULTS

From 7344 citations, we included 31 studies (3,529,493 patients). The weighted mean incidence of perioperative AF was 0.7%. During a mean follow-up of 28.1 ± 9.4 months, perioperative AF was associated with an increased risk of stroke (1.5 vs 0.9 strokes per 100 patient-years; RR: 2.9, 95% confidence interval [CI]: 2.1-3.9, I2 = 78%). Perioperative AF was also associated with a significantly higher risk of all-cause mortality (21.0 vs 7.6 deaths per 100 patient-years; RR: 1.8, 95% CI: 1.5-2.2, I2 = 94%). The pooled adjusted hazard ratios for stroke and all-cause mortality were 1.9 (95% CI: 1.6-2.2, I2 = 31%) and 1.5 (95% CI: 1.3-1.7, I2 = 20%), respectively.

CONCLUSIONS

Patients who had perioperative AF after noncardiac surgery had a higher long-term risk of stroke and mortality compared with patients who did not. Whether this risk is modifiable with oral anticoagulation therapy should be investigated.

Diltiazem Does Not Prevent Postoperative Atrial Fibrillation After Thoracoscopic Lobectomy

OBJECTIVE

Thoracoscopic lobectomy is associated with lower rates of adverse events compared to thoracotomy. Despite this, postoperative atrial fibrillation (POAF) occurs in at least 10% of patients. Our objective is to determine if prophylaxis with diltiazem significantly reduced POAF events.

METHODS

Patients without prior history of atrial fibrillation who underwent thoracoscopic lobectomy from 2007 to 2016 at one institution were analyzed in a retrospective cohort study utilizing a prospective database. Patients treated from 2007 to 2012 received no prophylaxis. Patients treated after 2012 received diltiazem postoperatively. All patients were monitored with continuous telemetry postoperatively. Multivariate direct logistic regression was performed to determine independent predictors of POAF. We report adjusted odds ratios and accompanying 95% confidence intervals, with P < 0.05 denoting statistical significance.

RESULTS

The final regression model included 416 patients (52 with POAF, 364 without). In univariate analysis, the variables of body mass index and history of congestive heart failure, diabetes, or hypertension, and prophylaxis status did not meet inclusion criteria. Age, gender, history of stroke or transient ischemic attack, and vascular disease were included. Only ages 65 to 74 (P = 0.03) and ≥75 (P = 0.02), compared to <65, were statistically significant predictors of POAF. Adjusted odds ratios of ages 65 to 74 and ≥75 were 2.88 and 2.62, respectively.

CONCLUSIONS

Diltiazem prophylaxis did not significantly reduce POAF incidence following thoracoscopic lobectomy. Further study is warranted since POAF remains an unwanted source of morbidity and cost for lobectomy patients.

Postoperative Atrial Fibrillation in Lung Cancer Lobectomy-Analysis of Risk Factors and Prognosis

BACKGROUND

The incidence of postoperative atrial fibrillation (POAF) after pulmonary lobectomy ranges from 6.4 to 12.6%. This study aimed to analyze the postoperative risk factors and prognosis for POAF in lobectomy for lung cancer.

METHODS

Data were collected from patients undergoing pulmonary lobectomy from April 2010 to March 2019. We analyzed risk factors for POAF among perioperative factors and compared postoperative complications or overall survival between POAF and non-POAF groups. We classified POAF as either the temporary or non-temporary type and compared perioperative factors, postoperative complications, and overall survival.

RESULTS

POAF was identified in 49 (5.2%) of the 947 lobectomies. The POAF group included more males, patients with poor performance status (PS), history of paroxysmal atrial fibrillation (AF), chronic obstructive pulmonary disease (COPD), and intraoperative blood transfusions. Poor PS, COPD, previous paroxysmal AF, and intraoperative blood transfusion were independent risk factors for POAF in multivariate analysis. The POAF group had a poorer prognosis than the non-POAF group (p = 0.0045). POAF was divided into 29 temporary and 20 non-temporary types. The onset date of non-temporary-type POAF was significantly later than that of the transient type (P < 0.01), and diabetes mellitus was significantly higher in non-temporary-type POAF. Non-temporary-type POAF had a significantly poorer prognosis in terms of overall survival (p = 0.005).

CONCLUSIONS

Poor PS, COPD, history of PAF, and intraoperative blood transfusion were independent risk factors for POAF. Non-temporary-type POAF occurred significantly later than transient type and caused poorer prognosis after lobectomy for lung cancer.

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 utility of transthoracic echocardiographic measures of right ventricular systolic function in a lung resection cohort

Right ventricular (RV) dysfunction occurs following lung resection and is associated with post-operative complications and long-term functional morbidity. Accurate peri-operative assessment of RV function would have utility in this population. The difficulties of transthoracic echocardiographic (TTE) assessment of RV function may be compounded following lung resection surgery, and no parameters have been validated in this patient group. This study compares conventional TTE methods for assessing RV systolic function to a reference method in a lung resection population. Right ventricular index of myocardial performance (RIMP), fractional area change (FAC), tricuspid annular plane systolic excursion (TAPSE) and S′ wave velocity at the tricuspid annulus (S′), along with speckle tracked global and free wall longitudinal strain (RV-GPLS and RV-FWPLS respectively) are compared with RV ejection fraction obtained by cardiovascular magnetic resonance (RVEF_CMR). Twenty-seven patients undergoing lung resection underwent contemporaneous CMR and TTE imaging; pre-operatively, on post-operative day two and at 2 months. Ability of each of the parameters to predict RV dysfunction (RVEF_CMR <45%) was assessed using the area under the receiver operating characteristic curve (AUROCC). RIMP, FAC and S′ demonstrated no predictive value for poor RV function (AUROCC <0.61, P > 0.05). TAPSE performed marginally better with an AUROCC of 0.65 (P = 0.04). RV-GPLS and RV-FWPLS demonstrated good predictive ability with AUROCC’s of 0.74 and 0.76 respectively (P < 0.01 for both). This study demonstrates that the conventional TTE parameters of RV systolic function are inadequate following lung resection. Longitudinal strain performs better and offers some ability to determine poor RV function in this challenging population.

The right ventricular response to lung resection

OBJECTIVES

Lung cancer is a leading cause of cancer death and in suitable cases the best chance of cure is offered by surgery. Lung resection is associated with significant postoperative cardiorespiratory morbidity, with dyspnea and reduced functional capacity as dominant features. These changes are poorly associated with deterioration in pulmonary function and a potential role of right ventricular (RV) dysfunction has been hypothesized. Cardiovascular magnetic resonance imaging is a reference method for noninvasive assessment of RV function and has not previously been applied to this population.

METHODS

We used cardiovascular magnetic resonance imaging to assess the RV response to lung resection. Cardiovascular magnetic resonance imaging with volume and flow analysis was performed on 27 patients preoperatively, on postoperative day 2 and at 2 months. Left ventricular ejection fraction and RV ejection fraction, the ratio of stroke volume to end systolic volume, pulmonary artery acceleration time, and distensibility of main and branch pulmonary arteries were studied.

RESULTS

Mean ± standard deviation RV ejection fraction deteriorated from 50.5% ± 6.9% preoperatively to 45.6% ± 4.5% on postoperative day 2 and remained depressed at 44.9% ± 7.7% by 2 months (P = .003). The ratio of stroke volume to end systolic volume deteriorated from median 1.0 (quartile 1, quartile 3: 0.9, 1.2) preoperatively to median 0.8 (quartile 1, quartile 3: 0.7, 1.0) on postoperative day 2 (P = .011). On postoperative day 2 there was a decrease in pulmonary artery acceleration time and operative pulmonary artery distensibility (P < .030 for both). There were no changes in left ventricular ejection fraction during the study period (P = .621).

CONCLUSIONS

These findings suggest RV dysfunction occurs following lung resection and persists 2 months after surgery. The deterioration in the ratio of stroke volume to end systolic volume suggests a mismatch between afterload and contractility. There is an increase in indices of pulsatile afterload resulting from the operative pulmonary artery.

The Utility of Eccentricity Index as a Measure of the Right Ventricular Function in a Lung Resection Cohort

Context

Right ventricular (RV) dysfunction occurs after lung resection and is associated with postoperative morbidity. Noninvasive evaluation of the RV is challenging, particularly in the postoperative period. A reliable measure of RV function would have value in this population.

Aims

This study compares eccentricity index (EI) obtained by transthoracic echocardiography (TTE) with cardiovascular magnetic resonance (CMR) determined measures of RV function in a lung resection cohort. CMR is the reference method for noninvasive assessment of RV function.

Design and Setting

Prospective observational cohort study at a single tertiary hospital.

Materials and Methods

Twenty-eight patients scheduled for elective lung resection underwent contemporaneous TTE and CMR imaging preoperatively, on postoperative day (POD) 2 and at 2-month. Systolic and diastolic EI was measured offline from anonymized and randomized TTE and CMR images.

Statistical Analysis

Bland-Altman analysis was performed to determine agreement between EI^TTE and EI^CMR. Changes over time and comparison with CMR determined RV ejection fraction (RVEF^CMR) was assessed.

Results

Bland-Altman analysis showed a negligible mean difference between EI^TTE and EI^CMR, but limits of agreement were wide (SD 0.24 and 0.28). There were no significant changes in EI^TTE and EI^CMR over time (P > 0.35). We found no association between EI^TTE with RVEF^CMR at all-time points (P > 0.22). Systolic and diastolic EI^CMR on POD 2 demonstrated moderate association with RVEF^CMR (r = -0.54 and r = -0.59, P ≤ 0.01). At 2-month, only diastolic EI^CMR correlated with RVEF^CMR (r = -0.43, P = 0.03). There were no meaningful associations between EI^TTE and EI^CMR with TTE-derived RV systolic pressure (P > 0.31).

Conclusions

TTE determined EI is not useful as a noninvasive method of assessing RV function following lung resection.

Stroke Prevention for Patients with Atrial Fibrillation: Beyond the Guidelines

Atrial fibrillation (AF) is the most common serious heart rhythm disorder, with a lifetime incidence of 1 in 4 for patients >40 years of age[1]. AF is a major cause of death and disability, as it is associated with a 4-5 fold increase in the risk of ischemic stroke[2]. In patients with AF, oral anticoagulation (OAC) therapy can reduce the risk of stroke by about two-thirds and the risk of all-cause mortality by approximately one-quarter, but is associated with an increased risk of bleeding[3], [4]. Atrial fibrillation (AF) is the most common serious heart rhythm disorder and is associated with an increased risk of ischemic stroke. This risk can be moderated with oral anticoagulation therapy, but the decision to do so must be balanced against the risks of bleeding. Herein, we discuss three emerging areas where more high-quality evidence is required to guide risk stratification: 1) the relationships between the pattern and burden of AF and stroke 2) the risk conferred by short episodes of device-detected "sub-clinical" atrial fibrillation (SCAF) and 3) the significance of AF that occurs transiently with stress (AFOTS), as is often detected during medical illness or after surgery. Risk stratification is important to identify patients with AF who can benefit from OAC therapy. There are, however, several common clinical scenarios where guidelines do not yet provide direction for stroke prevention; or do so based on limited high-quality evidence.

Landiolol infusion during general anesthesia does not prevent postoperative atrial fibrillation in patients undergoing lung resection

OBJECTIVE

We aimed to determine whether intraoperative low-dose infusion of landiolol, an ultra-short-acting beta blocker, can prevent postoperative atrial fibrillation (POAF) after lung resection.

METHODS

A double-blind, randomized, controlled, preliminary study was performed in university academic hospital, single center. Fifty lung surgical patients were key-opened before enrollment of the originally planned 100 patients, who were randomized in a 1:1 ratio in each treatment arm. Landiolol was infused with a dosage of 5 μg/kg/min during general anesthesia in the landiolol group, which was compared with the placebo control group with no landiolol. Atrial fibrillation (AF)-free survival curves were generated by means of Kaplan-Meier estimates and differences in survival were compared with the use of the log-rank test. We examined independent predictors of POAF by the multivariate logistic regression analysis using the perioperative parameters detected with the univariate analysis.

RESULTS

The AF events were recorded for 7 days with Holter monitor in 5 of 25 patients in the landiolol group and 4 of 25 patients in the control group. Kaplan-Meier analysis showed that the landiolol group could not avoid the incidence of POAF in comparison with the placebo saline group (P = 0.806). The multivariate logistic regression analysis for prevalence of POAF identified only one statistically significant predictor: interleukin-6 (IL-6) sampled at 6 h after end of surgery.

CONCLUSIONS

We failed to demonstrate that low-dose infusion of landiolol during general anesthesia could prevent the incidence of AF after lung resection. Only IL-6 sampled at 6 h after end of surgery significantly predicted POAF among pulmonary surgical patients.

The Influence of Perioperative Dexmedetomidine on Patients Undergoing Cardiac Surgery: A Meta-Analysis

Background

The use of dexmedetomidine may have benefits on the clinical outcomes of cardiac surgery. We conducted a meta-analysis comparing the postoperative complications in patients undergoing cardiac surgery with dexmedetomidine versus other perioperative medications to determine the influence of perioperative dexmedetomidine on cardiac surgery patients.

Methods

Randomized or quasi-randomized controlled trials comparing outcomes in patients who underwent cardiac surgery with dexmedetomidine, another medication, or a placebo were retrieved from EMBASE, PubMed, the Cochrane Library, and Science Citation Index.

Results

A total of 1702 patients in 14 studies met the selection criteria among 1,535 studies that fit the research strategy. Compared to other medications, dexmedetomidine has combined risk ratios of 0.28 (95% confidence interval [CI] 0.15, 0.55, P = 0.0002) for ventricular tachycardia, 0.35 (95% CI 0.20, 0.62, P = 0.0004) for postoperative delirium, 0.76 (95% CI 0.55, 1.06, P = 0.11) for atrial fibrillation, 1.08 (95% CI 0.74, 1.57, P = 0.69) for hypotension, and 2.23 (95% CI 1.36, 3.67, P = 0.001) for bradycardia. In addition, dexmedetomidine may reduce the length of intensive care unit (ICU) and hospital stay.

Conclusions

This meta-analysis revealed that the perioperative use of dexmedetomidine in patients undergoing cardiac surgery can reduce the risk of postoperative ventricular tachycardia and delirium, but may increase the risk of bradycardia. The estimates showed a decreased risk of atrial fibrillation, shorter length of ICU stay and hospitalization, and increased risk of hypotension with dexmedetomidine.

A Double-Blind Placebo-Controlled Study of the Effects of Olprinone, a Specific Phosphodiesterase III Inhibitor, for Preventing Postoperative Atrial Fibrillation in Patients Undergoing Pulmonary Resection for Lung Cancer

BACKGROUND

We previously reported that patients with elevated preoperative B-type natriuretic peptide (BNP) levels have an increased risk for postoperative atrial fibrillation following lung cancer surgery. The present study evaluated whether the specific phosphodiesterase III inhibitor olprinone can reduce the incidence of postoperative atrial fibrillation in patients with elevated BNP levels undergoing pulmonary resection for lung cancer.

METHODS

A prospective randomized study was conducted with 40 patients who had elevated preoperative BNP levels (≥ 30 pg/mL) and underwent scheduled lung cancer surgery. All patients were in sinus rhythm at surgery. Low-dose olprinone or placebo was continuously infused for 24 h and started just before anesthesia induction. The primary end point was the incidence of postoperative atrial fibrillation. The secondary end points were perioperative hemodynamics and levels of BNP, WBC counts, and C-reactive protein.

RESULTS

The incidence of postoperative atrial fibrillation was significantly lower in the olprinone group than in the placebo group (10% vs 60%, P < .001). Patients in the olprinone group showed significantly lower BNP, WBC counts, and C-reactive protein levels after surgery.

CONCLUSIONS

Continuous infusion of olprinone during lung cancer surgery was safe and reduced the incidence of postoperative atrial fibrillation following pulmonary resection in patients with elevated preoperative BNP levels.

TRIAL REGISTRY

Japan Primary Registries Network; No.: JPRN-UMIN2404; URL: http://www.umin.ac.jp/ctr/.

Incidence and 1-Year Outcomes of Perioperative Atrial Arrhythmia in Elderly Adults After Hip Fracture Surgery

OBJECTIVES

To determine the incidence and 1-year outcomes of an elderly population with perioperative atrial arrhythmia (PAA) within 7 days of hip fracture surgery.

DESIGN

Retrospective cohort study.

SETTING

The Rochester Epidemiology Project (REP).

PARTICIPANTS

Elderly adults consecutive undergoing hip fracture repair from 1988 to 2002 in Olmsted County, Minnesota (N = 1,088, mean age 84.0 ± 7.4, 80.2% female).

MEASUREMENTS

Baseline clinical variables were analyzed in relation to survival using Cox proportional hazards methods for comparison.

RESULTS

Sixty-one participants (5.6%) developed PAA within the first 7 days. During 1 year of follow-up, 239 (22%) participants died. PAA was associated with greater mortality (45% vs 21%; hazard ratio (HR) = 2.8, 95% confidence interval (CI) = 1.9-4.2). Other mortality risk factors were male sex (HR = 2.0, 95% CI = 1.5-2.6), congestive heart failure (HR = 2.1, 95% CI = 1.7-2.8), chronic renal insufficiency (HR = 2.0, 95% CI = 1.5-2.8), dementia (HR = 2.9, 95% CI = 2.2-3.7), and American Society of Anesthesiologists risk Class III, IV, or V (HR = 3.3, 95% CI = 1.9-5.9).

CONCLUSION

Elderly adults undergoing hip fracture surgery who develop PAA within 7 days have significantly higher 1-year mortality than those who do not. Further studies are indicated to determine whether prevention of PAA will reduce mortality in this population.

Postoperative atrial fibrillation: incidence, mechanisms, and clinical correlates

Atrial fibrillation is the most commonly encountered arrhythmia after cardiac surgery. Although usually self-limiting, it represents an important predictor of increased patient morbidity, mortality, and health care costs. Numerous studies have attempted to determine the underlying mechanisms of postoperative atrial fibrillation (POAF) with varied success. A multifactorial pathophysiology is hypothesized, with inflammation and postoperative β-adrenergic activation recognized as important contributing factors. The management of POAF is complicated by a paucity of data relating to the outcomes of different therapeutic interventions in this population. This article reviews the literature on epidemiology, mechanisms, and risk factors of POAF, with a subsequent focus on the therapeutic interventions and guidelines regarding management.

Association of thoracic epidural analgesia with risk of atrial arrhythmias after pulmonary resection: a retrospective cohort study

PURPOSE

Atrial arrhythmias are common after non-cardiac thoracic surgery. We tested the hypothesis that TEA reduces the risk of new-onset atrial arrhythmias after pulmonary resection.

METHODS

We evaluated patients who had pulmonary resection. New-onset atrial arrhythmias detected before hospital discharge was our primary outcome. Secondary outcomes included other cardiovascular complications, pulmonary complications, time-weighted average pain score over 72 h, and duration of hospitalization. Patients with combination of general anesthesia and TEA were matched on propensity scores with patients given general anesthesia only. The matched groups were compared by use of logistic regression, linear regression, or Cox proportional hazards regression, as appropriate.

RESULTS

Among 1,236 patients who had pulmonary resections, 937 received a combination of general anesthesia and TEA (TEA) and 299 received general anesthesia only (non-TEA). We successfully matched 311 TEA patients with 132 non-TEA patients. We did not find a significant association between TEA and postoperative atrial arrhythmia (odds ratio (95 % CI) of 1.05 (0.50, 2.19), P = 0.9). TEA was not significantly associated with length of hospital stay or postoperative pulmonary complications (odds ratio (95 % CI) of 0.71 (0.22, 2.29), P = 0.47). TEA patients experienced fewer postoperative cardiovascular complications; although the association was not statistically significant (odds ratio (95 % CI) of 0.30 (0.06, 1.45), P = 0.06). Time-weighted average pain scores were similar in the two groups.

CONCLUSION

TEA was not associated with reduced occurrence of postoperative atrial arrhythmia. Although postoperative pulmonary complications were similar with and without TEA, TEA patients tended to experience fewer cardiovascular complications.

Vagus-preserving technique during minimally invasive esophagectomy: the effects on cardiac parameters in a swine model

BACKGROUND

Cardiac complications are an important cause of morbidity and mortality observed after esophageal resections. We examined whether an high intrathoracic vagotomy during abdominothoracic esophagectomy would have an effect on intraoperative and early postoperative cardiac function in the setting of a minimally invasive resection. Two hypotheses were generated for this study: (1) Vagotomy would cause cardiac changes, and (2) vagus-preserving esophagectomy would prevent cardiac problems during resection and in the early postoperative phase.

METHODS AND RESULTS

Thirty male pigs were operated on while cardiac parameters (heart rate [HR], cardiac index [CI], preload recruitable stroke work [PRSW], contractility speed [dp/dtmax], relaxation speed [dp/dtmin], and relaxation time [tau]) were monitored using a conductance catheter and the thermodilution method. Animals were randomized into 4 groups (each n = 7): (1) control, thoracoscopy only, (2) thoracoscopy with vagotomy, (3) esophageal resection with vagotomy, and (4) esophageal resection with vagus nerve preservation. To evaluate the first hypothesis, we compared groups 1 and 2; to evaluate the second hypothesis, we compared groups 3 and 4. HR, CI, PRSW, dp/dtmax, and tau were different in the 2 groups without resection (area under the curve; each P < .05). Vagotomy with esophagectomy resulted in nonsignificant differences between groups 3 and 4. The requirement for metoprolol administration to avoid severe tachycardia was greater in the groups that underwent vagotomy (P < .05; Fisher's exact test).

CONCLUSION

An high intrathoracic vagotomy results in loss of vagal tone and a greater rate of tachycardia during thoracoscopy and esophagectomy. There were no differences, however, in cardiac dynamics between the esophagectomy groups. Thus, vagal injury is not the sole reason for cardiac dysfunction after esophagectomy.

Atrial Fibrillation in the Intensive Care Setting

Atrial fibrillation (AF) is the commonest cardiac arrhythmia both in the general population and in the intensive care unit (ICU) setting. Its incidence continues to rise, affecting up to 10% of patients admitted to a general ICU and up to 50% of those admitted to a cardiac ICU. Uncontrolled AF has detrimental effects on the cardiovascular system, including heart failure, thromboembolic events, reduced quality of life and prolonged hospital stay. This article reviews the risk factors for developing AF, possible underlying mechanisms, clinical features and diagnosis, and focuses particularly on its management according to the latest guidelines with a specific focus on the ICU patient. We also discuss novel anticoagulants that will revolutionise the management of antithrombotic therapy in AF patients by replacing warfarin.

Preoperative left atrial dysfunction and risk of postoperative atrial fibrillation complicating thoracic surgery

OBJECTIVE

Postoperative atrial fibrillation complicating general thoracic surgery increases morbidity and stroke risk. We aimed to determine whether preoperative atrial dysfunction or other echocardiographic markers are associated with postoperative atrial fibrillation.

METHODS

In 191 patients who had undergone anatomic lung or esophageal resection, preoperative clinical and echocardiographic data were compared between patients with and without postoperative atrial fibrillation. Presence of postoperative atrial fibrillation lasting more than 5 minutes during hospitalization was detected using continuous telemetry or 12-lead electrocardiography. Maximal left atrial volume and indices of left atrial function were assessed.

RESULTS

Patients with postoperative atrial fibrillation (33/191, 17%) were older (71 ± 5 years vs 64 ± 12 years, P < .0001), were taking β-blockers more often, had greater left atrial volume, had decreased left atrial emptying fraction, and had lower E' and A' septal velocities compared with patients without postoperative atrial fibrillation. The incidence of postoperative atrial fibrillation in patients with left atrial volume 32 mL/m(2) or greater was 37% (11/30) and greater than in those with left atrial volume less than 32 mL/m(2) (14%, 22/160, P = .002). Length of hospital stay was significantly increased in patients with postoperative atrial fibrillation compared with patients without (P = .04). Older age was significantly associated with greater β-blocker use and left atrial volume and lower left atrial emptying fraction. On multivariate analysis, lower left atrial emptying fraction (odds ratio, 1.03 per unit decrement; 95% confidence interval, 1.002-1.065; P = .04) and preoperative use of β-blockers (odds ratio, 2.82; 95% confidence interval, 1.18-6.77; P = .02) were the only independent risk factors associated with postoperative atrial fibrillation.

CONCLUSIONS

These data show that an echocardiogram before major thoracic surgery, increased use of preoperative β-blockers, and decreased left atrial emptying fraction were associated with postoperative atrial fibrillation. Echocardiographic predictors of left atrial mechanical dysfunction may prove clinically useful in risk stratifying patients in whom postoperative atrial fibrillation is more likely to develop and to benefit from prevention strategies aimed at mitigating atrial function before surgery.

Post-operative atrial fibrillation: a maze of mechanisms

Post-operative atrial fibrillation (POAF) is one of the most frequent complications of cardiac surgery and an important predictor of patient morbidity as well as of prolonged hospitalization. It significantly increases costs for hospitalization. Insights into the pathophysiological factors causing POAF have been provided by both experimental and clinical investigations and show that POAF is ‘multi-factorial’. Facilitating factors in the mechanism of the arrhythmia can be classified as acute factors caused by the surgical intervention and chronic factors related to structural heart disease and ageing of the heart. Furthermore, some proarrhythmic mechanisms specifically occur in the setting of POAF. For example, inflammation and beta-adrenergic activation have been shown to play a prominent role in POAF, while these mechanisms are less important in non-surgical AF. More recently, it has been shown that atrial fibrosis and the presence of an electrophysiological substrate capable of maintaining AF also promote the arrhythmia, indicating that POAF has some proarrhythmic mechanisms in common with other forms of AF. The clinical setting of POAF offers numerous opportunities to study its mechanisms. During cardiac surgery, biopsies can be taken and detailed electrophysiological measurements can be performed. Furthermore, the specific time course of POAF, with the delayed onset and the transient character of the arrhythmia, also provides important insight into its mechanisms.

This review discusses the mechanistic interaction between predisposing factors and the electrophysiological mechanisms resulting in POAF and their therapeutic implications.

Atrial fibrillation after esophagectomy: an indicator of postoperative morbidity

PURPOSE

The relevance of new-onset atrial fibrillation (AF) after esophagectomy remains poorly defined. This study's primary goal is to better define the incidence, clinical patterns, and outcomes associated with the development of AF after esophagectomy.

METHODS

The study is a retrospective review of patients undergoing esophagectomy at a single academic center between May 1996 and December 2007. Patients with new-onset AF were evaluated by univariate and multivariate analyses for risk factors associated with AF onset and outcomes.

RESULTS

New-onset AF was noted in 32 of 156 (20.5%) patients after esophagectomy. Most (16/32, 50%) developed AF within 48 h, and 28 of 32 (87.5%) developed new AF within 72 h of surgery. Pulmonary complications were more frequent in patients with AF than those without AF (59.4% vs. 15.3%, P < 0.01) and usually immediately preceded or occurred concurrently with AF. Anastomotic leaks were significantly more common in patients with AF than those without (28.1% vs. 6.45%, P < 0.01) and were identified, on average, 4.2 days after the onset of AF. In the multivariate analysis, anastomotic leaks, pulmonary complications, and number of complications were significantly associated with AF. Although 60-day survival was worse for patients developing AF (P < 0.01), multivariate analysis suggests that non-AF complications were the independent predictor of mortality.

CONCLUSION

New-onset AF after esophagectomy is associated with anastomotic leaks, pulmonary complications, and decreased 60-day survival. Although pulmonary complications typically occurred coincident with the onset of AF, anastomotic leaks were usually diagnosed 4 days after AF onset. New postesophagectomy AF should prompt vigilance for the presence of other concurrent complications.

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.).