External validity of a model to predict postoperative atrial fibrillation after thoracic surgery

Risk Factors and Prognosis of Perioperative Atrial Fibrillation in Elderly Patients Undergoing VATS Lung Surgery: A Retrospective Cohort Study

Background

Atrial fibrillation (AF) has become the most common postoperative arrhythmia of thoracic surgery. This study aimed to investigate the risk factors and complications of perioperative atrial fibrillation (PoAF) in elderly patients who underwent video-assisted thoracoscopic surgery (VATS).

Methods

Data were collected from patients who underwent VATS between January 2013 and December 2022 at Peking Union Medical College Hospital (PUMCH). Univariable analyses and multivariable logistic regression analyses were used to determine the factors correlated with PoAF. Receiver operating characteristic (ROC) curve was used to evaluate the discrimination of the indicators to predict PoAF.

Results

The study enrolled 2920 patients, with a PoAF incidence of 5.2% (95% CI 4.4%-6.0%). In the logistic regression analyses, male sex (OR=1.496, 95% CI 1.056-2.129, P=0.024), left atrial anteroposterior dimension (LAD) ≥40 mm (OR=2.154, 95% CI 1.235-3.578, P=0.004), hypertension (HTN) without regular treatment (OR=2.044, 95% CI 0.961-3.921, P=0.044), a history of hyperthyroidism (OR=4.443, 95% CI 0.947-15.306, P=0.030), surgery of the left upper lobe (compared to other lung lobes) (OR=1.625, 95% CI 1.139-2.297, P=0.007), postoperative high blood glucose (BG) (OR=2.482, 95% CI 0.912-5.688, P=0.048), and the time of chest tube removal (per day postoperatively) (OR=1.116, 95% CI 1.038-1.195, P=0.002) were found to be significantly associated with PoAF. The area under the ROC curve was 0.707 (95% CI 0.519-0.799). 86.9% patients were successfully converted to sinus rhythm. Compared with the non-PoAF group, the PoAF group had significantly greater risks of prolonged air leakage, postoperative acute coronary syndrome, longer ICU stays, and longer hospital stays.

Conclusion

Male sex, LAD≥40 mm, HTN without regular treatment, a history of hyperthyroidism, surgery of the left upper lobe, postoperative BG, and the time of chest tube removal were associated with PoAF. These findings may help clinicians identify high-risk patients and take preventive measures to minimize the incidence and adverse prognosis of PoAF.

Development and external validation of a novel model for predicting new clinically important atrial fibrillation after thoracoscopic anatomical lung cancer surgery: a multicenter retrospective cohort study

BACKGROUND

New clinically important postoperative atrial fibrillation (POAF) is the most common arrhythmia after thoracoscopic anatomical lung cancer surgery and is associated with increased morbidity and mortality. The full spectrum of predictors remains unclear, and effective assessment tools are lacking. This study aimed to develop and externally validate a novel model for predicting new clinically important POAF.

METHODS

This retrospective study included 14 074 consecutive patients who received thoracoscopic anatomical lung cancer surgery from January 2016 to December 2018 in Shanghai Chest Hospital. Based on the split date of 1 January 2018, we selected 8717 participants for the training cohort and 5357 participants for the testing cohort. For external validation, we pooled 2941 consecutive patients who received this surgical treatment from July 2016 to July 2021 in Shanghai Ruijin Hospital. Independent predictors were used to develop a model and internally validated using a bootstrap-resampling approach. The area under the receiver operating characteristic curves (AUROCs) and Brier score were performed to assess the model discrimination and calibration. The decision curve analysis (DCA) was used to evaluate clinical validity and net benefit. New clinically important POAF was defined as a new-onset of POAF that causes symptoms or requires treatment.

RESULTS

Multivariate analysis suggested that age, hypertension, preoperative treatment, clinical tumor stage, intraoperative arrhythmia and transfusion, and operative time were independent predictors of new clinically important POAF. These seven candidate predictors were used to develop a nomogram, which showed a concordance statistic (C-statistic) value of 0.740 and good calibration (Brier score; 0.025). Internal validation revealed similarly good discrimination (C-statistic, 0.736; 95% CI: 0.705-0.768) and calibration. The decision curve analysis showed positive net benefits with the threshold risk range of 0-100%. C-statistic value and Brier score were 0.717 and 0.028 in the testing cohort, and 0.768 and 0.012 in the external validation cohort, respectively.

CONCLUSIONS

This study identified seven predictors of new clinically important POAF, among which preoperative treatment, intraoperative arrhythmia, and operative time were rarely reported. The established and externally validated model has good performance and clinical usefulness, which may promote the application of prevention and treatment in high-risk patients, and reduce the development and related adverse outcomes of this event.

Ventilatory efficiency is superior to peak oxygen uptake for prediction of lung resection cardiovascular complications

Introduction

Ventilatory efficiency (V_E/VCO₂ slope) has been shown superior to peak oxygen consumption (VO₂) for prediction of post-operative pulmonary complications in patients undergoing thoracotomy. V_E/VCO₂ slope is determined by ventilatory drive and ventilation/perfusion mismatch whereas VO₂ is related to cardiac output and arteriovenous oxygen difference. We hypothesized pre-operative VO₂ predicts post-operative cardiovascular complications in patients undergoing lung resection.

Methods

Lung resection candidates from a published study were evaluated by post-hoc analysis. All of the patients underwent preoperative cardiopulmonary exercise testing. Post-operative cardiovascular complications were assessed during the first 30 post-operative days or hospital stay. One-way analysis of variance or the Kruskal–Wallis test, and multivariate logistic regression were used for statistical analysis and data summarized as median (IQR).

Results

Of 353 subjects, 30 (9%) developed pulmonary complications only (excluded from further analysis), while 78 subjects (22%) developed cardiovascular complications and were divided into two groups for analysis: cardiovascular only (n = 49) and cardiovascular with pulmonary complications (n = 29). Compared to patients without complications (n = 245), peak VO₂ was significantly lower in the cardiovascular with pulmonary complications group [19.9 ml/kg/min (16.5–25) vs. 16.3 ml/kg/min (15–20.3); P<0.01] but not in the cardiovascular only complications group [19.9 ml/kg/min (16.5–25) vs 19.0 ml/kg/min (16–23.1); P = 0.18]. In contrast, V_E/VCO₂ slope was significantly higher in both cardiovascular only [29 (25–33) vs. 31 (27–37); P = 0.05] and cardiovascular with pulmonary complication groups [29 (25–33) vs. 37 (34–42); P<0.01)]. Logistic regression analysis showed V_E/VCO₂ slope [OR = 1.06; 95%CI (1.01–1.11); P = 0.01; AUC = 0.74], but not peak VO₂ to be independently associated with post-operative cardiovascular complications.

Conclusion

V_E/VCO₂ slope is superior to peak VO₂ for prediction of post-operative cardiovascular complications in lung resection candidates.

Resting heart rate as a preoperative predictor of postoperative atrial fibrillation after pulmonary thromboendarterectomy

BACKGROUND

As a marker of the autonomic nervous system, resting heart rate is a predictor of postoperative atrial fibrillation (POAF). However, its predictive value for POAF after pulmonary thromboendarterectomy (PTE) has not been adequately studied.

METHODS

We enrolled 97 patients who underwent PTE in our hospital from December 2016 to November 2021 in this retrospective study. Almost all preoperative characteristics, including electrocardiogram, demographics, hematologic and biochemical indices, echocardiography, and pulmonary hemodynamics, were compared between patients with and without POAF. Multivariate logistic regression analysis was used to identify the independent risk factors for POAF after PTE.

RESULTS

Overall, 21 patients (21.6%) suffered from POAF after PTE. Compared with patients without POAF, those with POAF were older (p = .049), with a higher resting heart rate (p = .012), and higher platelet count (p = .040). In the binary logistic regression analysis, the resting heart rate (odds ratio [OR] = 1.043, 95% confidence interval [CI] = 1.009-1.078, p = .012) and age (OR = 1.051, 95% CI = 1.003-1.102, p = .037) were independent risk factors for POAF after PTE. The optimal cutoff point of resting heart rate was 89.5 with sensitivity and specificity of 47.6% and 77.6%. When the cutoff value of the age was 54.5, its sensitivity for predicting POAF was 71.4%, with a specificity of 59.2%.

CONCLUSIONS

POAF is common after PTE surgery, and the incidence may be underestimated. The resting heart rate and age are independent preoperative risk factors for POAF after PTE. Considering the lower predictive power of the resting heart and age, further large-scale studies are needed.

Prediction of Postcoronary Artery Bypass Grafting Atrial Fibrillation: POAFRiskScore Tool

BACKGROUND

 Atrial fibrillation (AF), a condition that might occur after a heart bypass procedure, has caused differing estimates of its occurrence and risk. The current study analyses the possible risk factors of post-coronary artery bypass grafting (post-CABG) AF (postoperative AF [POAF]) and presents a software for preoperative POAF risk prediction.

METHODS

 This retrospective research was performed on 1,667 patients who underwent CABG surgery using the hospital database. The associations between the variables of the patients and AF risk factors after CABG were examined using multivariable logistic regression (LR) after preprocessing the relevant data. The tool was designed to predict POAF risk using Shiny, an R package, to develop a web-based software.

RESULTS

 The overall proportion of post-CABG AF was 12.2%. According to the results of univariate tests, in terms of age (p < 0.001), blood urea nitrogen (p = 0.005), platelet (p < 0.001), triglyceride (p = 0.0026), presence of chronic obstructive pulmonary disease (COPD; p = 0.01), and presence of preoperative carotid artery stenosis (PCAS; p < 0.001), there were statistically significant differences between the POAF and non-POAF groups. Multivariable LR analysis disclosed the independent risk factors associated with POAF: PCAS (odds ratio [OR] = 2.360; p = 0.028), COPD (OR = 2.243; p = 0.015), body mass index (OR = 1.090; p = 0.006), age (OR = 1.054, p < 0.001), and platelet (OR = 0.994, p < 0.001).

CONCLUSION

 The experimental findings from the current research demonstrate that the suggested tool (POAFRiskScore v.1.0) can help clinicians predict POAF risk development in the preoperative period after validated on large sample(s) that can represent the related population(s). Simultaneously, since the updated versions of the proposed tool will be released periodically based on the increases in data dimensions with continuously added new samples and related factors, more robust predictions may be obtained in the subsequent stages of the current study in statistical and clinical terms.

Prophylaxis for patients at Risk to Eliminate Post-operative Atrial Fibrillation (PREP-AF trial): a protocol for a feasibility randomized controlled study

Background

Postoperative atrial fibrillation (POAF) is a frequent adverse event after thoracic surgery with associated morbidity, mortality, and healthcare costs. It has been shown to be preventable with prophylactic amiodarone, which is only recommended in high-risk individuals due to the potential associated side effects. Risk factors for POAF have been identified and incorporated into a prediction model to identify high-risk patients. Further evaluation in the form of a multicenter clinical trial is required to assess the effectiveness of prophylaxis specifically in this high-risk population. The feasibility of such a trial first needs to be assessed.

Methods

The PREP-AF trial is a double-blind randomized controlled feasibility trial. Individuals undergoing major thoracic surgery who are identified to be high-risk by the POAF prediction model will be randomized 1:1 to receive a short course of amiodarone vs. placebo in the immediate postoperative period. The primary outcome is feasibility, which will be measured by the number of eligible patients identified, consented, and randomized; intervention adherence; and measurement of future outcomes of a full trial.

Discussion

This study will determine the feasibility of a randomized controlled trial to assess the effectiveness of prophylactic amiodarone, in high-risk patients undergoing major thoracic surgery. This will inform the development of a multi-center trial to establish if prophylactic amiodarone is safe and effective at reducing the incidence of POAF. Preventing this adverse event will not only improve outcomes for patients but also reduce the associated health resource utilization and costs.

Trial registration

ClinicalTrials.gov NCT04392921. Registered on 19 May 2020.

Postoperative atrial fibrillation in pneumonectomy for primary lung cancer

Background

This study assessed the incidence and risk factors (RFs) of postoperative atrial fibrillation (POAF) and its impact on clinical outcomes in patients undergoing pneumonectomy for lung cancer.

Methods

Between 2013 and 2018, this monocentric retrospective study enrolled 324 consecutive pneumonectomy patients for primary lung cancer from our institution and 350 lobectomy and 349 segmentectomy cases matched by age, sex and body mass index (BMI). RF for POAF and postoperative death in pneumonectomy patients were assessed by logistic regression, and long-term outcomes after a median follow-up of 30 (range, 2–61) months by Cox proportional hazard model. Electrophysiology study (EPS) files of 30 AF patients with lung resection history were reviewed.

Results

POAF developed more often after pneumonectomy than lobectomy and segmentectomy (23.2% vs. 6.6% vs. 1.4%, respectively; P<0.001). Among 75 pneumonectomy patients with POAF, POAF was solitary in 55 patients (73.3%) and concurrent with other complications in 3 patients (4%). POAF risk after pneumonectomy was 4 and 22 times that after lobectomy and segmentectomy, respectively, with age >60 years and left atrial diameter (LAd) ≥35 mm as independent predictors. POAF, infection and hemorrhage were independent RFs for perioperative death after pneumonectomy; however, POAF was not RF for long-term death. Pulmonary vein (PV) trigger was identified in 60% (18/30) of AF patients with lung resection history, with stump PVs being more active than non-stump PVs (38.2% vs. 10.5%, P<0.001).

Conclusions

Post-pneumonectomy AF, with remarkable incidence, risk and independent predictors including age >60 years and LAd ≥35 mm, was mostly solitary and possibly secondary to stump and non-stump PV triggers. POAF, along with infection and hemorrhage, was a RF for perioperative death.

Variation in management of post-operative atrial fibrillation (POAF) after thoracic surgery

OBJECTIVES

New-onset post-operative atrial fibrillation (POAF) is a frequent adverse event following major thoracic surgery and is associated with increased risk of perioperative morbidity, length of stay and stroke. It is managed initially with rate and rhythm control therapy; however, optimal duration and the need for anticoagulation are poorly understood. This study aims to assess practice variation regarding POAF management and duration.

METHODS

This retrospective, single-center cohort study included patients who underwent major thoracic surgery and developed POAF between 2008 and 2017, managed with rate and rhythm control therapy alone. Demographic, clinical, and surgical variables/outcomes, POAF management, and incidence of POAF recurrence in the 30-day post-operative period were collected. Chi-square and T-tests determined significance.

RESULTS

Of 2054 patients undergoing thoracic surgery, 155 (75%) patients developed POAF. Different rate and rhythm control agents were used, most commonly metoprolol. 107 (69%) continued rate and rhythm control therapy upon hospital discharge for a mean of 56 days. Among the 48 patients with discontinuation of rate and rhythm control therapy on discharge, none demonstrated recurrence of POAF; in contrast to 3 of 107 patients who continued on therapy. Among patients with CHA₂DS₂-VASc score ≥ 2, 15% were prescribed anticoagulation on discharge.

CONCLUSIONS

Use of rate and rhythm control therapy and anticoagulation for POAF is significantly varied in practice. Many patients are not continued on rate and rhythm control after hospital discharge, which does not appear to impact risk of POAF recurrence. Further research to inform guidelines for POAF management, including therapy duration and indications for anticoagulation is warranted.

The role of surgery type in postoperative atrial fibrillation and in-hospital mortality in esophageal cancer patients with preserved left ventricular ejection fraction

BACKGROUND

Postoperative atrial fibrillation (POAF) is one of the most common complications of esophagectomy, which may extend the inpatient hospital stay. Minimally invasive esophagectomy (MIE) has been increasingly used in clinical practice; however, its POAF risk and short-term mortality remain unclear. This study aimed to examine the POAF risk and in-hospital mortality rate between patients receiving MIE and open esophagectomy (OE).

METHODS

Esophageal cancer patients who underwent MIE or OE from a retrospective cohort study were evaluated. A multivariate logistic regression model was built to assess the associations between esophagectomy (MIE vs. OE) and various outcomes (POAF, in-hospital mortality). Covariates included age, sex, body mass index, neoadjuvant therapy, tumor stage, surgery incision type, comorbidities, cardia conditions, peri-operative medication, and complications.

RESULTS

Of the 484 patients with esophageal cancer, 63 received MIE. A total of 53 patients developed POAF. Compared to patients receiving OE, MIE patients had 81% reduced odds of POAF (adjusted odds ratio [aOR] 0.185, 95% CI 0.039-0.887, P = 0.035). No statistically significant association was found for in-hospital mortality (aOR 0.709, 95% CI 0.114-4.409, P = 0.712).

CONCLUSIONS

MIE is associated with a lower risk of POAF, compared to traditional surgery. No significant short-term survival benefit was found for MIE.