Pericardial Effusion Provoking Atrial Fibrillation After Cardiac Surgery: JACC Review Topic of the Week

Intrapericardial Administration to Achieve Localized and Targeted Treatment for Cardiac Disease

Intrapericardial administration has been proposed as an alternative delivery route of pharmacological agents via the bilaminar sac of pericardium surrounding the heart. To date, intrapericardial administration has entailed the localized administration of a broad spectrum of therapeutic agents. These agents include stem cells, extracellular matrix, growth factor, drugs, bioactive materials, and genetic materials, to the heart and coronary arteries. The route not only overcomes the limitations associated with traditional systemic administration methods, but also presents multiple intrinsic advantages over the other approaches, allowing greater therapeutic actions. Intrapericardial administration exhibits versatility in addressing certain cardiac conditions and ongoing research in this field certainly holds promise for further innovations and advancements to improve cardiac treatment. Thus, this review discusses the anatomy and physiology of the pericardium, the intrapericardial administration access routes, the recent application of intrapericardial delivery in the context of cardiac repair as well as the challenges associated with the approach.

Effect of Ticagrelor Versus Clopidogrel After Off-Pump Coronary Artery Bypass Grafting on Postoperative Atrial Fibrillation: A Cohort Study

BACKGROUND

This study aimed to explore the effect of a P2Y12 inhibitor regimen on the occurrence of postoperative atrial fibrillation (POAF) after off-pump coronary artery bypass graft surgery in carriers with the cytochrome P450 family 2 subfamily C member19 loss-of-function allele.

METHODS AND RESULTS

From May 2019 to November 2023, patients containing the cytochrome P450 family 2 subfamily C member19*2 or *3 allele undergoing elective first-time off-pump coronary artery bypass graft surgery including aspirin 100 mg/d and ticagrelor 180 mg/d (AT group; n=95) versus clopidogrel 75 mg/d (aspirin and clopidogrel group; n=95) were prospectively followed. The primary end point was the cumulative incidence of POAF in a week. The secondary end points were POAF burden, platelet aggregability, systemic immune-inflammation index and heart rate variability. The incidence of POAF was 21.1% in the AT group versus 41.1% in the aspirin and clopidogrel group (hazard ratio, 0.46 [95% CI, 0.27-0.76]; P=0.003). POAF burden, ADP-induced platelet aggregation and systemic immune-inflammation index was notably lower in the AT group than the aspirin and clopidogrel group. Heart rate variability data showed an increase in both high-frequency and SD of normal-to-normal RR intervals in the AT group with a decreased low-frequency/high-frequency ratio, suggesting that the sympathetic/parasympathetic activation was balanced.

CONCLUSIONS

In patients carrying the cytochrome P450 family 2 subfamily C member19 loss-of-function allele, an AT regimen after off-pump coronary artery bypass grafting was associated with a lower incidence of POAF, paralleled by lower atrial fibrillation burden, ADP-induced platelet aggregation, lower systemic immune-inflammation index reaction, and a balanced automatic nerve system compared with an aspirin and clopidogrel regimen. Inhibiting the systemic immune-inflammation response and sustaining automatic nerve balance may underlie the therapeutic effect of POAF by a potent antiplatelet combination.

Association of CYP2C19 genotypes with postoperative atrial fibrillation after coronary artery bypass surgery

This cohort study aims to assess the connection between cytochrome P450 family 2 subfamily C member 19 (CYP2C19) genotyping, platelet aggregability following oral clopidogrel administration, and the occurrence of postoperative atrial fibrillation (POAF) after off-pump coronary artery bypass graft (CABG) surgery. From May 2017 to November 2022, a total of 258 patients undergoing elective first-time CABG surgery, receiving 100 mg/day oral aspirin and 75 mg/day oral clopidogrel postoperatively, was included for analysis. These patients were categorized based on CYP2C19 genotyping. Platelet aggregability was assessed serially using multiple-electrode aggregometry before CABG, 1 and 5 days after the procedure, and before discharge. The incidences of POAF were compared using the log-rank test for cumulative risk. CYP2C19 genotyping led to categorization into CYP2C19*1*1 (WT group, n = 123) and CYP2C19*2 or *3 (LOF group, n = 135). Baseline characteristics and operative data showed no significant differences between the two groups. The incidence of POAF after CABG was 42.2% in the LOF group, contrasting with 22.8% in the WT group (hazard risk [HR]: 2.061; 95% confidence interval [CI]: 1.347, 3.153; p = 0.0013). Adenosine diphosphate-stimulated platelet aggregation was notably higher in the LOF group compared to the WT group 5 days after CABG (30.4% ± 6.5% vs. 17.9% ± 4.1%, p < 0.001), remaining a similar higher level at hospital discharge (25.6% ± 6.1% vs. 12.2% ± 3.5%, p < 0.001). The presence of CYP2C19 LOF was linked to a higher incidence of POAF and relatively elevated platelet aggregation after CABG surgery under the same oral clopidogrel regimen.

Association between red blood cell distribution width-to-albumin ratio and prognosis in non-ischaemic heart failure

AIMS

Red blood cell distribution width-to-albumin ratio (RAR), an innovate biomarker of inflammation, can independently predict adverse cardiovascular outcomes. However, the association between RAR and prognosis in patients with non-ischaemic heart failure (NIHF) remains unclear.

METHODS AND RESULTS

A total of 2077 NIHF patients admitted to the Heart Failure Care Unit, Fuwai Hospital, were consecutively enrolled from December 2006 to October 2017 in this retrospective study. The primary endpoint was a composite outcome of all-cause mortality and heart transplantation. The correlation between RAR and the composite outcome was assessed by the Kaplan-Meier survival analysis and the Cox regression analysis. Incremental predictive values and the clinical performance of RAR for all-cause mortality or heart transplantation were also assessed based on a 12-variable traditional risk model. The median follow-up time in this study was 1433 (1341, 1525) days. As the gender no longer satisfied the Cox proportional risk assumption after 1150 days, we set 1095 days as the follow-up time for analysis. A total of 500 patients reached the composite outcome. Multivariable Cox regression showed that per log2 increase of RAR was significantly associated with a 132.9% [hazard ratio 2.329, 95% confidence interval (CI) 1.677-3.237, P < 0.001] increased risk of all-cause mortality or heart transplantation. Better model discrimination [concordance index: 0.766 (95% CI 0.754-0.778) vs. 0.758 (95% CI 0.746-0.770), P < 0.001], calibration (Akaike information criterion: 1487.3 vs. 1495.74; Bayesian information criterion: 1566.25 vs. 1569.43; Brier score: 1569.43 vs. 1569.43; likelihood ratio test P < 0.001), and reclassification (integrated discrimination improvement: 1.35%, 95% CI 0.63-2.07%, P < 0.001; net reclassification improvement: 13.73%, 95% CI 2.05-27.18%, P = 0.034) were improved after adding RAR to the traditional model (P < 0.001 for all). A higher overall net benefit was also obtained in the threshold risk probability of 20-55%.

CONCLUSIONS

High level of RAR was an independent risk factor of poor outcome in NIHF.

Association Between Serum Levels of Nicotinamide-Adenine Dinucleotide Phosphate Oxidase 2 and the Development of Atrial Fibrillation After Isolated Coronary Artery Bypass Grafting: A Prospective Pilot Study

INTRODUCTION

To investigate the levels of nicotinamide-adenine dinucleotide phosphate oxidase 2 (NOX2) in serum and pericardial drainage samples in the early stage after coronary artery bypass grafting (CABG) and determine whether NOX2 is predictive of postoperative atrial fibrillation (POAF).

MATERIALS AND METHODS

This prospective pilot study involved 152 adults without history of atrial fibrillation who underwent first-time elective isolated CABG. Serum and pericardial fluid samples were simultaneously obtained from patients at baseline and 4, 12, and 24 h post operation. NOX2 levels were determined using enzyme-linked immunosorbent assays. The heart rhythm of patients was continuously monitored through a Holter monitor until discharge. Logistic regression and receiver-operating characteristic (ROC) curve analyses were performed, as appropriate.

RESULTS

Fifty-one patients (33.6%) experienced in-hospital POAF. NOX2 concentration in serum and pericardial drainage samples was increased after surgery, reached its peak at 12 h, and gradually declined thereafter toward the baseline levels by 24 h. At 12 h, patients with POAF had higher levels of serum NOX2 than those without (3.96 ± 0.35 vs. 3.70 ± 0.75 μg/mL, respectively, p = 0.004). There were no discernible differences in pericardial NOX2 between the 2 groups. Multivariate analysis revealed that serum NOX2 at 12 h post operation was the strongest independent predictor of POAF (odds ratio: 2.179, 95% confidence interval: 1.084-4.377). The area under the ROC curve of the POAF predictive model was 0.732 (95% confidence interval: 0.654-0.801).

CONCLUSION

Serum NOX2 may be useful in the identification of POAF. Larger studies are warranted to substantiate these findings.

Baseline Intraoperative Left Ventricular Diastolic Function Is Associated with Postoperative Atrial Fibrillation after Cardiac Surgery

BACKGROUND

Detailed understanding of the association between intraoperative left atrial and left ventricular diastolic function and postoperative atrial fibrillation is lacking. In this post hoc analysis of the Posterior Left Pericardiotomy for the Prevention of Atrial Fibrillation after Cardiac Surgery (PALACS) trial, we aimed to evaluate the association of intraoperative left atrial and left ventricular diastolic function as assessed by transesophageal echocardiography (TEE) with postoperative atrial fibrillation.

METHODS

PALACS patients with available intraoperative TEE data (n = 402 of 420; 95.7%) were included in this cohort study. We tested the hypotheses that preoperative left atrial size and function, left ventricular diastolic function, and their intraoperative changes were associated with postoperative atrial fibrillation. Normal left ventricular diastolic function was graded as 0 and with lateral e' velocity 10 cm/s or greater. Diastolic dysfunction was defined as lateral e' less than 10 cm/s using E/e' cutoffs of grade 1, E/e' 8 or less; grade, 2 E/e' 9 to 12; and grade 3, E/e' 13 or greater, along with two criteria based on mitral inflow and pulmonary wave flow velocities.

RESULTS

A total of 230 of 402 patients (57.2%) had intraoperative diastolic dysfunction. Posterior pericardiotomy intervention was not significantly different between the two groups. A total of 99 of 402 patients (24.6%) developed postoperative atrial fibrillation. Patients who developed postoperative atrial fibrillation more frequently had abnormal left ventricular diastolic function compared to patients who did not develop postoperative atrial fibrillation (75.0% [n = 161 of 303] vs. 57.5% [n = 69 of 99]; P = 0.004). Of the left atrial size and function parameters, only delta left atrial area, defined as presternotomy minus post-chest closure measurement, was significantly different in the no postoperative atrial fibrillation versus postoperative atrial fibrillation groups on univariate analysis (-2.1 cm2 [interquartile range, -5.1 to 1.0] vs. 0.1 [interquartile range, -4.0 to 4.8]; P = 0.028). At multivariable analysis, baseline abnormal left ventricular diastolic function (odds ratio, 2.02; 95% CI, 1.15 to 3.63; P = 0.016) and pericardiotomy intervention (odds ratio, 0.46; 95% CI, 0.27 to 0.78, P = 0.004) were the only covariates independently associated with postoperative atrial fibrillation.

CONCLUSIONS

Baseline preoperative left ventricular diastolic dysfunction on TEE, not left atrial size or function, is independently associated with postoperative atrial fibrillation. Further studies are needed to test if interventions aimed at optimizing intraoperative left ventricular diastolic function during cardiac surgery may reduce the risk of postoperative atrial fibrillation.

EDITOR’S PERSPECTIVE

The Effect of Posterior Pericardiotomy on the Incidence of Atrial Fibrillation After Cardiac Surgery-Extended Follow-Up study (PALACS-EF): rationale and design

Aims

Postoperative atrial fibrillation (POAF) is the most common complication of cardiac surgery and has been associated with increased postoperative morbidity and hospital costs. The Posterior left pericardiotomy for the prevention of AtriaL fibrillation After Cardiac Surgery (PALACS) trial found that posterior pericardiotomy significantly reduced the incidence of POAF (17% vs. 32%, P < 0.001). We present the protocol for The Effect of Posterior Pericardiotomy on the Incidence of Atrial Fibrillation After Cardiac Surgery-Extended Follow-Up study (PALACS-EF): a prospective, extended follow-up of the original PALACS trial. The aim of PALACS-EF is to gain more data regarding the effect of posterior pericardiotomy on postdischarge clinical outcomes. The primary outcome is the time to the first occurrence of the composite of all-cause mortality or hospital cardiovascular readmission. The key secondary outcome is the time to the first occurrence of the composite of all-cause mortality and all-cause hospital readmission. Hospital readmission, myocardial infarction, stroke, transient ischaemic attack, heart failure, systemic embolism, or new arrhythmias with onset since 30-day follow-up will also be recorded.

Methods and results

All 420 patients enrolled in the PALACS trial will be included; extended follow-up will be conducted via telephone by blinded research personnel utilizing a standardized script to ensure uniformity and completeness of follow-up. If an event has occurred, documentation will be obtained, and an independent adjudication committee blinded to group assignment will adjudicate outcome events. Results will be reported when a median follow-up of 5 years is achieved.

Conclusion

PALACS-EF will provide data to answer the question of whether posterior pericardiotomy improves postdischarge outcomes in patients undergoing cardiac surgery, and it will provide information on the relationship between POAF and adverse postdischarge outcomes including mortality, hospitalization, heart failure, and stroke.

Registration

PALACS: NCT02875405, PALACS-EF: NCT05903222.

Differences in Postoperative Atrial Fibrillation Incidence and Outcomes After Cardiac Surgery According to Assessment Method and Definition: A Systematic Review and Meta-Analysis

BACKGROUND

Postoperative atrial fibrillation (POAF) is the most frequent complication of cardiac surgery. Despite clinical and economic implications, ample variability in POAF assessment method and definition exist across studies. We performed a study-level meta-analysis to evaluate the influence of POAF assessment method and definition on its incidence and association with clinical outcomes.

METHODS AND RESULTS

A systematic literature search was conducted to identify studies comparing the outcomes of patients with and without POAF after cardiac surgery that also reported POAF assessment method. The primary outcome was POAF incidence. The secondary outcomes were in-hospital mortality, stroke, intensive care unit length of stay, and postoperative length of stay. Fifty-nine studies totaling 197 774 patients were included. POAF cumulative incidence was 26% (range: 7.3%-53.1%). There were no differences in POAF incidence among assessment methods (27%, [range: 7.3%-53.1%] for continuous telemetry, 27% [range: 7.9%-50%] for telemetry plus daily ECG, and 19% [range: 7.8%-42.4%] for daily ECG only; P>0.05 for all comparisons). No differences in in-hospital mortality, stroke, intensive care unit length of stay, and postoperative length of stay were found between assessment methods. No differences in POAF incidence or any other outcomes were found between POAF definitions. Continuous telemetry and telemetry plus daily ECG were associated with higher POAF incidence compared with daily ECG in studies including only patients undergoing isolated coronary artery bypass grafting.

CONCLUSIONS

POAF incidence after cardiac surgery remains high, and detection rates are variable among studies. POAF incidence and its association with adverse outcomes are not influenced by the assessment method and definition used, except in patients undergoing isolated coronary artery bypass grafting.

Construction and validation of a nomogram of risk factors for new-onset atrial fibrillation in advanced lung cancer patients after non-surgical therapy

Objective

Risk factors of new-onset atrial fibrillation (NOAF) in advanced lung cancer patients are not well defined. We aim to construct and validate a nomogram model between NOAF and advanced lung cancer.

Methods

We retrospectively enrolled 19484 patients with Stage III-IV lung cancer undergoing first-line antitumor therapy in Shanghai Chest Hospital between January 2016 and December 2020 (15837 in training set, and 3647 in testing set). Patients with pre-existing AF, valvular heart disease, cardiomyopathy were excluded. Logistic regression analysis and propensity score matching (PSM) were performed to identify predictors of NOAF, and nomogram model was constructed and validated.

Results

A total of 1089 patients were included in this study (807 in the training set, and 282 in the testing set). Multivariate logistic regression analysis showed that age, c-reactive protein, centric pulmonary carcinoma, and pericardial effusion were independent risk factors, the last two of which were important independent risk factors as confirmed by PSM analysis. Nomogram included independent risk factors of age, c-reactive protein, centric pulmonary carcinoma, and pericardial effusion. The AUC was 0.716 (95% CI 0.661-0.770) and further evaluation of this model showed that the C-index was 0.716, while the bias-corrected C-index after internal validation was 0.748 in the training set. The calibration curves presented good concordance between the predicted and actual outcomes.

Conclusion

Centric pulmonary carcinoma and pericardial effusion were important independent risk factors for NOAF besides common ones in advanced lung cancer patients. Furthermore, the new nomogram model contributed to the prediction of NOAF.

Postoperative pericardial effusion, pericardiotomy, and atrial fibrillation: An explanatory analysis of the PALACS trial

BACKGROUND

In the Posterior left pericardiotomy for the prevention of atrial fibrillation after cardiac surgery (PALACS) trial, posterior pericardiotomy was associated with a significant reduction in postoperative atrial fibrillation (POAF) after cardiac surgery. We aimed to investigate the mechanisms underlying this effect.

METHODS

We included PALACS patients with available echocardiographic data (n = 387/420, 92%). We tested the hypotheses that the reduction in POAF with the intervention was associated with 1) a reduction in postoperative pericardial effusion and/or 2) an effect on left atrial size and function. Spline and multivariable logistic regression analyses were used.

RESULTS

Most patients (n = 307, 79%) had postoperative pericardial effusions (anterior 68%, postero-lateral 51.9%). The incidence of postero-lateral effusion was significantly lower in patients undergoing pericardiotomy (37% vs 67%; P < .001). The median size of anterior effusion was comparable between patients with and without POAF (5.0 [IQR 3.0-7.0] vs 5.0 [IQR 3.0-7.5] mm; P = .42), but there was a nonsignificant trend towards larger postero-lateral effusion in the POAF group (5.0 [IQR 3.0-9.0] vs 4.0 [IQR 3.0-6.4] mm; P = .06). There was a non-linear association between postero-lateral effusion and POAF at a cut-off at 10 mm (OR 2.70; 95% CI 1.13, 6.47; P = .03) that was confirmed in multivariable analysis (OR 3.5, 95% CI 1.17, 10.58; P = 0.02). Left atrial dimension and function did not change significantly after posterior pericardiotomy.

CONCLUSIONS

Reduction in postero-lateral pericardial effusion is a plausible mechanism for the effect of posterior pericardiotomy in reducing POAF. Measures to reduce postoperative pericardial effusion are a promising approach to prevent POAF.

Effect of posterior pericardiotomy in cardiac surgery: A systematic review and meta-analysis of randomized controlled trials

Background

Posterior pericardiotomy (PP) has been shown to reduce the incidence of pericardial effusion and postoperative atrial fibrillation (POAF) after cardiac surgery. However, the procedure and the totality of its effects are poorly known in the cardiac surgery community. We performed a study-level meta-analysis of randomized controlled trials (RCTs) to evaluate the impact of PP in cardiac surgery patients.

Methods

A systematic literature search was conducted on three medical databases (Ovid MEDLINE, Ovid Embase, Cochrane Library) to identify RCTs reporting outcomes of patients that received a PP or no intervention after cardiac surgery. The primary outcome was the incidence of POAF. Key secondary outcomes were operative mortality, incidence of pericardial and pleural effusion, cardiac tamponade, length of stay (LOS), pulmonary complications, amount of chest drainage, need for intra-aortic balloon pump, and re-exploration for bleeding.

Results

Eighteen RCTs totaling 3,531 patients were included. PP was associated with a significantly lower incidence of POAF (odds ratio [OR] 0.45, 95% confidence interval [CI] 0.32-0.64, P < 0.0001), early (OR 0.18, 95% CI 0.10-0.34, P < 0.0001) and late pericardial effusion (incidence rate ratio 0.13, 95% CI 0.06-0.29, P < 0.0001), and cardiac tamponade (risk difference -0.02, 95% CI -0.04 to -0.01, P = 0.001). PP was associated with a higher incidence of pleural effusion (OR 1.42, 95% CI 1.06-1.90, P = 0.02), but not pulmonary complications (OR 0.82, 95% CI 0.56-1.19; P = 0.38). No differences in other outcomes, including operative mortality, were found.

Conclusions

PP is a safe and effective intervention that significantly decreases the incidence of POAF and pericardial effusion following cardiac surgery.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=261485, identifier: CRD42021261485.