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.

Minimally invasive mitral valve surgery after previous sternotomy: A propensity-matched analysis.

BACKGROUND: Although the incidence of mitral valve (MV) surgery after previous open-heart surgery is increasing, there is no consensus regarding the optimal surgical approach. Reoperative MV surgery is most commonly performed via sternotomy (ST). We sought to determine whether minimally-invasive (MIS) reoperative MV surgery is safe and feasible. METHODS: All patients with a history of ST undergoing MV surgery with or without concomitant tricuspid or atrial fibrillation surgery at a single institution from 2007 to 2018 were retrospectively reviewed. ST and MIS approaches were compared using propensity-matched analysis. The coprimary endpoints were operative mortality and 1-year survival, and secondary endpoints were operative complications and length of stay. RESULTS: A total of 305 isolated MV reoperations were performed: 199 (65%) MIS and 106 (35%) ST. MIS patients were older than ST patients (71 [63, 76.5] vs. 66 [56, 72] years, p < .01), more likely to have undergone prior coronary artery bypass grafting (57% vs. 27%, p < .01), and less likely to have had prior valve surgery (55% vs. 78%, p < .01). In unmatched comparisons, operative mortality was significantly lower among MIS patients (3.0% vs. 8.5%, p = .04), but 1-year mortality was similar (14.4% vs. 15.6%, p = .8). After propensity matching, 88 pairs had excellent balance across baseline characteristics. Mortality was similar among MIS and ST patients at 30 days (3.4% vs. 8%, p = .19) and 1 year (15.9% vs. 16.5%, p = .9). RBC and fresh frozen plasma transfusions were significantly lower in the MIS group (p < .01). CONCLUSIONS: A minimally invasive approach is a safe alternative in patients with prior ST undergoing MV surgery.

Convergent epicardial-endocardial ablation for treatment of long-standing persistent atrial fibrillation: A review of literature.

BACKGROUND AND AIM OF STUDY: The convergent procedure (CVP) is a hybrid ablation technique via a subxiphoid incision that has recently emerged as a treatment option for non-paroxysmal atrial fibrillation (npAF). By combining endocardial and epicardial ablation into a simultaneous or staged procedure, the pulmonary vein and posterior left atrium can be isolated with transmural lesion sets while minimizing the risk of proarrhythmic gaps that are a known limitation with endocardial linear lesion sets. We reviewed the 12-month outcomes in patients who underwent CVP compared to those who underwent endocardial catheter ablation (CA) and surgical ablation (SA). METHODS: A literature search was conducted using the PubMed database for publications related to CVP. Selected studies included detailed 12-month follow-up of patients, patient characteristics, periprocedural complications, use of antiarrhythmic drugs (AADs), and monitoring method. RESULTS: Five studies with 340 patients who underwent CVP between January 2009 and March 2017 were selected for this review. A total of 8.5% of patients had paroxysmal AF (pAF), 42.2% had persistent AF (peAF), and 49.1% had long-standing persistent AF (lspAF). At 12 months, 81.9% of patients were in sinus rhythm, while 54.1% of patients were in sinus rhythm while not taking AADs. The overall complication rate was 10%. CONCLUSION: CVP had better 1-year efficacy in eliminating AF when compared to CA. However, SA, specifically the Cox Maze IV, had lower rates of AF recurrence in the npAF patient population. Despite its promising 1-year efficacy rates, the periprocedural complication rate for CVP was significantly higher than both CA and SA.

Human lung epithelial cells progressed to malignancy through specific oncogenic manipulations.

We used CDK4/hTERT-immortalized normal human bronchial epithelial cells (HBEC) from several individuals to study lung cancer pathogenesis by introducing combinations of common lung cancer oncogenic changes (p53, KRAS, and MYC) and followed the stepwise transformation of HBECs to full malignancy. This model showed that: (i) the combination of five genetic alterations (CDK4, hTERT, sh-p53, KRAS(V12), and c-MYC) is sufficient for full tumorigenic conversion of HBECs; (ii) genetically identical clones of transformed HBECs exhibit pronounced differences in tumor growth, histology, and differentiation; (iii) HBECs from different individuals vary in their sensitivity to transformation by these oncogenic manipulations; (iv) high levels of KRAS(V12) are required for full malignant transformation of HBECs, however, prior loss of p53 function is required to prevent oncogene-induced senescence; (v) overexpression of c-MYC greatly enhances malignancy but only in the context of sh-p53+KRAS(V12); (vi) growth of parental HBECs in serum-containing medium induces differentiation, whereas growth of oncogenically manipulated HBECs in serum increases in vivo tumorigenicity, decreases tumor latency, produces more undifferentiated tumors, and induces epithelial-to-mesenchymal transition (EMT); (vii) oncogenic transformation of HBECs leads to increased sensitivity to standard chemotherapy doublets; (viii) an mRNA signature derived by comparing tumorigenic versus nontumorigenic clones was predictive of outcome in patients with lung cancer. Collectively, our findings show that this HBEC model system can be used to study the effect of oncogenic mutations, their expression levels, and serum-derived environmental effects in malignant transformation, while also providing clinically translatable applications such as development of prognostic signatures and drug response phenotypes.

Lung penetration by thoracostomy tubes: imaging findings on CT.

We have analyzed the radiographic and computed tomographic (CT) appearance of thoracostomy (chest) tubes inadvertently placed into the lungs. We have studied the clinical sequela of such malpositioning and discussed treatment options. Cases were collected from chest CT log book reports between January 1998 and January 31, 2005 which indicated or suggested intrapulmonary thoracostomy tube placement. CT scans were reviewed by the authors. The chest radiographs and medical records--including thoracic surgical reports--of those patients whose scans demonstrated intrapulmonary tube placement or indeterminate tube location were reviewed. Fifty patients, in whom 51 thoracostomy tubes were placed into the lungs, are included in this series. None of these tubes were described as intrapulmonary on reports of chest radiographs done before CT scanning. In 13 patients (26%), thoracostomy tube placements produced immediate improvement in pleural abnormalities. Dramatic increase or development of chest wall emphysema or pneumothorax was noted in 4 (8%) patients after tube placement. Twenty-five patients (50%) demonstrated either abrupt or gradual increase in pulmonary or pleural opacity on postplacement chest radiographs. Twenty-one (42%) had no apparent clinical complications. Thirteen (26%) had either prolonged air leaks or recurrent pneumothorax. Ten (20%) developed pneumonia. Retained hemothorax or empyema occurred in 8 (16%). Twelve patients (24%) required subsequent thoracic surgery. Intrapulmonary placement of thoracostomy tubes is probably more common than previously reported. This possibility should be considered when radiographs and CT scans are evaluated.