Molecular mechanisms of postoperative atrial fibrillation in patients with obstructive sleep apnea.

Obstructive sleep apnea (OSA) promotes atrial remodeling and fibrosis, providing a substrate for atrial fibrillation (AF). Herein, we investigate the pathophysiological mechanisms of AF in association with OSA in a cohort of cardiac surgery patients. A prospective study including patients undergoing cardiac surgery. Biomarkers reflective of AF pathophysiology (interleukin [IL-6], C-reactive protein [CRP], von Willebrand factor [vWF], N-terminal pro-brain natriuretic peptide [NT-proBNP], high-sensitivity Troponin T [hs-TnT], and Galectin-3 [Gal-3]) was assessed by functional or immunological assays. miRNAs involved in AF were analyzed by reverse transcription-polymerase chain reaction (RT-PCR). Using atrial tissue samples, fibrosis was assessed by Masson's trichrome. Connexin 40 and 43 (Cx40; Cx43) were evaluated by immunolabeling. Fifty-six patients (15 with OSA and 41 non-OSA) were included in this hypothesis-generating pilot study. OSA group had a higher incidence of postoperative AF (POAF) (46.7% vs. 19.5%; p = .042), presented an increased risk of POAF (OR 3.61, 95% CI 1.01-12.92), and had significantly higher baseline levels of NT-proBNP (p = .044), vWF (p = .049), Gal-3 (p = .009), IL-6 (p = .002), and CRP (p = .003). This group presented lower levels of miR-21 and miR-208 (both p < .05). Also, lower Cx40 levels in POAF and/or OSA patients (50.0% vs. 81.8%, p = .033) were found. The presence of interstitial fibrosis (according to myocardial collagen by Masson's trichrome) was raised in OSA patients (86.7% vs. 53.7%, p = .024). Several biomarkers and miRNAs involved in inflammation and fibrosis were dysregulated in OSA patients, which together with a higher degree of interstitial fibrosis, altered miRNA, and Cxs expression predisposes to the development of a substrate that increases the AF risk.

Incidence and causes of pacemaker implantation during postoperative period of aortic valve replacement with rapid deployment prosthesis.

BACKGROUND: Aortic stenosis is currently the most frequently occurring valve pathology. Developments, such as transcatheter prostheses and rapid deployment prostheses, allow for the offer of a valve replacement to higher risk patients, but these techniques are linked with a higher need for a permanent pacemaker during the immediate postoperative period. METHODS: We studied the incidence and the factors associated with permanent pacemaker implantation after aortic valve replacement with Edwards Intuity rapid deployment prosthesis. RESULTS: Between October 2012 and December 2016, the Edwards Intuity prosthesis was implanted in 71 patients (68% male, 75.3 ± 5 years old). Six patients (8%) required a permanent pacemaker during immediate postoperative period. Univariate analysis showed that a history of acute myocardial infarction (AMI) (P = .046, B = 7.5, 95% CI [1.039-54.1]) and preoperative amiodarone (P = .009, B = 31.5; 95% CI [2.32-426]) were associated with a higher need for a pacemaker during the postoperative period. CONCLUSIONS: The incidence of permanent pacemaker implantation during the immediate postoperative period of aortic valve replacement with Edwards Intuity prosthesis was 8%, a value which is within the limits reported for conventional aortic prostheses. Preoperative amiodarone treatment and previous AMI may increase the need for a pacemaker during the postoperative period of these aortic prostheses.

Von Willebrand factor is associated with atrial fibrillation development in ischaemic patients after cardiac surgery.

AIMS: Atrial fibrillation (AF) is associated with an increased morbidity and mortality after cardiac surgery. Von Willebrand factor (vWF) has been proposed as a biomarker of endothelial damage/dysfunction. We hypothesized that vWF levels could be used as valuable biomarker for AF occurrence after cardiac surgery. Moreover, we explored the potential association between vWF and tissue remodelling as possible implication in post-surgical AF. METHODS AND RESULTS: We prospectively recruited 100 consecutive patients who undergoing programmed cardiac surgery with cardiopulmonary bypass and with no previous history of AF. Plasma vWF levels were determined from citrated plasma samples. Right atrial appendage tissue was obtained during cardiac surgery, and vWF expression as well as interstitial fibrosis was analysed by immunostaining and Masson's trichrome, respectively. We found raised vWF plasma levels in ischaemic vs. valvular patients (200.2 ± 66.3 vs. 157.2 ± 84.3 IU/dL; P = 0.015). Fibrosis degree was associated with plasma vWF levels. Plasma vWF was an independent prognostic marker for AF development in ischaemic patients [odds ratio, OR 6.44 (95% confidence interval, CI 1.40-36.57), P = 0.035]. CONCLUSION: Plasma vWF levels are associated with tissue fibrosis in patients undergoing cardiac surgery and with post-surgical AF development in ischaemic patients. These findings suggest an association among vWF levels, atrial remodelling, and AF development. It is supported by higher vWF expression in right atrial tissue in ischaemic patients, who developed post-surgical AF.

Risk Factors for Postoperative Pacemaker Implantation After Rapid Deployment Aortic Valve Replacement: Results from the RADAR Registry.

INTRODUCTION: Rapid deployment aortic valve replacement has been recently introduced in clinical practice. Different studies have reported a significant reduction in surgical times with excellent hemodynamic profiles and short-term results. However, an increase in permanent pacemaker requirements compared with conventional aortic valve replacement has been described. Nevertheless, risk factors for postoperative pacemaker implantation are not well known. The aim of this study is to report our early outcomes with rapid deployment aortic valve replacement within the RADAR Registry, especially focusing on risk factors for postoperative pacemaker implantation. METHODS: Between April 2012 and January 2016, 164 patients undergoing isolated or combined aortic valve replacement with Edwards INTUITY Elite (Edwards Lifesciences, Irvine, CA, USA) were included in the RADAR Registry. Pre-, intra- and postoperative clinical data results and complications were recorded, especially focusing on risk factors for the development of postoperative complete or high-grade AV block requiring pacemaker implantation. Patients were followed up for up to 1 year with evaluation of clinical and echocardiographic outcomes. RESULTS: A total of 164 consecutive patients were included in this study, where 128 patients (78.05%) had an isolated aortic valve replacement (group 1) and 36 (21.95%) a concomitant procedure (group 2). The surgical approach was ministernotomy in 61 patients (37.20%) and median sternotomy in 100 patients (60.98%). Complications with valve implantation were observed in three patients. Postoperative complete or high-degree AV block requiring a permanent pacemaker implantation developed in ten patients (6.9%). Seven patients died in-hospital (4.27%). No significant differences between groups were found in terms of stroke, postoperative infection, mortality, atrial fibrillation and postoperative atrioventricular block. Seven patients presented acute renal impairment (5.51%) in group 1 versus seven patients (20%) in group 2 (p = 0.007). In multivariate analysis, low weight and preoperative arrhythmia (atrial fibrillation, bifascicular block, left bundle branch block) emerged as risk factors for postoperative AV block requiring a pacer. In median follow-up of 1 year, seven (4.27%) patients died, and no cases of structural valve deterioration or endocarditis were observed. Significant patient-prosthesis mismatch was found in seven (4.27%) patients. CONCLUSION: Initial experience with rapid deployment aortic valve replacement in the RADAR Registry demonstrates low rates of implantation complications and good perioperative and 1-year clinical and echocardiographic outcomes. Incidence of postoperative AV block requiring a pacer correlated with low weight and preoperative arrythmias (atrial fibrillation, bifascicular block and left bundle branch block). Avoidance of oversizing and careful consideration of implantation of this technology in patients with pre-existing arrythmias could minimize the risk for postoperative pacemaker implantation.

Statins and postoperative risk of atrial fibrillation following coronary artery bypass grafting.

Atrial fibrillation (AF) is a common complication after coronary artery bypass grafting. Atrial remodeling has been observed in AF and has been associated with the development of this arrhythmia. Because 3-hydroxy-3-methylglutaryl coenzyme A inhibitors (statins) have been demonstrated to modify remodeling, we hypothesized a protective role of statins against postoperative AF. We also hypothesized that extracellular matrix turnover and brain natriuretic peptide (BNP) might be related to such atrial remodeling. We studied 234 consecutive patients who underwent coronary artery bypass grafting (173 men; 65 +/- 9 years of age) in whom the occurrence of postoperative AF was monitored. In a subgroup of 66 patients, we measured plasma levels of matrix metalloproteinase-1 (MMP-1), its inhibitor, tissue inhibitor matrix metalloproteinase-1 (TIMP-1; as indexes of extracellular matrix remodeling), and N-terminus pro-BNP (related to left ventricular function) at baseline and at 24 hours after surgery. Of 234 patients, 66 (28.2%) developed postoperative AF. In multivariate analysis, previous AF was related to an increase in the development of AF (odds ratio 11.92, 95% confidence interval 2.37 to 59.98, p = 0.026), whereas statin use was related to a decrease in arrhythmia (odds ratio 0.52, 95% confidence interval 0.28 to 0.96, p = 0.038). A higher TIMP-1/MMP-1 ratio at 24 hours after surgery was present in those who did not develop postoperative AF (p = 0.043). Statin use was associated with increased TIMP-1 levels and TIMP-1/MMP-1 ratio (p = 0.027 and 0.036, respectively). No significant relations to N-terminus pro-BNP were seen. In conclusion, previous AF and nonuse of statins are significantly associated with AF after coronary artery bypass grafting. Statin use may be protective against AF after coronary artery bypass grafting, possibly due to alterations in the extracellular matrix and remodeling after coronary artery bypass grafting.

Ellis-van Creveld syndrome in adulthood: extending the clinical spectrum.

Ellis-van Creveld (EvC) syndrome is a rare autosomal recessive malformation disorder. Cardiac defects are observed in about 50% of EvC cases. Surgical data is lacking on the prognosis and life expectancy of EvC patients. Herein, we report the case of a 38-year-old man with EvC syndrome who underwent two surgical corrections for cardiac anomalies. This report supplements the available information on the clinical course of EvC syndrome in older patients.

DXA in the assessment of subchondral bone mineral density in knee osteoarthritis--A semi-standardized protocol after systematic review.

INTRODUCTION: Subchondral bone mineral density (sBMD) contributes to the initiation and progression of knee osteoarthritis (OA). Reliable methods to assess sBMD status may predict the response of specific OA phenotypes to targeted therapies. While dual-energy X-ray absorptiometry (DXA) of the knee can determine sBMD, no consensus exists regarding its methodology. OBJECTIVE: Construct a semi-standardized protocol for knee DXA to measure sBMD in patients with OA of the knee by evaluating the varying methodologies present in existing literature. METHODS: We performed a systematic review of original papers published in PubMed and Web of Science from their inception to July 2014 using the following search terms: subchondral bone, osteoarthritis, and bone mineral density. RESULTS: DXA of the knee can be performed with similar reproducibility values to those proposed by the International Society for Clinical Densitometry for the hip and spine. We identified acquisition view, hip rotation, knee positioning and stabilization, ROI location and definition, and the type of analysis software as important sources of variation. A proposed knee DXA protocol was constructed taking into consideration the results of the review. CONCLUSIONS: DXA of the knee can be reliably performed in patients with knee OA. Nevertheless, we found substantial methodological variation across previous studies. Methodological standardization may provide a foundation from which to establish DXA of the knee as a valid tool for identification of SB changes and as an outcome measure in clinical trials of disease modifying osteoarthritic drugs.

High-sensitivity troponin T as a biomarker for the development of atrial fibrillation after cardiac surgery.

OBJECTIVES: Atrial fibrillation (AF) occurs in ∼ 30% of patients undergoing coronary artery bypass grafting (CABG) and in 40% of patients after valve surgery. High-sensitivity cardiac troponin T (hsTnT) is a specific and high-sensitivity marker of myocardial injury, while N-terminal proB-type natriuretic peptide (NT-proBNP) is an established biomarker for wall remodelling. We investigated whether hsTnT and NT-proBNP levels could be used as valuable biomarkers for AF occurrence after cardiac surgery. METHODS: We included consecutive haemodynamically stable patients undergoing programmed cardiac surgery with cardiopulmonary bypass pump. We determined hsTnT and NT-proBNP levels before and after cardiac surgery and recorded AF development by prolonged electrocardiogram monitoring. RESULTS: We included 100 patients with predominantly aortic valve (n = 42) or ischaemic heart (n = 58) diseases. Twenty-nine patients (29%) developed post-surgical AF. Patients developing AF had a longer hospital stay (P = 0.005). hsTnT levels increased after surgery [P < 0.001], indicating perioperative myocardial injury, with higher presurgery levels in patients who developed AF [P = 0.015]. Body mass index and EuroSCORE risk scale were independently associated with higher hsTnT levels presurgery. On univariate analysis, age (P = 0.048), male sex (P = 0.031), indexed left atrial volume (P = 0.042), ß-blockers treatment (P = 0.024), type of surgery (valve surgery vs CABG; P = 0.034), EuroSCORE risk scale (P = 0.025) and higher preoperative hsTnT levels (P = 0.009) were predictors of AF development, but NT-proBNP did not reach statistical significance (P = 0.060). hsTnT levels in blood samples obtained the day after surgery were not associated with post-surgical AF development (P = 0.165). In a multivariate model, only higher hsTnT levels before cardiac surgery (>11.87 ng/l) [Odds Ratio, OR; (95% Confidence interval, CI) 4.27 (1.43-12.77), P = 0.009] and male sex [OR 5.10 (1.72-15.13), P = 0.003)] were independently associated with the occurrence of post-surgical AF. CONCLUSION: High presurgical hsTnT levels were independently predictive of patients developing AF after cardiac surgery. hsTnT levels determined post-surgery suggest that cardiac perioperative myocardial injury is not associated with postoperative AF development. NT-proBNP did not reach statistical significance as a biomarker for AF prediction.

Radiotherapeutic management of the chyloperitoneum following abdominal aortic aneurysm repair.

Chyloperitoneum is a rare but life-threatening complication with no uniformity concerning the treatment. We present a 77-year-old male with chylous ascites after open abdominal aneurysmectomy refractory to conservative and surgical strategies. After failure of re-exploration with periaortic lymphatic cauterization and drainage, he was treated with five cycles of retroperitoneal radiotherapy. At 12 months of follow-up, the patient remains asymptomatic without any objective evidence of chyloperitoneum relapse. Periaortic radiotherapy may be a feasible alternative in the management of the chylous ascites following abdominal aortic aneurysm surgery.

Intraoperative myocardial rupture heralded by contrast echocardiography.

This case report shows the use of bedside transthoracic contrast echocardiography in the diagnosis of subacute myocardial rupture after acute myocardial infarction and indication of urgent surgery. Usefulness of intraoperative transesophageal echocardiography for detection of sudden complete myocardial rupture leading to pericardial tamponade during anesthetic induction, and prompt lifesaving surgical procedure are also presented.