Morteza Tavakkoli Hosseini

Protective effect of epicardial adiponectin on atrial fibrillation following cardiac surgery

OBJECTIVE Inflammation has been implicated in the pathogenesis of postoperative atrial fibrillation (AF). Adipose tissue secretes both pro-inflammatory cytokines such as interleukin-6 (IL-6) and anti-inflammatory mediators such as adiponectin. We set out to examine the association of adiponectin and IL-6, both circulating and locally produced by the epicardial adipose tissue, with AF development after cardiac surgery. METHODS A total of 90 consecutive patients undergoing cardiac surgery were evaluated. Blood samples were collected before induction of anaesthesia. Epicardial fat was obtained upon commencement of cardiopulmonary bypass. IL-6 and adiponectin levels were determined in serum and supernatant of epicardial adipose tissue organ cultures with two-site enzyme-linked immunosorbent assay (ELISA). Heart rhythm was assessed with continuous tele-monitoring for 72 h postoperatively, and with 6-hourly clinical examinations and daily electrocardiograms (ECGs) thereafter. RESULTS A total of 36 patients developed postoperative AF (40%). Baseline-serum IL-6 and adiponectin were not associated with AF (p = 0.86 and 0.95, respectively). Epicardial adipose tissue IL-6 levels did not correlate with the development of the arrhythmia either (p = 0.37). However, epicardial adiponectin release was lower in patients who developed AF than in those who remained in sinus rhythm (76 (interquartile range (IQR) 35-98) vs 53 ((IQR) 35-69) ng h(-1)g(-1) of tissue cultured, p = 0.066). Following linear regression, the association of epicardial adiponectin with AF almost reached statistical significance (p = 0.066). Multivariate logistic regression analysis of identified risk factors for AF, with the inclusion of epicardial adiponectin as an independent variable, revealed increased age (odds ratio (OR) 1.09, 95% confidence interval (CI) 1.02-1.17, p = 0.013) and epicardial adiponectin levels (OR 0.98, 95% CI 0.97-1.00, p = 0.054) as independent predictors of postoperative AF. CONCLUSIONS Increased epicardial adiponectin is associated with maintenance of sinus rhythm following cardiac surgery. This reinforces the inflammatory hypothesis in the pathogenesis of postoperative AF and may represent a novel therapeutic target for its effective prevention.

Preoperative high-dose atorvastatin for prevention of atrial fibrillation after cardiac surgery: A randomized controlled trial

OBJECTIVE The preventative effect of statins on postoperative atrial fibrillation has been hypothesized. However, all studies to date have examined patients who did not receive statins before their further allocation to treatment or no treatment. Because guidelines recommend the routine use of statins in patients with coronary artery disease, we set out to examine the effect of intensive statin pretreatment versus continuation of usual statin dose on atrial fibrillation after cardiac surgery. METHODS Patients receiving routine statin treatment and undergoing coronary artery bypass surgery or aortic valve replacement with no history of atrial fibrillation or antiarrhythmic medication were randomized to receive atorvastatin 80 mg or atorvastatin 10 mg for 7 days before surgery in a single-blind fashion. The primary end point was the development of postoperative atrial fibrillation during hospital stay. RESULTS A total of 104 consecutive patients were included. Postoperative atrial fibrillation occurred in 33 patients (32.4%). No significant differences were found in demographics, medical history, or intraoperative variables between treatment groups, with the exception of higher rate of β-blocker use in the atorvastatin 10 mg group (75% vs 53%, P = .002) and previous myocardial infarction (62% vs 42%, P = .049). The incidence of postoperative atrial fibrillation was lower in the atorvastatin 80 mg group when compared with the atorvastatin 10 mg group, but this difference did not reach statistical significance (29% vs 36%, P = .43). CONCLUSIONS High-dose atorvastatin for 7 days before cardiac surgery conferred a nonsignificant reduction in postoperative atrial fibrillation when compared with a low-dose regimen. A larger study would be necessary to confirm the beneficial effect of high-dose statins in this setting.

Substrate Modifications Precede the Development of Atrial Fibrillation After Cardiac Surgery: A Proteomic Study

BACKGROUND Atrial fibrillation (AF) is an important cause of morbidity and mortality after cardiac surgery. The pathogenesis of AF appears to be multifactorial but little is known about the cause-effect relationship of substrate modifications with the onset of the arrhythmia. With the use of modern proteomics, this study aims to identify preexisting changes in the left atrium of patients susceptible to postoperative AF. METHODS We analyzed 20 matched patients undergoing elective, first-time coronary artery bypass grafting with no history of AF. They were divided into 2 equal groups according to the development of postoperative AF. Proteomic analysis was performed in left atrial tissue obtained during surgery using two-dimensional difference in gel electrophoresis techniques. Mass spectrometry identified proteins that were differentially expressed in patients who developed AF against those who remained in sinus rhythm. RESULTS Proteomic analysis of left atrial tissue identified 19 differentially expressed protein spots between patients who developed postoperative AF and their sinus rhythm counterparts. In patients who developed AF, proteins associated with oxidative stress and apoptosis (peroxiredoxin 1, apoptosis-inducing factor, and 96S protease regulatory subunit 8) as well as acute phase response components (apolipoprotein A-I, fibrinogen) were found to be increased. Conversely, the expression of proteins responsible for glycolysis (enolase) and pyruvate metabolism (pyruvate dehydrogenase) was reduced. CONCLUSIONS We describe protein changes that precede the development of postoperative AF and which might be suggestive of increased oxidative stress and glycolytic inhibition in the left atrium of patients predilected to AF.

Transaortic Mitral Valve Repair in Double Valve Infective Endocarditis

Abstract  We present a case of a transaortic mitral valve repair in double valve infective endocarditis. Through a conventional oblique aortotomy, the aneurysmal part of the anterior leaflet of the mitral valve was excised, an artificial neo chorda was implanted, and the aortic valve was replaced. (J Card Surg 2010;25:651‐653)

Short-term outcome following cardiac surgery – a comparison between consultant and trainees' performance

Comparison of the outcome of cardiac operations performed by surgical trainees with those performed by consultant surgeons has been an interesting topic in recent years. We set out to examine the outcome of a high volume-training firm. Cardiac operations performed by surgical trainees and a consultant between January 2006 and March 2009 were studied. Hospital mortality and morbidity were compared in the two groups. Eight hundred and seventy-two operations were performed, 687 (79%) were operated by consultant and 185 (21%) by surgical trainees. Mean logistic EuroSCORE in consultant and surgical trainees groups was 3.7 and 2.7, respectively (P<0.001). One hundred and forty-two (77%) of the cases performed by trainees were coronary artery bypass grafting (CABG). Interestingly, the ratio of urgent cases was higher in the trainees group [156 (23%) compared to 59 (32%), P=0.004]. Mortality in consultant and surgical trainees groups for all operations was 18 (2.6%) and six (3.2%), respectively (P=NS). Mortality for CABG in consultant and surgical trainees groups was six (1.7%) and six (4.2%), respectively (P=NS). There was no significant difference in morbidity outcome measures comparing the two groups. The non-significant higher overall mortality in operations performed by trainees in a fully supervised setting, may reflect the influence of experience and confidence, which are difficult to measure.

Hemodynamic effects of peri-operative statin therapy in on-pump cardiac surgery patients

BackgroundPeri-operative statin therapy in cardiac surgery cases is reported to reduce the rate of mortality, stroke, postoperative atrial fibrillation, and systemic inflammation. Systemic inflammation could affect the hemodynamic parameters and stability. We set out to study the effect of statin therapy on perioperative hemodynamic parameters and its clinical outcome.MethodsIn a single center study from 2006 to 2007, peri-operative hemodynamic parameters of 478 patients, who underwent cardiac surgery with cardiopulmonary bypass, were measured. Patients were divided into those who received perioperative statin therapy (n = 276; statin group) and those who did not receive statin therapy (n = 202; no-statin group). The two groups were compared together using Kolmogorov-Smirnov-Test, Fisher’s-Exact-Test, and Student’s-T-test. A p value < 0.05 was considered as significant.ResultsThere was no significant difference in the preoperative risk factors. Onset of postoperative atrial fibrillation was not affected by statin therapy. Extended hemodynamic measurements revealed no significant difference between the two groups, apart from Systemic Vascular Resistance Index (SVRI) . The no-statin group had a significantly higher SVRI (882 ± 206 vs. 1050 ± 501 dyn s/cm5/m2, p = 0.022). Inotropic support was the same in both groups and no significant difference in the mortality rate was noticed. Also, hemodynamic parameters were not affected by different types and doses of statins.ConclusionsPerioperative statin therapy for patients undergoing on-pump coronary bypass grafting or valvular surgery, does not affect the hemodynamic parameters and its clinical outcome.

Left ventricular assist device thrombosis due to clopidogrel resistance

A 53-year-old man presented with acute ST-elevation myocardial infarction and cardiogenic shock, due to proximal left main stem artery occlusion. Recovery was complicated by end-stage ischemic heart failure, and he was referred for left ventricular assist device (LVAD) implantation 2 months after his original presentation. A HeartMate II LVAD was implanted via a median sternotomy with cardiopulmonary bypass. He had an uneventful postoperative recovery and was started on clopidogrel and heparin infusion. Antithrombin 3 levels were in the normal range, and the activated partial thromboplastin time was 60–100 sec at all times. On postoperative day 9, he developed sudden severe hemodynamic compromise, and the LVAD stopped working. An emergency re-sternotomy showed that the LVAD was completely blocked by blood clots in the inflow and outflow cannulae (Figure 1). The LVAD was explanted and replaced with a CentriMag Levitronix system as a salvage operation. After 6 weeks, the CentriMag Levitronix system was replaced with a new HeartMate II LVAD, and the patient was started on heparin and aspirin. Later, heparin was changed to warfarin. The LVAD revealed diffuse thrombosis with no evidence of mechanical failure. Screening of the patient for clotting disorders and platelet dysfunction was remarkable for clopidogrel resistance.

Surgical implantation of a biventricular pacing system via lower half mini sternotomy.

We present a case of surgical implantation of biventricular epicardial pacing leads and a defibrillating patch via lower half mini sternotomy. Although median sternotomy is routinely used for this purpose, lower half mini sternotomy could provide the surgeon with the same surgical field exposure and a faster post operative recovery.

Giant saphenous vein bypass graft aneurysm.

(J Card Surg 2011;26:299‐299)

Aberrant Left Coronary Artery, Modified Unroofing Technique, and Patch Angioplasty

Abstract  Background: We present a case of surgical correction of an aberrant left coronary artery arising from the right sinus of Valsalva. Method: In order to prevent stenosis and kinking of the neo‐ostium, modified unroofing technique was combined with patch angioplasty. Results: The clinical outcome was excellent with complete preservation of ventricular function, resolution of angina, and absence of aortic regurgitation. Conclusion: Addition of patch angioplasty to the unroofing technique improves outcome. (J Card Surg 2010;25:508‐510)