Atrial fibrillation after isolated coronary surgery. Incidence, long term effects and relation with operative technique.

INTRODUCTION: Postoperative atrial fibrillation after isolated coronary revascularization has been associated with increased morbidity and mortality. Aim of present investigation was to evaluate incidence of postoperative atrial fibrillation and its prognostic role in patients undergoing isolated coronary artery by-pass and disclose possible differences between off-pump and cardiopulmonary assisted revascularization. METHODS: Prospective cohort study of 229 patients undergoing isolated coronary artery by-pass at a tertiary heart surgery Centre. Off-pump treated patients were significantly older (70.5 vs 64.9 years, p<0.001). No other baseline differences were found. Patients who developed postoperative atrial fibrillation were followed up for an average period of 2 years. RESULTS: Post-operative occurred in 56/229 (24.1% after cardiopulmonary and 24.6% after off-pump coronary artery by-pass). Left atrium diameter was the only independent predictive factor (odds ratio =1.15, 95% confidence interval 1.02-1.30, p<0.001). All patients with postoperative atrial fibrillation were treated and discharged in sinus rhythm, in 6/56 recurred, only in one persisted. One patient died during follow up. No stroke was recorded. CONCLUSIONS: After isolated surgical revascularization, atrial fibrillation occurred in 24% without differences related to operative technique. Recurrence of atrial fibrillation occurred in 6/56 patients (10.7%) however only in 1 persisted. Early and late mortality did not show relation with post-operative atrial fibrillation probably due to immediate treatment with recovery of sinus rhythm before discharge.

Surgical RF ablation of atrial fibrillation in patients undergoing mitral valve repair for Barlow disease.

OBJECTIVES: At present, limited experience exists on the treatment of atrial fibrillation (AF) in patients undergoing mitral valve repair (MVR) for Barlow disease. The aim of this investigation was to prospectively evaluate the radiofrequency ablation of AF in patients undergoing MVR for severe regurgitation due to Barlow disease. METHODS: From January 1, 2007 to December 31, 2010, out of 85 consecutive patients with Barlow disease, 27 with AF underwent RF ablation associated with MVR. They were examined every 4 months in the first year after surgery and thereafter twice yearly. RESULTS: At follow-up, AF was observed in 4/25 (16.0%). NYHA (New York Heart Association) functional class improved significantly, with no patients in class III or IV (before surgery, 81.5% had been). Otherwise, among 58 patients in sinus rhythm, 6 (11%) developed AF during follow-up. No clinical or echocardiographic predictive factor was found in this subgroup. CONCLUSIONS: Results from our investigation suggest that radiofrequency ablation of AF in patients with Barlow disease undergoing MVR for severe regurgitation is effective and should be considered in every patient with Barlow disease and AF undergoing valve surgical repair.

The double-orifice technique in mitral valve repair: a simple solution for complex problems.

OBJECTIVE: The aim of this study is to report our results with the central double-orifice technique used for the treatment of complex mitral valve lesions. METHODS: The central double-orifice repair has been used in 260 patients (mean age, 56 +/- 14.3 years) over a period of 7 years. The mechanism responsible for mitral regurgitation was prolapse of both leaflets in 148 patients, prolapse of the anterior leaflet in 68, prolapse of the posterior leaflet with annular calcification or other unfavorable features in 31, and lack of leaflet coaptation for restricted motion or erosion of the free edge in 13. Degenerative disease was the cause of mitral regurgitation in 80.8% of the patients, rheumatic disease was the cause in 9.6%, endocarditis was the cause in 6.1%, and ischemic disease was the cause in 2.3%. RESULTS: Hospital mortality was 0.7%, and the overall survival at 5 years was 94.4% +/- 2.59%. Thirteen patients required a reoperation (2 early postoperatively and 11 late during the follow-up), for an overall freedom from reoperation of 90.0% +/- 3.37% at 5 years. Freedom from reoperation was lower in patients with rheumatic valve disease and in patients who did not undergo an annuloplasty procedure. CONCLUSIONS: The effectiveness and durability of the central double-orifice technique were assessed in this study. This type of repair can be a useful addition to the surgical armamentarium in mitral valve reconstruction.

[Asymptomatic severe aortic stenosis: always surgical treatment? The opinion of the surgeon]. / Stenosi aortica severa asintomatica: intervento chirurgico sempre? Il parere del chirurgo.

Prophylactic valve replacement in asymptomatic patients with severe aortic stenosis is controversial. Most authors consider that patients could be managed without surgery until symptoms develop. The incidence of sudden death in patients without symptoms is low, < 1%/year and valve replacement is complicated by an operative mortality up to 5 and 1-2% of incidence of valve-related major events. Early surgical approach is suggested by several observations. The first one is the unpredictable risk of myocardial fibrosis after long standing left ventricular hypertrophy and pressure overload, with associated systolic and diastolic dysfunction. Left ventricular impairment can persist after valve replacement influencing exercise capacity and survival in selected patients. On the other hand, major improvement in myocardial protection techniques, intraoperative monitoring with transesophageal echocardiography, prosthetic design (stentless, supra-annular), all have reduced in-hospital mortality and morbidity. More precise recommendations can be made according to an improved characterization of the patients from fast to slow evolution, according to age, type of aortic stenosis, degree of calcification, changes in transaortic gradients over time, tolerance to exercise test and response of aortic valve area to dobutamine. In patients with high risk of progression (severely calcified valve, Doppler velocity > 4 m/s, rapidly increasing with time), indirect evidence of myocardial fibrosis (excessive left ventricular hypertrophy, systolic or diastolic dysfunction), and need of myocardial revascularization, an early surgical approach should be considered.

A simple way to treat chronic atrial fibrillation during mitral valve surgery: the epicardial radiofrequency approach.

OBJECTIVE: We describe an original radiofrequency ablation technique to treat chronic atrial fibrillation in patients undergoing mitral valve surgery. Most of the procedure is carried out epicardially, in order to avoid an undue increase of surgical time and trauma. METHODS: The ablations are performed using a temperature-controlled multipolar radiofrequency catheter. Two encircling lesions around the ostia of the right and of the left pulmonary veins are carried out epicardially, usually before cardiopulmonary bypass. Through a conventional left atriotomy the ablation procedure is completed with two endocardial lesions connecting the two encirclings between them and to the mitral valve annulus. After the mitral valve procedure is performed, the left appendage is sutured. RESULTS: From February 1998 to May 1999, 40 patients with chronic atrial fibrillation (43. 1+/-51.9 months) underwent combined radiofrequency ablation and mitral valve surgery. Mean left atrial diameter was 56.8+/-10.7 mm. Mean cardiopulmonary bypass and aortic cross-clamp time were, respectively, 119.1+/-26.3 and 76.7+/-21.0 min. Mean postoperative blood loss was 287.2+/-186.6 ml. No reexploration for bleeding occurred. One patient died of pneumonia 12 days after operation. No patient needed permanent pacemaker implantation. Mean postoperative hospital stay was 7.3+/-5.6 days. At follow-up (mean 11.6+/-4.7 months), 30/39 (76.9%) of the patients were in stable sinus rhythm. All patients in sinus rhythm 3 months after operation recovered both left and right atrial contractility at echocardiographic control (mean 7.3+/-3.4 months). The left atrial diameter decreased significantly in patients recovering sinus rhythm. CONCLUSIONS: Epicardial radiofrequency ablation is a safe means to achieve surgical ablation of atrial fibrillation with a high success rate. The simplicity of the technique and the low procedure-related risk should dictate combined treatment virtually in all patients with atrial fibrillation undergoing open heart operations.

The edge-to-edge technique: a simplified method to correct mitral insufficiency.

OBJECTIVE: Repair of mitral regurgitation (MR) is more demanding in case of prolapse of the anterior leaflet, posterior leaflet with calcified annulus, or prolapse of both leaflets. We evaluated a repair which consists of anchoring the free edge of the prolapsing leaflet to the corresponding free edge of the facing leaflet: the 'edge-to-edge' (E-to-E) technique. The correction results in a double orifice valve when the prolapse is in the middle portion of the leaflet and in a smaller valve orifice when the prolapse is close to a commissure. METHODS: Out of 432 patients with MR submitted to valve repair between January 1991 and September 1997, 121 (mean age 56 +/- 15.8 years) underwent E-to-E correction. The most prevalent etiology was degenerative disease (82 patients, 68%). The mechanism of MR was anterior leaflet prolapse (61 patients), posterior leaflet prolapse (24 patients), prolapse of both leaflets (28 patients) and other complex mechanisms (8 patients). In 72 patients, a double orifice was created, the paracommissural repair was done in 49 patients. RESULTS: Hospital mortality was 1.6%. Overall survival was 92 +/- 3.1% at 6 years with 95 +/- 4.8% freedom from reoperation. Mortality was unrelated to the type of repair. Mitral stenosis was never observed after the correction. At the follow-up (mean 2.2 +/- 1.5 years), all patients but 15 are class I or II. Symptoms at the follow-up are not related to residual MR. CONCLUSIONS: Midterm results of this alternative repair technique are promising, considering the high prevalence of complex anatomical lesions. The technique is simple, easily reproducible and rapidly feasible also when mitral exposure is suboptimal.

Myocardial protection with and without leukocyte depletion: a comparative study on the oxidative stress.

We tested the hypothesis that controlled reperfusion with leukocyte-depleted blood could improve myocardial protection by reducing the oxidative stress in patients undergoing myocardial revascularization. Thirty-four patients receiving antegrade/retrograde blood cardioplegia were divided into: group A: 11 patients with ejection fractions (EF) less than 35%, treated with leukocyte-depleted controlled blood reperfusion, group B: 11 patients with EF less than 35% in whom no leukocyte depletion was performed, group C: 6 patients with EF more than 45% treated as group A and group D: 6 patients with EF more than 45% without leukocyte depletion. To asses the oxidative stress, we evaluated total, total oxidized (GSSX), and reduced glutathione (GSH) in coronary sinus plasma, immediately before cross-clamping the aorta (T0), and at 0 (T1), 15 (T2) and 30 (T3) min after unclamping it. In groups A and B a significant shift towards oxidation of redox status of glutathione (GSH/GSSX) at T1 vs T0 was observed. Glutathione redox ratio remained low in group B while in group A it returned to the basal value at T2 with a significant difference from group B at T2 and T3. No differences were observed between groups C and D. In conclusion, our data show that leukocyte-depleted reperfusion can afford a better myocardial protection in patients with left ventricular dysfunction, while it seems unnecessary in patients with normal EF.

[Autoantibodies against oxidised low density lipoproteins in patients with coronary disease]. / Autoanticorps contre les lipoprotéines de basse densité oxydées chez des patients coronariens.

OBJECTIVES: Evidence has been obtained indicating that oxidation of low-density lipoproteins (LDL) plays a relevant role in the pathogenesis of atherosclerosis and it has been proposed that, due to the antigenic properties of oxidized LDL, the anti-oxLDL antibody titre could represent a useful index of in vivo LDL oxidation. METHODS: Sixty-nine control subjects and 64 patients scheduled for selective coronary revascularization were investigated before surgery. RESULTS: The coronary disease patients had a higher level of total plasma cholesterol, LDL cholesterol and triglycerides, and a lower level of HDL cholesterol. Plasma anti-oxLDL antibody titre was measured as the ratio of antibody binding to CuSO4-oxidised LDL versus native LDL. The antibody ratio was higher in coronary patients as compared with control subjects (1.56 +/- 0.5 vs 1.0 +/- 0.3, p < 0.01). A ratio higher than 1.34 (mean of controls +/- one standard deviation) was present in 60% of the coronary patients. Subclass analysis indicated that the presence of diabetes mellitus and hypercholesterolaemia (but not of hypertension, generalized arteriosclerosis, myocardial infarction and cigarette smoking) increased the anti-oxLDL antibody ratio to 1.72 +/- 0.4 and 1.68 +/- 0.3 respectively. CONCLUSION: The results obtained indicate that a) a high titre of anti-oxLDL antibodies is present in plasma of patients with coronary atherosclerosis, b) in these patients LDL oxidation takes place in vivo and probably plays a critical role in the development and progression of atherosclerosis.

Myocardial revascularization with bilateral internal thoracic artery in patients with left main disease: an incremental risk?

Although the long-term patency of the internal thoracic artery (ITA) has been well proved, there is still some concern about its preoperative performance. We considered 80 patients with left main disease (mean age 60.2 years) who underwent coronary artery bypass grafting in our institute from March 1988 to September 1992. Patients with left main disease were divided into 2 groups: group I-38 patients receiving only ITA grafts on the left coronary system and group II-42 patients having a single ITA graft together with saphenous vein grafts on the left coronary system. No patients in group I received a saphenous graft on the left coronary system and three patients with right coronary artery involvement received total arterial myocardial revascularization with the use of the inferior epigastric artery. Perioperative complications in group I and group II patients were, respectively: myocardial necrosis in 2 (6.9%) and 3 (8.8%), use of intraaortic balloon pump in 2 (6.9%) and 2 (5.9%). No death occurred in either group. In our experience, the use of bilateral ITA grafts in patients with left main stenosis was not related to an incremental risk. We conclude that left main disease should not be considered as counterindication to the extensive use of arterial conduits.

Specificity of autoantibodies against oxidized LDL as an additional marker for atherosclerotic risk.

BACKGROUND: LDL oxidation is a crucial step in the development and progression of atherosclerotic lesions. The detection of an increase in the anti-oxidized LDL antibody titre may thus represent a biological marker of enhanced LDL oxidation in vivo. METHODS: The occurrence of anti-oxidized LDL autoantibodies was investigated in control patients, in patients with atherosclerotic coronary artery disease, in those without clinically relevant signs of atherosclerosis, but considered at risk, and in patients with chronic alcohol-related liver disease. RESULTS: Anti-oxidized LDL autoantibodies were present in the plasma of the majority of patients with overt coronary atherosclerosis. An increased antibody titre can also be detected well before the onset of clinically relevant signs of the atherosclerotic disease in patients classically considered at risk, indicating the occurrence of in-vivo LDL oxidation during atherosclerosis development. The specificity of molecular targets (LDL) for oxidative modifications is supported by the demonstration that anti-oxidized LDL autoantibodies are absent in the plasma of alcoholic patients who exhibit a marked increase in biological markers of oxidative stress but do not classically develop atherosclerosis. CONCLUSION: These data demonstrate that the occurrence of anti-oxidized LDL autoantibodies could be specifically related to the promotion and progression of atherosclerosis and is not a simple epiphenomenon of any oxidative process occurring in vivo.

Mitral valve prosthetic endocarditis: development of left ventricular-coronary sinus fistula following replacement.

We report the history and course of a patient in whom a left ventricular-coronary sinus fistula developed following mitral valve replacement due to prosthetic endocarditis. Six months after the intervention the patient suddenly presented with deterioration of her symptoms, holosystolic murmur and signs of congestive heart failure. Transesophageal echocardiography showed a left-to-right shunt but did not show its exact location. At surgery, exploration of the right atrium revealed a left ventricular-coronary sinus communication due to discontinuation of the left ventricular free wall next to the coronary sinus; repair of the defect was successfully performed by direct suture. The postoperative course was uneventful and the patient recovered quickly. This case is reported to stress that debridement of the mitral annulus and removal of an old prosthesis must be very carefully performed and to facilitate the diagnosis of this rare but severe complication of repeated mitral valve replacement.

[Ultrastructural changes in the saphenous vein removed during aorto-coronary bypass]. / Modifications ultrastructurales de la veine saphène prélevée en cours d'intervention de pontage aorto-coronarien.

In order to observe ultrastructural changes of the saphenous vein before implantation during coronary artery by-pass surgery, 58 fragments from a series of 29 consecutive patients, were studied by means of scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Two fragments were taken: the first just before the distal anastomosis; the second just before the last anastomosis on the aorta. The vein graft was kept in a finger solution of 10% nitroglycerin. Forced dilatation was avoided. The EM showed areas of early loss of the endothelial layer, not time-related, deposits of fibrin and blood corpuscular elements with muscular contraction in 75% of the examined grafts. From our experience and according to the literature, loss of the endothelial layer, spasm and early platelet and fibrin aggregation, are constant features of the explanted saphenous vein. In clinical practice, we emphasize, in addition to the "no touch technique", the early use of antiplatelet drugs during coronary artery by-pass coronary surgery.