Valter Casati

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.

Surgical ablation of atrial fibrillation using the epicardial radiofrequency approach: mid-term results and risk analysis

BACKGROUND The minor technical and time requirements with respect to the maze operation combined with a comparable efficacy has led to an increasing popularity of left atrial approaches to treat atrial fibrillation. We report our experience with a left atrial procedure based on extensive use of epicardial radiofrequency ablation in an effort to minimize cardiac arrest time. METHODS A total of 132 consecutive patients with atrial fibrillation (121 chronic, 11 paroxysmal) undergoing open heart surgery had combined intraoperative ablation. An original set of left atrial lesions was performed using a radiofrequency linear catheter. Most of the ablations were performed epicardially before aortic cross-damping. Patients with contraindications to the epicardial approach had the whole lesion set performed endocardially. RESULTS The mean cardiac arrest time spent for open heart ablations was significantly shorter (5.2 +/- 0.9 minutes with modem catheters) when the epicardial approach was used (107 of 132 patients, 81%). Hospital mortality was 0.8%. Freedom from atrial fibrillation was 77% 3 years after the operation. Of all the variables analyzed, only age at surgery and early postoperative arrhythmias increased the risk of recurrent atrial fibrillation. Overall 3-year survival was 94%. The 3-year actuarial freedom from stroke was 98%. No patient required implantation of a permanent pacemaker. Atrial contractility was recovered in all patients with stable sinus rhythm. CONCLUSIONS Left atrial radiofrequency ablation allows recovery of sinus rhythm and atrial function in the great majority of patients with atrial fibrillation who undergo open heart surgery. The epicardial radiofrequency approach is a safe and effective means to cure atrial fibrillation with negligible technical and time requirements.

Activation of coagulation and fibrinolysis during coronary surgery: on-pump versus off-pump techniques.

Background The authors studied the changes in selected hemostatic variables in patients undergoing coronary surgery with on-pump coronary artery bypass grafting (CABG) or off-pump coronary artery bypass surgery (OPCAB) techniques. Methods Platelet counts and plasma concentrations of antithrombin, fibrinogen, D dimer, &agr;2 antiplasmin, and plasminogen were measured preoperatively, 5 min after administration of heparin, 10 min after arrival in the intensive care unit, and 24 h after surgery in patients scheduled to undergo OPCAB (n = 15) or CABG (n = 15). To correct for dilution, hemostatic variables and platelet counts were adjusted for the changes in immunoglobulin G plasma concentrations and hematocrit, respectively. Results Adjusting for dilution, antithrombin and fibrinogen concentrations decreased to a similar extent in patients undergoing OPCAB or CABG (pooled means and 95% confidence limits of the mean: 95.5% of baseline, 93–98%, P = 0.002, and 91.7% of baseline, 88–95%, P = 0.0001), respectively, whereas &agr;2-antiplasmin concentrations were unchanged. Only CABG was associated with a reduction in platelet counts (76% of baseline, 66–85%, P = 0.0001), plasminogen concentrations (96% of baseline, 91–99%, P = 0.011), and increased D-dimer formation (476%, 309–741%, P = 0.004). Twenty-four hours after surgery, platelet counts were still lower in patients undergoing CABG (P = 0.049), but all the investigated variables adjusted for dilution were similar in the two groups. Conclusions Coronary surgery causes a net consumption of antithrombin and fibrinogen. A transient decrease in platelet counts, with plasminogen activation and increased D-dimer formation, however, is only observed with CABG. Twenty-four hours after surgery, the hemostatic profiles of patients in both groups are similar.

Hemostatic effects of aprotinin, tranexamic acid and ϵ-aminocaproic acid in primary cardiac surgery

Abstract Background . The effects of ϵ-aminocaproic acid (EACA) and tranexamic acid (TA) on bleeding and allogeneic transfusions, and the cost of pharmacological and transfusional treatment were compared to aprotinin (AP). Methods . We randomized 210 patients subjected to elective cardiac surgery. Of these, 68 patients received EACA (a bolus of 5 g, an infusion of 2 g/h, and 2.5 g in the priming), 72 patients received TA (a bolus of 1 g, an infusion of 400 mg/h, and 500 mg in the priming), and 70 patients received AP (a bolus of 280 mg, an infusion of 70 mg/h, and 280 mg in the priming). Postoperative blood loss and homologous transfusions were collected and the cost of pharmacological treatment and homologous transfusions were calculated. Results . Bleeding but not allogeneic transfusions was significantly higher in the EACA group (467 ± 234 versus TA, 311 ± 231 versus AP, 283 ± 233; p p Conclusions . Compared to AP, TA has the same effects on bleeding and transfusions, but with a significant reduction of costs. Patients treated with EACA showed a significantly higher postoperative bleeding with an increased trend of transfusion requirement.

Heparin-coated circuits for high-risk patients: a multicenter, prospective, randomized trial

BACKGROUND Heparin-coated circuits (HCCs) in low-risk cardiac patients who have coronary revascularization have a limited impact on postoperative outcome. In this prospective, randomized investigation, we studied high-risk patients who had cardiac operations with or without HCCs. METHODS A total of 886 patients who had cardiac operations with cardiopulmonary bypass and at least one patient-related or procedure-related risk factor were enrolled in a multicenter study. They were randomly allocated to have cardiopulmonary bypass with Duraflo II HCCs (HCC group, n = 442) or conventional circuits (control group, n = 444). Postoperative outcome was investigated with respect to the occurrence of organ dysfunction. RESULTS HCCs are associated with a shorter intensive care unit and postoperative hospital stay and with a lower rate of patients having a severely impaired clinical outcome (stay in intensive care unit for more than 5 days or death) (relative risk 0.66, p = 0.045). Lung dysfunction rate was significantly lower for the patients in HCC group affected by chronic obstructive pulmonary disease or who had mitral procedure (relative risk, respectively, 0.31, p = 0.018 and 0.05, p = 0.02). Renal dysfunction rate was significantly (p = 0.05) lower for diabetics in the HCC group (relative risk 0.28). CONCLUSIONS When HCCs were used postoperative times decreased and they had a protective effect on lung and kidney function in high-risk patients.

TRANEXAMIC ACID IN OFF-PUMP CORONARY SURGERY: A PRELIMINARY, RANDOMIZED, DOUBLE BLIND, PLACEBO-CONTROLLED STUDY

BACKGROUND We evaluated the hemostatic effects of tranexamic acid, a synthetic antifibrinolytic drug, in patients undergoing beating-heart coronary surgery. METHODS Forty consecutive patients were in a double-blind manner, prospectively randomized into two groups: 20 patients received tranexamic acid (bolus of 1 g before skin incision, followed by continuous infusion of 400 mg/hr during surgery), and 20 patients received saline. As primary outcomes, bleeding and allogeneic transfusions were considered. D-dimer and fibrinogen plasma levels were also evaluated to monitor the activation of fibrinolysis. Major postoperative thrombotic events, as a potential consequence of antifibrinolytic treatment, were recorded. RESULTS The treatment group had significantly lower postoperative bleeding (median [25th to 75th percentiles]: 400 mL [337 to 490 mL] vs 650 ml [550 to 862 mL], p < 0.0001), lower need for allogeneic blood products (1,200 vs 5,300 mL, p < 0.001), and lower postoperative D-dimer plasma levels. No postoperative thrombotic complications were observed in either group. CONCLUSIONS In this initial series of patients undergoing off-pump coronary surgery, tranexamic acid appears to be effective in reducing postoperative bleeding and the need for allogeneic blood products.

Tranexamic acid administration after cardiac surgery: a prospective, randomized, double-blind, placebo-controlled study.

BackgroundMany different doses and administration schemes have been proposed for the use of the antifibrinolytic drug tranexamic acid during cardiac surgery. This study evaluated the effects of the treatment using tranexamic acid during the intraoperative period only and compared the results with the effects of the treatment continued into the postoperative period. MethodsPatients undergoing elective cardiac surgery with use of cardiopulmonary bypass (N = 510) were treated intraoperatively with tranexamic acid and then were randomized in a double-blind fashion to one of three postoperative treatment groups: group A: 169 patients, infusion of saline for 12 h; group B: 171 patients, infusion of tranexamic acid, 1 mg · kg-1 · h-1 for 12 h; group C: 170 patients, infusion of tranexamic acid, 2 mg · kg-1 · h-1 for 12 h. Bleeding was considered to be a primary outcome variable. Hematologic data, allogeneic transfusions, thrombotic complications, intubation time, and intensive care unit and hospital stay duration also were evaluated. ResultsNo differences were found among groups regarding postoperative bleeding and outcomes; however, the group treated with 1 mg·kg-1·h-1 tranexamic acid required more units of packed red blood cells because of a significantly lower basal value of hematocrit, as shown by multivariate analysis. ConclusionsProlongation of treatment with tranexamic acid after cardiac surgery is not advantageous with respect to intraoperative administration alone in reducing bleeding and number of allogeneic transfusions. Although the prevalence of postoperative complications was similar among groups, there is an increased risk of procoagulant response because of antifibrinolytic treatment. Therefore, the use of tranexamic acid during the postoperative period should be limited to patients with excessive bleeding as a result of primary fibrinolysis.

Intraoperative Low-volume Acute Normovolemic Hemodilution in Adult Open-heart Surgery

Background Recently, various studies have questioned the efficacy of intraoperative acute normovolemic hemodilution (ANH) in reducing bleeding and the need for allogeneic transfusions in cardiac surgery. The aim of the present study was to reevaluate the effects of a low-volume ANH in elective, adult open-heart surgery. Methods Two hundred four consecutive adult patients undergoing cardiac surgery were prospectively randomized in a nonblinded manner into two groups: ANH group (103 patients), where 5–8 ml/kg of blood was withdrawn before systemic heparinization and replaced with colloid solutions, and a control group, where no hemodilution was performed (101 patients). Procedures included single and multiple valve surgery, aortic root surgery, coronary surgery combined with valve surgery, or partial left ventriculectomy. The purpose of the study was to evaluate the efficacy of ANH in reducing the need for allogeneic blood components. Routine hematochemical evaluations, perioperative blood loss, major complications, and outcomes were also recorded. Results No differences were found between the groups regarding demographics, baseline hematochemical data, and operative characteristics. There was no difference in the amount of transfusions of packed red cells, fresh frozen plasma, platelet concentrates, total number of patients transfused (control group, 36%vs. ANH group, 34.3%;P = 0.88), and amount of postoperative bleeding (control group, 412 ml [313–552 ml]vs. ANH group, 374 ml [255–704 ml]) (median [25th–75th percentiles]);P = 0.94. Further, perioperative complications, postoperative hematochemical data, and outcomes were not different. Conclusions In patients undergoing elective open-heart surgery, low-volume ANH showed lack of efficacy in reducing the need for allogeneic transfusions and postoperative bleeding.

Unexpected Diagnosis and Management of a Type A Interrupted Aortic Arch in an Adult Male Scheduled for Mitral Valve Surgery

r s e ORTIC ARCH INTERRUPTION is a rare congenital malformation frequently associated with other intracardiac efects, such as bicuspid aortic valve and ventricular septal efect.1 The widely accepted classification is that proposed by eloria and Patton2 based on the site of aortic arch interruption s follows: type A, discontinuity distal to the left subclavian rtery, which involves about 43% of the patients; type B, etween the left carotid and left subclavian arteries, which is he most common with about 53% of cases; and type C (the ost rare), between the innominate and left carotid arteries, hich occurs in 4% of the cases. If not surgically treated, 5% of the patients die within the first month of life and 90% ithin the first year.3,4 The development of a collateral aortic irculation during gestation is the cause of perinatal survival nd the diagnosis in adulthood.1 The worldwide literature reports 20 cases of interrupted ortic arch surgically treated in adults, testifying to the rarity of his condition.5 The first case of interrupted aortic arch incientally diagnosed in a patient scheduled for mitral valve urgery is described.

Safety of aprotinin (again)

www.thelancet.com Vol 372 July 5, 2008 27 identifi ed as a signifi cant risk factor (p<0·001) and was included in the model used to calculate the baseline renal risk score. Third, the need for an IABP postoperatively was considered, alongside the propensity score and other covariates for inclusion in the propensity-adjusted renal risk models (top panel table 2). Postoperative IABP was identifi ed as a signifi cant risk factor for renal dysfunction in fi ve of the eight subgroup analyses; all four models comparing tranexamic acid and control and the analysis comparing aprotinin and control in off -pump patients not given ACE inhibitors. The need for an IABP postoperatively was not included in the base line risk treatment eff ect models (bottom panel table 2). These analyses were adjusted for renal risk score and numbers of units of red cells only. We are unable to respond to the concerns of Sebastian Schneeweiss and colleagues at this time. We will provide a response at a later date.