Michele Oppizzi

The double-orifice technique as a standardized approach to treat mitral regurgitation due to severe myxomatous disease: surgical technique

OBJECTIVES Mitral-valve repair in Barlows disease is challenging; conventional techniques are difficult to perform, and there is a high risk of a postoperative suboptimal result. Double-orifice repair has been applied in a standardized approach to treat patients with severe mitral regurgitation and bileaflet prolapse due to Barlows disease. METHODS Since 1993, 82 patients with severe mitral regurgitation due to Barlows disease underwent correction applying the edge-to-edge concept. They were submitted to double-orifice repair in a standardized fashion, suturing the middle portions of both leaflets. RESULTS There were no hospital deaths. The repair was unsatisfactory in one patient who underwent valve replacement soon after the repair. The mean postoperative valve area was 3.7+/-0.79 cm(2) against a mean preoperative value of 9.2+/-2.1 cm(2). No or mild regurgitation was found in all but three patients who showed moderate residual regurgitation. There were no late deaths. Freedom from reoperation was 86+/-14% at 5 years. At the latest follow-up, all patient but one were New York Heart Association (NYHA) functional class I, and echo-Doppler assessment of valve reconstruction showed stable valve function in all patients. CONCLUSIONS The double-orifice repair can be used as a standardized approach to treat valve regurgitation due to Barlow disease with low risk and good early and mid-term results.

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.

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.

Pulsed tissue Doppler imaging detects early myocardial dysfunction in asymptomatic patients with severe mitral regurgitation

Objective: To assess whether tissue Doppler myocardial imaging (TDI) indices can predict postoperative left ventricular function in patients with mitral regurgitation (MR) after surgical correction. Methods: 84 patients (mean (SD) age 54.3 (10.8) years) with asymptomatic severe MR, an end systolic diameter < 45 mm, and an ejection fraction (EF) > 60% were subdivided in two groups: 43 patients with a postoperative EF reduction < 10% (group 1) and 41 patients with a postoperative EF reduction ⩾ 10% (group 2).TDI systolic indices of the lateral annulus were analysed preoperatively to assess myocardial systolic wave (Sm) velocity, myocardial precontraction time (PCTm), myocardial contraction time (CTm), and the PCTm:CTm ratio. Results: Postoperative EF decreased significantly (from 67 (5)% to 60 (5.5)%, p  =  0.0001). Group 2 had a higher PCTm, CTm, and PCTm:CTm ratio and a lower Sm velocity than group 1 (PCTm 100.4 (19) ms v 82 (21.8) ms, p  =  0.004; CTm 222 (3.1) ms v 215 (2.3) ms, p  =  0.01; PCTm:CTm 0.45 (0.08) v 0.38 (0.09), p  =  0.001; Sm velocity 10.4 (1.1) cm/s v 13 (1.3) cm/s, p  =  0.0001). Multivariate regression analysis showed that the combination of PCTm:CTm ratio ⩾ 40 ms and Sm velocity ⩽ 10.5 cm/s was the main independent predictor of postoperative EF reduction ⩾ 10% (sensitivity 78%, specificity 95%). Conclusions: TDI systolic indices can predict postoperative left ventricular function in patients with asymptomatic MR undergoing surgical correction.

Long‐term prognosis of medically treated patients with functional mitral regurgitation and left ventricular dysfunction

To assess long‐term prognosis in patients with functional mitral regurgitation (FMR) and left ventricular (LV) dysfunction, receiving current standard pharmacological therapy.

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.

Role of regional mechanical dyssynchrony as a determinant of functional mitral regurgitation in patients with left ventricular systolic dysfunction

Objective: To assess regional mechanical dyssynchrony as a determinant of the degree of functional mitral regurgitation (FMR). Setting: Tertiary cardiology clinic. Patients: 74 consecutive patients with left ventricular (LV) dysfunction (ejection fraction < 40%, mean 32.2 (SD 7.3)%) were evaluated. Methods: Effective regurgitant orifice (ERO) area, indices of mitral deformation (systolic valvular tenting, mitral annular contraction) and of global LV function and remodelling (ejection fraction, end systolic volume, sphericity index) and local remodelling (papillary-fibrosa distance, regional wall motion score index), and tissue Doppler-derived dyssynchrony index (DI) (regional DI, defined as the standard deviation of time to peak myocardial systolic contraction of eight LV segments supporting the papillary muscles attachment) were measured. Results: All the assessed variables correlated significantly with ERO. By multivariate analysis, systolic valvular tenting was the strongest independent predictor of ERO (R2  =  0.77, p  =  0.0001), with a minor influence of papillary-fibrosa distance (R2  =  0.77, p  =  0.01) and regional DI (R2  =  0.77, p  =  0.03). Local LV remodelling (regional wall motion score index: R2  =  0.58, p  =  0.001; papillary-fibrosa distance: R2  =  0.58, p  =  0.002) and global remodelling indices (sphericity index: R2  =  0.58, p  =  0.003) were the main determinants of systolic valvular tenting, whereas regional DI did not enter into the model. Regional DI was an independent predictor of ERO (R2  =  0.56, p  =  0.005) in patients with non-ischaemic LV dysfunction but not in patients with ischaemic LV dysfunction when these groups were analysed separately. Conclusions: The degree of FMR is associated mainly with mitral deformation indices. The regional dyssynchrony also has an independent association with ERO but with a minor influence; however, it is not a determinant of FMR in patients with ischaemic LV dysfunction.

Stress echocardiography in heart failure

Echocardiography has the ability to noninvasively explore hemodynamic variables during pharmacologic or exercise stress test in patients with heart failure. In this review, we detail some important potential applications of stress echocardiography in patients with heart failure. In patients with coronary artery disease and chronic LV dysfunction, dobutamine stress echocardiography is able to distinguish between viable and fibrotic tissue to make adequate clinical decisions. Exercise testing, in combination with echocardiographic monitoring, is a method of obtaining accurate information in the assessment of functional capacity and prognosis. Functional mitral regurgitation is a common finding in patients with dilated and ischaemic cardiomyopathy and stress echocardiography in the form of exercise or pharmacologic protocols can be useful to evaluate the behaviour of mitral regurgitation. It is clinical useful to search the presence of contractile reserve in non ischemic dilated cardiomyopathy such as to screen or monitor the presence of latent myocardial dysfunction in patients who had exposure to cardiotoxic agents. Moreover, in patients with suspected diastolic heart failure and normal systolic function, exercise echocardiography could be able to demonstrate the existence of such dysfunction and determine that it is sufficient to limit exercise tolerance. Finally, in the aortic stenosis dobutamine echocardiography can distinguish severe from non-severe stenosis in patients with low transvalvular gradients and depressed left ventricular function.

Impact of functional tricuspid regurgitation on heart failure and death in patients with functional mitral regurgitation and left ventricular dysfunction

The prognostic role of tricuspid regurgitation (TR) associated with organic left‐sided valvular heart disease is well known. However, no data are available regarding the prognostic value of functional TR (FTR) in patients with functional mitral regurgitation (FMR) and left ventricular (LV) dysfunction. The purpose of this study was to evaluate the prognostic role of FTR for occurrence of heart failure (HF) and mortality in patients with FMR.

Left Atrial Appendage: Physiology, Pathology, and Role as a Therapeutic Target

Atrial fibrillation (AF) is the most common clinically relevant cardiac arrhythmia. AF poses patients at increased risk of thromboembolism, in particular ischemic stroke. The CHADS2 and CHA2DS2-VASc scores are useful in the assessment of thromboembolic risk in nonvalvular AF and are utilized in decision-making about treatment with oral anticoagulation (OAC). However, OAC is underutilized due to poor patient compliance and contraindications, especially major bleedings. The Virchow triad synthesizes the pathogenesis of thrombogenesis in AF: endocardial dysfunction, abnormal blood stasis, and altered hemostasis. This is especially prominent in the left atrial appendage (LAA), where the low flow reaches its minimum. The LAA is the remnant of the embryonic left atrium, with a complex and variable morphology predisposing to stasis, especially during AF. In patients with nonvalvular AF, 90% of thrombi are located in the LAA. So, left atrial appendage occlusion could be an interesting and effective procedure in thromboembolism prevention in AF. After exclusion of LAA as an embolic source, the remaining risk of thromboembolism does not longer justify the use of oral anticoagulants. Various surgical and catheter-based methods have been developed to exclude the LAA. This paper reviews the physiological and pathophysiological role of the LAA and catheter-based methods of LAA exclusion.