Adalberto Grossi

Relation between left ventricular function and oxidative stress in patients undergoing bypass surgery

Objective To determine whether preoperative left ventricular ejection fraction (LVEF) is related to the degree of myocardial oxidative stress during bypass surgery in man. Design Observational study. Setting Tertiary care centre. Patients and interventions 31 patients (LVEF range was 20% to 68%) undergoing elective coronary bypass surgery with blood cardioplegic reperfusion were studied. Arterial and coronary sinus blood was collected before aortic cross clamping (T0) and at 0 (T1), 15 (T2), and 30 (T3) minutes after unclamping. Transmural left ventricular biopsies were also obtained from 15 patients at T0 and at T1. Main outcome measures Glutathione and adenine nucleotides were measured in myocardial biopsies, while coronary sinus–artery differences for glutathione, nucleotides, and products of lipid peroxidation were calculated from blood specimens. Creatine kinase (myocardial band; CK-MB) was measured in plasma at four and 12 hours after operation. Results Myocardial glutathione and adenine nucleotides were correlated (p < 0.02) with preoperative LVEF both at T0 (r = 0.909 and 0.672) and T1 (r = 0.603 and 0.605). Oxidised glutathione released from the heart during reperfusion was inversely correlated with LVEF (r = −0.448, −0.466, and −0461 at T1, T2, and T3, p < 0.01), while reduced glutathione (r = 0.519 and 0.640 at T1 and T2) and glutathione redox ratio (r = 0.647, 0.714, 0.645, and 0.702 at T0, T1, T2, and T3) showed a direct correlation (p < 0.01). Lipid peroxidation at T1 was negatively related to LVEF (r = −0.492). CK-MB was also negatively related to LVEF (r = −0.440 at 4 h and −0.462 at 12 h). Conclusions The capacity to counterbalance oxidative burst following ischaemia and reperfusion appears to be related to the functional ability of the heart.

Thromboangiitis obliterans of coronary and internal thoracic arteries in a young woman

Coronary artery disease may rarely be due to vasculitis. Angina pectoris and acute myocardial infarction have been reported in patients with Takayasus disease, polyarteritis nodosa, and thromboangiitis obliterans. TM In this article we report a case of Buergers disease localized to coronary and internal thoracic arteries (ITAs) in a young nonsmoking woman. The diagnosis was made by histologic examination of the ITAs that were discarded at the time of bypass surgery. A 39-year-old woman had a 2-year history of epigasmc pain of unknown origin and sporadic episodes of typical angina for the past 8 months. Because of worsening of symptoms she underwent a treadmill exercise test. which showed signs of myocardial ischemia. The patient appeared to be otherwise in good health, without evidence of risk factors including diabetes mellitus, hypercholesterolemia, hypertension, obesity, or family history of isch-

Identification and revascularization of hibernating myocardium in angina-free patients with left ventricular dysfunction

We examined 17 angina-free patients with left ventricular dysfunction, referred for surgical decision-making, who presented with no or few signs and symptoms of myocardial ischemia according to treadmill stress test. On cardiac catheterization they were affected by severe multi-vessel coronary artery disease; the mean left end-diastolic pressure of this population was 26.3 +/- 5.5 mm Hg (mean +/- SD) and their mean ejection fraction was 27.6 +/- 4.9% (mean +/- SD). They all were investigated for the presence of viable myocardium by the combined assessment of cardiac perfusion and metabolism using single photon emission tomography with [99mTc] labelled hexakis-2-methoxy-isobutyl-isonitrile [99mTc]MIBI/SPET) and positron emission tomography with [18F]-2-fluoro-2-deoxy-D-glucose ([18F]FDG/PET), respectively. Patients were considered for coronary surgery when [18F]FDG was detectable in at least two cardiac segments with wall motion abnormalities and perfusion defects. Nine patients were operated on, six were medically treated and two were scheduled for heart transplantation. We recorded no in-hospital mortality. At a mean follow-up of 28.4 +/- 9.8 (mean +/- SD) months all surgical patients were alive and their NYHA functional classes have improved, except in one case. Among the patients refused for bypass surgery, three are in stable conditions, three have worsened clinical statuses and two died while waiting for heart transplantation. In conclusion, for patients with bypassable coronaries, left ventricular dysfunction and lack of angina, successful coronary revascularization may be predicted by the presence of viable myocardium demonstrated with positron emission tomography.

Surgical treatment for life-threatening acute myocardial infarction: a prospective protocol.

OBJECTIVE In this paper we describe the preliminary results of a prospective operative protocol designed in order to define the role of emergent myocardial revascularization in extensive acute myocardial infarction and in post-infarction cardiogenic shock. METHODS Entry criteria are: age < 75 years; anterior acute myocardial infarction with ST segment elevation > 4 leads, infero-postero-lateral or inferior and right ventricular within 6 h from onset of chest pain; post-infarction cardiogenic shock within 3 h from onset of shock. From November 1994 to July 1995, after emergency coronary arteriography, 23 patients were treated by coronary artery bypass grafting. Fifteen were operated for extensive acute myocardial infarction (group A, mean age 54.1 +/- 9.4 years) and eight for post-infarction cardiogenic shock (group B mean age 65.0 +/- 8.7 years). Mean time from onset was 4.4 +/- 1.3 h in group A and 2.2 +/- 0.8 h in group B. Mean left ventricular ejection fraction was 39.3 +/- 12.7% in group A and 22.6 +/- 3.5% in group B. Six out of eight group B patients needed intraaortic balloon counterpulsation preoperatively, and 2/8 cardiopulmonary resuscitation. RESULTS Myocardial revascularization consisted in 3.4 +/- 1.1 grafts in group A (vein grafts, except for 8 patients who also received a left internal thoracic artery graft) and 3.3 +/- 1.1 vein grafts in group B. All patients in group B and 3/15 (20%) in group A underwent intraaortic balloon counterpulsation. In-hospital death occurred in 1/15 (6.7%) patients of group A and in 4/8 (50%) patients of group B. At a mean follow-up of 4.1 +/- 3.4 months for group A and 3.9 +/- 2.2 months for group B left ventricular ejection fraction was 43.4 +/- 9.0% in group A and 35.7 +/- 13.1% in group B. CONCLUSIONS Experience of 9 months with this prospective protocol showed its effectiveness in the management of critically ill patients with acute coronary occlusion leading to low mortality rate in acute myocardial infarction and improved survival rate in post-infarction cardiogenic shock.

Three dimensional time-of-flight magnetic resonance angiography in carotid artery surgery: A comparison with digital subtraction angiography

Three dimensional time-of-flight magnetic resonance angiography (MRA) and intra-arterial digital subtraction angiography (DSA), considered the gold-standard technique, were compared for pre- and postoperative evaluation of the carotid bifurcation. Images of suitable quality of 194 bifurcations were available with both techniques. Percentage stenosis was graded into 5 groups: A = 0-29%, B = 30-59%, C = 60-89%, D = 90-99%, E = 100% (occlusion). Preoperative MRA (126 bifurcations) overgraded the stenosis in 14 cases and undergraded it in 11. The two techniques agreed in 101 cases and the extent of misgrading was never more than one category. Regression analysis showed a good correlation between the two methods. Severe ulceration was better identified by DSA. As far as the surgical indication was concerned, MRA had a sensitivity of 92.6% and a specificity of 98.3%. In 68 operated cases, postoperative MRA and intraoperative completion angiography showed a satisfactory endarterectomy with no residual stenosis in any of the cases. In conclusion, MRA seems an accurate modality for imaging of carotid bifurcations. Significant limitations still exist for an adequate demonstration of intracranial circulation.

Role of leucocytes in free radical production during myocardial revascularisation.

OBJECTIVE: To evaluate the role of leucocytes in free radical production in patients with depressed or normal ejection fraction undergoing coronary bypass. DESIGN: Two randomised control trials. SETTING: Tertiary care centre. PATIENTS AND INTERVENTIONS: In the first study, 22 patients with ejection fractions of < or = 40% received blood cardioplegic reperfusion with (n = 11) or without (n = 11) leucocyte depletion. In the second study, 22 patients with ejection fractions > or = 45% received either leucocyte depleted (n = 11) or blood cardioplegia (n = 11). MAIN OUTCOME MEASURES: Glutathione, hypoxanthine, and lipid peroxidation products were measured in coronary sinus blood and plasma before aortic cross clamping and at 0, 15, and 30 minutes after unclamping. Haemodynamic variables and creatine kinase MB isoenzymes were monitored on the first postoperative day. Comparison between treatments was performed on difference (delta) between measurements at time 0 and at baseline, and on slopes obtained by fitting measurements after unclamping with a linear regression model. RESULTS: At unclamping no difference in delta for plasma glutathione redox ratio (oxidised/total glutathione, %) was observed between treated and control groups with low ejection fraction (delta = 16 (SD 8.39) and 24 (7.0) redox ratio %, respectively). Baseline value recovery rate (redox ratio %/min) was significantly faster in treated v control patients (slope -0.912 (0.380) v -0.158 (0.200), P < 0.005, respectively). Cardiac index showed a trend to greater improvement in the treated group (slope 0.04 (0.03) v 0.003 (0.002) 1/min/m2/h, P < 0.02, treated v controls, respectively). In patients with normal ejection fraction, leucocyte depletion did not result in significant improvement v controls. CONCLUSIONS: Leucocyte depletion seems to provide benefit only in patients with left ventricular dysfunction.

Avidin and 111In-labelled biotin scan: A new radioisotopic method for localising vascular graft infection

OBJECTIVES To evaluate a new imaging technique, for diagnosis of prosthetic vascular graft infection. Avidin is a protein which accumulates nonspecifically at sites of inflammation or infection. Due to its extremely low dissociation constant with biotin sites of infection can be imaged, using avidin as a pre-target, followed by injection of 111In-labelled biotin. This technique is much simpler than the common scintigraphic methods which employ labelling of blood components and its target-to-background ratio is greater than the methods employing radiolabelled proteins. DESIGN Prospective clinical study. SETTING A single department of vascular surgery and one of nuclear medicine of a Northern Italian hospital. MATERIALS Between May 1993 and May 1994, 31 grafts in 26 patients were studied; the series included 23 men and three women with a mean age of 65.5 years (range 54-76 years). The prosthetic graft (Dacron -16, ePTFE -15) were: aortoaortic 5, aortobifemoral 15, aortoiliac 1, and femoropopliteal 10. Sixteen patients were suspected of having a vascular graft infection (Group A), the other 10 patients served as controls (Group B). 20 mg of Avidin were injected iv, followed 24 h later by i.v. injection of 500 micrograms of Biotin labelled with 74 MBq of 111In. CHIEF OUTCOME MEASURES Whole-body imaging was performed at 10 min and 2 h post-injection, along with SPECT imaging when indicated. Scan results were correlated with the traditional imaging modalities and the clinical outcome of the patients. MAIN RESULTS In Group A: two patients (three grafts) were excluded from the study, there were six true-positives, one false-positive and 11 true-negatives. Results in Group B: 10 true-negatives. The overall sensitivity was 100%, the specificity 95%, the accuracy 96%, the positive predictive value 86% and the negative predictive value 100%. CONCLUSIONS These data suggest that Avidin/111In-labelled Biotin scintigraphy is a useful non invasive diagnostic method for early diagnosis of suspected prosthetic vascular graft infection.

Posterior mitral valve restoration for ischemic regurgitation

Chronic ischemic mitral regurgitation is traditionally a complex lesion to repair. Only restrictive annuloplasty has become an accepted strategy to avoid valve replacement, but results are unsatisfactory in some subgroups of patients. We describe an original technique that addresses the pathophysiologic mechanisms responsible for one of the most common subtypes of ischemic mitral regurgitation, ie, asymmetric tethering of the mitral leaflets after inferior myocardial infarction. The technique includes partial detachment of the posterior leaflet from the mitral annulus, annular plication, and posterior cusp plasty.

Chordal plication and free edge remodeling for mitral anterior leaflet prolapse repair: 8-year follow-up

BACKGROUND Chordal suture plication and free edge remodeling represent a personal technique for the repair of anterior leaflet prolapse. We report the results of an 8-year experience. METHODS Sixty-one patients with degenerative mitral regurgitation caused by prolapse of the anterior leaflet (11) or both leaflets (50) underwent anterior leaflet prolapse repair. Twenty patients who had associated cardiac procedures are included. RESULTS There were two perioperative deaths. Postoperative mitral regurgitation fell to 0.4 +/- 0.7 versus 3.7 +/- 0.4 preoperative (p < 0.0001). Mean follow-up was 40.5 months. There were 3 late deaths and 3 mitral reoperations (1 of 3 repairs, 2 of 3 replacements). Thromboembolism and endocarditis occurred in 1 patient each. Actuarial overall survival, freedom from cardiac death, and freedom from mitral reoperation at 92 months were 85.1% +/- 7.9%, 88.9% +/- 7.7%, and 94.6% +/- 3.0%, respectively. CONCLUSIONS Our technique of anterior leaflet prolapse repair appears effective, safe, and durable at mid- to long-term follow-up, and may be used in the presence of extensive disease of both leaflets.

Combined carotid and cardiac procedures: improved results and surgical approach.

Severe cerebrovascular complications following cardiac surgical procedures remain a major concern, particularly in patients with significant carotid atherosclerotic involvement (14% of perioperative stroke). Operative mortality for carotid operations in patients with documented Coronary Artery Disease (CAD) may be as high as 20%. Seventy patients underwent combined operations (unilateral carotid stenosis > 70%, unilateral stenosis > 50% with ulcerated plaque or bilateral stenoses > 50%; and this also included patients with unilateral occlusion). Cardiac procedures were 69 coronary artery bypass grafts, four left ventricular aneurysmectomies, three aortic valve replacements and surgery on two mitral valves. Seven perioperative deaths occurred, which were all caused by cardiac events. There were no perioperative strokes. Carotid endarterectomy immediately before cardiopulmonary bypass is a safe and expeditious approach to coexisting significant cardiac and carotid disease. In our experience, technical details in monitoring and minimizing cerebral ischemia are possibly more crucial in these severe vasculopathic patients. Moreover, it is probably advantageous from an economic standpoint compared with other therapeutic treatments.