Left ventricular surgical remodeling after the STICH trial.

Surgical treatment of anteroseptal scars has been, and still is, a challenging task for cardiac surgeons. Most patients are in heart failure and the infarcted areas can include different parts of the septum and the anterior wall. The core problem of ischemic congestive heart failure is the undue demand placed on the residual viable left ventricle myocardium. The surgical techniques used to correct the mismatch between contractile and asynergic areas differ, but the evolution of surgical techniques for left ventricular surgical remodeling (LVSR) is still a work in progress. The most popular one was proposed by Dor et al. in the 1980s and is still in general use. This technique addressed the problem of recovering a predictable volume but not necessarily the problem of rebuilding a physiologically conical shape. This anatomical aspect is becoming increasingly important, and the purpose of septal reshaping, as proposed by us in 2004, is more to recover a conical shape than to achieve volume reduction. Thus, we use the Dor operation only when septoapical scars are present. The need for a different surgical strategy is emphasized by the result of the STICH trial, which reports the data of 1000 patients randomized for coronary artery bypass grafting (CABG, n = 499) or CABG and LVSR (n = 501) and which failed to show any benefit of LVSR. However, the only surgical technique used was the classic Dor operation, where the purpose was to reestablish volume and not to recreate a physiological shape. This study, however, does not provide a definitive answer, as echocardiography results included only 212 patients in the CABG arm and 161 in the CABG and LVSR arm. Furthermore, previous myocardial infarction (MI) was not a prerequisite for study inclusion (13 % of patients in each group had no previous MI) and whether a previous MI was Q-wave or not was not specified. In conclusion, the long-term results after LVSR are satisfactory but appear to be better if a conical shape has been recreated. The role of preemptive surgery in selected cases and how to establish the limits of LVSR (grade of preoperative diastolic dysfunction, diastolic diameter, ventricular volumes, function of the remote zone, etc.) is still unclear. The impact of each individual treatment in the individual patient (medical treatment, CABG alone, CABG and LVSR) has still to be identified.

Paradoxical inhibition of cardiac lipid peroxidation in cancer patients treated with doxorubicin. Pharmacologic and molecular reappraisal of anthracycline cardiotoxicity.

Anticancer therapy with doxorubicin (DOX) and other quinone anthracyclines is limited by severe cardiotoxicity, reportedly because semiquinone metabolites delocalize Fe(II) from ferritin and generate hydrogen peroxide, thereby promoting hydroxyl radical formation and lipid peroxidation. Cardioprotective interventions with antioxidants or chelators have nevertheless produced conflicting results. To investigate the role and mechanism(s) of cardiac lipid peroxidation in a clinical setting, we measured lipid conjugated dienes (CD) and hydroperoxides in blood plasma samples from the coronary sinus and femoral artery of nine cancer patients undergoing intravenous treatments with DOX. Before treatment, CD were unexpectedly higher in coronary sinus than in femoral artery (342 +/- 131 vs 112 +/- 44 nmol/ml, mean +/- SD; P < 0.01), showing that cardiac tissues were spontaneously involved in lipid peroxidation. This was not observed in ten patients undergoing cardiac catheterization for the diagnosis of arrhythmias or valvular dysfunctions, indicating that myocardial lipid peroxidation was specifically increased by the presence of cancer. The infusion of a standard dose of 60 mg DOX/m(2) rapidly ( approximately 5 min) abolished the difference in CD levels between coronary sinus and femoral artery (134 +/- 95 vs 112 +/- 37 nmol/ml); moreover, dose fractionation studies showed that cardiac release of CD and hydroperoxides decreased by approximately 80% in response to the infusion of as little as 13 mg DOX/m(2). Thus, DOX appeared to inhibit cardiac lipid peroxidation in a rather potent manner. Corollary in vitro experiments were performed using myocardial biopsies from patients undergoing aortocoronary bypass grafting. These experiments suggested that the spontaneous exacerbation of lipid peroxidation probably involved preexisting Fe(II) complexes, which could not be sequestered adequately by cardiac isoferritins and became redox inactive when hydrogen peroxide was included to simulate DOX metabolism and hydroxyl radical formation. Collectively, these in vitro and in vivo studies provide novel evidence for a possible inhibition of cardiac lipid peroxidation in DOX-treated patients. Other processes might therefore contribute to the cardiotoxicity of DOX.

Paclitaxel and docetaxel enhance the metabolism of doxorubicin to toxic species in human myocardium.

Doxorubicin cardiotoxicity is a multifactorial process in which the alcohol metabolite doxorubicinol mediates the transition from reversible to irreversible damage. We investigated whether the tubulin-active taxane paclitaxel increases conversion of doxorubicin to doxorubicinol, thus explaining the high incidence of congestive heart failure when doxorubicin is used with paclitaxel. Specimens of human myocardium from patients undergoing bypass surgery were processed to obtain cytosolic fractions in which doxorubicin was converted to doxorubicinol by NADPH-dependent aldo/keto or carbonyl reductases. In this model, clinically relevant concentrations of paclitaxel (1-2.5 microM) increased doxorubicinol formation by mechanisms consistent with allosteric modulation of the reductases. Stimulation was observed over a broad range of basal enzymatic activity, and was accompanied by a similar pattern of enhanced formation of doxorubicinol aglycone, a metabolite potentially involved in the reversible phase of cardiotoxicity. The closely related analogue docetaxel had effects similar to paclitaxel, but increased doxorubicinol formation over a narrower range of enzymatic activity. The unrelated tubulin-active alkaloid vinorelbine had no effect. These results demonstrate that taxanes have a unique potential for enhancing doxorubicin metabolism to toxic species in human myocardium. The effects on doxorubicinol formation provide clues to explain the clinical pattern of doxorubicin-paclitaxel cardiotoxicity and also caution against the potential toxicity of combining docetaxel with high cumulative doses of doxorubicin.

Vitamins E, C and lipid peroxidation in plasma and arterial tissue of smokers and non-smokers.

An imbalance between pro-oxidants and antioxidants is operative in atherosclerosis. Cigarette smoke is a major risk factor of atherosclerosis and has been reported to contain large amounts of oxidants. We assessed arterial (internal mammary artery) and plasma levels of vitamins E and C and lipid peroxides in 48 male patients, 24 smokers and 24 non-smokers, undergoing coronary bypass surgery. Lipid peroxidation was studied using fluorescent products of lipid peroxidation (FPLs). Tissue vitamins E and C levels were significantly lower and FPLs significantly higher in smokers than in non-smokers (P < 0.0006, 0.0005 and 0.0005, respectively). This pattern was associated with lower vitamin C and higher lipid peroxide plasma levels in smokers than in non-smokers (P < 0.0002 and 0.0005, respectively). Vitamins E and C plasma levels were strongly related to their tissue content both in smokers (r = 0.60, P < 0.005 and r = 0.57, P < 0.01) and in non-smokers (r = 0.42, P < 0.05 and r = 0.46, P < 0.05). Moreover, vitamin E content was significantly related to that of vitamin C only in the arterial tissue of both groups, pointing to the existence of a functional interaction between these antioxidants. In both groups, FPLs were significantly and inversely related to vitamin C in plasma and to vitamin E in tissue, suggesting the antioxidant primary of vitamin C and vitamin E in the plasma and arterial tissue compartments, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Age-dependence of risk factors for carotid stenosis: an observational study among candidates for coronary arteriography.

In order to identify subjects at higher risk for carotid stenosis and to provide insights into mechanisms of disease development at different age-intervals, a color duplex ultrasound of extracranial arteries was performed in 624 consecutive patients (mean age 62.9+/-10.7, 483 males) undergoing coronary angiography. Significant carotid atherosclerosis (> or =50% stenosis) was documented in 87 patients (14%): the disease was moderate (50/69% stenosis) in 51 patients (8%), severe (> or =70% stenosis) in 36 patients (6%). Age (P<0.0001), smoking (P<0.0001), diabetes (P=0.0002), renal dysfunction (P=0.0119) and hypertension (P=0.0202) were independent predictors of significant carotid atherosclerosis; age (P=0.0001), smoking (P=0.0009) and diabetes (P=0.0201) were independent predictors of severe disease. Among 262 candidates for cardiac surgery, significant carotid artery disease was identified in 57 cases (2.63 Relative Risk, 95% Confidence Intervals: 1.32/5.24). Correlation and regression tree analysis demonstrated that diabetes was associated with greater severity of carotid stenosis in younger patients and hypertension in older ones. In conclusion age is the primary determinant of carotid artery disease; diabetes and smoking accelerate progression of atherosclerosis in younger patients, hypertension and smoking in older ones. Among patients undergoing coronary angiography, carotid ultrasonography should be recommended in high risk subgroups of patients.

Bilateral internal thoracic artery grafting: long-term clinical and angiographic results of in situ versus Y grafts.

BACKGROUND: We evaluated whether bilateral internal thoracic arteries provide the same long-term results when used as in situ grafts and as Y grafts. METHODS AND RESULTS: From October 1991 to February 2000, 1818 patients had bilateral internal thoracic arteries used as in situ (n = 1378, group A) or as Y grafts (n = 440, group B). The number of anastomoses per patient and the number of bilateral internal thoracic artery anastomoses per patient were higher in group B (3.1 +/- 0.9 and 2.7 +/- 0.9) than in group A (2.9 +/- 0.8 and 2.2 +/- 0.6) (both P <.001). The number of right internal thoracic artery anastomoses per patient rose from 1.0 +/- 0. 3 in group A to 1.4 +/- 0.6 in group B (P <.001), and the number of sequential anastomoses per right internal thoracic artery graft rose from 4.1% to 34.3% (P <.001). Thirty-day mortality was 2.0% in group A versus 2.5% in group B (P = not significant). No difference in postoperative course was detected. Eight-year survivals were 95.8% +/- 2.7% in group A versus 94.8% +/- 4.0% in group B (P = not significant), and event-free survivals were 95.2% +/- 2.9% in group A versus 93.6% +/- 4.4% in group B (P = not significant). Early angiograms were obtained in 295 patients (945 anastomoses, 863 distal and 82 proximal Y grafts), 213 patients (611) in group A and 82 patients (334) in group B. Patency rate was 98.8% in group A and 96.0% in group B (P = not significant), whereas grade A patency rate was 97.2% in group A and 96.4% in group B (P = not significant). Late angiograms were obtained in 88 patients (25 in group A and 63 in group B) at a mean of 17.5 +/- 18.4 months: patency rate was 100% in group A and 99.2 in group B (P = not significant), and grade A patency rate was 98.6% in group A and 98.8% in group B (P = not significant). No Y anastomosis was occluded or stenosed. COMMENT: Survival, incidence of cardiac events, and angiographic patency in the early and late phases are similar for bilateral internal thoracic arteries used either in situ or as Y grafts. However, Y grafting with bilateral internal thoracic arteries increases the number of anastomoses per bilateral thoracic artery, as well as the flexibility of the right internal thoracic artery.

Intermittent antegrade warm cardioplegia reduces oxidative stress and improves metabolism of the ischemic-reperfused human myocardium.

The aim of this study was to compare the effect of intermittent antegrade warm blood cardioplegia and intermittent antegrade cold blood cardioplegia on myocardial metabolism and free radical generation of the ischemic-reperfused human myocardium. Thirty patients undergoing mitral valve procedures were randomly allocated to two groups: group 1 (15 patients) received warm blood cardioplegia and group 2 (15 patients), cold blood cardioplegia. Myocardial metabolism was assessed before aortic clamping, 1 minute after crossclamp removal, and after 20 minutes of reperfusion, by collecting blood simultaneously from the radial artery and coronary sinus. All samples were analyzed for lactate, creatine kinase, reduced and oxidized glutathione, ascorbic acid, fluorescent products of lipid peroxidation, and leukocyte activation (elastase). In all patients, early reperfusion was associated with significant coronary sinus lactate release. In group 2, but not in group 1, significant coronary sinus release of reduced and oxidized glutathione, fluorescent products of lipid peroxidation, and creatine kinase was also found; moreover, arterial-coronary sinus difference of ascorbic acid content was increased only in group 2, suggesting a transmyocardial consumption of this antioxidant vitamin. After 20 minutes of reperfusion, coronary sinus lactate release was no longer present in group 1, whereas significant production was still evident in group 2. In this group, significant coronary sinus release of fluorescent products of lipoperoxidation and reduced and oxidized glutathione was also observed at this time. No significant release of elastase from the coronary sinus was noted in the two groups throughout the study. The left ventricular stroke work index measured at the end of the study indicated a better functional recovery in group 1 than in group 2. In conclusion, intermittent antegrade warm blood cardioplegia protects the myocardium from ischemia-reperfusion injury better than intermittent antegrade cold blood cardioplegia; this phenomenon may be partly due to the decreased tissue oxidant burden mediated by intermittent warm blood cardioplegia.

A 31P-nuclear magnetic resonance study of intermittent warm blood cardioplegia.

This study was designed to assess the effects of intermittent warm blood cardioplegia on myocardial energy metabolites, intracellular pH, and contractile function. The isolated blood-perfused pig hearts were divided into three groups. After 30 minutes of control perfusion, the hearts in group 1 (n = 10) received 90 minutes of continuous warm (37 degrees C) blood cardioplegia; the hearts in group 2 (n = 9) received six 5-minute periods of warm blood cardioplegia, interrupted by six 10-minute episodes of ischemia (37 degrees C). The hearts were then reperfused for 30 minutes. The hearts in group 3 underwent 150 minutes of control perfusion without cardioplegia or ischemic episodes. Phosphorus 31-nuclear magnetic resonance spectra showed that a 10-minute interruption of warm blood cardioplegia decreased phosphocreatine levels and intracellular pH by approximately 47% (p < 0.01) and 0.12 unit (p < 0.05), respectively, and increased inorganic phosphate levels by approximately 87%, whereas resumption of cardioplegia for 5 minutes resulted in almost 100% recovery of phosphocreatine and inorganic phosphate levels and intracellular pH. More important, subsequent interruptions did not result in any cumulative changes in phosphocreatine level, inorganic phosphate level, or intracellular pH beyond those changes observed after the initial cardioplegic interruption. Moreover, during reperfusion there were no significant differences in adenosine triphosphate and phosphocreatine levels among the three groups of hearts. Furthermore, hearts from groups 1 and 2 showed comparable recovery of contractile function. These results indicate that six 10-minute interruptions and six 5-minute restorations of warm blood cardioplegia caused only mild and reversible changes in myocardial energy metabolites and intracellular pH and these changes were not cumulative. This study suggests that antegrade intermittent warm blood cardioplegia may provide as much myocardial protection as does antegrade continuous warm blood cardioplegia in the normal heart.

Midterm results after minimally invasive coronary surgery (LAST operation)

BACKGROUND: Our experience with a left internal thoracic artery graft to the left anterior descending artery via a left anterior small thoracotomy is reviewed to evaluate midterm results. METHODS: From November 1994 to April 1997, four hundred sixty patients were scheduled to undergo a left internal thoracic artery graft to the left anterior descending coronary artery via a left anterior small thoracotomy; 26 of these patients (5.7%) were converted and 434 of them had the operation. Two hundred fourteen patients (49.3%) had isolated disease of the left anterior descending artery, and 220 patients (50.7%) had multiple vessel disease. A sufficient length of the left internal thoracic artery was harvested to reach the left anterior descending artery. RESULTS: Three hundred nine patients (71.2%) underwent extubation by hour 2. Mean intensive care unit stay was 4.2 +/- 4.5 hours; mean postoperative hospital stay was 66 +/- 29 hours; the 30-day mortality rate was 1.1%; the late mortality rate was 1.4%. Eighteen patients underwent reoperation early (< or = 30 days), and eight patients underwent reoperation late (> 30 days) because of conduit/anastomotic malfunction. Four patients underwent reoperation with patent anastomosis for progression of disease (n = 3) or pericarditis (n = 1). Three patients had a percutaneous transluminal coronary angioplasty. Cumulating angiographic and stress Doppler flow assessment results, a patent anastomosis was obtained in 417 patients and a nonrestrictive anastomosis in 404 patients. Twenty-nine months after surgery, survival was 97.1% +/- 0.7% (95% confidence interval 90.5% to 100%) and event-free survival 89.4% +/- 1.2% (95% confidence interval 78.2% to 100%). In the last 190 patients, with our increased experience and better instruments, we obtained a patent anastomosis in 188 patients (98.9%) and a nonrestrictive anastomosis in 185 (97.4%). CONCLUSIONS: Left anterior small thoracotomy gives acceptable midterm results. Incidence of patent and nonrestrictive anastomoses was satisfactory, especially in the most recent part of our experience, when the learning curve ended.

Composite lengthened arterial conduits: long-term angiographic results of an uncommon surgical strategy.

BACKGROUND: We sought to evaluate the long-term patency rate of composite lengthened conduits. METHODS AND RESULTS: From December 1991 to April 2000, 43 patients had a composite lengthened arterial conduit. There was a mean of 2.83 +/- 1.23 anastomoses per patient. No 30-day mortality occurred. Five patients died from 3 to 84 months after the operation (mean, 38.6 +/- 34.6 months). After a mean follow-up of 57.0 +/- 32.3 months (range, 3-99 months), all the survivors are asymptomatic. The only cardiac major events recorded were 2 (4.6%) late acute myocardial infarctions in the patients who died. Eight-year survival and event-free survival were both 80.4% +/- 9.1% (range, 3%-93%). In the early period (13.5 +/- 4.8 days) in 26 patients, 26 arterial composite lengthened conduits and 37 distal anastomoses had postoperative angiographic control; all the anastomoses were rates as grade A, according to Fitzgibbon classification. In the late period (29 +/- 30 months) in 23 patients, 23 arterial composite lengthened conduits and 34 distal anastomoses were checked; the patency rate was 22 (95.6%) of 23 for the composite lengthened conduits and 33 (97%) of 34 for the distal anastomoses. CONCLUSIONS: In particular situations, when the length of an arterial conduit is not enough to allow a correct use of the graft, lengthening of an arterial conduit can be a safe and effective technique.

Early clinical experience with a new sutureless anastomotic device for proximal anastomosis of the saphenous vein to the aorta.

BACKGROUND: Avoiding aortic side clamping is useful to avoid local particulate embolization. A device that allows a saphenous vein graft to be anastomosed to the aorta without aortic manipulation is clinically evaluated. METHODS AND RESULTS: From July 1999 to March 2000, 17 patients who underwent myocardial revascularization had an aorta-saphenous vein graft anastomosis performed by means of an aortic anastomotic device. Eight were operated on with cardiopulmonary bypass and 9 without. The proximal anastomoses created by the aortic anastomotic device were performed before the institution of cardiopulmonary bypass or before the related distal anastomosis was performed. In 11 patients transcranial Doppler ultrasound was used. In 1 (6%) patient the saphenous vein graft was not deployed, and in 2 (12%) a single suture was added for minor bleeding. None of the 11 patients evaluated with transcranial Doppler ultrasound had evidence of particulate embolization during the procedure. No patient died or was reoperated on for bleeding. Six (35%) patients had a postoperative angiogram 48 +/- 26 days after the operation that showed widely patent proximal anastomoses. CONCLUSIONS: Use of an aortic anastomotic device allows a sutureless anastomosis to be created between the aorta and saphenous vein graft. The device could be used in totally endoscopic myocardial revascularization. A second-generation device is ready to solve the problems encountered and to increase the ease in handling the device.

Radial artery from left subclavian artery in redo coronary artery bypass grafting.

In redo coronary artery bypass grafting a left anterior thoracotomy can be used, if necessary, to avoid a dangerous repeat median sternotomy. In 2 patients with a well-functioning left internal mammary artery graft to a left anterior descending artery attached to the sternum, a radial artery was used with the left subclavian artery as the blood source. This technique can be used successfully in selected cases when a left thoracotomy is advisable and an arterial graft is preferred to a saphenous vein.

Minimally invasive coronary artery bypass grafting.

Minimally invasive coronary artery bypass grafting has recently been introduced into cardiac surgery. The procedure promises to become an important addition to the surgical treatment of coronary artery disease. This current review gives a historical perspective and an overview of this growing field, based on the experience of three international centers with experience with minimally invasive coronary artery bypass grafting. It is predicted that the field will grow, and that future generation of cardiac surgeons will have to become familiar with this new procedure.

Composite arterial conduits for a wider arterial myocardial revascularization.

From October 1991 to May 1993, 130 patients were submitted to myocardial revascularization using complex preformed arterial conduits. The age ranged from 29 to 75 years (mean age, 60.1 years); 121 patients were male. One hundred twenty-six patients had double- or triple-vessel disease. The mean ejection fraction was 0.53 (range, 0.22 to 0.79); only 6 patients had an ejection fraction less than 0.35. In 6 cases the procedure was a reoperation. We used 360 arterial conduits, 163 of which as free grafts (3 left internal mammary arteries, 16 right internal mammary arteries, 86 inferior epigastric arteries, 57 radial arteries, and 1 right gastroepiploic artery). One hundred fifty-four free grafts were anastomosed to one or both internal mammary arteries and one to a radial artery. We constructed 136 complex arterial conduits (branched, lengthened, or both). In 6 cases a double arterial system had to be used in a single patient. There was no operative mortality, and no inotropic or mechanical supports were used. The overall mortality rate was 1.5%. Early angiographic controls (between the 7th and 15th postoperative days) demonstrated 100% patency; late angiographic controls (at a mean interval of 9.5 months after operation) documented a mean patency rate ranging from 94.1% of the radial arteries to 100% of the left internal mammary arteries and right gastroepiploic arteries. At a mean follow-up of 7.2 months (range, 1 to 15 months) all patients are alive without recurrence of symptoms.

The LAST operation: techniques and results before and after the stabilization era.

BACKGROUND: Left anterior descending artery stabilization allows performance of left internal mammary artery grafting via a left anterior small thoracotomy on a beating heart. Our surgical experience was reviewed to assess if surgical results have improved as result of specialized instrumentation. METHODS: Of 545 patients who had the left anterior small thoracotomy operation, 261 underwent this procedure for single left anterior descending artery disease. Two groups were considered, before and after the use of specialized instrumentation: group A (n = 93), operated on from November 21, 1994, to April 20, 1996; and group B (n = 168), operated on from April 21, 1996, to December 1997. RESULTS: Early mortality was similar in the two groups. The further revascularization (operation or percutaneous transluminal coronary angioplasty) and the rate of occlusion of the conduit were higher in group A, whereas anastomotic or conduit malfunction was not. Cumulating angiography and Doppler flow evaluation, 92.5% of the anastomoses in group A and 98.8% in group B (p = 0.026) were patent, and 90.3% in group A and 97.6% in group B (p = 0.031) were patent and not restrictive. At 19 months, survival was similar, but the event-free survival was higher in group B. CONCLUSIONS: Both left anterior descending artery stabilization and safer left internal mammary artery harvesting contributed to improve angiographic and clinical results after the left anterior small thoracotomy operation.

Radial artery and inferior epigastric artery in composite grafts: improved midterm angiographic results.

BACKGROUND: The improving results with use of the radial artery and the inferior epigastric artery as coronary bypass conduits were analyzed to assess the suitability of these arteries for myocardial revascularization. METHODS: Both arteries were used in composite arterial conduits with an internal mammary artery as the blood source. The proximal anastomosis was always constructed before the initiation of cardiopulmonary bypass. From October 1991 to January 1995, 240 patients underwent myocardial revascularization using 163 radial arteries and 124 inferior epigastric arteries with one (224 instances) or both (two instances) internal mammary arteries as inflow conduits. Twenty-five saphenous veins were concomitantly used. There were 208 men and 32 women with a mean age of 60.8 +/- 8.6 years (range, 28 to 80 years). In 73 patients (30.4%), the operation was performed on an urgent basis, and in 11 (4.6%), it was a repeat operation. The mean left ventricular ejection fraction was 0.55 +/- 0.12, and in 21 patients (8.8%), it was less than 0.35. Of 681 distal anastomoses, 188 were constructed using the radial artery (35 double and one triple sequential anastomosis) and 125, using the inferior epigastric artery (one double sequential anastomosis). A mean of 3.0 arterial anastomoses per patient were constructed (3.1 anastomoses/patient including saphenous veins). Six patients (2.5%) underwent associated procedures: aortic valve replacement (2), carotid endarterectomy (2), mitral valve replacement (1), and aortic valve and ascending aorta replacement (1). Most of the inferior epigastric arteries were grafted on diagonal branches and most of the radial arteries, the circumflex territory. RESULTS: No deaths occurred in the operating room. Three patients (1.3%) died postoperatively, and 2 patients (0.8%) died 6 months after operation. At a mean follow-up of 18.5 +/- 10.4 months (range, 1 to 39 months), 227 patients (96.6%) were asymptomatic. The cumulative patency rate of the radial artery grafts was 93.1% and of the inferior epigastric artery grafts, 95.7%. CONCLUSIONS: Our data suggest that use of the RA and the IEA in composite conduits for myocardial revascularization is feasible. These arteries can be safely used when bilateral internal mammary artery or sequential internal mammary artery grafting is not advisable.

Blood cardioplegia reduces oxidant burden in the ischemic and reperfused human myocardium.

In 20 patients receiving cold crystalloid cardioplegia (n = 10) or cold blood cardioplegia (n = 10) during elective coronary artery bypass grafting, the atrial myocardium was tested for glutathione-related antioxidant defenses and lipid peroxidation. In both groups, ischemia and reperfusion induced a significant increase in lipid peroxidation values (p < 0.05) that was associated with a depression of nonprotein thiol compound levels (p < 0.05). Compared with the cold crystalloid cardioplegia-treated patients, the cold blood cardioplegia-treated patients showed a lower lipid peroxidation (p < 0.05) and higher values of nonprotein thiol compounds (p < 0.05). Moreover, a significant ischemia and reperfusion-dependent activation of glutathione transferase was observed only in the cold crystalloid cardioplegia-treated patients. Selenium-dependent glutathione peroxidase and glutathione reductase activities did not change after release of the aortic cross-clamp and did not differ between the two groups. The highest postoperative plasma level of the myocardial-specific isoenzyme of creatine kinase was significantly more elevated in the cold crystalloid cardioplegia patients. Overall, these tissue biochemical features indicate a lower oxidant burden in the myocardium of cold blood cardioplegia-treated patients, a finding suggesting superior protection for the ischemic and reperfused human myocardium also through antioxidant-type mechanisms, apparently medicated by the antioxidant capacity of erythrocytes and specific plasma molecules.

Intermittent antegrade warm blood cardioplegia.

Intermittent antegrade warm blood cardioplegia has been used routinely at our institution over the last 3 years. We report here a comparison between the first 250 consecutive patients undergoing elective coronary artery bypass grafting in which intermittent antegrade warm blood cardioplegia was used (group A) and the last 250 consecutive patients who received intermittent antegrade cold blood cardioplegia, during bypass grafting (group B). There were no differences in sex, age, number of grafts, and functional status between the two groups; left ventricular ejection fraction was lower in group A. The overall mortality rate in group A was 0.8% versus 3.6% in group B (p < 0.05). There was no in-hospital mortality among high-risk patients (ejection fraction < or = 0.35) in group A (0/53) versus two deaths in group B (2/28) (p < 0.05). No patient in group A needed circulatory assistance; 4 patients in group B received intraaortic balloon pumping. Only 1 patient in group A required inotropic support versus 20 patients in group B (p < 0.0005), and 5 patients in group A received lidocaine hydrochloride for ventricular arrhythmias versus 18 in group B (p < 0.01). The rates of myocardial infarction and stroke were not different between the two groups. The peak concentration of the myocardial-specific isoenzyme of creatine kinase were higher in group B in absolute value (51 +/- 30 IU/L) than in Group A (38 +/- 38 IU/L) (p < 0.0005) and in percent of total creatine kinase (8.2% +/- 4.1% versus 6.2% +/- 2.9%, respectively).

Minimally invasive coronary artery bypass grafting on a beating heart.

BACKGROUND: We reviewed our experience with left internal mammary artery (LIMA)-to-left anterior descending artery (LAD) anastomosis on a beating heart through a left anterior small thoracotomy. METHODS: This procedure was performed in 343 of 358 scheduled patients; in 15 (4.2%) the LAD was not suitable or was too small. The chest was opened in the fourth (127, 37.0%) or fifth (197, 57.4%) intercostal space, or both (19, 5.6%); the length of the harvested LIMA was 4-15 cm. The LAD was occluded by means of two 4-0 Prolene (Ethicon, Somerville, NJ) sutures, both snared on a small piece of silicone tubing. The anastomosis was performed with two 8-0 Prolene sutures. In the early postoperative period all patients underwent angiography or a doppler flow assessment of the LIMA or both. RESULTS: In 310 patients the LIMA was connected directly to the LAD; to elongate the LIMA, in 30 patients an inferior epigastric artery and in 3 patients a saphenous vein was used. In 2 patients the diagonal branch was also grafted using an inferior epigastric artery from the LIMA. Three patients (0.9%) died during the first 30 days after the operation, and 4 other patients (1.2%) died after the first month. Twenty-five patients (7.3%) were reoperated on because of anastomotic or conduit failure, 18 (5.2%) early and 7 (2.1%) late; one additional patient had a late percutaneous transluminal coronary angioplasty for anastomotic stenosis. At a mean of 9.5 +/- 5.7 months of follow-up, 336 patients (98.0%) were alive, asymptomatic with or without medical treatment, and without cardiac events. COMMENT: Left internal mammary artery-to-LAD anastomosis performed on a beating heart through a left anterior small thoracotomy is a procedure that can be performed with low risk and acceptable midterm results in selected patients.