Twenty-four hour hyperinsulinemic-euglycemic clamp improves postoperative nitrogen balance only in low insulin sensitivity patients following cardiac surgery

BACKGROUND

Critically ill patients often suffer from a protein catabolic state. The aim of this study was to demonstrate that nitrogen balance (NB) in cardiac patients admitted to the intensive care unit (ICU) is related to their insulin sensitivity level and that supraphysiologic doses of insulin can restore anabolism.

MATERIALS AND METHODS

Twenty-eight patients that were admitted to ICU in enteral and/or parenteral nutrition have been enrolled in this study. All patients received a standard nutrition protocol for at least 3 days before starting the study. These patients received either enteral or parenteral nutrition based on 1.4 kcal/kg/h and 1.1 g/kg/24 h of proteins. Participants were studied for three 24 h periods (P1 , P2 , and P3 ). Twenty-four hour NB was calculated from urinary urea nitrogen excretion, fixed protein and energy intake during each of the three periods (P1 , P2 , and P3 ). Simultaneous to P2, a 24 h hyperinsulinemic-euglycemic clamp (HEC) was performed to determine patients' insulin sensitivity (IS) or insulin resistance (IR), as well as the impact of high doses of insulin on NB.

RESULTS

Nitrogen balance remained consistently positive in the IS group regardless of the clamp. In IR patients, NB was negative before the clamp and became positive during P2 and P3 . Insulin sensitivity improved during the HEC in IR patients (P < 0.001).

CONCLUSIONS

A negative NB was found only in insulin resistant patients admitted to the ICU for more than 7 days. A 24-h period HEC improved NB in these patients.

Diet-derived phytochemicals: from cancer chemoprevention to cardio-oncological prevention

Cardiovascular diseases and cancer are the leading causes of death in most countries. These diseases share many common risk factors as well as pathogenetic determinants, and their incidence is related to age in an exponential manner. Furthermore, it has become apparent that several treatments used in therapy or even in prevention of cancer can impair the structural and functional integrity of the cardiovascular system, giving rise to an interdisciplinary field: cardio-oncology. However, tumors and cardiovascular diseases also share common protective factors: they can be prevented either by avoiding exposure to recognized risk factors, and/or by favoring the intake of protective compounds and by modulating the host defense machinery. These latter approaches are generally known as chemoprevention. A great variety of dietary and pharmacological agents have been shown to be potentially capable of preventing cancer in preclinical models, most of which are of plant origin. Phytochemicals, in particular diet-derived compounds, have therefore been proposed and applied in clinical trials as cancer chemopreventive agents. There is now increasing evidence that some phytochemicals can be also protective for the heart, having the potential to reduce cancer, cardiovascular disease and even anticancer drug-induced cardiotoxicity. We introduce the concept that these compounds induce pre-conditioning, a low level cellular stress that induces strong protective mechanisms conferring resistance to toxins such as cancer chemotherapeutics. Cancer cells and cardiomyocytes have fundamental differences in their metabolism and sensitivity to preconditioning, autophagy and apoptosis, so that dosage of the prevention compounds is important. Here we discuss the mechanisms responsible for the cardiotoxicity of anticancer drugs, the possibility to prevent them and provide examples of diet-derived phytochemicals and other biological substances that could be exploited for protecting the cardiovascular system according to a joint cardio-oncological preventative approach.

Correlation between pre-operative metabolic syndrome and persistent blood glucose elevation during cardiac surgery in non-diabetic patients

BACKGROUND

Cardiopulmonary-bypass (CPB) induces hyperglycemia. There is growing evidence that perioperative maintenance of blood glucose within the physiological range improves patients' outcome. Nevertheless, perioperative normoglycemia is often difficult to achieve during surgery with CPB and the response to insulin infusion is characterized by a considerable variability. The aim of this study was to determine to what extent the presence of pre-operative metabolic syndrome (MS) influences the blood glucose and insulin response during cardiac surgery.

METHODS

Forty-five patients scheduled for elective cardiac surgery were screened for the presence of MS according to the International Diabetes Federation definition. Patients were then assigned to two groups: those with metabolic syndrome (MSP) and those without (control). During surgery, blood glucose levels were measured in all patients and hyperglycemia was treated with a standard protocol of continuous insulin infusion.

RESULTS

The mean blood glucose levels during CPB increased only in the MSP group (P<0.001). Mean blood glucose in control patients did not increase during CPB (P=0.4). Patients with MS received 13.3+/-8.4 IU of insulin during CPB, while the control group did not require insulin treatment (P<0.001). Forty percent of patients in the control group and 100% of those in the MSP group developed post-operative insulin resistance. C-reactive protein was higher in the MSP group before, during and at 48 h after surgery.

CONCLUSIONS

The mean blood glucose levels during CPB increased only in patients with MS, while they remained unchanged in patients in the control group.

[Clinical use of spinal or epidural steroids]

Steroids, drugs with potent antiinflammatory properties on the damaged nervous roots, have been especially used as adjuvants of local anesthetics, by spinal route, in the treatments of low-back pain. Spinal route was chosen to obtain a higher local concentration of drug, with few systemic side effects and to improve drug's action mechanism. Steroids seem to interact with GABA receptors and thus control neural excitability through a stabilising effect on membranes, modification of nervous conduction and membrane hyperpolarization, in supraspinal and spinal site. Epidural steroids are especially used in the treatment of low back pain due to irritation of nervous roots. They have been administered alone or in association with local anesthetics and/or saline solution. Slow release formulations have been generally used (methylprednisolone acetate, and triamcinolone diacetate). Other indications of epidural steroids are: postoperative hemilaminectomy pain, prevention of post herpetic neuralgia, degenerative ostheoartrithis. Intra-thecal steroids have been frequently used in the treatment of lumbar radiculopathy due to discopathy, as an alternative treatment when epidural administration is ineffective. Positive results have been obtained with methylprednisolone acetate, alone or in association with local anesthetics. Complications related to intraspinal steroids injections are due to execution of the block and side effects of drugs. Complications associated with intrathecal steroids are more frequent and severe than epidural injections and include: adhesive arachnoiditis, aseptic meningitis, cauda equina syndrome. Steroidal toxicity seems to be related to the polyethylenic glycole vehicle. Anyway, slow release formulations contain less concentrated polyethylenic glycole. The epidural administration, a correct dilution of steroid with local anesthetics solution and/or saline solution, and a limited number of injections (no more than three) allows a significant reduction of steroid neurotoxicity.

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.

[Repair of anterior mitral leaflet prolapse: state of the art]

Surgical repair of anterior leaflet prolapse has evolved and widely expanded over the past decade. A number of surgical techniques have been developed. In this study a review of all reparative techniques has been provided. A classification has been proposed according to the involvement of valve components and, eventually, to graft employment. For each technique the following points have been detailed: a) advantages and drawbacks; b) likelihood of effective valve repair based on morpho-pathologic variability of degenerative mitral disease; c) long-term outcome as freedom from reoperation. The authors provide indications for early surgical anterior leaflet prolapse repair and recommend that surgeons should be familiar with many reparative procedures to select the right option and improve their operative results.

Effect of aspirin and ticlopidine on plasma tissue factor levels in stable and unstable angina pectoris

Patients with unstable angina have an increased activation of the coagulation system. Aspirin and ticlopidine given in combination may potentiate each other by the combination of different action mechanisms and may reduce the risk of coronary occlusion and clinical instability. Plasma tissue factor (TF) levels collected into the stenotic coronary artery may be an index of TF expression within the vasculature. In 160 patients undergoing angioplasty for a 81+/-5% coronary lesion, we measured TF in blood samples collected from a vein and from the coronary ostium. Immediately after and 10 minutes after the dilation procedures the samples were withdrawn also beyond the lesion. Heparin 150 U/kg was given as an anticoagulant. All patients were pretreated with 250 mg/day of aspirin. One hundred twenty patients were randomly assigned to receive 24, 48, or 72 hours of ticlopidine treatment (250 mg/twice daily). TF levels did not increase during angioplasty but there was a significantly higher TF expression in unstable than in stable patients, irrespective of the invasiveness of debulking procedures. When ticlopidine was given for 72 hours, TF levels were similar to normal laboratory values both in stable and unstable patients. This combined antiplatelet pretreatment may be of benefit in unstable angina patients, with a favorable cost/benefit ratio.

Haemodynamic effects of intravenous clonidine on propofol or thiopental induction

The study evaluated the effects of premedication with intravenous clonidine on thiopental or propofol requirements for induction and haemodynamic changes associated with both induction and endotracheal intubation. Clonidine administered intravenously before induction of anaesthesia reduced propofol or thiopental requirements. The association of clonidine and propofol caused, after injection of the induction drug, a decrease in mean arterial pressure which was significantly greater than with thiopental. Moreover, a major haemodynamic stability was registered before and after laryngoscopy in the clonidine-thiopental group. These findings might contraindicate the clonidine-propofol combination in patients with cardiovascular disease.

[High-risk pulmonary surgery in potential candidates for a heart transplant]

Severe ventricular dysfunction and concomitant infection are considered absolute contraindications for major thoracic operations and immunosuppressive therapy, respectively. However, cardiac transplantation represents the first-choice treatment in advanced heart failure. We report the case of a patient with dilated cardiomyopathy and severe left ventricular dysfunction (ejection fraction = 25%), initially not considered as a potential heart transplant candidate due to the presence of a lung abscess. The patient subsequently underwent atypical pulmonary resection with intraoperative and perioperative intraaortic balloon counter-pulsation for circulatory support and was then listed for cardiac transplant. Pitfalls and intra/postoperative strategy, all of which are potentially important aspects in minimizing operative risk, are discussed.

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.

Inferior epigastric artery as a conduit for myocardial revascularization: a two-year clinical and angiographic follow-up

The inferior epigastric artery has been proposed as a suitable conduit for myocardial revascularization but its mid-term patency rate has not been assessed. A prospective clinical and angiographic study on the use of the inferior epigastric artery as an additional arterial conduit together with bilateral internal thoracic artery grafting was conducted in 38 patients. No deaths or major postoperative complications occurred. Twenty-three patients underwent repeat angiography after an average of 21.2 months. The left and right internal thoracic artery grafts patency rate was 95.6% (44/46), while inferior epigastric artery patency rate was 52.2% (12/23). By relating patency to the grafted coronary branch, the following results were obtained: 100% for the left anterior descending (3/3), right coronary (1/1) and ramus medianus (1/1); 40% (4/10) and 37.5% (3/8) for diagonals and obtuse marginals respectively. The low patency rates observed when the inferior epigastric artery is used on diagonals and obtuse marginals indicate that this vessel cannot be considered a suitable conduit for extensive application of arterial revascularization. We suggest that the inferior epigastric artery should only be used in patients presenting with contraindications to bilateral internal thoracic artery or right gastroepiploic artery grafting, or exhibiting unsuitable saphenous veins.

Myocardial metabolism studied during warm blood antero-retrograde reperfusion in ischaemic human hearts

We propose modified warm blood antegrade-retrograde reperfusion (WBARR) of arrested hearts as a metabolic model with which to study substrate exchange and energy metabolism during the recovery phase after 90 min of ischaemia in man. Eleven anaesthetized patients undergoing aorto-coronary bypass were studied during WBARR. The protocol was designed as follows: period 1, a warm blood reperfusion with potassium (3 min); period 2, a warm blood reperfusion without potassium (2 min). The perfusion flow rate averaged 250+/-2 ml/min at the beginning of period 1 and 218+/-19 ml/min at the beginning and at the end of period 2; the perfusion was performed antegradely and retrogradely in the arrested hearts. Samples were simultaneously taken from the coronary venous sinus (CVS) and from the aortic root needle (AR). At the beginning of WBARR lactate release was 85+/-44 micromol/min and at the end it had significantly decreased to 21+/-99 micromol/min (P<0.03). Simultaneously, non-esterified fatty acids (NEFA) and beta-hydroxy-butyrate were initially released (71+/-61 and 22+/-66 micromol/min, respectively), while at the end of the WBARR there was an uptake of both NEFA (20+/-22 micromol/min; P<0.01) and beta-hydroxy-butyrate (12+/-35 micromol/min; P=0.290). Alanine, glycerol and branched chain amino acid balance across the heart did not significantly change. In summary after 90 min of ischaemia the heart energy metabolism is mainly anaerobic and based on glucose consumption, with lactate, NEFA and amino acids, which are mainly released. After 5 min of WBARR (recovery from ischaemia), lactate release is significantly reduced and NEFA becomes the energy supply of the heart. In conclusion, (1) WBARR is a valuable method with which to study myocardial metabolism in anaesthetized humans and may be combined with the use of tracers; (2) the study of myocardial metabolism in arrested hearts eliminates the imprecisions arising from the noncontinuous coronary blood flow; (3) NEFA become an important source of energy utilized by human hearts in the recovery phase from ischaemia.

Mycotic aortic aneurysm presenting as multiple cerebral abscesses

A 68-year-old male presented with multiple cerebral abscesses. Possible intrathoracic embolic sources were not detected by echocardiography and chest radiography and the main lesion was surgically excised. Following deterioration of the neurological status, computerized tomography performed 2 weeks later revealed a mycotic aneurysm of the ascending aorta, probably related to a previous cardiac operation. This is the first case in the literature of aortic infection presenting as multiple brain abscesses.

Surgery of cavo-atrial renal carcinoma employing circulatory arrest: immediate and mid-term results

From 1990 to 1995, 12 patients with cavo-atrial renal cell carcinoma underwent resection of the tumor. Circulatory arrest was employed in 11/12 cases. The neoplasm extended to the inferior vena cava in two patients and to the intrahepatic veins or right atrium in five cases. Two severely cardiac compromised patients died perioperatively. Of five patients who showed preoperative suspicion of isolated metastases, 3 patients died postoperatively because of relapsing disease after a mean period of 10.8 months. Five patients are alive and doing well after a mean follow-up of 14.8 months. In our experience myocardial dysfunction determined poor immediate survival. Mid-term survival was influenced by preoperative metastases and lymph-node involvement, but not by intracaval extension. Circulatory arrest appears to be a relatively safe technique to remove renal carcinoma with cavo-atrial extension and should be indicated whenever there are no metastases.

Timing for surgical treatment in native infective endocarditis. A seven-year experience

BACKGROUND

Early surgical intervention in infective endocarditis is performed only when there is persistence of sepsis, hemodynamic instability or when arterial embolism has occurred, otherwise a 4-week antibiotic therapy before surgery is considered necessary. Our 7-year experience in the surgical treatment of native endocarditis in 28 patients, is here revised focusing on the timing of surgery.

METHODS

Patients were retrospectively divided into group A (n. 16) with blood cultures that became negative before surgery and group B (n. 11) with blood cultures positive at the time of urgent surgery. One patient with constantly negative blood cultures was not assigned to any group. In group A antibiotic therapy was administered until 3 consecutive blood cultures became negative and the patients were then operated on the basis of echocardiographic findings after a mean duration of antibiotic therapy of 17.4 +/- 6.3 days.

RESULTS

Twenty-six patients out of 28 underwent replacement of the infected valve (mechanical bileaflets in 16 patients, porcine stented in 7 and porcine stentless in 3). Valve repair was performed in 2 patients. Overall operative mortality was) 7.1% (2/28); death occurred in 2 patients of group B, operated on for cardiogenic shock. Two/26 patients died (1 acute renal failure and 1 stroke) at a mean follow-up of 32.5 +/- 24.8 (range 3-95) months.

CONCLUSIONS

Patients who underwent surgery for infective endocarditis after blood culture negativization showed no mortality and no recurrence of disease even if a 4 weeks antibiotic course was not completed. This experience suggests that earlier operations can be performed safely, lowering the incidence of hemodynamic impairment and arterial embolism.

Aortic diverticulum without vascular ring: a rare cause of dysphagia

In an adult with severe dysphagia, diagnosis of aneurysmal aberrant subclavian artery was suspected on computed tomogram; no vascular ring was visible on arteriogram. A diverticulum of the aortic isthmus was surgically resected. Histologic analysis ruled out acquired disease. In conclusion, dysphagia related to esophageal compression may be caused by an isolated congenital aortic diverticulum.

[Transmyocardial laser revascularization in patients with peripheral coronary atherosclerosis. Indications and preliminary results]

BACKGROUND

Surgical intervention for coronary artery disease (CAD) is determined by the viability of coronary artery branches. When peripheral coronary artery disease is present, conventional bypass grafting is not suitable. Research has recently been done on alternative methods such as transmyocardial laser revascularization (TMLR). TMLR works through the vascular connections that are present between the cardiac chambers and the myocardial muscle in the human heart. The creation of 1-mm transmural cardiotomies through a CO2 laser should improve myocardial perfusion.

METHODS

From February to June of 1996, twelve patients (9 males and 3 females with a mean age of 67.8 +/- 4.6) with CAD (mean n0 of diseased vessels 2.7), angina (mean CCS class 3.5 +/- 0.5), mean ejection fraction 47.8% and viable ischemic myocardium on scintiscan in segments without graftable coronary branches, underwent TMLR at our institute. Nine of the 12 patients also underwent associated CABG (mean number of anastomoses per patient: 2.5). Cardiopulmonary bypass was never used, since coronary anastomoses and laser cardiotomies were performed on the beating heart.

RESULTS

Perioperative mortality was 2/12 (16.6%). Postoperative inotropic support and diuretic therapy was required in most cases. At a mean follow-up period of 4.2 months, all remaining patients are still alive: 5/10 are angina-free (CCS 0), 4/10 are in CCS class 1 and 1/10 is in CCS class 2 (mean 0.6 +/- 0.7).

CONCLUSIONS

We believe that TMLR could be considered an effective mean to treat symptomatic myocardial ischemic disease in which coronary bypass grafting is not suitable. During the immediate postoperative period, contractile myocardial dysfunction occurs in a high percentage of patients treated using TMLR and consequently it would be worthwhile to invest in further research.

Six-and-half years' experience with the St. Jude BioImplant porcine prosthesis

BACKGROUND AND AIMS OF THE STUDY

In this study, we reviewed our experience in heart valve replacement with the St. Jude BioImplant heart valve, which is a low-profile, low-pressure glutaraldehyde-fixed porcine prosthesis mounted on a flexible Delrin stent.

METHODS

During the period May 1989-January 1996, 117 patients were implanted with 132 BioImplant prostheses; three patients were lost to follow up and excluded from the series. Mean age was 67.5 +/- 9.8 years (range: 19 to 82 years); myocardial revascularization was performed in 22 (19.3%) patients. In-hospital mortality rate was 6% (7/117 patients). By January 1996, 114 patients (53 males, 61 females), in whom 59 aortic, 35 mitral, 15 mitro-aortic and five tricuspid prostheses had been implanted, were eligible for the analysis. Mean follow up was 40.4 +/- 21.7 months (range: 1 to 76 months).

RESULTS

The survival probability of survivors was 72.1 +/- 6.5 at 77 months. Seventeen patients died during follow-up. The mean NYHA class improved from 3.1 +/- 0.6 preoperatively to 1.4 +/- 0.6 postoperatively. The freedom probabilities were respectively 89.5 +/- 5.3% from thromboembolism, 93.2 +/- 3.7% from infective endocarditis, 84.5 +/- 10.3% from structural dysfunction, 99.1 +/- 0.9% from non-structural dysfunction, and 80.1 +/- 10.2% from reoperation. The freedom probability for valve-related events was respectively 75.3 +/- 12.3%, 98.0 +/- 1.9% and 67.2 +/- 17.2% for patients who underwent mitral, aortic and mitro-aortic heart valve replacement (p = 0.05 comparing only patients who underwent mitral or aortic replacement); moreover the freedom probability from valve-related events was 71.6 +/- 11.2% in patients aged < or = 65 years and 90.2 +/- 6.6% in patients aged > 65 years (p = 0.006).

CONCLUSIONS

The BioImplant heart valve, in our experience, seems to be a valuable device which shows a mid-term performance similar to that of other porcine prostheses.

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.

[Emergency surgical revascularization in acute myocardial infarct. The preliminary results of a prospective study]

In this paper we describe 1-year experience with a perspective operative protocol of emergency myocardial revascularization in extensive acute myocardial infarction (AMI). Entry criteria were: age < 75 years; anterior AMI with ST segment elevation > 4 leads, infero-postero-lateral or inferior and right ventricular AMI, within 6 hours from symptom onset. After coronary arteriography, an emergency staff, composed by cardiologists and cardiac surgeons, addresses the patients to coronary artery bypass grafting (CABG) or to percutaneous transluminal coronary angioplasty (PTCA). From November 1994 to November 1995, 35 patients were enrolled: 19 (mean age 54.3 +/- 9.7 years) underwent CABG and 16 were treated with PTCA. Myocardial protection was such as to restore energetic substrates and to prevent reperfusion injury: surgical technique consisted of antegrade-retrograde substrate-enriched blood cardioplegic solution delivery, early cardioplegic delivery on the infarcting area via a saphenous graft, retrograde controlled reperfusion before aortic unclamping and then prolonged reperfusion of the infarcted myocardium. In 8 patients (mean age 50.9 +/- 8.6 years), with anterior AMI and stable hemodynamics, a left internal thoracic artery graft was used, performing the prolonged controlled reperfusion retrogradely before aortic unclamping. In hospital death occurred in 1/19 (5.3%) patients because of cerebral hemorrhage. At a mean follow-up of 5.1 +/- 3.7 months 17 patients (94.4%) were in NYHA functional class I-II and 1 patient (5.6%) complained of effort angina, that was well controlled with medical therapy. Left ventricular ejection fraction calculated by echocardiography preoperatively, before discharge and at follow-up was respectively 39.3 +/- 12.7, 43.1 +/- 8.9 and 43.4 +/- 9.0%. In the last 8 consecutive patients thermodilution and transesophageal echocardiography monitoring were performed preoperatively and 12 hours after CABG: in all cases ejection fraction and cardiac index increased after CABG, from 42.2 +/- 13.5 to 48.6 +/- 14.3% (p = 0.01) and from 2.8 +/- 0.5 to 3.4 +/- 0.6 l/min/m2 (p = 0.005), respectively. The preliminary results show the effectiveness of this perspective protocol in the management of critically ill patients with extensive AMI.

Primary cardiac malignancy presenting as left atrial myxoma. Clinical and surgical considerations

Primary heart neoplasms occur in 0.002-0.3% of autopsies: 30% are myxomas and 20-30% are malignancies, almost always sarcomas. Cardiac metastases are 10 to 40 times more frequent than primary heart cancer. We describe a case of a left atrial sarcoma erroneously diagnosed as myxomas preoperatively. Standard surgical indication for resection of cardiac myxomas is based on echocardiography. Because of the severity of cardiac malignant lesions than can mimic atrial myxomas at echocardiography, through preoperative investigation should be accomplished, best by magnetic resonance imaging. In case of suspected malignancy, total body computed tomography should be performed to avoid unnecessary cardiac operations in case of disseminated cancer. To date the only good medium and long-term results in the therapeutic management of heart sarcomas have been achieved by transplantation: the probable explanation is that criteria of surgical radicality should be those followed for soft tissue tumors located elsewhere in the organism.

[Acute myocardial infarction in bacterial endocarditis]

The authors report on a 47-years old woman with bacterial endocarditis involving both the mitral and aortic valves. At first echocardiographic examination, the mitral vegetation was small, while the aortic one was large highly mobile. Despite adequate antibiotic therapy, the aortic vegetation had become bigger and the valve regurgitation, initially mild to moderate, resulted severe and was associated with left heart failure. While awaiting surgery, the patient sustained an acute non Q wave myocardial infarction with ST segment elevation in inferior and anterolateral leads, complicated by ventricular arrhythmias. Thirty-six hours later, the patient received mitral and aortic valve replacement: at surgical view, the aortic vegetations was found to be very close to the right coronary orifice. After a period of further antibiotic therapy, the woman discharged and at a six months follow-up, she was fairly well. The authors review the mechanisms of acute coronary insufficiency in infective endocarditis and suggest an embolic pathogenesis in the case reported. Taking into account the possible life threatening embolic complications, it seems reasonable not to delay surgery when antibiotic therapy fails to reduce the size and mobility of valve vegetations.

Advantages of delayed sternal closure in cardiac-compromised adult patients

Severe hemodynamic dysfunction may follow closure of the median sternotomy in patients with myocardial edema, cardiac dilatation, postcardiotomy shock, or raised end-expiratory alveolar pressure. Open sternotomy and delayed sternal closure (DSC) is a well described adjunct in complicated cardiac operations, which is more widely applied in neonates. In this article we report our results in using open sternotomy in eight adult patients from January 1994 to February 1995 (excluding patients who needed ventricular assistance devices [VADs]). Three patients died in hospital: 1 case of multiorgan failure; 1 cases of refractory low cardiac output syndrome; and 1 case of respiratory distress syndrome. Our experience confirms that DSC is an effective means of dealing with postoperative hemodynamic impairment. Furthermore, this technique may represent an intermediate step between intraaortic balloon counterpulsation and VADs and should be given a role in the prophylaxis of low postoperative cardiac output and multiorgan failure, particularly when contraindications to VAD exist.

Warm heart surgery in cold haemagglutinin disease

Continuous warm retrograde blood cardioplegia and systemic normothermia are a promising method for heart surgery in patients with cold autoimmune disorders in order to avoid the adverse effects of both systemic and coronary hypothermia during cardiac arrest and cardiopulmonary bypass. A 59-year-old white man with cold haemagglutinin disease who underwent coronary surgery using continuous retrograde normothermic blood cardioplegia and systemic normothermia is reported.

Combined carotid endarterectomy and myocardial revascularization: personal experience

A significant percentage of patients undergoing myocardial revascularization suffer from extracranial cerebrovascular disease; recognition of such combined lesions identifies patients at risk for cerebrovascular accidents during the cardiac procedure. Simultaneous or staged coronary artery bypass graft (CABG) and carotid endarterectomy operations have been performed for the last 20 years, however, the clinical indications and the timing of the procedures remain controversial issues. Between November 1988 and January 1994, 1122 patients underwent myocardial revascularization at our Institute and in 35 cases (3.7%) carotid endarterectomy was simultaneously performed; 502 isolated carotid endarterectomies were performed in the same period. Trivascular coronary artery disease was found in 27 cases and low ejection fraction in six. Each patient received an average of 3.7 coronary grafts. Hospital mortality was 5.7% and major neurologic morbidity 2.8%. We believe that a simultaneous approach is recommended in patients with unstable angina and symptomatic carotid artery disease; in patients with a critical but asymptomatic carotid artery stenosis the indication for operation is subject to individual clinical judgment.

Identification of hibernating myocardium: a comparison between dobutamine echocardiography and study of perfusion and metabolism in patients with severe left ventricular dysfunction

The distinction between fibrotic and viable myocardium is a key issue in patients with coronary artery disease and left ventricular dysfunction. Metabolic imaging with positron emission tomography (PET) and labeled tracers, along with the study of myocardial perfusion, is now available to identify hibernating myocardium. However, PET imaging of myocardial metabolism is a high-cost and time-consuming technique, and requires an on-site cyclotron. The aim of this study is to test the reliability of dobutamine echocardiography (DE) compared with PET imaging, for the identification of hibernating myocardium. In 16 patients, scheduled for myocardial revascularization, left ventricular shapes were divided in eight segments both for echocardiographic and nuclear study evaluation. All patients underwent a technetium 99m MIBI single-photon emission tomography stress-rest study of perfusion, a fluorine-18-labeled deoxyglucose (FDG(/PET study of metabolism, and a DE test (baseline, at a 5 micrograms/kg/min infusion of dobutamine for 8 minutes and at a 10 micrograms/kg/min dose for additional 8 minutes). Neither myocardial ischemia nor arrhythmia occurred during the DE test. Baseline echocardiograms showed 90 segments with wall motion abnormalities: wall motion impairment was decreased or reversed in 33 of 90 segments; it remained unchanged in 57 of 90 segments. In 32 of 33 segments considered viable on the basis of DE and in 21 of 57 segments with unchanged kinesis, some degree of FDG was detected. Thus, sensitivity and specificity of DE compared with nuclear studies was 60% and 97% respectively. Moreover, a good correlation and agreement (kappa = 0.51) between DE and the presence of FDG were found. We conclude that DE is a safe and reliable test for the screening of hibernating myocardium in patients with chronic coronary artery disease and left ventricular dysfunction.

Measurement of cardiac troponin T and myosin to detect perioperative myocardial damage during coronary surgery

This study evaluated the use of monitoring blood levels of the isoenzyme of creatine phosphokinase, troponin T (tnT) and myosin in the detection of perioperative myocardial damage after coronary artery surgery. Serial blood samples were collected in 24 patients undergoing myocardial revascularization. The patients were retrospectively divided into three groups: group A with no changes in their electrocardiogram; group B showing non-specific signs of perioperative myocardial infarction such as deep and permanent T wave inversion; and group C with definite electrocardiographic signs of perioperative myocardial infarction (new persistent Q-waves and loss of R-waves). Group A (n = 17) demonstrated a mean(s.d.) troponin T peak blood level of 0.64(0.35) ng/ml at 12-24 h after surgery, a myosin peak of 1030(670) mu units/l at 3-6 days afterwards, and a creatine phosphokinase isoenzyme peak of 25.8(10.6) units/l. In group B (n = 5), mean(s.d.) troponin T levels were elevated to a peak of 4.8(3.9) ng/ml 24 h after intervention, while myosin rose to 2074(340) mu units/l 3-6 days after surgery and creatine phosphokinase isoenzyme reached 57.8(38) units/l. Group C (n = 2) had a mean(s.d.) troponin T peak of 4.8(2.6) ng/ml, a myosin peak of 2404(392) mu unit/l and a creatine phosphokinase isoenzyme peak of 88.5(20) units/l. Peak values of troponin T and myosin in groups B and C were statistically different from those in group A (P < 0.001). These results suggest that troponin T and myosin are reliable indicators of perioperative myocardial damage. In particular, troponin T may allow the differentiation of reversible from irreversible myocardial injury.

[Myocardial revascularization in patients with impaired left ventricular function]

From March 1988 to May 1993, 1,125 patients with coronary artery disease (CAD) underwent coronary surgery at our Institute. In the same period 74 patients (mean age 59 +/- 7 years; range 36-73) with left ventricular dysfunction (LVD) were referred for surgical decision making. All patients underwent [99mTc]MIBI/SPET to assess perfusion at rest and [99mTc]MIBI first pass radionuclide angiography to assess the ejection fraction (EF). In 44/74 patients we performed [18F]FDG/PET in fasting conditions and pharmacologic wash-out, in order to identify viable myocardium. We divided patients with LVD into 3 groups: Group A (30 patients) operated on without preoperative [18F]FDG/PET, Group B (37 patients) operated on with FDG uptake in segments with wall motion abnormalities, and Group C (7 patients) with no FDG uptake, who were excluded from coronary surgery; there was no significant difference among the 3 groups with respect to age, sex, CAD, risk factors and EF (Group A: 29.1% +/- 6.6%, range 16-39%; Group B: 30.8 +/- 5.6%, range 20-40%; Group C: 26.5 +/- 6.8%, range 18-37%). The study of perfusion and EF was repeated 6 months postoperatively in Group A and B. Left ventricular end-dyastolic pressure at cardiac catheterization was 19.9 +/- 5.1 mmHg, 20.4 +/- 4.7 mmHg and 26.8 +/- 9.2 mmHg in Group A, B and C, respectively. Myocardial protection was achieved according to the Buckberg protocol.(ABSTRACT TRUNCATED AT 250 WORDS)

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

Although long-term patency of the internal thoracic artery (ITA) is well stated, there is still some concern about its perioperative performance. We considered 122 consecutive patients, 63 with left main disease (LMD; mean age 60 years) and 59 with left ventricular dysfunction (LVD; mean age 59 years) who underwent coronary artery bypass grafting in our Institute from March 1988 to September 1992. Patients with LMD were divided into 2 groups: LMD I: 29 patients receiving only ITA grafts on the left coronary system and LMD II: 34 patients having a single ITA graft on the left coronary system. Patients with LVD were divided into: LVD I: 44 patients operated with bilateral ITA and LVD II: 15 patients receiving a single ITA graft. Perioperative complications in LMD I and LMD II patients were respectively: myocardial necrosis in 2 (6.9%) versus 3 (8.8%), use of intra-aortic balloon pump (IABP) in 2 (6.9%) versus 2 (5.9%); no death occurred in both groups. Perioperative results in groups LVD I and LVD II were: death in 1 patient (2.2%) versus 1 (6.7%), myocardial necrosis in 2 (4.5%) versus 1 (6.7%) and IABP in 4 (9.1%) versus 2 (13.3%). In our experience the use of bilateral ITA grafts in patients with LMD and LVD was not related to an incremental risk. We conclude that LMD and LVD should not be considered as contraindications to the extensive use of arterial conduits.