P54 MORTALITY AFTER CORONARY ARTERY BYPASS GRAFT IN PATIENTS WITH PRIOR PERCUTANEOUS CORONARY INTERVENTION

Background

The clinical impact of prior percutaneous coronary intervention (PCI) in patients requiring surgical revascularization (CABG) is not well investigated. We explore whether prior PCI is associated with adverse outcome after CABG.

Methods and Results

Operations conducted between October 2014 and July 2021 at Magna Graecia University were analyzed using propensity weighted methodology to adjust for confounding. Of a total of 1410 adult patients included in the study, (24%) patients had a history of PCI. At multivariable level, prior PCI was not associated with an increased hospital mortality in both unweighted and weighted patient groups (odds ratio, 0.77; 95%; P = 0.41 and odds ratio, 0.93; 95% confidence interval; P = 0.84, respectively). Subgroup analyses confirmed that prior PCI had no impact on hospital mortality and morbidity, including reexploration for bleeding, blood transfusion, hospital resource use, and neurological, renal, and cardiac complications.

Conclusions

Our study showed that prior PCI was not associated with an increased risk of mortality or other adverse outcomes in patients undergoing CABG. Further studies are needed to ascertain the prognostic impact of prior PCI in the outcome after CABG.

Extensive endovascular repair of thoracic aorta: observational analysis of the results and effects on spinal cord perfusion

AIM

The study aims to analyze retrospective results of extensive endovascular repair of the descending thoracic aorta with special attention to spinal cord malperfusion.

METHODS

From April 2002 through November 2011, 21 patients underwent stent-graft coverage of the thoracic aorta from the aortic arch at the origin of the left subclavian artery to the celiac trunk, 6 (mean age =72.3±8.1) for aneurysm disease, 13 (mean age =74.3±8.4) for type B aortic dissection and 2 (mean age =52.1±6.5) for aortic rupture. The mean of aortic diameter in cases with aneurysm disease was 7.1±1.6 cm and the causes of aortic rupture were post-traumatic and aneurysm pathology respectively. In all cases needing coverage of the left subclavian artery duplex ultrasonography and flowmetry were performed to evaluate patency and flow of both the vertebral arteries.

RESULTS

Technical success was 100% with 0% in-hospital mortality. The left subclavian artery was crossed with the uncovered portion of the stent-graft in 11 cases (52.4%) and the covered segment in the other 10 patients (47.6%) without subclavian revascularization because no pre-operative hemodynamic alterations of vertebral arteries were revealed by duplex ultrasonography. The incidence of paraplegia was 9.5% in 2 patients who had prior abdominal aortic aneurysm repair: the first case with preoperative type B aortic dissection presented significant lower extremity paresis within 24 hours after the procedure and in the second patient with a large thoracic aneurysm the signs of paraplegia were evident 3 weeks after discharge from Hospital probably due to delayed occlusion of a major medullary artery. The cumulative survival rate after 1, 3 and 9 years was 91%, 81%, and 71%.

CONCLUSIONS

The coverage of the entire thoracic aorta is an effective procedure with high probability of success. Spinal cord malperfusion remains a serious complication especially in patients with prior aortic surgery but if collateral blood supply is maintained the occlusion of intercostal arteries do not determine paraplegia or paraparesis. In order to consider acute or chronic occlusion of subclavian, lumbar or hypogastric arteries so preventing spinal cord ischemia, strong preoperative evaluation including analysis of previous surgery for abdominal aortic aneurysm repair and avoidance of T12 aortic segment coverage if feasible is mandatory.

Valve preservation in acute type A aortic dissection: 13-year experience

AIM

Aortic dissection is frequently complicated by regurgitation of the aortic valve resulting from leaflet prolapse or tearing of the annulus or leaflet. The authors have evaluated the results using the technique of aortic valve preservation in patients with acute type A aortic dissection (AAD).

METHODS

In a consecutive series of 79 AAD observed from January 1994 to September 2007, 51 (64.6%) presented aortic valve insufficiency (AI). All patients were emergency operated on via median sternotomy and femoral (46/79, 58.2%) or axillary artery-right atrium (33/79, 41.8%) cardiopulmonary bypass with 60 cases (75.9%) of antegrade selective cerebral perfusion. The dissected aorta was resected and the aortic valve was replaced in 2 patients/51 (3.9%) and was preserved in the remaining 49 cases as follows: 42 (85.7%) commissural resuspensions due to commissural prolapse, 3 (6.1%) resuspensions due to cusp prolapse, 3 (6.1%) commissural plication and 1 (2.1%) circumclusion due to annular dilatation.

RESULTS

The overall hospital mortality was 20.3% (16/79) with a percentage of 19.6% (10/51) in the AI group. 1 patient presented a type B dissection at 1 months and died after reoperation. The remaining 40 patients with a preserved native valve were followed by echocardiography and computed tomography (CT) (follow-up ranged from 3 to 165 months) with 4 late deaths. Twenty-six patients had absent or grade I AI (72.2%), 8 had grade II AI (22.2%) and 2 presented grade III or IV AI (5.6%). Actuarial freedom from significant AI was 96.2+/-2.4% and 94.2+/-2.3% at 5 and 10 years respectively.

CONCLUSION

The experience with this technique demonstrates the effectiveness of valve conservative treatment within a vascular graft. The reconstruction of the sinotubular junction reducing annular dilatation with appropriated sized graft is obviously mandatory. Although this procedure is not applicable to every patient, we firmly believe that is a valid option when a morphologically intact valve is present.

Aortic tube grafts wrapping with hemostatic fleeces reduces postoperative pericardial effusions

Pericardial effusions often complicate the postoperative course of ascending aortic surgery. We evaluated whether an unconventional use of hemostatic fleeces (TachoSil, Nycomed; Austria), wrapped around aortic tube grafts, may reduce such complication. Twenty-nine consecutive patients undergoing button-Bentall were submitted - according to surgeon's choice - to 360 degrees wrapping of the aortic grafts with hemostatic fleeces immediately before sternal wiring (11 patients - group A) or sternal wiring without any wrapping of the prosthesis (18 patients - group B). Hospital outcome was recorded. No differences were recorded in hospital mortality and major organ morbidity. When pericardial complications were considered, group A showed lower chest drains (P=0.0001), time of chest drainage (P=0.002), pretamponade/tamponade with need for pericardiocentesis (P=0.039), predischarge echocardiographic amount of pericardial effusion (P=0.026), fever (P=0.029), need for anti-inflammatory (P=0.05) or antibiotic drugs (P=0.007), hospital stay (P=0.010) and white blood cell count (P=0.016 on postoperative day 3; P=0.014 on day 6). Wrapping of aortic tube grafts with hemostatic fleeces is effective in reducing pericardial effusion and its deleterious effects following aortic surgery.

Usefulness of the axillary artery as vascular access for cardiopulmonary bypass

AIM

In this paper we report our clinical experience with extended utilization of axillary artery cannulation for cardiopulmonary bypass (CPB) and discuss the indications and the results of the procedure in terms of complications and usefulness.

METHODS

Between January 1999 and May 2004, 26 patients underwent right axillary artery cannulation for CPB. Fifteen patients presented acute type A aortic dissection and were operated urgently. Axillary cannulation was also used in 11 elective cases: 3 reoperative coronary surgery, 3 valve redo-operations and 5 cases of aortic valve regurgitation+aneurysm of the ascending aorta.

RESULTS

All axillary artery cannulations were successful (21 direct and 5 with a side graft) without neurologic or vascular injuries to the right upper extremities. Hospital mortality was 7.7% and included 2 patients operated in an emergency procedure because of acute type A aortic dissection. In all cases, this cannulation site provided adequate perfusion, with a range of peak flows from 4.1 to 5.7 L/min.

CONCLUSION

Our preliminary results demonstrate that the right axillary artery may be considered an alternative cannulation site for achieving full CPB and providing antegrade flow, thus avoiding complications related to retrograde flow when femoral artery perfusion is performed. This safe and useful method may be used not only in aortic surgery but in other such complex cardiac procedures as redo-operations.

Myocardial protection in diabetics with left main stem disease: which is the best strategy?

AIM

Diabetes mellitus is a well known risk factor for extensive coronary disease. The optimal route for cardioplegia administration in patients with severe ischaemic heart disease undergone surgery, especially with left main stem disease (LMSD) is still under debate. Aim of the study is to compare 2 different strategies of myocardial protection in diabetics with LMSD.

METHODS

Between January 2000 and June 2003 90 consecutive patients with type II diabetes mellitus and LMSD undergoing isolated myocardial revascularization were divided into 2 groups according to the route of cardioplegia delivery: antegrade in 45 patients (group A), antegrade followed by intermittent retrograde in 45 (group B). ECG, Troponin I, MB-CPK, MB-CPK mass were performed at 12, 24, 48, and 72 hours postoperatively. Echocardiography was performed preoperatively and before hospital discharge.

RESULTS

Groups were homogeneous in preoperative and intraoperative variables, apart from higher incidence of unstable angina and longer cardiopulmonary bypass time in Group B and hypertension in Group A. Hospital deaths, in intensive care units (ITU) stay, perioperative acute myocardial infarction, intra-aortic balloon pump support, postoperative recovery of left ventricle ejection fraction and wall motion score index were similar in both groups. In hospital stay proved shorter in group B (p=0.002), whereas postoperative atrial fibrillation was higher in group A (p<0.001), as postoperative inotropic support (p=0.006). Troponin I proved significantly higher in group A from the 12 degrees to the 72 degrees postoperative hour (p<0.0001).

CONCLUSIONS

Despite major in hospital end-points did not differ with strategy of cardioplegia administration, combined route of intermittent blood cardioplegia allows better biochemical and perioperative results in diabetics with LMSD.

Intermittent warm blood cardioplegia induces the expression of heat shock protein-72 by ischemic myocardial preconditioning

OBJECTIVE

Recent studies have demonstrated that the induction of heat shock protein-72 (HSP72) by different stimuli preserves the heart function after cardioplegic arrest. Based on these findings, we investigated whether intermittent warm blood cardioplegia would induce changes in the myocardial expression of HSP72.

METHODS

Forty patients scheduled for aortocoronary bypass were randomly assigned to receive either cold or warm intermittent blood cardioplegia. In all patients HSP72 and HSP72 mRNA were assayed in biopsies from the right atrium at baseline, and during the reperfusion period. Plasma CK-MB and troponin-T, and myocardial oxygen extraction and lactate release were also measured.

RESULTS

In both groups, myocardial expression of HSP72 increased throughout the reperfusion period, but the values of HSP72 band lengths were significantly higher in the warm group. Correspondingly, HSP72 mRNA levels increased progressively in both groups, with significant difference between groups observed in biopsies at the reperfusion. Warm blood cardioplegia was associated with lower levels of CK-MB and troponin-T. Myocardial oxygen extraction and lactate release were higher during intermittent warm cardioplegia, indicating a more profound ischemic anaerobic metabolism in the warm group.

CONCLUSIONS

Intermittent warm blood cardioplegia induces an increased expression of HSP72 and it is associated with a better myocardial protection, by a mechanism involving a variant of the classical ischemic preconditioning model.

Simvastatin attenuates leucocyte-endothelial interactions after coronary revascularisation with cardiopulmonary bypass

OBJECTIVE

To investigate the effects of preoperative simvastatin treatment on leucocyte-endothelial interactions following coronary artery bypass surgery with cardiopulmonary bypass.

DESIGN

Double blind crossover study. Experiments on polymorphonuclear cells (neutrophils) were done at the end of cardiopulmonary bypass and one hour postoperatively. Endothelial P-selectin expression and neutrophil/endothelial adhesion were evaluated under either normoxic or hypoxic conditions.

SETTING

University hospital (tertiary referral centre).

PATIENTS

Three groups of patients undergoing coronary bypass surgery: 20 patients taking simvastatin for cholesterol control, 16 patients not responsive to simvastatin, and 20 controls.

MAIN OUTCOME MEASURES

Expression of neutrophil CD11b and endothelial P-selectin; adhesion of neutrophils to endothelium.

RESULTS

Cardiopulmonary bypass resulted in a significant increase in neutrophil CD11b expression in all groups. Similarly, the exposure of saphenous vein to hypoxia/reoxygenation induced an augmentation of endothelial P-selectin. However, both neutrophil CD11b expression and endothelial P-selectin exocytosis were less in the simvastatin groups than in the controls. Cardiopulmonary bypass and controlled hypoxia/reoxygenation stimulated neutrophil/endothelial adhesion, but the number of adhering cells was less in the simvastatin groups than in the controls, irrespective of the cholesterol concentration. Treatment of endothelial cells with L-NAME completely reversed the effects of simvastatin.

CONCLUSIONS

Pretreatment with simvastatin reduces neutrophil adhesion to the venous endothelium in patients undergoing coronary surgery, irrespective of its efficacy at lowering cholesterol concentration.

Pseudoaneurysm of the thoracic aorta in patients with human immunodeficiency virus infection

Arterial pseudoaneurysm has been reported as a possible complication of immunodeficiency virus infection. We report two cases of HIV-positive patients with a pseudoaneurysm at the level of the descending thoracic aorta. The first patient refused surgery and has been followed up to 14 months, whereas the second patient underwent successful surgical repair. The importance of magnetic resonance imaging in the diagnosis of thoracic aorta pseudoaneurysm is also discussed.

Prognostic significance of endothelial dysfunction in hypertensive patients

BACKGROUND

Forearm endothelial dysfunction, characterized by an impaired vasodilating response to acetylcholine (ACh), may be associated with several cardiovascular risk factors, including essential hypertension. Although the prognostic value of coronary endothelial dysfunction has been demonstrated, that of forearm endothelial dysfunction is still unknown. Methods and Results-- Endothelium-dependent and -independent vasodilation was investigated in 225 never-treated hypertensive patients (age, 35 to 54 years) by intra-arterial infusion of increasing doses of ACh and sodium nitroprusside. Patients were divided into tertiles on the basis of their increase in ACh-stimulated forearm blood flow (FBF) from basal: group 1, from 30% to 184%; group 2, from 185% to 333%; and group 3, from 339% to 760% increase from basal. During a mean follow-up of 31.5 of months (range, 4 to 84 months), there were 29 major adverse events at the cardiac (n=19), cerebrovascular (n=9), or peripheral vascular (n=1) level. Events included myocardial infarction, angina, coronary revascularization procedures, stroke, transient cerebral ischemic attack, and aortoiliac occlusive disease. Event rate per 100 patient-years was 8.17, 4.34, and 2.02 in the first, second, and third tertiles of peak percent increase in FBF during ACh infusion. The excess risk associated with an FBF increase in the first tertile was significant (relative risk, 2.084; 95% CI, 1.25 to 3.48; P=0.0049) after controlling for individual risk markers, including 24-hour ambulatory blood pressure.

CONCLUSIONS

Our data suggest that forearm endothelial dysfunction is a marker of future cardiovascular events in patients with essential hypertension.

Plasma levels of atrial and brain natriuretic peptides as indicators of recovery of left ventricular systolic function after coronary artery bypass

OBJECTIVE

The purpose of this study was to investigate the effectiveness of atrial and brain natriuretic peptides (ANP and BNP, respectively) as indicators of recovery of left ventricular (LV) function after coronary surgery.

METHODS

We measured the concentrations of these peptides in 31 patients with poor LV function (ejection fraction, EF<35%) undergoing coronary artery bypass, and evaluated their correlation with the echocardiographic indexes of LV function.

RESULTS

Pre-operatively, the plasma levels of both ANP and BNP were markedly higher in coronary patients than in normal control subjects, and strongly correlated with both EF (BNP: r=-0.8, P<0.001; ANP: r=-0.6, P<0.001) and wall motion score index (WMSI). At post-operative follow up, plasma levels of both natriuretic peptides were markedly reduced compared with pre-operative values in 21 patients. In addition, the post-operative-pre-operative differences of BNP (Delta(BNP)) and ANP (Delta(ANP)) plasma levels strongly correlated with the differences of both EF (r=-0.7, P<0.0001 vs. Delta(BNP); r=-0.6, P=0.0003 vs. Delta(ANP)) and WMSI (r=0.6, P=0.002 vs. Delta(BNP); r=0.6, P=0.04 vs. Delta(ANP)). Finally, by logistic regression analysis, BNP appeared a significant predictor of LVEF recovery after surgery.

CONCLUSION

Plasma levels of ANP and BNP might be used in routine clinical practice as a support to echocardiography in detecting recovery of the LV function after coronary surgery.

Duromedics original prosthesis: what do we really know about diagnosis and mechanism of leaflet escape?

The Edwards-Duromedics (ED) is a bileaflet pyrolitic carbon mechanical valve introduced by Hemex Scientific Inc in 1982, subsequently acquired by Baxter Healthcare Corp, withdrawn from the market in 1988, and modified and reintroduced in 1990. From 1982 to date, 46 cases of leaflet escape have been registered by the manufacturer of an estimated total of 20,000 valves implanted. Disc embolization 12 years after an ED mitral prosthesis implantation is reported in a 45-year-old man operated on when he was in cardiogenic shock because a preliminary transthoracic Doppler echocardiography did not show malfunction of the valve. A correct diagnosis was made four days after the onset of the symptoms by transesophageal echocardiography. During the operation, the posterior leaflet of the ED valve was not found, a 29 mm St Jude Medical bileaflet mechanical prosthesis was implanted and the patient died in the intensive care unit because of low cardiac output syndrome. Cavitation damage is generally considered the most frequent mechanism in cases of such fracture. Thus, any patient with a mechanical valve presenting with acute pulmonary edema must be immediately transferred to a surgical unit; cinefluoroscopy or transesophageal echocardiography may be performed rapidly to achieve successful management of patients with leaflet embolization.

Effects of atorvastatin and vitamin C on endothelial function of hypercholesterolemic patients

We tested the effects of vitamin C and atorvastatin treatment on endothelium-dependent and endothelium-independent vasodilation in 18 hypercholesterolemic patients (ten men and eight women, aged 20-46 years) in comparison with 12 normal volunteers (seven men and five women, aged 20-45 years). The responses of the forearm blood flow (FBF) to acetylcholine (ACh) (7.5, 15 and 30 microg/min), sodium nitroprusside (SNP) (0.8, 1.6, 3.2 microg/min) and L-NMMA (2, 4, 8 micromol/min) were evaluated at baseline and after 1 month of atorvastatin (10 mg/day) treatment. Drugs were infused into the brachial artery and FBF was measured by strain-gauge plethysmography. At baseline, the response to ACh was significantly attenuated in hypercholesterolemics versus controls: at the highest dose (30 microg/min), FBF was 27.0+/-3.4 versus 11.5+/-1.9 ml.100 ml tissue(-1).min(-1) respectively (P<0.0001). No significant differences were found between groups during SNP infusion. The atorvastatin treatment significantly improved ACh-stimulated FBF: at highest dose the FBF increased to 14.9+/-1.5 ml.100 ml tissue(-1). min(-1) (P<0.0001). Similarly, the L-NMMA endothelial effects were significantly enhanced by lipid-lowering treatment, supporting the improvement of basal nitric oxide. Vitamin C increased ACh-vasodilation in the same way before and after atorvastatin treatment. In conclusion, the endothelial dysfunction in hypercholesterolemics is due to an oxidative stress and atorvastatin rapidly improves both basal and stimulated endothelium-dependent vasodilation.

Emergency thoracoabdominal aortic aneurysm repair: clinical outcome

OBJECTIVE

Emergency repair of thoracoabdominal aortic aneurysm remains a formidable operation with high morbidity and mortality. Although advanced surgical and perioperative care techniques have reduced the risks in elective repair of these aneurysms, the mortality rate has remained high when emergency surgery is performed. We have evaluated the outcome of patients undergoing emergency repair of thoracoabdominal aortic aneurysm.

METHODS

Of 47 consecutive patients with thoracoabdominal aortic aneurysm observed from January 1993 to September 1998, 19 required an emergency operation. Twelve had a ruptured aneurysm and 7 an acute dissection. Twelve type I, 3 type II, 1 type III, and 3 type IV thoracoabdominal aortic aneurysms (Crawford's classification) were diagnosed. All patients were operated on via a thoracolaparotomy with partial femoral-femoral extracorporeal circulation. The cerebrospinal fluid pressure was monitored, and the aorta was replaced with a vascular graft. Patent intercostal arteries were reimplanted when feasible.

RESULTS

The early (30-day) mortality was 42.1%; there were 2 late deaths. Complications in the 11 surviving patients are summarized as follows: paraplegia/paraparesis, 3 cases; renal, 4 cases; pulmonary, 4 cases; cardiac, 1 case; cerebrovascular, 1 case; and reexploration for bleeding, 1 case. Hemodialysis and aortic dissection were predictive factors of hospital mortality.

CONCLUSIONS

Our surgical experience in emergency repair of thoracoabdominal aortic aneurysm must be considered encouraging in terms of late outcome despite the in-hospital mortality of 42.1% and serious postoperative complications in the surviving patients. Moreover, our results show that acute aortic dissection and the need for hemodialysis are predictive factors for mortality.

Hypertensive left ventricular remodeling and ACE-gene polymorphism

OBJECTIVE

To evaluate the relationship between ACE-gene polymorphism and left ventricular geometry in never treated hypertensives.

METHODS

We enrolled 200 hypertensive outpatients that underwent clinical and ambulatory blood pressure measurements, echocardiographic evaluation and analysis for insertion (I)/deletion (D) polymorphism by PCR. Patients with normal or increased (> 125 g/m2 in males and > 110 g/m2 in females) left ventricular mass were considered to have concentric remodeling or concentric left ventricular hypertrophy if their relative wall thickness was > or = 0.45.

RESULTS

The left ventricular mass index values (g/m2) were 136 +/- 30 in DD genotype, 124 +/- 26 in ID genotype, and 116 +/- 20 in II genotype (DD vs. ID P < 0.005; DD vs. II P < 0.05), and were unrelated to blood pressure. Ninety-six patients presented left ventricular hypertrophy (48.0%): 51 with concentric and 45 with eccentric hypertrophy. The eccentric left ventricular hypertrophy was detected in 32 (36.8%) DD patients, in ten (10.5%) ID patients (P < 0.05), and in three (16.6%) II patients. The relative septal thickness was 0.43 +/- 0.09 in DD genotype, 0.45 +/- 0.08 in ID genotype, and 0.43 +/- 0.10 in II genotype. In DD and ID genotypes, the relative posterior wall thickness (0.37 +/- 0.07 vs. 0.41 +/- 0.07; P < 0.0001) and the end-diastolic left ventricular internal dimension (52.8 +/- 3.3 mm vs. 48.3 +/- 2.8 mm; P < 0.0001) were statistically different.

CONCLUSIONS

The DD genotype of the ACE-gene is associated with an increased left ventricular mass and with a significantly higher prevalence of eccentric left ventricular hypertrophy, when compared to ID genotype.

Inhibition by dipyridamole of neutrophil adhesion to vascular endothelium during coronary bypass surgery

BACKGROUND

Release of reactive oxygen radicals by activated neutrophils and neutrophil adhesion to endothelial cells have been observed after cardiopulmonary bypass. The aim of the present study was to evaluate the effects of preoperative dipyridamole treatment on neutrophil superoxide anion generation and endothelial cell-neutrophil interactions.

METHODS

Two groups of patients scheduled for elective coronary artery bypass grafting were randomized to receive oral dipyridamole or a placebo. Nitro blue tetrazolium scores of circulating neutrophils, neutrophil CD11b/CD18 expression, and their adhesion to human umbilical vein endothelial cells were assayed before anesthesia, 30 minutes after the beginning of cardiopulmonary bypass, at the end of bypass, and 60 minutes postoperatively.

RESULTS

In both groups, cardiopulmonary bypass resulted in a significant increase in nitro blue tetrazolium scores in circulating neutrophils as well as a significant increase in both neutrophil CD11b/CD18 expression and neutrophil adhesion to endothelial cells. The extent of neutrophil superoxide anion generation was higher in the control group; a significant (p < 0.01) reduction in neutrophil adhesion to endothelial cells was observed 1 hour postoperatively in the dipyridamole group. In 5 patients treated with dipyridamole, the incubation of activated polymorphonuclear leukocytes with adenosine deaminase significantly increased their adhesion to endothelial cells (p < 0.05).

CONCLUSIONS

Our study demonstrated that preoperative treatment with oral dipyridamole significantly reduces both neutrophil superoxide anion generation and extent of neutrophil adhesion to endothelial cells after coronary bypass grafting procedures with cardiopulmonary bypass. The mechanism is probably mediated by endogenous adenosine.

Calcium antagonist isradipine improves abnormal endothelium-dependent vasodilation in never treated hypertensive patients

OBJECTIVE

To examine whether middle (two months) and long-term (six months) isradipine sustained-release treatment improves endothelium-dependent vasodilation in never treated hypertensive patients.

METHODS

The responses of the forearm vasculature to acetylcholine (7.5, 15 and 30 micrograms/min) and sodium nitroprusside (0.8, 1.6, 3.2 micrograms/min) were evaluated in 12 normotensive controls (seven men and five women, aged 25 to 49 years), and in 12 hypertensives (eight men and four women, aged 20 to 47 years) at baseline and after two and six months of isradipine sustained-release treatment. Drugs were infused into the brachial artery, and forearm blood flow was measured by strain-gauge plethysmography.

RESULTS

At baseline, the response to acetylcholine was significantly lower in hypertensives vs controls: at the highest dose (30 micrograms/min), forearm blood flow was 28.6 +/- 2.4 ml/100 ml of tissue per min in the controls vs 8.9 +/- 1.0 ml/100 ml of tissue per min in hypertensive (p < 0.0001). Similarly, vascular resistance was significantly (p < 0.0001) higher in hypertensives: 4.8 +/- 0.5 units (controls) vs 15.1 +/- 1.7 units (hypertensives). After isradipine treatment, the forearm blood flow in hypertensive patients changed from 8.9 +/- 1.0 ml/100 ml of tissue per min to 16.0 +/- 1.2 ml/100 ml of tissue per min (two months; p < 0.0001) and 15.2 +/- 1.4 ml/100 ml of tissue per min (six months; p < 0.0001). Isradipine treatment did not modify the vasodilating effect of sodium nitroprusside.

CONCLUSIONS

Our data demonstrate for the first time that the calcium antagonist isradipine improves acetylcholine-induced vasodilation in hypertensives.

Neutrophil-endothelial cells modulation in diabetic patients undergoing coronary artery bypass grafting

OBJECTIVE

Diabetes mellitus is a well-known risk factor in patients undergoing coronary artery bypass grafting. Myocardial and pulmonary injury often occurs after cardiopulmonary bypass (CPB), mediated in part by neutrophil activation and adhesion to endothelial cells. The objectives of the present study are to compare the degree of neutrophil activation and neutrophil-endothelial cells adhesive interactions in diabetic patients after CPB.

METHODS

Nitro-blu tetrazolium scores, CD 11b expression and neutrophil-endothelial cells adhesion were assessed in blood samples from 15 diabetic and 15 control patients who had undergone elective coronary bypass grafting. Blood samples were obtained at baseline, 30 min after beginning CPB, at the end of CPB and 60 min postoperatively. At the same sampling points as above, blood glucose levels were also checked in all patients.

RESULTS

Diabetes was associated with a significant basal increase in neutrophil CD1 lb expression and adhesion to endothelial cells as well as with an increased superoxide anion production. The increased adhesion of diabetic neutrophils persisted by the end of the CPB to 60 min postoperatively independently of the blood glucose levels. Antibodies directed against CD1 lb and CD18 significantly reduced the degree of neutrophil adhesion observed 60 min postoperatively.

CONCLUSIONS

These results indicate that diabetes mellitus is associated with an increased neutrophil-endothelial cell adhesion probably mediated by the CD1 1b/CD18 molecule; this, in turn, might be responsible for the increased risk of postoperative complications observed in diabetic patients undergoing coronary artery bypass grafting.

Nitric oxide inhibits neutrophil adhesion during experimental extracorporeal circulation

BACKGROUND

Myocardial and pulmonary injuries often occur after cardiopulmonary bypass, mediated in part by neutrophil activation and adhesion to endothelial cells. The effects of nitric oxide (NO) administration on neutrophil adhesion to endothelial cells after simulated extracorporeal circulation were investigated.

METHODS

Two identical extracorporeal circulation circuits were primed with fresh human blood and circulated for 2 h at 37 degrees C. Nitric oxide at a 40-ppm concentration was added to one of the oxygenators in each pair. Neutrophil CD11b/CD18 expression and their adhesion to human umbilical vein endothelial cell monolayers were assayed in leukocytes isolated from samples drawn from the circuit 30, 60, 90, and 120 min after circulation began. In another series of experiments, blocking monoclonal antibodies to both neutrophil CD11b and CD18 were incubated with polymorphonuclear leukocytes after removal from the circuit before the adhesion assay.

RESULTS

After 60 min of circulation, the neutrophils from NO-treated circuits showed significantly reduced CD11b/CD18 surface expression compared with the control group. There was also a significant reduction in neutrophil-endothelial adhesion in the NO group after 120 min of circulation. Monoclonal antibodies to both CD11b and CD18 significantly inhibited the adhesion of polymorphonuclear leukocytes at endothelial cells after 120 min of circulation.

CONCLUSIONS

These results confirm that neutrophil activation occurs during cardiopulmonary bypass. The addition of NO to the circuits of extracorporeal circulation significantly affects neutrophil adhesion to endothelial cells.

Nitric oxide modulation of neutrophil-endothelium interaction: difference between arterial and venous coronary bypass grafts

OBJECTIVES

This study sought to evaluate the relation between the pattern of neutrophil-endothelial adhesion in saphenous vein (SV) and internal mammary artery (IMA) grafts and the endothelial production of nitric oxide (NO).

BACKGROUND

Autologous IMA and SV grafts (SVGs) are increasingly used as conduits for coronary bypass grafting. Previous studies have demonstrated a greater production of endothelial-derived relaxing factor (NO) from IMA than from SVGs. Because of the well known role of NO in modulating the adhesion of polymorphonuclear leukocytes to the endothelium, we studied the pattern of neutrophil adhesion to the endothelium of IMA and SVs under basal conditions and after inhibition of NO synthesis.

METHODS

Segments of IMA and SVs were obtained from 20 patients undergoing coronary artery bypass graft surgery. We evaluated the adhesion of both unstimulated and activated neutrophils to the endothelial surface of IMA and SVs in both basal conditions and after inhibition of NO synthesis with Nomega-nitro-L-arginine methyl ester.

RESULTS

Under basal conditions, no difference in unstimulated neutrophil adhesion to endothelium was observed between the two vessel conduits. After neutrophil activation, a significantly (p < 0.05) greater adhesion of neutrophils was observed in the SV than in the IMA. After inhibition of NO release, the adhesion of activated neutrophils increased in both vessels, and no significant difference between them was observed. The increased adhesion was attenuated by both L-arginine and sodium nitroprusside.

CONCLUSIONS

The lesser neutrophil adhesion to the endothelium of the IMA is a consequence of enhanced release of NO at this level; this effect could be responsible for the better early and long-term patency of this conduit over the SVG in coronary bypass grafting.

Intermittent warm blood cardioplegia preserves myocardial beta-adrenergic receptor function

BACKGROUND

Left ventricular dysfunction is frequently observed in patients after hypothermic cardioplegic arrest, and often inotropic intervention is necessary for patients to be successfully weaned from cardiopulmonary bypass (CPB). A myocardial beta-adrenergic receptor (beta AR) desensitization has been noted to occur after hypothermic CPB in patients undergoing coronary artery bypass grafting. This randomized study was undertaken to determine the effect of cardioplegic solution temperature on cardiac beta ARs.

METHODS

Two groups of patients (20 patients in each) scheduled for elective coronary artery bypass grafting underwent CPB with either intermittent warm or cold blood cardioplegia. The density of the beta ARs, the proportion of beta 1- to beta 2-adrenergic receptors, and the beta AR coupling capacity to adenylate cyclase were determined in specimens of the right atrial tissue at baseline, during CPB, and after discontinuation of CPB. Plasma concentrations of catecholamines were also measured in both arterial and coronary sinus samples.

RESULTS

In both cardioplegia groups, no significant modification in either the beta AR density or the proportion of beta 1- to beta 2-adrenergic receptors was detected. However, a significant decrease in adenylate cyclase activity after stimulation with isoproterenol was observed in the cold blood cardioplegia group during CPB (p < 0.01) and 30 minutes after its discontinuation (p < 0.05). Moreover, a significant decrease in adenylate cyclase activity during CPB was detected in this group after stimulation with sodium fluoride (p < 0.05), but this pattern was found to be completely reversed by 30 minutes after discontinuation of CPB. No modification in the basal or stimulated adenylate cyclase activity was observed in the warm blood cardioplegia group during or after CPB.

CONCLUSIONS

Our results confirm the finding from previous studies of a cardiac beta AR desensitization after hypothermic cardioplegic arrest, and provide evidence of the advantages of intermittent warm blood cardioplegia in preserving the autonomic sympathetic function of the heart.

Complement and neutrophil activation during cardiopulmonary bypass: a randomized comparison of hypothermic and normothermic circulation

OBJECTIVE

Activation of both complement and neutrophils has been demonstrated to be involved in many pathological reactions following cardiopulmonary bypass (CPB). The aim of the present study is to evaluate the effect of normothermic and hypothermic CPB on both complement and neutrophil activation.

METHODS

Two groups of patients (n = 20 each) scheduled for elective coronary artery bypass grafting, underwent CPB with intermittent warm or cold blood cardioplegia. Plasma concentration of C3a, C5a and C5b-9, as well as nitro-blu tetrazolium (NBT) scores of circulating neutrophils were measured before anesthesia, 10 and 30 min after the beginning of CPB, and 8, 16 and 24 h, postoperatively.

RESULTS

In both groups, CPB determined a significant complement activation, evidenced as a significant increase in plasma concentration of C3a, C5a and C5b-9. This in turn triggered the neutrophil activation, documented as a significant increase of NTB scores in circulating neutrophils at the end of CPB and in the early postoperative period. Interestingly, in the warm group the extent of both complement and neutrophil activation was significantly higher compared with the cold group during the whole sampling period.

CONCLUSION

In conclusion, our study clearly demonstrates that warm CPB is associated with an increased ability to activate complement and neutrophils in patients undergoing coronary surgery.

Protection by coenzyme Q10 of tissue reperfusion injury during abdominal aortic cross-clamping

PURPOSE

To evaluate the effect of coenzyme Q10 in reducing the skeletal muscle reperfusion injury following clamping and declamping the abdominal aorta.

METHODS

30 patients undergoing elective vascular surgery for abdominal aortic aneurysm or obstructive aorto-iliac disease were randomly divided into two groups: patients in group I were treated with coenzyme Q10 (150 mg/day) for seven days before operation, and those in group II received a placebo. We studied the hemodynamic profile in each patient during clamping and declamping of the abdominal aorta. The plasma concentrations of thiobarbituric acid reactive substances (malondialdhehyde), conjugated dienes, creatine kinase and lactate dehydrogenase were measured in samples from both arterial and inferior vena cava sites. Serial sampling was performed after induction of anesthesia, 5 and 30 minutes after abdominal aortic cross clamping, 5 and 30 minutes after aortic cross-clamp removal.

RESULTS

The concentrations of malondialdehyde, conjugated dienes, creatine kinase and lactate dehydrogenase in patients who received CoQ10 were significantly lower than in the placebo group. Decrease of plasma malondialdehyde concentrations correlated positively (p < 0.01) with decrease of both creatine kinase and lactate dehydrogenase release in samples from the inferior vena cava. The hemodynamic profile during clamping and declamping the abdominal aorta was similar in both groups.

CONCLUSIONS

Our findings suggest that pre-treatment with coenzyme Q10 may play a protective role during routine vascular procedures requiring abdominal aortic cross clamping by attenuating the degree of peroxidative damage.

Pericardial cyst with partial erosion of the superior vena cava. An unusual case

A case of pericardial cyst with partial erosion of the superior vena cava occasionally discovered is presented. The involvement of the vein was found on operation and the excision of the cyst was performed without cardiopulmonary bypass, repairing the vena cava by a direct suture. The pathologic examination showed multiple areas of acute and chronic inflammation without signs of infection. This exceedingly rare report indicates that both computed tomography and magnetic resonance are useful to localize the mediastinal mass and to characterize the cystic content. The cardiopulmonary bypass must be available to allow an easy repair of the structures possibly involved particularly in the case of infection.

Changes in the proportion of types I and III collagen in the left ventricular wall of patients with post-irradiative pericarditis

Pericardiectomy for post-irradiative constrictive pericarditis achieves poor results because of the extensive damage to the heart and pericardium caused by ionizing radiation. The extracellular structural protein, collagen, is responsible for the functional integrity of the myocardium and allows reversible interdigitation and the transmission of force between contracting myocytes. Collagen concentration and composition were examined in the cardiac tissue of three patients undergoing pericardiectomy and post-irradiative pericarditis. Normal heart tissue was taken at autopsy from patients without cardiac disease and acted as controls. Total collagen concentration (mean(s.e.m.)) was significantly increased in the ventricular tissue of patients with post-irradiative pericarditis compared with that of the controls (119.8(16.6) versus 50.4(5.2) mg/g dry weight, P<0.01). Although there was an increase in concentration of both type I and III collagen, a disproportional increase in type I was observed. The proportion of type III collagen was lower in patients with post-irradiative pericarditis than in the control group (33(2.6)% versus 38.2(3.7)%, P<0.05). The results of the present study suggest that this marked alteration in collagen concentration and proportion may contribute to the impaired diastolic distensibility of the ventricles seen in this group of patients.

Reduction by indobufen of neutrophil activation in peripheral arterial occlusive disease

We evaluated the effectiveness of indobufen administration in reducing neutrophil activation in a clinical model of ischemia-reperfusion. Thirty stable patients with intermittent claudication due to occlusive peripheral arterial disease of the leg were randomly assigned to two groups. Patients in group I were treated with indobufen [200 mg orally twice daily (p.o. b.i.d.) for a week]; patients in group II received a placebo. Both groups of patients were submitted to standardized treadmill exercise until onset of claudication. Plasma levels of thromboxane B2 (TxB2) and 6-keto-prostaglandin F1alpha(6-k-PGF1alpha) neutrophil filterability, and neutrophil activation (by nitro-blue tetrazolium test) were assessed in blood samples from the femoral vein draining the ischemic leg. The values were obtained at rest and 5, 30, and 60 min after onset of claudication. Urinary albumin excretion was measured at rest and 1 h after onset of claudication. Plasma levels of TxB2 and 6-k-PGF1alpha increased significantly in the placebo group 5 min after onset of claudication, whereas only a slight nonsignificant increase was observed in the indobufen-treated group at the same timepoint.

Collagen network remodelling and left ventricular function in constrictive pericarditis

OBJECTIVE

To investigate whether patients with constrictive pericarditis have changes in collagen content and architecture that could influence left ventricular function.

DESIGN

Cohort study.

SETTING

University teaching hospital.

PATIENTS

Biopsy specimens of myocardium from 13 patients admitted consecutively for treatment of chronic constrictive pericarditis were compared with normal heart tissue taken at necropsy from 15 patients free of cardiac disease.

INTERVENTION

Pericardiectomy through median sternotomy. Biopsy specimens (4 or 5) were taken from the left ventricular free wall.

MAIN OUTCOME MEASURES

Biochemical and histological assessment of total collagen content, relative proportion of type I and III collagen, and amount of orthogonal collagen fibre meshwork (crosshatching) in the left ventricular tissue.

RESULTS

There was more collagen in the myocardium of patients with constrictive pericarditis than in controls when measured either biochemically by hydroxyproline content (89.4 v 50.4 mg/g dry weight) or by histological measurement of the collagen fraction of the myocardium (2.4% v 7.0%). Neither of these measurements, however, correlated with left ventricular ejection fraction, pulmonary wedge pressure, or right ventricular end diastolic pressure. The thickness of the fibrous trabeculae in the myocardium was, however, inversely related to both left ventricular ejection fraction (r = -0.76) and deceleration time (r = -0.68). Trabecular thickening was also related to NYHA class, with those in class III and IV having the greatest thickening.

CONCLUSION

Changes in collagen content and architecture may contribute to impaired ventricular function in patients with chronic constrictive pericarditis.

Elevated circulating levels of von Willebrand factor and D-dimer in patients with heart failure and mechanical prosthesis

To test the hypothesis of association between heart failure and altered haemostatic balance in patients with a mechanical valve prosthesis, comparisons were made between 20 patients with mitral valve replacement and stable chronic heart failure (group A), 20 with the same prosthesis but satisfactory haemodynamics (group B) and 20 age-matched controls (group C). The left ventricular ejection fraction was significantly highest (p < 0.001) in group A. The pulmonary artery systolic pressure was also highest in group A (p < 0.001), without significant difference between groups B and C. Two group A patients had a transient ischaemic attack. The D-dimer plasma concentrations and the antigenic and biologic von Willebrand factor activities were significantly greatest in group A. Significant correlation was found between the plasma concentrations of these activities and pulmonary artery systolic pressure and between D-dimer and ejection fraction. Platelet-activating factor was detected only in six group A patients. The observed relationship between haemostatic factors and heart failure in patients with mechanical heart-valve prosthesis advocates careful evaluation of von Willebrand factor and D-dimer in order to prevent embolic events in such cases.

Improved beta-adrenergic receptor function after coronary artery bypass grafting in patients with congestive heart failure

BACKGROUND

To evaluate whether coronary artery bypass grafting (CABG) in patients with congestive heart failure (CHF) modifies beta-adrenergic receptor dysfunction, we measured lymphocytic beta-adrenergic receptor density and function, and plasma catecholamine levels in patients with congestive ischaemic disease scheduled for CABG.

METHODS

Assays were performed on 20 patients with CHF at admission and 6 months following CABG; 20 age-matched healthy subjects served as the control group.

RESULTS

Preoperative lymphocyte beta-adrenergic receptor density was significantly reduced in patients with CHF compared with the control group. Similarly, basal adenylyl cyclase as well isoproterenol- and NaF-stimulated adenylyl cyclase activity was significantly reduced in lymphocytic membranes of patients with CHF compared with controls. Conversely, no difference was found in forskolin-stimulated adenylyl cyclase activity between the two groups of patients. Preoperatively, plasma levels of both noradrenaline and adrenaline were significantly higher in patients with CHF compared with the control group. CABG was associated with clinical and haemodynamic improvement in all patients. Lymphocyte beta-adrenergic receptor density and function were also improved. Basal beta-adrenergic receptor density improved from 39.2 +/- 1.7 to 46 +/- 1.5 fmol/mg protein. Basal adenylyl cyclase activity increased from 33.1 +/- 2.6 40 +/- 2.4 pmol/mg protein per min; a significant increase in activity stimulated by isoproterenol (from 41.5 +/- 3.1 to 61 +/- 3.8 pmol/mg protein per min) and by NaF (from 71.8 +/- 2.7 to 85.3 +/- 3.5 pmol/mg protein per min) was also observed. Although postoperative plasma catecholamine levels tended to decrease, the difference compared with preoperative values was not significant.

CONCLUSION

The results of our study indicate that CABG in patients with CHF is accompanied by the restoration of an almost normal functional state of the lymphocytic beta-adrenergic receptor system.

Suppressed fibrinolysis after administration of low-dose aprotinin: reduced level of plasmin-alpha2-plasmin inhibitor complexes and postoperative blood loss

Various clinical investigation have shown that aprotinin therapy reduces bleeding after open-heart operations. In this study low-dose aprotinin, 30,000 KIU/kg in the cardiopulmonary bypass (CPB) priming volume and 7,500 KIU/kg intravenously each hour during CPB, was used in ten patients undergoing primary myocardial revascularization or surgery for valvular diseases. Another ten patients served as controls. Blood loss, platelet count and plasma levels of hemoglobin, antithrombin III, fibrinogen, fibrinogen degradation products (FDP), total plasmin inhibitor and alpha2-plasmin inhibitor-plasmin complexes were evaluated at nine preoperative, intraoperative and postoperative points. Intraoperative and postoperative blood loss was significantly reduced in the aprotinin group. There was no significant difference between the two groups in platelet count and levels of hemoglobin and antithrombin III. A significant increase in FDP during CPB in the control group indicated hyperfibrinolysis. The levels of plasmin inhibitor were significantly reduced during CPB in the control group. The alpha 2-plasmin inhibitor-plasma complex levels, indicating the plasmin activity, were significantly reduced in the aprotinin group. These results confirmed that low-dose aprotinin reduced blood loss with the prevention of hyperfibrinolysis during CPB and demonstrated improved hemostasis.

Combined mitral valve prolapse and atrial septal aneurysm. A cause for embolic events

The "association" atrial septal aneurysm and mitral valve prolapse is often asymptomatic with an incidence of about 1% in autopsied adults. Occasionally, however, embolic phenomena can occur. The two-dimensional echocardiography allows an accurate diagnosis of these two cardiac lesions when present. In this paper the Authors report on three patients affected by mitral valve prolapse associated with atrial septal aneurysm, one of whom complicated by a cerebral embolism. Owing to the significant incidence of peripheral or cerebral vascular embolic events in this group of patients, the Authors conclude that long-term anticoagulation therapy is mandatory in all cases, whereas a surgical repair could be advisable when a previous embolism or interatrial shunting is demonstrated.

Protection by coenzyme Q10 from myocardial reperfusion injury during coronary artery bypass grafting

To evaluate the effect of coenzyme Q10 in reducing postoperative cardiac complications after ischemia and reperfusion, we randomly divided 40 patients undergoing elective coronary artery bypass into two groups: patients in group 1 received coenzyme Q10 (150 mg/day) for 7 days before operation, and those in group 2 were the control group. Concentrations of thiobarbituric acid-reactive substances (malondialdehyde), conjugated dienes, and cardiac isoenzymes of creatine kinase were measured in samples from both arterial and coronary sinus sites. Serial sampling was performed 5 minutes after heparin administration, at 10 and 30 minutes during cardiopulmonary bypass, 15 and 30 minutes after aortic cross-clamp removal, and 5 minutes after protamine administration. The concentrations of malondialdehyde, conjugated dienes, and creatine kinase in group 1 were significantly lower than those in group 2. The decrease in plasma malondialdehyde concentrations correlated positively with the decrease in creatine kinase levels in the coronary sinus. The treatment group showed a significantly lower incidence of ventricular arrhythmias during the recovery period than did the control group (p < 0.05). Although the percentage of patients requiring inotropic agents was not significantly different between the two groups, the mean dosage of dopamine required to maintain stable hemodynamics was significantly lower in patients of group 1 than in those of group 2 (p < 0.01). Our findings suggest that pretreatment with coenzyme Q10 may play a protective role during routine bypass grafting by attenuating the degree of peroxidative damage.

Primary malignant melanoma of the oesophagus with a left atrial metastasis

A 75 year old man with an eight month history of dysphagia and weight loss underwent pericardiocentesis for a massive pericardial effusion. The echocardiogram showed a mass in the left atrium, and computed tomography also showed distal oesophageal narrowing, which was found to be due to a malignant melanoma. The left atrial mass, investigated by immunoscintigraphy with technetium-99m labelled monoclonal antibody, was diagnosed as metastatic melanoma. This represents a rare case of primary oesophageal melanoma with left atrial metastasis.