Mitral valve replacement with beating heart technique via right thoracotomy in a patient with previous Bentall operation.

Traditionally, reoperations for mitral valve replacement are carried out under cardioplegic arrest with cross-clamping of the ascending aorta via a median sternotomy. In this case, the mitral valve replacement operation was performed with an on-pump beating heart technique without cross-clamping the aorta and via a right thoracotomy because of diffuse adhesions around the ascending aortic tube graft. A 44-year-old male patient had undergone a Bentall operation via a median sternotomy for annulo-aortic ectasia 3 years ago. He was admitted to the hospital complaining of palpitation and dyspnea. Transthoracic echocardiography revealed 4th degree mitral insufficiency. Mitral valve replacement was carried out through a right thoracotomy using an on-pump beating heart technique without cross clamping the aorta. In conclusion, mitral valve replacement with an on-pump beating heart technique via a right thoracotomy offers a safe approach when excessive dissection is required to place a cross-clamp to the ascending aorta.

Redo valve surgery with on-pump beating heart technique.

AIM: Reoperations have become of increasing frequency in the last four decades. Redo surgery is more complex than primary surgery and is associated with higher mortality and morbidity. We present our immediate and mid-term results of mitral and aortic prosthetic valve replacement undertaken with beating heart technique. METHODS: The prospective study included 26 consecutive redo valve surgery patients who underwent valve re-replacement. The operation was carried out on a beating heart using normothermic bypass without cross-clamping the aorta for mitral valve surgery and retrograde coronary sinus normothermic noncardioplegic blood perfusion during cross-clamping the aorta for aortic valve procedures. RESULTS: Twenty-six patients (mean age 50+/-15 years) underwent reoperation with beating heart technique. Twenty (76.9%) mitral prosthetic replacements, 4 (15.4%) aortic prosthetic replacements, and 2 (7.7%) double valve replacements were achieved. Fourteen patients (53.8%) were operated for prosthetic valve dysfunction. Eighteen patients (69.2%) were in NYHA class III or IV preoperatively. Mean bypass time was 85+/-30 min. Mean duration of ventilation was 13.6+/-6 h, mean intensive unit stay was 2.8+/-6.4 days, and mean hospital stay was 8.3+/-7.2 days. Two (7.7%) patients required high dose inotropic support and in one patient (3.8%) intra-aortic balloon support was required. Pulmonary complication occurred in 1 patient (3.8%), low cardiac output in 1 patient (3.8%), and re-exploration for bleeding in 2 patients (7.7%). Operative mortality was not observed. CONCLUSION: Normothermic on-pump beating heart valve replacement offers a safe alternative to cardioplegic arrest in high-risk group. Complication rates are low and perioperative mortality is lower than with conventional surgery. Beating heart technique has the advantage of maintaining physiologic condition of the heart throughout the procedure.

Cardiopulmonary bypass as a cause of free radical-induced oxidative stress and enhanced blood-borne isoprostanes in humans.

Free radicals are believed to be involved in postsurgery-related complications. We studied whether cardiopulmonary bypass (CPB) operation has any immediate impact on the initiation of oxidative stress and inflammatory response by measuring isoprostanes and prostaglandin F2alpha during and 24 h following CPB. The levels of 8-iso-PGF2alpha (a major F2-isoprostane and biomarker of oxidative stress) and 15-keto-dihydro-PGF2alpha (a major metabolite of PGF2alpha and biomarker of inflammatory response) were measured in frequently collected plasma samples before, during, and up to 24 h postsurgery in 21 patients. 8-Iso-PGF2alpha levels significantly increased within 3 min (p <.0001) and continued until 50 min (p <.0001) during CPB. On the contrary, no significant increase of inflammatory response indicator, 15-keto-dihydro-PGF2alpha was found during and up to 24 h postoperatively. These findings establish an increased free radical-induced oxidative stress activity rather than inflammatory response after CPB.

Oxidative stress and changes in alpha- and gamma-tocopherol levels during coronary artery bypass grafting.

We studied whether cardiopulmonary bypass (CPB) has any immediate impact on the initiation of antioxidative defenses in the body by measuring F(2)-isoprostanes and alpha- and gamma-tocopherol, respectively. 8-iso-PGF(2alpha) levels increased significantly within 3 minutes and until the end of CPB. alpha-Tocopherol levels increased gradually at 20 min during CPB and continued until 6 hours after CPB. gamma-Tocopherol levels followed a similar fashion at the end of CPB. 8-iso-PGF(2alpha) and tocopherol levels kept at basal level 12 and 24 hours post CPB. These findings suggest that an increased free radical-induced oxidative stress together with a gradual appearance of antioxidative defense system during and after CPB.

Effects of prostacyclin on spinal cord ischemia: an experimental study.

BACKGROUND: Paraplegia after thoracic aortic aneurysm has an incidence of 2.2% to 24%. This study was planned to show the beneficial effects of prostacyclin on spinal cord ischemia. METHODS: Twelve rabbits underwent 30 minutes of aortic occlusion. Six rabbits received prostacyclin, whereas the remaining rabbits did not. Prostacyclin administration was started with a rate of 5 ng/kg/min 5 minutes before aortic occlusion. This dosage was increased to 25 ng/kg/min during aortic occlusion. Prostacyclin administration after aortic occlusion was maintained for a period of 5 minutes. During this period, prostacyclin dosage was 5 ng/kg/min. RESULTS: One rabbit in the prostacyclin group and five rabbits in the control group were paraplegic. Arterial pressure proximal to the clamp was 65 +/- 7 mm Hg before aortic occlusion and 78 +/- 10 mm Hg during aortic occlusion in the control group and 68 +/- 12 mm Hg before aortic occlusion and 65 +/- 6 mm Hg during aortic occlusion in the prostacyclin group. Arterial pressure distal to the clamp was 11 +/- 4 mm Hg during aortic occlusion in the control group and 18 +/- 5 mm Hg during aortic occlusion in the prostacyclin group (p = 0.02). CONCLUSIONS: Intravenous prostacyclin reduced the neurologic injury caused by spinal cord ischemia and reperfusion after 30 minutes of aortic occlusion in the rabbit model.

Preservation of myocardial metabolism in acute coronary artery occlusions with retrograde coronary sinus perfusion and iloprost.

A total of 12 healthy mongrel dogs were subjected to the study. The left anterior descending artery was occluded. The occlusion was done for 15 min. At the end of this period, without removing the occlusion, the heart was retroperfused for 3 h. Then, occlusion was removed and reperfusion was supplied. Animals were divided into two equal groups. Six animals received iloprost and the other six control did not receive any additional treatment. In the iloprost group, the drug was administered into the coronary sinus. After 15 min following occlusion, iloprost was infused at a rate of 50 microg/min continuously. Cardiac output (CO), mean arterial pressure (MAP), mean pulmonary arterial pressure (MPAP), heart rate (HR), pulmonary capillary wedge pressure (PCWP), right atrium pressure (RAP), myocardial oxygen extraction (MOE) and myocardial lactate extraction (MLE) parameters were examined in the two groups, before and during retroperfusion and during the reperfusion (1-4 h). Iloprost retroperfusion (50 microg/min) was started at the fifteenth minute of occlusion and continued till the end of the observation period (3 h). The measured hemodynamic data showed that the hearts treated with iloprost had satisfactory preservation of cardiac function. At the end of the reperfusion period cardiac output was 1.5 +/- 0.06 L/min in the control and 1.7 +/- 0.04 L/min in the iloprost group (P < 0.05). At the end of the reperfusion period, tumor necrosis factor level was raised significantly in the control group (P < 0.05). Myocardial lactate release was also high in the control group (P < 0.05). CPK-MB release was low in the iloprost group (P < 0.05). We conclude that retrogradely administered iloprost reduced the risk of myocardial injury and it is probable that this drug effectively distributes to the area of myocardium at risk.

Warm blood cardioplegia: ultrastructural and hemodynamic study.

Forty patients with coronary artery disease were included in this study. Half of them received cold crystalloid and cold blood cardioplegia (group 1), and half received normothermic blood cardioplegia (group 2). In group 1, left ventricular stroke work index was 24 +/- 3 g.m/m2 1 hour after the operation, 29 +/- 8 g.m/m2 12 hours after the operation, and 33 +/- 6 g.m/m2 24 hours after the operation. In group 2, left ventricular stroke work index was 37 +/- 4 g.m/m2 1 hour after the operation, 37 +/- 4 g.m/m2 12 hours after the operation, and 44 +/- 7 g.m/m2 24 hours after the operation. Myocardial oxygen extraction 20 minutes after the termination of cardiopulmonary bypass was 0.28 +/- 0.03 in group 1 and 0.44 +/- 0.08 in group 2. Myocardial lactate extraction at the same time was -0.09 +/- 0.02 in patients receiving cold blood cardioplegia and 0.17 +/- 0.07 in patients receiving normothermic blood cardioplegia. Electron microscopic study revealed no calcium accumulation in the mitochondria in group 2 patients, whereas calcium accumulation was present in the other group.

Perinatal mitral valve interventions: a report of 10 cases.

BACKGROUND: Rheumatic mitral valve stenosis is still an endemic disease in some parts of the world and may complicate pregnancy and perinatal period. During the 10-year period between January 1988 and December 1997, 10 pregnant women with mitral stenosis were operated on. METHODS: Combined cesarean delivery and closed mitral valvulotomy (CMV) were performed on 6 patients, combined cesarean delivery and Mitral Valve Replacement (MVR) were performed on 1 patient, and 3 patients had CMV during their third trimester. RESULTS: There was 1 stillbirth. All other patients and delivered babies were healthy. MVR was necessary for mitral restenosis in one patient 5 years after her CMV. Three of the remaining patients had some degree of restenosis but did not require reoperation. CONCLUSION: CMV when indicated during pregnancy can be performed with low risk. For symptomatic patients responding to medical therapy, a combined approach of cesarean section and CMV will prevent possible complications that may arise on perinatal period due to hemodynamic fluctuation.

Iloprost added to the cardioplegic solutions improves myocardial performance.

A total of 12 mongrel dogs were divided into two equal groups. Six animals received IIoprost and the other 6 animals did not receive any additional treatment. In the Iloprost group, Iloprost was added to the cardioplegic solution (25 ng). Also, Iloprost was used (10 ng/kg/min.) 5 min. before and after cross-clamping. All cardiac output and biochemical measurements were evaluated before cross-clamp and 15 min., 1 h, and 4 h after cross-clamp. The measured dp/dt shows that the hearts treated with Iloprost preserved left ventricular function. Comparison of contractility indices between the groups revealed that contractile recovery was 59% in the control group and 71% in the Iloprost group (p < 0.05). Tumor necrosis factor (TNF) alpha level was significantly elevated in the control group (p < 0.001). Its level was 22.2 +/- 2.2 pg/mL in the control group and 13.8 +/- 1.0 pg/mL in the Iloprost group. E- and P-selectin levels were elevated in the control group (p < 0.001). ICAM-1 level was also elevated in the control group. ICAM-1 level was 17.7 +/- 1.8 ng/mL in the control group and 8.5 +/- 1.8 ng/mL in the Iloprost group. The Iloprost that was added to the cardioplegic solution and low dose administration during the pre- and post-ischemic period inhibits the toxic mediator release from endothelium-leukocyte interaction and reduces the severity of ischemia-reperfusion injury.

Reduction of the infarcted area with the use of simplified coronary sinus retroperfusion during experimental coronary artery occlusion.

This study examined if the use of simplified coronary sinus retroperfusion would lead to any reduction in the infarcted area associated with improved right and left ventricular function. Twelve mongrel dogs were entered in this study. Following anesthesia, a fast response thermistor was placed on the pulmonary artery via the jugular vein and aorta via the left ventricular apex. The left anterior descending artery (LAD) was separated from the vein. A retrograde cardioplegia catheter was inserted into the coronary sinus. Following these procedures, LAD was occluded for a period of 3.5 h. After 30 min ischemia, the aorta-coronary sinus connection was established. The animals were divided into two equal groups. One group was not treated and was considered the control group (six animals). In the remaining group (six animals), retroperfusion was used and was considered the retroperfusion group. At the end of the study, the left ventricular ejection fraction was 65+/-15% in the retroperfusion group and 48+/-5% in the control group (P<0.05). The left ventricular stroke work index was 0.44+/-0.04 (g m/kg) in the retroperfusion group and 0.31+/-0.05 (g m/kg) in the control group (P<0.05). Cardiac output was 1650+/-75 ml/min in the retroperfusion group and 1250+/-125 ml/min in the control group. The ratio of the infarct size to the area at risk was 49+/-5% in the control group and 7+/-3% in the retroperfusion group. In light of these studies, we conclude that simplified coronary sinus retroperfusion appears to be an effective method that must be taken into consideration.

ATP-MgCl2 treatment after experimental acute myocardial ischemia and reperfusion.

BACKGROUND: The effect of ATP-MgCl2 on myocardial metabolism and hemodynamics was investigated in this study. METHODS: Twelve dogs were entered in this research. Six dogs received ATP-MgCl2 and the remaining dogs were considered as controls. The amount of ATP and MgCl2 concentration of this solution is 100 mumol/ml each. The volume administered to the animals during the aortic occlusion is 0.25 ml/kg/hour; in the solution are 100 mumol/ml dose each. The volume administered to the animals during reperfusion is 0.25 ml/kg/hour. The left anterior descending artery was occluded for a period of one hour and the drug was administered during reperfusion. RESULTS: Three hours after reperfusion, cardiac output was 1524 +/- 26 ml/min in the control group and 1638 +/- 47 ml/min in the ATP-MgCl2 group (p < 0.05), pulmonary capillary wedge pressure was 14 +/- 3 in the control group and 8 +/- 2 in the ATP-MgCl2 group. At the same time interval tissue ATP and lactate level was 7 +/- 3, 1.3 +/- 0.4 in the control group and 14 +/- 2, 0.0 +/- 0.2 in the ATP-MgCl2 group respectively (p < 0.05). CONCLUSIONS: In this study we demonstrated that ATP-MgCl2 usage after one hour of arterial occlusion protects the heart from the adverse effects of ischemia/reperfusion.

Effects of ATP-MgCl2 administration in hypovolemic dogs.

BACKGROUND: The aim of the study was to evaluate the efficacy of ATP-MgCl2 on myocardial insufficiency associated with hypovolemic shock in dogs. We designed the study as a controlled randomized study. METHODS: Six mixed-breed dogs weighing 22 +/- 3 kg were included in the control group and 20 +/- 3 kg in the ATP-MgCl2 group. After the animals were anesthetized 40 ml/kg of blood was withdrawn in 15 minutes. Animals were observed for 45 minutes after removal of blood. Six animals received 45 ml/kg of lactated Ringer's solution and the other animals were treated with 45 ml/kg of lactated Ringer's solution and ATP-MgCl2. All measurements were made before removal of blood, 45 min after exsanguination and at 1 hour intervals for 3 hours. The following parameters were measured; systemic and pulmonary arterial pressures, pulmonary capillary wedge pressure, central venous pressure, cardiac output, rectal temperature, arterial pH, PCO2 and PO2 and mixed venous hemoglobin oxygen saturation. In addition blood samples were collected for the analysis of lactate and tumor necrosis factor (TNF) concentrations. RESULTS: After hemorrhage, cardiac index (CI) decreased significantly from 122 +/- 9 to 52 +/- 9 ml/kg/min in the control group (p < 0.0001) and from 124 +/- 11 ml/kg/min to 50 +/- 6 ml/kg/min in the ATP-MgCl2 group, respectively (p < 0.0001). After volume replacement, Cl was 93 +/- 6 ml/kg/min in the control group and 111 +/- 4 ml/kg/min in the ATP-MgCl2 group 3 hours after the onset of reinfusion, respectively (p < 0.05). TNF was 36 +/- 5 pg/ml in the control group and 21 +/- 3 pg/ml in the ATP-MgCl2 group (p < 0.05). Three hours after the onset of hemorrhagic shock, oxygen consumption and delivery were 126 +/- 14 and 206 +/- 19 ml/min in the control group and 198 +/- 16 and 305 +/- 27 ml/min in the ATP-MgCl2 group, respectively. At the same time point the oxygen extraction ratio was 0.49 +/- 0.04 in the control group and 0.61 +/- 0.03 in the ATP-MgCl2 group (p < 0.01). CONCLUSIONS: Hemorrhagic shock causes TNF release which may cause multiple organ failure. Organ dysfunction still persists even after the appropriate treatment. ATP-MgCl2 attenuates the release of TNF which may improve the adverse effects of hemorrhagic shock.

Preservation of myocardial functions by pentoxyphylline cardioplegia during and after cardiopulmonary bypass.

BACKGROUND: The aim of the presented study was to evaluate the preservation effect of the pentoxyphylline-blood cardioplegia on myocardial functions during and after the cardiopulmonary bypass in an experimental dog model. METHODS: Central hemodynamics and metabolic variables such as creatine phosphokinase, myocardial oxygen extraction and myocardial lactate extraction were obtained during and following 4 hours after the cardiopulmonary bypass after the baseline scores were recorded. Twelve mongrel dogs were divided into two equal groups. The first group of animals served as controls. The second group of animals was treated with pentoxyphylline cardioplegia that was added to each blood cardioplegia as 15 mg/100 ml. RESULTS: After bypass, the hemodynamic parameters were better in the pentoxyphylline group. Cardiac index fell in all animals, but it was significantly less in the control group. Pulmonary capillary wedge pressure was lower in the pentoxyphylline group as an index of better preservation of ventricular filling pressure. CPK-MB was significantly higher in the control group both at 2 and 4 hours after the bypass. It was 79 +/- 13 iu/L in the control group and 41 +/- 9 iu/L in the pentoxyphylline group 4 hours after cardiopulmonary bypass. MLE was also higher both on bypass and following bypass in the control group. CONCLUSIONS: In conclusion, pentoxyphylline usage may reduce the risks of ischemic-reperfusion injury during and following cardiopulmonary bypass and aortic cross-clamping. It can be an administered drug during cardioplegia.

Protein C, S and antithrombin III levels in patients with acute mechanical valve thrombosis.

BACKGROUND: Mechanical prosthetic heart valve thrombosis is a serious complication with an incidence of 1-6%. The reduction in active vitamin-K dependent protein C and S levels caused by warfarin treatment also results in a prothrombotic state. This study was conducted to investigate the connection between protein C (PC), protein S (PS), antithrombin III (ATIII) deficiency and prosthetic mechanical valve thrombosis. METHODS: Twenty-nine of the 283 patients who underwent valve replacement with St. Jude medical prosthesis had mechanical valve thrombosis (group 2). The rest were considered as group 1. Twelve of the 29 patients (41.4%) had isolated aortic valve replacement, 12 had isolated mitral valve replacement (41.4%) and 5 patients had double valve replacement (17.2%). Most of the patients had rheumatic valve disease at their 1st operation. The mean time of occurrence for mechanical valve occlusion was 4.1+/-1.0 years following surgery. RESULTS: The values of PC, PS and ATIII were obtained when the mechanical valves stuck or at routine follow-up. PC, PS and ATIII levels were significantly lower in the mechanical valve thrombosis group. PC levels were 75.4+/-37.6% and 49.9+/-32.2% in group 1 and 2, respectively (p=0.001). PC, PS and ATIII values were mostly lower in the 2nd group but this difference only became significant after at least 2 years of warfarin usage. CONCLUSIONS: Natural anticoagulant levels can be low during the use of warfarin. In which case the dose can be increased in order to hold the international normalized ratio (INR) at 3-3.5. However, more frequent follow-up is required and patients should be investigated for hypercoagulation states or deficiency in anticoagulant proteins. Patients referred to hospital with any mechanical valve thrombosis or recurrent thromboembolism should be evaluated for hypercoagulant proteins.

Beneficial effects of iloprost during experimentally induced hemorrhagic shock.

BACKGROUND: The aim of the study was to evaluate the efficacy of iloprost on myocardial insufficiency associated with hypovolemic shock in dogs. We designed the study as a controlled randomized study. METHODS: Sixteen mixed-breed dogs were included into the study and divided into two equal groups as the control and iloprost groups. Mean arterial pressure was reduced to 45 mmHg by withdrawing the arterial blood into citrated bags. The control group did not receive any drug but the other group received iloprost at a rate of 20 ng/kg/min by an infusion pump. Iloprost infusion was started 30 min after the blood pressure was reduced to 45 mmHg. All measurements were made before removal of blood, 45 min after exsanguination and at 1 hour intervals for 3 hours. Left ventricular stroke work index was measured 72 hours after the study. The hemodynamic and biochemical parameters and blood gas analysis were obtained. RESULTS: After hemorrhage, cardiac index (CI) decreased significantly from 132 +/- 14 to 51 +/- 8 ml/kg/min in the control group and from 128 +/- 11 ml/kg/min to 47 +/- 13 ml/kg/min in the iloprost group, respectively but at the end of the third hour it was 81 +/- 8 ml/kg/min in the control group and 105 +/- 6 ml/kg/min in the iloprost group (p < 0.05). Tumor necrosis factor-alpha (TNF alpha) was 41 +/- 8 pg/ml in the control group and 18 +/- 6 in the iloprost group 3 hours after bleeding (p < 0.05). Tumor necrosis factor-alpha concentration was significantly higher in the control group than in the iloprost group. There was no significant difference in pH between the groups but actual bicarbonate concentrations were different between the groups (p < 0.05). At the end of the third hour total body oxygen consumption was 105 +/- 11 ml/min in the control group and 132 +/- 12 ml/min in the iloprost group (p < 0.05). Oxygen delivery 3 hours after hemorrhage was 201 +/- 19 ml/min in the control group and 252 +/- 24 ml/min in the iloprost group (p > 0.05). Left ventricular stroke work index was higher in the iloprost group (p < 0.05). CONCLUSIONS: Hemorrhagic shock causes tumor necrosis factor-alpha release which may lead to multiple organ failure. Organ dysfunction still persists even after the appropriate treatment. Iloprost attenuates the release of tumor necrosis factor-alpha which may improve the adverse effects of hemorrhagic shock.

Mg++SO4 treatment improves the hemodynamics following the acute myocardial ischemia and reperfusion.

BACKGROUND: The effect of Mg++SO4 on myocardial hemodynamics was investigated in this study. METHODS: Twelve dogs were entered in this research. Six dogs received Mg++SO4 and the remaining dogs were considered as controls. The amount of Mg++SO4 that was administered to the animals was 0.15 mmol/kg/hr each. The left anterior descending artery was occluded for a period of 1 hour and the drug was administered during reperfusion. RESULTS: Two hours after reperfusion, cardiac output was 1275+/-50 ml/min in the control group and 1475+/-25 ml/min in the Mg++SO4 group (p<0.05), pulmonary capillary wedge pressure was 18+/-3 mmHg in the control group and 12+/-2 mmHg in the Mg++SO4 group. CONCLUSIONS: In this study it was shown that Mg++SO4 usage after 1 hour arterial occlusion and 2 hours reperfusion protects the heart from the adverse effects of ischemia/reperfusion and had a better central hemodynamics.

Mitral valve replacement with St. Jude Medical prosthesis and low-dose anticoagulation in patients aged over 50 years.

BACKGROUND AND AIMS OF THE STUDY: These studies were designed to assess the effect of low-dose anticoagulation in elderly patients after mitral valve replacement. METHODS: Between 1986 and 1995, 250 patients aged > or = 50 years underwent isolated mitral valve replacement at the Cardiovascular Surgery Clinic of Turkiye Yuksek Ihtisas Hospital. The overall hospital mortality rate was 8%. Postoperatively, all patients received 2.5 mg/day warfarin, and 225 mg/day dypridamole and 250 mg/day aspirin following removal of mediastinal tubes. This regimen was continued indefinitely thereafter. RESULTS: Postoperatively, the mean International Normalized Ratio (INR) was 1.4 +/- 0.67 (range: 0.9 to 4.19) and mean prothrombin time 13.33 +/- 1.98 min (range: 11.7 to 21.3 min). Mean follow up was 1.42 +/- 1.2 years (range: 2 months to 8.3 years); total cumulative follow up was 322.75 patient-years (pt-yr). During follow up, six patients (1.85% per pt-yr) developed thromboembolic complications (including mechanical valve thrombosis), two (0.62% per pt-yr) developed oral anticoagulant-related bleeding, and two (0.62% per pt-yr) developed paravalvular leak. Five patients died during follow up (late mortality rate 1.2% per pt-yr). The nine-year actuarial survival rate was 93.9 +/- 4.8% for the entire group. CONCLUSIONS: Low-dose oral anticoagulation after mitral valve replacement with St. Jude Medical prosthesis in elderly patients provided satisfactory clinical results.

Low-dose oral anticoagulation and antiplatelet therapy with St. Jude Medical heart valve prosthesis.

BACKGROUND AND AIM OF THE STUDY: Since 1986, the St. Jude Medical (SJM) mechanical heart valve prosthesis has been implanted in patients at the authors' institution. We present our experience of low-dose oral anticoagulation and antiplatelet therapy following SJM valve implantation. METHODS: Among 2,585 patients (mean age 40.3 +/- 13.5 years) living in a rural environment, 865 underwent aortic valve replacement (AVR), 1,231 mitral valve replacement (MVR) and 489 double valve replacement (DVR). All patients received 2.5 mg/day warfarin and a combination of antiaggregation therapy (dypridamole 3 x 75 mg/day plus aspirin 100 mg/day), irrespective of their prothrombin time and cardiac rhythm. RESULTS: Postoperatively, 139 adverse events occurred (51 in AVR patients, 58 in MVR, 30 in DVR). Operative mortality rate was 5.9%, 4.7% and 6.1%, respectively, in the three groups (overall mortality rate 5.4%). The most frequent cause of operative mortality was low cardiac output. During follow up, there were 88 anticoagulant hemorrhages (1.2%/patient-year (pt-yr)), 11 paravalvular leaks (0.2%/pt-yr), 52 thromboembolisms (0.7%/pt-yr), 60 mechanical valve thromboses (0.8%/pt-yr) and 78 reoperations (1.1%/pt-yr). These complications occurred in 101 patients after AVR, in 125 after MVR, and in 63 after DVR (4.2%, 3.7% and 4.6% per pt-yr, respectively). Patient age (p = 0.0004), concomitant surgery (p = 0.0017) and late valve-related complications (p = 0.0159) were statistically significant mortality factors after AVR. Previous surgery was a significant risk factor for operative mortality after MVR (p <0.05). Female gender (p = 0.0059) and age (p = 0.017) were significant risk factors for operative mortality after DVR (p <0.01). CONCLUSIONS: Following implantation of the St. Jude Medical mechanical heart valve prosthesis, a fixed dose of 2.5 mg/day warfarin and combined dipyridamole/aspirin provided satisfactory results in terms of thrombosis, embolism and bleeding.

Treatment of functional tricuspid regurgitation by bicuspidalization annuloplasty during mitral valve surgery.

BACKGROUND AND AIMS OF THE STUDY: Surgical treatment of functional tricuspid regurgitation associated with advanced valvular disease remains controversial, mainly due to the difficulty in choosing between valve replacement or reconstructive surgery. Failure to correct tricuspid regurgitation during valvular surgery carries a poor prognosis, as reoperation may represent a significant risk to the patient. Thus correct tricuspid valve surgery is vital to achieve improved early and long-term clinical results. METHODS: A total of 142 patients underwent concomitant tricuspid annuloplasty with mitral valve replacement and their clinical outcome was assessed. RESULTS: Overall hospital mortality rate was 11.3%. Seven patients died during follow up. The overall actuarial survival rate for 10 years was 74.1 +/- 14.2%. Postoperatively, 75.8% of the patients had no residual tricuspid insufficiency, while 24.2% had first- or second-degree tricuspid insufficiency and were treated medically. All patients were in NHYA functional class I or II postoperatively. CONCLUSION: Clinically, it is important to assess the severity of functional tricuspid insufficiency before and/or during the operation. Bicuspidalization annuloplasty for functional tricuspid insufficiency has provided good results, with a low incidence of reoperation and significant clinical improvement. The technique could be used in most patients with functional tricuspid regurgitation.

Myocardial preservation in acute coronary artery occlusion with coronary sinus retroperfusion and carnitine.

BACKGROUND: Effectiveness of retrograde coronary sinus perfusion with the use of carnitine supplementation over the severity of ischemia/reperfusion injury, in acute coronary occlusion. METHODS: Eighteen mongrel dogs, divided equally into control, retrograde perfusion (retroperfusion) and carnitine retroperfusion (retrocarnitine) groups. After taking the basal values, the left anterior descending artery was occluded. At the fifteenth minute, without ending the occlusion, retrograde coronary sinus cardioplegia in the retroinfusion group and in the carnitine group, 0.15 mmol/kg of L-carnitine retroperfusion was performed. Then, hemodynamic and biochemical measurements were taken till the end of 120 minutes. The control group had no retroperfusion or medical therapy. RESULTS: Between the three groups, there was a statistically significant difference in cardiac index, mean arterial pressure, mean pulmonary artery pressure, pulmonary capillary wedge pressure, right atrial pressure as hemodynamic parameters and myocardial oxygen extraction, myocardial Lactate extraction, protein thiols and Malonyl dialdehyde (MBA) as biochemical parameters, at different time intervals (p<0.05). CONCLUSION: Coronary sinus retroperfusion with carnitine is found to be very effective in reducing oxygen free radical release and however this advantage did not switch to the hemodynamic function between the retrograde coronary sinus infusion group and retroinfusion carnitine group. In our opinion retrograde coronary sinus perfusion with the use of carnitine supplementation reduces the severity of ischemia/reperfusion injury.