Volume 28 - Número 4
Animal research and cardiovascular surgery
Innovation and Excellence: Changing to Prevail The Brazilian Cardiovascular Surgery
Three-dimensional ultrasound STIC-HDlive rendering: new technique to assessing of fetal heart
Does preoperative beta-blocker offer myocardial protection during coronary artery bypass grafting?
Repair of aortic root in patients with aneurysm or dissection: comparing the outcomes of valvesparing root replacement with those from the Bentall procedure
INTRODUCTION: Management of aortic root aneurysm or dissection has been the subject of much discussion that has led to some modifications. The current trend is a valve-sparing root replacement. We compared the outcome following valve sparing root repair with Bentall procedure.
METHODS: We retrospectively evaluated 70 patients who underwent root replacement for aneurysm or dissection and compared the outcomes of valve-sparing root replacement with those of the Bentall procedure from January 2007 to December 2011 at our institution.
RESULTS: Twenty-five patients had valve-sparing aortic root replacement (VSR, including reimplantation or remodeling) (23 males and 2 females), and 45 patients had the Bentall procedure (34 males and 11 females). Patients who underwent a VSR were younger with a mean age of 55.4 ± 14.8 years compared to those who underwent the Bentall procedure with a mean age of 60.6 ± 12.7 (P=ns). The preoperative aortic insufficiency (AI) in the VSR group was moderate in 8 (32%) patients, and severe in 6 (24%). Preoperative creatinine was 1 ± 0.35 mg/dl in the VSR group and 1.1 ± 0.87 mg/dl in the Bentall group. In the VSR group, 3 (12%) patients had emergency surgery; by contrast, in the Bentall group, 8 (17%) patients had emergent surgery. Concomitant coronary artery bypass grafting (excluding coronary reimplantation) was performed in 8 (32%) patients in the VSR group and in 12 (26.6%) patients in the Bentall group (P=0.78); additional valve procedures were performed in 2 (8%) patients in the VSR group and in 11 (24.4%) patients in the Bentall group. The perioperative mortality was 8% (n=2) and 13.3% (n=6), for the VSR and Bentall procedures, respectively (P=0.7, ns). The total duration of intensive care unit stay was 116.6 ± 106 hours for VSR patients and 152.5 ± 218.2 hours for Bentall patients (P=0.5). The overall length of stay in the hospital was 10 ± 8.1 days for VSR and 11 ± 9.52 days for Bentall (P=0.89). The one-year survival was 92% for the VSR group and 79.0% for the Bentall group. The seven-year survival for the VSR group was 92% and 79% for the Bentall group (95% CI [1.215 to 0.1275], P=0.1).
CONCLUSION: Aortic valve-sparing root replacement can be performed with acceptable morbidity and mortality with a comparable long-term survival to the Bentall procedure.
Myocardial protection with prophylactic oral metoprolol during coronary artery bypass grafting surgery: evaluation by troponin I
INTRODUCTION: Biochemical markers of myocardial injury are frequently altered after cardiac surgery. So far there is no evidence whether oral beta-blockers may reduce myocardial injury after coronary artery bypass grafting.
OBJECTIVE: To determine if oral administration of prophylactic metoprolol reduces the release of cardiac troponin I in isolated coronary artery bypass grafting, not complicated by new Q waves.
METHODS: A prospective randomized study, including 68 patients, divided in 2 groups: Group A (n=33, control) and B (n=35, beta-blockers). In group B, metoprolol tartrate was administered 200 mg/day. The myocardial injury was assessed by troponin I with 1 hour and 12 hours after coronary artery bypass grafting.
RESULTS: No significant difference between groups regarding pre-surgical, surgical, complication in intensive care (15% versus 14%, P=0.92) and the total number of hospital events (21% versus 14%, P=0.45) was observed. The median value of troponin I with 12 hours in the study population was 3.3 ng/ml and was lower in group B than in group A (2.5 ng/ml versus 3.7 ng/ml, P<0,05). In the multivariate analysis, the variables that have shown to be independent predictors of troponin I release after 12 hours were: no beta-blockers administration and number of vessels treated.
CONCLUSION: The results of this study in uncomplicated coronary artery bypass grafting, comparing the postoperative release of troponin I at 12 hours between the control group and who used oral prophylactic metoprolol for at least 72 hours, allow to conclude that there was less myocardial injury in the betablocker group, giving some degree of myocardial protection.
Pressure support-ventilation versus spontaneous breathing with “T-Tube” for interrupting the ventilation after cardiac operations
OBJECTIVE: To compare pressure-support ventilation with spontaneous breathing through a T-tube for interrupting invasive mechanical ventilation in patients undergoing cardiac surgery with cardiopulmonary bypass.
METHODS: Adults of both genders were randomly allocated to 30 minutes of either pressure-support ventilation or spontaneous ventilation with "T-tube" before extubation. Manovacuometry, ventilometry and clinical evaluation were performed before the operation, immediately before and after extubation, 1h and 12h after extubation.
RESULTS: Twenty-eight patients were studied. There were no deaths or pulmonary complications. The mean aortic clamping time in the pressure support ventilation group was 62 ± 35 minutes and 68 ± 36 minutes in the T-tube group (P=0.651). The mean cardiopulmonary bypass duration in the pressure-support ventilation group was 89 ± 44 minutes and 82 ± 42 minutes in the T-tube group (P=0.75). The mean Tobin index in the pressure support ventilation group was 51 ± 25 and 64.5 ± 23 in the T-tube group (P=0.153). The duration of intensive care unit stay for the pressure support ventilation group was 2.1 ± 0.36 days and 2.3 ± 0.61 days in the T-tube group (P=0.581). The atelectasis score in the T-tube group was 0.6 ± 0.8 and 0.5 ± 0.6 (P=0.979) in the pressure support ventilation group. The study groups did not differ significantly in manovacuometric and ventilometric parameters and hospital evolution.
CONCLUSION: The two trial methods evaluated for interruption of mechanical ventilation did not affect the postoperative course of patients who underwent cardiac operations with cardiopulmonary bypass.
Laser Doppler anemometry measurements of steady flow through two bi-leaflet prosthetic heart valves
INTRODUCTION: In vitro hydrodynamic characterization of prosthetic heart valves provides important information regarding their operation, especially if performed by noninvasive techniques of anemometry. Once velocity profiles for each valve are provided, it is possible to compare them in terms of hydrodynamic performance. In this first experimental study using laser doppler anemometry with mechanical valves, the simulations were performed at a steady flow workbench.
OBJECTIVE: To compare unidimensional velocity profiles at the central plane of two bi-leaflet aortic prosthesis from St. Jude (AGN 21 - 751 and 21 AJ - 501 models) exposed to a steady flow regime, on four distinct sections, three downstream and one upstream.
METHODS: To provide similar conditions for the flow through each prosthesis by a steady flow workbench (water, flow rate of 17L/min.) and, for the same sections and sweeps, to obtain the velocity profiles of each heart valve by unidimensional measurements.
RESULTS: It was found that higher velocities correspond to the prosthesis with smaller inner diameter and instabilities of flow are larger as the section of interest is closer to the valve. Regions of recirculation, stagnation of flow, low pressure, and flow peak velocities were also found.
CONCLUSIONS: Considering the hydrodynamic aspect and for every section measured, it could be concluded that the prosthesis model AGN 21 - 751 (RegentTM) is superior to the 21 AJ - 501 model (Master Series). Based on the results, future studies can choose to focus on specific regions of the these valves.
Results of medium-term survival in patients undergoing cardiac transplantation: institutional experience
INTRODUCTION: The heart transplant became a consecrated therapy for patients with terminal heart failure, increasingly improving the survival.
OBJECTIVE: To identify the medium-term results in patients undergoing cardiac transplantation.
METHODS: This is a descriptive, documentary and retrospective study, using a quantitative approach, developed in a Unit of Transplant and Heart Failure, of a tertiary level public hospital, located in Fortaleza, CE, Brazil. The data were obtained from a sample of 188 patients (154 men and 34 women), submitted to the heart transplant, in the period from October 1997 to March 2011. There were calculated survival rates based on Kaplan-Meier methods.
RESULTS: There were identified information about the patient's gender (male 81.91%), medical diagnosis which determined the heart transplantation (idiopathic cardiomyopathies 23.98%, ischemic 23.4% and Chagasic 17.02%). The median age of patients was 48 years old (interquartile range = 17.25 years) and the median observation period was 877 days. During this period, 78 patients died, resulting in survival ratios of 72%, 59% and 47% after 1, 5 and 9 years of cardiac transplantation, respectively. Younger patients had longer survival (P=0.0418).
CONCLUSION: The medium-term survival of patients undergoing cardiac transplantation is significant, especially for younger patients.
Fetal heart assessment in the first trimester of pregnancy: influence of crown-rump length and maternal body mass index
OBJECTIVE: To evaluate the influence of the crown-rump length and body mass index on sonographic evaluation of the fetal heart using abdominal and vaginal routes in the first trimester of pregnancy.
METHODS: We conducted a cross-sectional study with 57 pregnant women between 12-14 weeks (CRL< 84 mm). We evaluated the following fetal cardiac plans using the abdominal and vaginal routes: four-chamber view, right ventricle outflow tract, left ventricle outflow tract and aortic arch. We used the B-mode, color Doppler and four-dimensional ultrasonography (spatio-temporal image correlation). To evaluate the influence of crown-rump length and body mass index in the assessment of fetal cardiac planes, we used the t test unpaired.
RESULTS: There were no statistically significant differences in the rates of success and failure between abdominal and vaginal routes in relation to body mass index, however, there was a higher failure rate in vaginal assessment using B mode associated with color Doppler (P<0.01).
CONCLUSION: The crown-rump length and body mass index had no interference in fetal cardiac assessment in the first trimester of pregnancy.
Depression after CABG: a prospective study
INTRODUCTION: Depression during or shortly after hospitalization elevated two to three times the risk of mortality or nonfatal cardiac events, significantly increasing the morbidity and mortality of these patients.
OBJECTIVE: To assess the impact of revascularization on symptoms of depression in patients with coronary artery disease.
METHODS: A prospective cohort study of 57 patients of both sexes undergoing coronary artery bypass grafting between June 2010 and June 2011. We used the SF-36 to assess quality of life, and the Beck Depression Inventory to detect depressive symptoms, applied preoperatively and six months.
RESULTS: The prevalence of patients aged 60-69 years was 22 patients (38.60%), 39 men (68.42%), 26 described themselves as mixed race (45.61%), 16 literate (28.07 %) and 30 married (52.63%). The beck depression inventory score demonstrated increased after revascularization: 15 patients mild (26.32%) at time zero to 17 (29.82%) after. And with moderate, seven patients (12.28%) before and 10 (17.54%) after. In the categories of individuals with decreased minimum degree of 32 (56.14%) to 28 (49.12%), and severe of three (5.26%) for two (3.51%) patients. Association was observed between beck depression inventory, gender, age, lifestyle, comorbidities and quality of life.
CONCLUSION: There was a high prevalence of elevated beck depression inventory scores, lowest scores of depressive symptoms among men and association between the improvement of quality of life scores and beck depression inventory.
Twenty four hour imaging delay improves viability detection by Tl-201 myocardial perfusion scintigraphy
OBJECTIVE: Since twenty-four-hour imaging by Tl-201 myocardial perfusion scintigraphy has been introduced as an effective additional procedure, the aim of this study was to compare this method's result with only rest redistribution procedure in the diagnosis of myocardial viability.
METHODS: Thirty patients (Seven female, 23 male; mean: 59.8 ± 10.7, 55.8-63.8 years old) with diagnosis of coronary artery disease were involved in this study. All patients had anamnesis of previous myocardial infarction and/or total occlusion of any main artery in the coronary angiography. Myocardial perfusion scintigraphy with Tl-201 with rest four hour (early) redistribution and 24 hour delayed redistribution protocol were performed to all of the patients. The images were evaluated according to 17 segment basis by an experienced nuclear medicine physician and improvement of a segment by visual interpretation was considered as viable myocardial tissue.
RESULTS: Viability was found at 52 segments in the early redistribution images and additional 18 segments in the 24 hour delayed redistribution images on segment basis in the evaluation of 510 segments of 30 patients. On per patient basis, among the 26 patients who had viable tissue, 14 (54%) had additional improvement in 24 hour delayed images. Three (12%) patients had viable tissue in only 24 hour delayed images.
CONCLUSION: Delayed imaging in Tl-201 MPS is a necessary application for the evaluation of viable tissue according to considerable number of patients with additional improvement in 24 hour images in our study, which is restricted to the patients with myocardial infarct.
Indicators of surgical treatment of patent ductus arteriosus in preterm neonates in the first week of life
OBJECTIVE: To identify clinical and echocardiographic indicators of the necessity for early surgical closure of patent ductus arteriosus in preterm neonates.
METHODS: The prospective study was conducted at the Neonatal Unit of Hospital Municipal Odilon Behrens between 2006 and 2010. The study population comprised 115 preterm neonates diagnosed with patent ductus arteriosus in the first week after birth, of whom 55 (group S) were submitted to clinical and or surgical closure and 60 (group NS) received non-surgical treatment. The parameters analyzed were birth weight, diameter of the ductus arteriosus (DAD), left atrial-to-aortic root diameter ratio (LA:Ao), the quotient of DAD2 and birth weight (mm2/kg), and ductal shunting.
RESULTS: The study population comprised 58 males and 57 females. The average birth weight of group S (924 ± 224.3 g) was significantly (P=0.049) lower than that of group NS (1012.3 ± 242.8 g). The probability of the preterm neonates being submitted to surgical closure was 62.1% (P=0.006) when the DAD2/birth weight index was > 5 mm2/kg, 72.2% (P=0.001) when the LA:Ao ratio was > 1.5, and 61.2% when ductal shunting was high (P=0.025).
CONCLUSION: The parameters DAD2/birth weight index > 5 mm2/kg, LA:Ao ratio > 1.5 and high ductal shunting were statistically significant indicators (P<0.05) of the need for surgical closure of patent ductus arteriosus in low birth weight preterm neonates. Moreover, when an LA:Ao ratio > 1.5 was associated with the occurrence of shock, the probability of surgical closure increased to 78.4%.
Mortality risk is dose-dependent on the number of packed red blood cell transfused after coronary artery bypass graft
INTRODUCTION: Transfusions of one or more packed red blood cells is a widely strategy used in cardiac surgery, even after several evidences of increased morbidity and mortality. The world's blood shortage is also already evident.
OBJECTIVE: To assess whether the risk of mortality is dose-dependent on the number of packed red blood cells transfused after coronary artery bypass graft.
METHODS: Between June 2009 and July 2010, were analyzed 3010 patients: transfused and non-transfused. Transfused patients were divided into six groups according to the number of packed red blood cells received: one, two, three, four, five, six or more units, then we assess the mortality risk in each group after a year of coronary artery bypass graft. To calculate the odds ratio was used the multivariate logistic regression model.
RESULTS: The increasing number of allogeneic packed red blood cells transfused results in an increasing risk of mortality, highlighting a dose-dependent relation. The odds ratio values increase with the increased number of packed red blood cells transfused. The death's gross odds ratio was 1.42 (P=0.165), 1.94 (P=0.005), 4.17; 4.22, 8.70, 33.33 (P<0.001) and the adjusted death's odds ratio was 1.22 (P=0.43), 1.52 (P=0.08); 2.85; 2.86; 4.91 and 17.61 (P<0.001), as they received one, two, three, four, five, six or more packed red blood cells, respectively.
CONCLUSION: The mortality risk is directly proportional to the number of packed red blood cells transfused in coronary artery bypass graft. The greater the amount of allogeneic blood transfused the greater the risk of mortality. The current transfusion practice needs to be reevaluated.
Association of pre and intraoperative variables with postoperative complications in coronary artery bypass graft surgery
OBJECTIVE: To associate the pre- and intraoperative variables with postoperative complications of patients undergoing coronary artery bypass graft surgery.
METHODS: The pre- and intraoperative risk factors of individuals of both genders with diagnosis of coronary insufficiency undergoing coronary artery bypass graft have been studied.
RESULTS: Fifty-eight individuals with median age 62 ± 10 year-old were included in the study, 67% of whom were male. Fourteen (24.1%) patients were smokers, 39 (67.2%) had previous myocardial infarction history, 11 (19%) had undergone coronary angioplasty, 74% had hypertension, 27% had diabetes mellitus, 64% had dyslipidemia and 15.5% had chronic obstructive pulmonary disease. Eighteen (31%) patients presented postoperative complications, most frequent being: infection in surgical incision, difficulties in deambulation, dyspnea, urinary infection and generalized weakness. Male patients had fewer complications than females (P=0.005). Patients with chronic obstructive pulmonary disease remained hospitalized for longer time periods (P=0.019). Postoperative complications occurred in 50% of the patients with creatinine increased, while only 27.1% of the patients with normal value of creatinine had complications (P=0.049). In addition, complications occurred in 50% of the patients with diabetes mellitus, while only 23.8% of patients without diabetes mellitus had complications (P=0.032). The intraoperative factors showed no statistically significant differences.
CONCLUSION: The preoperative factors are associated with postoperative complications in patients undergoing coronary artery bypass graft surgery.
Development of cardioplegic solution without potassium: experimental study in rat
INTRODUCTION: Myocardial preservation during open heart surgeries and harvesting for transplant are of great importance. The heart at the end of procedure has to resume its functions as soon as possible. All cardioplegic solutions are based on potassium for induction of cardioplegic arrest.
OBJECTIVE: To assess a cardioplegic solution with no potassium addition to the formula with two other commercially available cardioplegic solutions. The comparative assessment was based on cytotoxicity, adenosine triphosphate myocardial preservation, and caspase 3 activity. The tested solution (LIRM) uses low doses of sodium channel blocker (lidocaine), potassium channel opener (cromakalin), and actin/myosin cross bridge inhibitor (2,3-butanedione monoxime).
METHODS: Wistar rats underwent thoracotomy under mechanical ventilation and three different solutions were used for "in situ" perfusion for cardioplegic arrest induction: Custodiol (HTK), Braile (G/A), and LIRM solutions. After cardiac arrest, the hearts were excised and kept in cold storage for 4 hours. After this period, the hearts were assessed with optical light microscopy, myocardial ATP content and caspase 3 activity. All three solutions were evaluated for direct cytotoxicity with L929 and WEHI-164 cells.
RESULTS: The ATP content was higher in the Custodiol group compared to two other solutions (P<0.05). The caspase activity was lower in the HTK group compared to LIRM and G/A solutions (P<0.01). The LIRM solution showed lower caspase activity compared to Braile solution (P<0.01). All solutions showed no cytotoxicity effect after 24 hours of cells exposure to cardioplegic solutions.
CONCLUSION: Cardioplegia solutions without potassium are promised and aminoacid addition might be an interesting strategy. More evaluation is necessary for an optimal cardioplegic solution development.
Incidence of Stroke and Acute renal failure in patients of Postoperative Atrial Fibrillation after Myocardial Revascularization
INTRODUCTION: Postoperative atrial fibrillation is the most common arrhythmia in cardiac surgery, its incidence range between 20% and 40%.
OBJECTIVE: Quantify the occurrence of stroke and acute renal insufficiency after myocardial revascularization surgery in patients who had atrial fibrillation postoperatively.
METHODS: Cohort longitudinal bidirectional study, performed at Portuguese Beneficent Hospital (SP), with medical chart survey of patients undergoing myocardial revascularization surgery between June 2009 to July 2010. From a total of 3010 patients were weaned 382 patients that presented atrial fibrillation preoperatively and/or associated surgeries. The study was conducted in accordance with national and international following resolutions: ICH Harmonized Tripartite Guidelines for Good Clinical Practice - 1996; CNS196/96 Resolution, and Declaration of Helsinki.
RESULTS: The 2628 patients included in this study were divided into two groups: Group I, who didn't show postoperative atrial fibrillation, with 2302 (87.6%) patients; and group II, with 326 (12.4%) who developed postoperative atrial fibrillation. The incidence of stroke in patients was 1.1% without postoperative atrial fibrillation vs. 4% with postoperative atrial fibrillation (P<0.001). Postoperative acute renal failure was observed in 12% of patients with postoperative atrial fibrillation and 2.4% in the group without postoperative atrial fibrillation (P<0.001), that is a relation 5 times greater.
CONCLUSION: In this study there was a high incidence of stroke and acute renal failure in patients with postoperative atrial fibrillation, with rates higher than those reported in the literature.
Reversible pulmonary trunk banding. IX. G6PD activity of adult goat myocardium submitted to ventricular retraining
OBJECTIVE: Increased glucose 6-phosphate dehydrogenase activity has been demonstrated in heart failure. This study sought to assess myocardial glucose 6-phosphate dehydrogenase activity in retraining of the subpulmonary ventricle of adult goats.
METHODS: Eighteen adult goats were divided into three groups: traditional (fixed banding), sham, and intermittent (adjustable banding, daily 12-hour systolic overload). Systolic overload (70% of systemic pressure) was maintained during a 4-week period. Right ventricle, pulmonary artery and aortic pressures were measured throughout the study. All animals were submitted to echocardiographic and hemodynamic evaluations throughout the protocol. After the study period, the animals were killed for morphological and glucose 6-phosphate dehydrogenase activity assessment.
RESULTS: A 55.7% and 36.7% increase occurred in the intermittent and traditional right ventricle masses, respectively, when compared with the sham group (P<0.05), despite less exposure of intermittent group to systolic overload. No significant changes were observed in myocardial water content in the 3 groups (P=0.27). A 37.2% increase was found in right ventricle wall thickness of intermittent group, compared to sham and traditional groups (P<0.05). Right ventricle glucose 6-phosphate dehydrogenase activity was elevated in the traditional group, when compared to sham and intermittent groups (P=0.05).
CONCLUSION: Both study groups have developed similar right ventricle hypertrophy, regardless less systolic overload exposure of intermittent group. Traditional systolic overload for adult subpulmonary ventricle retraining causes upregulation of myocardial glucose 6-phosphate dehydrogenase activity. It may suggest that the undesirable "pathologic systolic overload" is influenced by activation of penthose pathway and cytosolic Nicotinamide adenine dinucleotide phosphate availability. This altered energy substrate metabolism can elevate levels of free radicals by Nicotinamide adenine dinucleotide phosphate oxidase, an important mechanism in the pathophysiology of heart failure.
On-pump versus off-pump coronary artery bypass graft surgery. What do the evidence show?
The main purpose of the off-pump coronary artery bypass surgery is to reduce morbidity and mortality due cardiopulmonary bypass. However, even though many studies have shown that off-pump coronary artery bypass is feasible and provides hospital morbidity and mortality similar to the on-pump coronary artery bypass graft surgery, probably better in some aspects, its long-term results have been questioned, since some trials have shown reduced survival with off-pump coronary artery bypass. It is likely that incomplete revascularization and/or poor graft patency with off-pump coronary artery bypass probably are responsible for such unfavorable outcome.
Keywords: Myocardial Revascularization; Coronary artery bypass, off-pump; Coronary artery bypass; Evidence-based medicineNursing assistance at the hospital discharge after cardiac surgery: integrative review
The study aimed to analyze the available evidence in the literature on nursing care in the hospital post-cardiac surgery. Data were collected from electronic databases LILACS, SciELO, MEDLINE, via DeCS thoracic surgery, hospital, nursing care, in the period 2001 to 2011. Ten articles were selected that showed the need to develop a plan of nursing discharge focusing on prevention of complications and coping with physical limitations resulting from heart surgery. Thus, the discharge should be considered from the time of admission, with carefully planned actions involving patient and family.
Keywords: Nursing care; Patient discharge; Cardiovascular surgical proceduresSupravalvular aortic stenosis in adult with anomalies of aortic arch vessels and aortic regurgitation
The supravalvular aortic stenosis is a rare congenital heart defect being very uncommon in adults. We present a case of supravalvular aortic stenosis in adult associated with anomalies of the aortic arch vessels and aortic regurgitation, which was submitted to aortic valve replacement and arterioplasty of the ascending aorta with a good postoperative course.
Keywords: Aortic Stenosis, Supravalvular; Aortic valve insufficiency; Adult; Subclavian artery; Carotid Artery, InternalUse of a stent-graft and vascular occlude to treat primary and re-entry tears in a patient with a Stanford type B aortic dissection
Thoracic endovascular aortic repair for aortic dissections is recognized as an effective treatment. We herein report the case of a 72-year-old male with a Stanford type B aortic dissection. A stent-graft and double-disk vascular occluder was used to repair the primary and re-entry tears, respectively. At 3 month postoperatively, computed tomographic angiography revealed no endoleaks, the stent-graft and vascular occluder to be in optimal positions, the false lumen was almost completely thrombosed, and the visceral arteries were patent. This case illustrates that it is feasible to treat re-entry tears with a vascular occluder after primary proximal stent-graft repairs.
Keywords: Vascular diseases; Cardiovascular surgical procedures; Aortic diseases