Ujjwal K. Chowdhury

Early goal-directed therapy in moderate to high-risk cardiac surgery patients

Early goal-directed therapy is a term used to describe the guidance of intravenous fluid and vasopressor/inotropic therapy by using cardiac output or similar parameters in the immediate post-cardiopulmonary bypass in cardiac surgery patients. Early recognition and therapy during this period may result in better outcome. In keeping with this aim in the cardiac surgery patients, we conducted the present study. The study included 30 patients of both sexes, with EuroSCORE >or=3 undergoing coronary artery bypass surgery under cardiopulmonary bypass. The patients were randomly divided into two groups, namely, control and early goal-directed therapy (EGDT) groups. All the subjects received standardized care; arterial pressure was monitored through radial artery, central venous pressure through a triple lumen in the right internal jugular vein, electrocardiogram, oxygen saturation, temperature, urine output per hour and frequent arterial blood gas analysis. In addition, cardiac index monitoring using FloTrac and continuous central venous oxygen saturation using PreSep was used in patients in the EGTD group. Our aim was to maintain the cardiac index at 2.5-4.2 l/min/m2 , stroke volume index 30-65 ml/beat/m2 , systemic vascular resistance index 1500-2500 dynes/s/cm5/m2 , oxygen delivery index 450-600 ml/min/m2 , continuous central venous oximetry more than 70%, stroke volume variation less than 10%; in addition to the control group parameters such as central venous pressure 6-8 mmHg, mean arterial pressure 90-105 mmHg, normal arterial blood gas analysis values, pulse oximetry, hematocrit value above 30% and urine output more than 1 ml/kg/h. The aims were achieved by altering the administration of intravenous fluids and doses of inotropic or vasodilator agents. Three patients were excluded from the study and the data of 27 patients analyzed. The extra volume used (330+/-160 v/s 80+/-80 ml, P=0.043) number of adjustments of inotropic agents (3.4+/-1.5 v/s 0.4+/-0.7, P=0.026) in the EGDT group were significant. The average duration of ventilation (13.8+/-3.2 v/s 20.7+/-7.1 h), days of use of inotropic agents (1.6+/-0.9 v/s 3.8+/-1.6 d), ICU stay (2.6+/-0.9 v/s 4.9+/-1.8 d) and hospital stay (5.6+/-1.2 v/s 8.9+/-2.1 d) were less in the EGDT group, compared to those in the control group. This study is inconclusive with regard to the beneficial aspects of the early goal-directed therapy in cardiac surgery patients, although a few benefits were observed.

Myocardial injury in coronary artery bypass grafting: On-pump versus off-pump comparison by measuring high-sensitivity C-reactive protein, cardiac troponin I, heart-type fatty acid-binding protein, creatine kinase- MB, and myoglobin release

OBJECTIVES We sought to investigate the release pattern of different cardiac biomarkers (high-sensitivity C-reactive protein, cardiac troponin I, heart-type fatty acid-binding protein, creatine kinase-MB, and myoglobin) and to establish the diagnostic discrimination limits of each marker protein to evaluate perioperative myocardial injury in patients undergoing coronary artery bypass grafting with or without cardiopulmonary bypass. METHODS Fifty patients were randomly assigned to on-pump or off-pump coronary artery bypass grafting. All cardiac biomarkers were measured in serial venous blood samples drawn before heparinization in both groups and after aortic unclamping at 1, 2, 4, 8, 24, 48, and 72 hours in the on-pump group. In the off-pump group samples were taken after the last distal anastomosis and at same time intervals as in the on-pump group. RESULTS The total amount of heart-type fatty acid-binding protein, cardiac troponin I, and high-sensitivity C-reactive protein released was significantly higher in the on-pump group than in the off-pump group. Receiver operating characteristic curve analysis of cardiac biomarkers indicated cardiac troponin I and heart-type fatty acid-binding protein as the superior diagnostic discriminators of myocardial injury, with an optimal cutoff value of greater than 0.92 ng/mL (area under the curve, 0.95 [95% CI, 0.88-1.00]; sensitivity, 92%; specificity, 92%; likelihood ratio [+], 11.50) and greater than 6.8 ng/mL (area under the curve, 0.94 [95% CI, 0.88-1.00]; sensitivity, 88%; specificity, 88%; likelihood ratio [+], 7.33), respectively. Logistic regression analysis revealed that patients with increased cardiac troponin I levels of greater than 0.92 ng/mL and heart-type fatty acid-binding protein levels of greater than 6.8 ng/mL were at 132.25 (95% confidence interval, 17.14-1020.49) times and 53.77 (95% confidence interval, 9.76-296.12) times higher risk of myocardial injury after on-pump coronary artery bypass grafting. CONCLUSIONS Off-pump coronary artery bypass grafting provides better myocardial protection than on-pump coronary artery bypass grafting. Cardiac troponin I and heart-type fatty acid-binding protein, but not high-sensitivity C-reactive protein, served as superior diagnostic discriminators of perioperative myocardial damage after on-pump coronary artery bypass grafting.

Histopathologic changes in ascending aorta and risk factors related to histopathologic conditions and aortic dilatation in patients with tetralogy of Fallot.

OBJECTIVE The purposes of this study were to evaluate the histologic characteristics of the aortic wall and the risk factors related to histopathology and aortic dilatation in patients undergoing intracardiac repair of tetralogy of Fallot. METHODS Operatively excised full-thickness aortic wall tissue from 98 consecutive patients undergoing intracardiac repair of tetralogy of Fallot aged 6 months to 47 years (mean 104.5 +/- 102.8 months; median 72 months) were studied by light microscopy. The receiver operating characteristic curve analysis was done to quantify the diagnostic accuracy of loss of lamellar counts and multiple logistic regression models. RESULTS Twenty-five (25.5%) aortic tissue specimens were indicated as histologically normal and were used as normal controls. The incidence of elastic fragmentation, increased ground substance, medionecrosis, smooth muscle disarray, and fibrosis was 74.5%, 54%, 39.8%, 26.5%, and 57.1%, respectively. A lamellar count of less than 60 was associated with a sensitivity of 80% and a specificity of 87.67%. Area under the receiver operating characteristic curve indicated that 93.37% (standard error +/- 0.039) of the time the value of lamellar count was lower for the abnormal histopathology group than for the normal group (P < .001). The risk of aortic dilatation was 15.97 times higher in patients with histopathologically abnormal aorta. CONCLUSIONS The majority of aortic media of the ascending aorta in cyanotic tetralogy of Fallot indicates significant loss of lamellar units and pre-existing intrinsic aortopathy. The changes are present since infancy and are more pronounced in older patients subjected to long-standing cyanosis and volume overload and may account for or may coexist with the higher incidence of aortic dilatation encountered in these patients.

One and a half ventricle repair with pulsatile bidirectional Glenn: results and guidelines for patient selection

BACKGROUND The guidelines for performing a one and a half ventricle repair with pulsatile bidirectional Glenn remains controversial. This retrospective report summarizes the experience of a single institution, with an attempt at providing an answer. METHODS Fifty consecutive patients, aged 4 months to 42 years, underwent intracardiac repair along with a superior cavopulmonary connection. Twenty-seven of the patients had had previous surgical palliation. Repair consisted of patch closure of the ventricular septal defect (n = 25), tricuspid valve repair (n = 26), reconstruction of the right ventricular outflow tract (n = 34), transpulmonary annular patch (n = 34), right ventricle to pulmonary artery homograft conduit (n = 4), and concomitant repair of atrioventricular canal (n = 9). Ten patients were left with a fenestration in the atrial septum. RESULTS There were six hospital deaths (12%) and two late deaths (4.5%). Forty-two survivors were followed from 8 months to 116 months. Eighty-eight percent are in functional class I. Actuarial survival at 97 months was 74%. CONCLUSIONS Moderate right heart hypoplasia constitutes a safe anatomic category for a pulsatile bidirectional Glenn. It is advisable not to proceed with a one and a half ventricle repair if postoperative residual pulmonary artery hypertension is anticipated. Patients requiring an intricate intracardiac repair and those with concomitant right heart hypoplasia may be better suited for a Fontan type of repair to reduce the complexity of the procedure.

Congenital Left Atrial Appendage Aneurysm: A Case Report and Brief Review of Literature

A 28-year-old woman with congenital aneurysm of the left atrial appendage was successfully treated by aneurysmectomy and is reported for its rarity. The exact diagnosis is relatively easy to make by contrast echocardiography, magnetic resonance imaging, and/or computerised tomographic angiography, provided the possibility is entertained. Because of supraventricular arrhythmias and systemic thromboembolism, surgical resection was deemed the best curative option to avoid further episodes and recurrence. Published reports detailing the diagnostic evaluation and surgical management for congenital left atrial appendage aneurysm are also discussed.

Specific issues after surgical repair of partial atrioventricular septal defect: Actuarial survival, freedom from reoperation, fate of the left atrioventricular valve, prevalence of left ventricular outflow tract obstruction, and other events

OBJECTIVE Our aim was to define the prevalence of specific sequelae after repair of partial atrioventricular septal defect. PATIENTS AND METHODS A total of 132 consecutive patients undergoing repair of partial atrioventricular septal defect were studied for mortality, left atrioventricular valve function, reoperations, left ventricular outflow tract obstruction, and supraventricular arrhythmias. Age was 2.5 months to 43 years (median, 54 months); 13 (9.8%) were more than 20 years old. Preoperatively, 26.5% patients were in New York Heart Association class III/IV, 15.9% had supraventricular arrhythmias, 25.7% had pulmonary artery hypertension, 16.6% had moderate-to-severe left valvular regurgitation, and 29.5% had additional left atrioventricular valvular malformations. Autologous pericardium (n = 127) and right atrial patch (n = 5) were used to patch the defect. Left atrioventricular valvuloplasty was performed in 91% of patients despite older age and additional malformations of the left atrioventricular valve. RESULTS Operative and late mortalities were 4.5% and 3.2%, respectively. Postoperative supraventricular arrhythmias were observed in 11.3% of patients. Reoperations were required in 5.8% patients because of a residual atrial septal defect (n = 1) and severe left atrioventricular valvular regurgitation (n = 6). At a mean follow-up of 106.82 +/-55.04 months, actuarial survival was 83.70% +/- 0.07%. The risk of death was 38.92 (95% confidence intervals: 7.8-195.1) and 6.88 (95% confidence intervals: 1.79-38.18) times higher in patients with grossly malformed left atrioventricular valve and preoperative pulmonary artery hypertension, respectively, by logistic regression analysis. CONCLUSIONS Detailed assessment of the valve morphology and individualized valvuloplasty techniques improves the long-term survival after repair of partial atrioventricular septal defects. The presence of grossly malformed left valvular apparatus, pulmonary artery hypertension, and moderate-to-severe left atrioventricular valve regurgitation are independent predictors of death and defect-related morbidity after surgical repair.

Isolated Idiopathic Pulmonary Artery Aneurysm

Aneurysm formation of the main pulmonary artery is rare. Its natural history is not well understood and there are no clear guidelines on optimal treatment. A 20-year-old woman with a huge saccular aneurysm of the main pulmonary artery, underwent repair with a pericardial patch and concomitant reconstruction of the pulmonary valve. The patient was doing well on follow-up at 6 months; echocardiography revealed a good repair with mild to moderate pulmonary regurgitation.

Changes in myocardial lactate, pyruvate and lactate-pyruvate ratio during cardiopulmonary bypass for elective adult cardiac surgery: Early indicator of morbidity.

Background: Myocardial lactate assays have been established as a standard method to compare various myocardial protection strategies. This study was designed to test whether coronary sinus (CS) lactates, pyruvate and lactate-pyruvate (LP) ratio correlates with myocardial dysfunction and predict postoperative outcomes. Materials and Methods: This prospective observational study was conducted on 40 adult patients undergoing elective cardiac surgery with the aid of cardiopulmonary bypass (CPB). CS blood sampling was done for estimation of myocardial lactate (ML), pyruvate (MP) and lactate-pyruvate ratio (MLPR) namely: pre-CPB (T1), after removal of aortic cross clamp (T2) and 30 minutes post-CPB (T3). Results: Baseline myocardial LPR strongly correlated with Troponin-I at T1 (σ: 0.6). Patients were sub grouped according to the median value of myocardial lactate (2.9) at baseline T1 into low myocardial lactate (LML) group, mean (2.39±0.4 mmol/l), n=19 and a high myocardial lactate (HML) group, mean (3.65±0.9 mmol/l), n = 21. A significant increase in PL, ML, MLPR and TropI occurred in both groups as compared to baseline. Patients in HML group had significant longer period of ICU stay. Patients with higher inotrope score had significantly higher ML (T2, T3). ML with a baseline value of 2.9 mmol/l had 70.83% sensitivity and 62.5% specificity (ROC area: 0.7109 Std error: 0.09) while myocardial pyruvate with a baseline value of 0.07 mmol/l has 79.17% sensitivity and 68.75% specificity (ROC area: 0.7852, Std error: 0.0765) for predicting inotrope requirement after CPB. Conclusion: CS lactate, pyruvate and LP ratio correlate with myocardial function and can predict postoperative outcome.

Acute hemodynamic effects of inhaled nitroglycerine, intravenous nitroglycerine, and their combination with intravenous dobutamine in patients with secondary pulmonary hypertension.

OBJECTIVES The presence of pulmonary artery hypertension (PAH) affects the prognosis of patients; therefore, it is important to treat it. The aim of this study is to compare the acute hemodynamic effects of inhaled nitroglycerine (iNTG), intravenous nitroglycerine (IV NTG) alone and their combination with intravenous dobutamine (IV DOB) during the early postoperative period, in patients with PAH undergoing mitral valve or double valve replacement surgery. MATERIALS AND METHODS In the study, 40 patients with secondary PAH were administered iNTG 2.5 microg/kg/min, IV NTG 2.5 microg/kg/min, a combination of iNTG 2.5 microg/kg/min + IV DOB 10 microg/kg/min, and IV NTG 2.5 microg/kg/min + IV DOB 10 microg/kg/min for 10 minutes each following valve replacement surgery, in random order. The hemodynamic parameters were recorded before (T0) and immediately after the intervention. (T1). RESULTS iNTG effectively decreased mean pulmonary arterial pressure (mPAP), pulmonary vascular resistance index (PVRI), and the PVR / SVR ratio, without affecting arterial pressures, systemic vascular resistance or mixed venous oxygen saturation (SvO2). IV NTG produced both systemic and pulmonary vasodilation along with a significant fall in SvO2. The combination of iNTG and IV DOB caused a significant decrease in mPAP and PVRI, with no significant change in SVRI, PVR / SVR ratio, and SvO2. A combination of IV NTG + IV DOB caused both pulmonary and systemic vasodilatation with a significant decrease in SvO2. None of the drugs caused any significant change in the cardiac index. CONCLUSION All drugs were of similar efficacy in reducing the pulmonary vascular resistance index. Only iNTG produced selective pulmonary vasodilatation, while IV NTG and its combination with IV dobutamine had a significant concomitant systemic vasodilatory effect.

A suggested new surgical classification for mixed totally anomalous pulmonary venous connection.

The morphologic variations of mixed totally anomalous pulmonary venous connection are many and varied. In this review, we give an account of all cases previously described as mixed totally anomalous pulmonary venous connection, analyzing in detail those cases where an accurate anatomical description was provided. We identified 182 suitable cases, from 54 investigations, and reviewed the clinical presentation, anatomic variations, diagnostic features, and management of the patients described.Cross-sectional echocardiography, and cardiac catheterization, provided the necessary diagnostic information, and defined the anatomy before surgery in 139 patients. Magnetic resonance imaging and computerized tomographic angiography had been used for further clarification of the pulmonary venous anatomy. An obstructive pattern of drainage, involving one or more pulmonary veins, had been described in over half of the patients. We then grouped the lesions into categories that have a bearing on the appropriate surgical approach, discussing the appropriate repair for each group. For the overall group, the operative mortality remains high, at 22.9%. We submit that an increased appreciation of various types of mixed totally anomalous pulmonary venous connection may well contribute to improved future surgical management.