Risk factors for vasoplegia after coronary artery bypass and valve surgery.

INTRODUCTION: Vasoplegia denotes a state of low tissue perfusion characterized by hypotension, tachycardia, and low systemic vascular resistance. This state results in increased mortality and morbidity following cardiac surgery. A better understanding of the associated risk factors will guide the surgical team in patient management. The aim of this study is to determine which risk factors are involved in its emergence. METHODS: This prospective observational study included adult cardiac surgery patients between February - September 2018 at a single cardiothoracic surgery center. Patients were evaluated for cardiac contractility, surgical drainage, inotrope, and vasopressor requirement perioperatively. The groups were compared for demographic, echocardiographic, and operative variables. Variables significant in univariate analysis were carried on to binary logistic regression for risk factor analysis. RESULTS: A total of 31 patients were vasoplegic among a total of 487 included patients, resulting in a 6.37% incidence. In the vasoplegia group, chronic kidney failure, use of angiotensin-converting enzyme (ACE) inhibitors, use of angiotensin receptor blockers, and use of diuretics were more frequent, cardiopulmonary bypass (CPB) and aortic cross-clamp durations were longer, and mean Euroscore II was higher. Vasoplegia was more frequent in valve surgery and resternotomy patients. CPB duration, use of ACE inhibitors, use of angiotensin receptor blockers, and chronic renal failure were independent risk factors. CONCLUSION: Patients with long CPB duration, preoperative use of ACE inhibitors or Angiotensin receptor blockers, and a history of renal failure requiring dialysis are under increased risk of vasoplegia. Vasoplegia necessitates large-scale studies for a better understanding of its risk factors.

The Effect of Left Ventricular Assist Device Implantation on Serum Albumin, Total Protein and Body Mass: A Short-Term, Longitudinal Follow-Up Study.

BACKGROUND: Cardiac cachexia and low serum albumin levels are poor prognostic signs in advanced heart failure, while overweight patients or patients who gain weight after treatment have more favourable outcomes. Weight gain following LVAD implantation is common, while the dynamic changes in body mass or serum proteins have not been studied adequately. Our aim was to study short-term changes in serum albumin, total protein and body weight following LVAD implantation and to compare these changes with heart failure patients treated medically. MATERIALS AND METHODS: A total of 15 patients scheduled for LVAD implantation and 15 patients receiving medical treatment were prospectively enrolled. Anthropometric and laboratory data for the patients were obtained at baseline and at first and sixth months after LVAD implantation. RESULTS: Anthropometric, demographic and clinical characteristics between two groups were similar at baseline. Both serum albumin (3.59±0.71 vs. 4.17±0.46g/dl, p=0.01) and total protein (6.45±0.80 vs. 7.12±0.35g/dl, p<0.01) levels were significantly lower in LVAD group at baseline. Both total protein and serum albumin levels increased significantly in LVAD group (final total protein 7.60±0.62g/dl and serum albumin 4.20±0.46g/dl; p<0.01 for both), while there was a nonsignificant small decrease in serum albumin in medical group. The change in serum albumin, but not total protein was significantly different between LVAD and medical groups at the sixth month. Body weight initially decreased in LVAD group at first month but was nonsignificantly higher compared to baseline and medical group at the sixth month. There was a moderate correlation between the percentage weight gain and percentage increase in serum albumin in LVAD group at six months (r=0.44). CONCLUSIONS: In suitable patients with advanced heart failure, LVAD treatment can correct hypoalbuminaemia associated with heart failure within six months after implantation.

Emergency management for critical left main coronary artery stenosis.

BACKGROUND: Increased experience and improvements in technology seem to have encouraged the use of percutaneous interventions for left main coronary artery (LMCA) occlusions. There is no consensus, however, and the data are inadequate on whether surgery or percutaneous procedures should be the intervention of choice for critical occlusions. METHODS: From January 2002 to December 2006, 108 patients with unprotected LMCA stenosis >80% were treated at our center. Eighty-three patients (77%) underwent bypass grafting and 20 (18%) underwent percutaneous intervention for the purpose of myocardial revascularization. We analyzed parameters demonstrated as risk factors for myocardial revascularization and their predicted effects on outcome. RESULTS: Five patients (5%) died following emergency cardiopulmonary resuscitation before any intervention was performed. The early survival rate was 84.1% in the coronary bypass group and 63% in the percutaneous intervention group. The mean (±SD) survival time was 55.7 ± 2.6 months in the bypass group and 7.6 ± 1.3 months in the percutaneous group. The late-survival rate was also significantly higher in the bypass group. The mean late-survival time was 44.5 ± 3.6 months in the bypass group and 2.3 ± 0.8 months in the percutaneous group. CONCLUSION: Although emergency percutaneous interventions are lifesaving in some cases, these results clearly demonstrate that coronary bypass grafting should be the intervention of choice for myocardial revascularization in patients with critical LMCA occlusion.

Microbiological Spectrum of Nosocomial ECMO Infections in a Tertiary Care Center.

INTRODUCTION: Extracorporeal membrane oxygenation (ECMO) is a life-saving treatment in cardiogenic and respiratory shock. It is prone to various complications, infection being among the most frequent. This study aims to define the prevalence and characteristics of infections in ECMO patients in a tertiary care center for cardiac diseases. METHODS: All ECMO patients between 2012 and 2016 in a single cardiac center were retrospectively included. Demographic data, ECMO indications, type, site, duration, and infection-related data were recorded. Data were analyzed among all patients and separately between pediatric and adult patient groups. RESULTS: One hundred and twenty-six patients, 66 (53.4%) pediatric and 60 (47.6%) adult, received ECMO within the study period. Mean age was 3.54±4.27 years in the pediatric group and 54.92±15.57 years in the adult group. The main indication for ECMO was postcardiotomy shock (77.8%). Forty-six (36.5%) of all cases developed a culture-proven nosocomial infection with a rate of 49/1000 ECMO days. Infection was associated with > 5 days of ECMO duration and hemodialysis requirement in all patients and lower age in the pediatric group. The most frequent infection site was the lower respiratory tract (14.3%), while the most common isolated organisms were Klebsiella (8.7%) and Streptococcus (4.8%) species. CONCLUSION: The respiratory tract is the most common site of infection, however, all sites impose a threat to recovery, with longer treatment durations required for patients with culture-proven infections. A better understanding of the infectious spectrum and its effect on the mortality and morbidity is required for more successful treatment of ECMO patients.

Telecardiographic measurements for device migration: A useful tool for follow-up.

OBJECTIVE: Pump thrombosis in left ventricular assist device (LVAD) patients is an important cause of mortality and morbidity. Inflow cannula migration is a predisposing factor for pump thrombosis. Telecardiographic measurements can be used to follow up apical cannula deviation. In this study, we aimed to evaluate the migration of the inflow cannulas in patients with LVADs using angle measurements on telecardiograms. METHODS: Twenty-three patients who were implanted left ventricular assist devices in our clinic between February 2013 and April 2016 were included in our study. During the first year of follow-up, changes in angle measurements on postoperative 1st, 3rd, 6th, and 12th month telecardiograms were compared against the incidence of device thrombus and serum Lactate Dehydrogenase (LDH) levels. RESULTS: Patients who were diagnosed with device thrombosis had more change in inflow cannula angles than patients without device thrombus (p<0.05 at 6th and 12th months). Patients with higher LDH values had more parallel angular changes at all intervals, and the change in angle was statistically significant at 3rd, 6th and 12th months (p<0.05). CONCLUSION: This study shows that it is possible to track the migration of inflow cannulas in patients with left ventricular heart failure using telecardiograms. The correlation between angle change and LDH levels and embolic events may suggest that telecardiographic follow up of angles may be a useful tool for ventricular assist devices teams for early detection of thrombus.

Usefulness of right ventricular contraction pressure index to predict short-term mortality and right heart failure in patients who underwent continuous-flow left ventricular assist device implantation.

BACKGROUND: Right ventricular stroke work index is a useful but invasively measured parameter that can be used to predict right heart failure following continuous-flow left ventricular assist device implantation. Right ventricular contraction pressure index is a novel parameter that was developed to measure right ventricular stroke work index with echocardiography. We aimed to investigate the clinical usefulness of right ventricular contraction pressure index to predict short-term mortality and right heart failure in patients who underwent continuous-flow left ventricular assist device implantation. METHODS: A total of 49 patients who participated in institutional advanced heart failure registry and underwent continuous-flow left ventricular assist device implantation with a bridge-to-candidacy indication were analyzed retrospectively. Right ventricular contraction pressure index was calculated using offline measurements. Demographic, clinical and outcome data were obtained from the registry data. Patients were grouped according to right ventricular contraction pressure index quartiles. RESULTS: Patients within the lowest right ventricular contraction pressure index quartile had a trend toward higher short-term mortality (46.2%, p = 0.056) and combined short-term mortality and definitive right heart failure (53.8%, p = 0.054) at 15th day postoperatively. Similarly, short-term survival or survival free of definite right heart failure were significantly lower in the lowest right ventricular contraction pressure index quartile (log-rank p = 0.045 and log-rank p = 0.03, respectively). In a proportional hazards model that included echocardiographic parameters, right ventricular contraction pressure index was an independent predictor for short-term mortality (odds ratio: 6.777, 95% confidence interval: 1.118-41.098, p = 0.037), but not for combined short-term mortality and definite right heart failure. No such associations were found for long-term mortality. Right ventricular contraction pressure index had a statistically significant correlation with invasively measured pulmonary capillary wedge pressure, pulmonary vascular resistance, mean pulmonary pressure, and right ventricular stroke work index. CONCLUSION: Right ventricular contraction pressure index was found as a useful parameter for determining short-term postoperative mortality in patients undergoing continuous-flow left ventricular assist device implantation.

Does the circadian rhythm of melatonin affect ischemia-reperfusion injury after coronary artery bypass grafting?

BACKGROUND: Melatonin is a potent scavenger of free radicals and an antioxidant. We studied the relationship between the protective effect of melatonin against ischemia-reperfusion injury (IRI) during cardiopulmonary bypass, the plasma level of melatonin, and the time of surgery. METHODS: Forty patients who were to undergo elective coronary artery bypass grafting (CABG) were divided into 2 groups, those who underwent their operations at 8 AM (group I; n = 20) and those who underwent their operations at 1 PM (group II; n = 20). The operations were carried out by the same surgical team and with the same standard surgical technique. Blood samples were collected before the operation (T1), when the aortic cross-clamp was removed (T2), and at 4 hours (T3) and 24 hours (T4) after the operation. RESULTS: Preoperative plasma levels of melatonin were substantially higher in group I than in group II. Intraoperative and postoperative melatonin levels were also significantly higher in patients who underwent their operations in the morning. The 2 groups had similar preoperative levels of intercellular adhesion molecule 1 and interleukin 8; however, intraoperative and postoperative values were lower in group I for all samples. This difference was statistically significant for both markers. Plasma levels of lactate dehydrogenase were significantly lower in group I. The 2 groups had similar aortic cross-clamp and cardiopulmonary bypass times. Preoperative and postoperative troponin I levels were lower in group I than in group II, but these differences were not statistically significant. The 2 groups showed no significant differences in plasma creatine kinase MB levels for either preoperative or postoperative measurements. CONCLUSION: High plasma levels of melatonin may be directly related to low levels of IRI markers. Melatonin may have a protective effect against IRI in CABG. This effect seems to be directly correlated with the plasma levels of melatonin and inversely related with light. If melatonin protects myocardium from IRI, additional studies may be planned for the preoperative use of melatonin in patients with coronary artery disease to improve myocardial protection.

Retrospective cohort study for evaluating the INR monitoring patterns in patients with deep vein thrombosis in daily practice: Analysis of 2010-2013 database of a tertiary care center.

OBJECTIVE: To evaluate the international normalized ratio (INR) monitoring patterns in patients with deep vein thrombosis. METHODS: Of 32,012 patients with ≥1 outpatient INR measurement and 42,582 patients with confirmed deep vein thrombosis diagnosis registered to our hospital between 1 January 2010 and 31 December 2013, 6720 records were identified to have both deep vein thrombosis and international normalized ratio measurement, and 4.377 out of 6.720 single patient records were determined to be statistically analyzable. RESULTS: Median INR measurement frequency was 6.47 times/year and patients had INR levels of 2-3 in 34.3% of follow-up time. Having ≥70% vs. <70% of follow-up time within therapeutic range was associated with lower hospital admission frequency (9.7 vs. 10.3 times/year). CONCLUSION: Our study revealed only one-third of the follow-up time to be spent within therapeutic INR, association of INR therapeutic range with lesser number of hospital admissions and INR monitoring frequency of 6.47 times/year despite lack of stable INR control in most of the deep vein thrombosis patients.

Reconstructive surgery of true aneurysm of the radial artery: A case report.

True radial artery aneurysms are uncommon pathologies and have an organic cause, unlike trauma-induced false aneurysms. A 52-year-old man presented with a pulsatile mass at the anatomical snuff box area of his left hand. The aneurysm was repaired with reconstructive procedure. Although many posttraumatic and iatrogenic cases of false aneurysm of the radial artery have been reported; there are a few reported cases of a true idiopathic aneurysm. A case of reconstructive surgery for true idiopathic radial artery aneurysm is reported in this paper.

Urban legend or real fact: Coronary artery size varies with demographics.

OBJECTIVE: This study aimed to determine the relationship between the diameter of coronary artery stents and age, gender, diabetes mellitus (DM), left ventricular ejection fraction (LVEF), renal dysfunction, and the clinical presentation of myocardial ischemia in the cohort of patients with implanted stents in coronary arteries with severe stenotic lesions. METHODS: This study included 2256 patients (mean age, 59.3±10.9 years; men, 62%) who underwent percutaneous coronary intervention (PCI). The clinical status of the patients at presentation was subcategorized as follows: ST-segment elevation myocardial infarction, non-ST segment elevation myocardial infarction, unstable angina pectoris, and stable angina pectoris. The diameters, without any type or brand differentiation, were divided into two groups as follows: Group I, which included 2.5- and 2.75-mm-diameter stents, and Group II, which included ≥3-mm-diameter stents. RESULTS: The type of procedure, including primary PCI, early invasive strategy, and elective stenting, was not found to be a significant factor affecting the diameter of coronary artery stents. Univariate and multivariate analyses revealed a relationship between the diameter of coronary artery stents and age, gender, DM, and LVEF. CONCLUSION: This study demonstrated that the diameter of coronary artery stents was independently associated with gender, age, a history of DM, and moderate-to-severe systolic left ventricular dysfunction.

Systemic and myocardial inflammation in traditional and off-pump cardiac surgery.

In this study, we attempted to determine the role of off-pump coronary artery bypass grafting (CABG) in the myocardial and systemic inflammatory responses. Twenty patients who underwent elective CABG were enrolled in this study. Ten patients underwent on-pump CABG, and 10 patients underwent off-pump CABG. There were no differences between patients in preoperative clinical variables. We took systemic venous blood samples for the measurement of tumor necrosis factor-alpha, the MB isoenzyme of creatine kinase (CK-MB), and cardiac troponin I, and we took myocardial biopsies from the interventricular septum for chemiluminescence assay of reactive oxygen species (hydroxyl, hydrogen peroxide, hypochlorite, and superoxide). There was no significant difference in the myocardial tissue release of hydrogen peroxide, hydroxyl, hypochlorite, and superoxide between the 2 groups (P > 0.05). The systemic tumor necrosis factor-alpha levels in the off-pump group were significantly lower than in the on-pump group (P <0.01). The cardiac troponin I and creatine kinase-MB levels at 6, 12, and 24 postoperative hours were not statistically different between the 2 groups (P >0.05). We conclude that off-pump CABG appears to reduce systemic inflammation, without reducing myocardial oxidative stress and inflammation.

A case of a large Chiari network mimicking a right atrial thrombus.

The Chiari network is described as a reticulated network of fibers connected to the Eustachian valve identified as the embryological remnant of the right valve of the sinus venosus. It is an incidental finding without any significant pathophysiological consequences. However, the presence of the Chiari network in the right atrium obliges the physician to differentiate from other right atrial pathologies. We present a case of a large Chiari network mimicking a right atrial thrombus with incidental finding in a 76-year-old man undergoing coronary artery bypass surgery.

Stent versus bypass: The reasons and risk factors for early readmission to hospital after myocardial revascularization.

OBJECTIVE: Though 30-day rates of readmission for coronary artery bypass graft (CABG) surgery and percutaneous coronary intervention (PCI) remain high, readmission rates and associated risk factors have not been well examined. The purpose of the present study was to determine the risk factors for and rates of readmission and to compare two revascularization methods on that basis. METHODS: The study included 2664 consecutive patients who underwent coronary revascularization either with CABG surgery or PCI. The study was performed retrospectively and a wide variety of risk factors related to readmission were selected for analysis, including demographic data, preoperative risk factors and postoperative complications. RESULTS: From the CABG group (Group 1, n=1103), 18.3% were readmitted, as were 15.2% of the PCI group (Group 2, n=1561). In multivariate analysis, age, gender, left ventricular ejection fraction (LVEF), chronic obstructive pulmonary disease (COPD), diabetes mellitus (DM), length of stay (>10 days), body mass index (BMI), and creatinine level on admission were associated with early readmission for group 1 (Table 3). In group 2, age, gender, LVEF, DM, length of stay (>10 days), and creatinine level on admission were associated with early readmission. CONCLUSION: When two methods of revascularization were compared, rates of readmission were found to be similar. Patients with cited risk factors are prone to readmission in the first 30 days, so extra precautions should be taken at discharge. Neither method can be concluded to be superior with regard to readmission rates.

Microbiological Spectrum of Nosocomial ECMO Infections in a Tertiary Care Center

Abstract Introduction: Extracorporeal membrane oxygenation (ECMO) is a life-saving treatment in cardiogenic and respiratory shock. It is prone to various complications, infection being among the most frequent. This study aims to define the prevalence and characteristics of infections in ECMO patients in a tertiary care center for cardiac diseases. Methods: All ECMO patients between 2012 and 2016 in a single cardiac center were retrospectively included. Demographic data, ECMO indications, type, site, duration, and infection-related data were recorded. Data were analyzed among all patients and separately between pediatric and adult patient groups. Results: One hundred and twenty-six patients, 66 (53.4%) pediatric and 60 (47.6%) adult, received ECMO within the study period. Mean age was 3.54±4.27 years in the pediatric group and 54.92±15.57 years in the adult group. The main indication for ECMO was postcardiotomy shock (77.8%). Forty-six (36.5%) of all cases developed a culture-proven nosocomial infection with a rate of 49/1000 ECMO days. Infection was associated with > 5 days of ECMO duration and hemodialysis requirement in all patients and lower age in the pediatric group. The most frequent infection site was the lower respiratory tract (14.3%), while the most common isolated organisms were Klebsiella (8.7%) and Streptococcus (4.8%) species. Conclusion: The respiratory tract is the most common site of infection, however, all sites impose a threat to recovery, with longer treatment durations required for patients with culture-proven infections. A better understanding of the infectious spectrum and its effect on the mortality and morbidity is required for more successful treatment of ECMO patients.

Coronary artery bypass graft operations can be performed safely in obese patients.

OBJECTIVES: Obesity is a major public health problem with an increasing prevalence. Although coronary artery bypass grafting (CABG) operations are now performed with low morbidity and mortality rates, obesity is still assumed to be an important risk factor for morbidity and mortality at these operations but there is no precise approach to define it as a risk factor. The aim of this study is to evaluate the effects of obesity on the clinical outcome of the CABG operations. METHODS: A total of 1206 patients, who underwent isolated CABG operation under cardiopulmonary bypass were evaluated retrospectively. The patients were divided into three groups. Group I was normal weight, with body mass index (BMI) of 18-24.9 kg/m(2), group II was overweight, with a BMI of 25-29.9 kg/m(2), and group III was obese, with a BMI of >30 kg/m(2). The clinical data of three groups were evaluated in aspects of postoperative morbidity and mortality. RESULTS: Except for the superficial wound infections, there were no differences in postoperative mortality and morbidity rates between the three groups. Obesity was not found to be an important risk factor for postoperative morbidity and mortality. CONCLUSIONS: Despite the perception that obesity increases the risk of mortality and morbidity in CABG operations, the clinical outcome of these patients are not so different from other patients. We may say that obese patients can be safely operated.

Functional results in aortic root enlargement.

BACKGROUND: The hemodynamically efficient valves with effective orifice areas that are used in aortic valve replacement have been positively determined to affect postoperative exercise capacity. The aim of this study was to evaluate the functional effects of aortic root enlargement in the late postoperative period for patients with a small effective orifice area. METHODS: Nineteen patients with a small effective orifice area were included in the study. The study group comprised 9 patients who underwent isolated aortic valve replacement with 23-mm St. Jude Medical prosthetic valves and posterior aortic root enlargement. The control group comprised 10 patients in whom 19-mm and 21-mm St. Jude Medical prosthetic valves were implanted without aortic root enlargement. The patients were evaluated in the late postoperative period with echocardiography and cardiopulmonary exercise testing. RESULTS: The 2 groups were similar in anthropometric parameter values, follow-up periods, echocardiographic findings, and the gradients at the prosthetic aortic valve at rest; however, the anaerobic threshold, peak oxygen uptake, minute ventilation volume, and walk time were significantly higher in the study group ( P <.05). CONCLUSION: The choice of aortic root enlargement for the implantation of a valve with a larger effective orifice area is preferred by most of the surgeons over the implantation of a valve with a smaller effective orifice area. The late postoperative functional capacity of the patient is significantly improved with root enlargement. Surgeons should be encouraged to perform root enlargement in patients with a small effective orifice area, and such surgery may even be performed routinely in these patients.

Preoperative risk factors for in-hospital mortality and validity of the Glasgow aneurysm score and Hardman index in patients with ruptured abdominal aortic aneurysm.

The aim of this study is to evaluate the validity of the Glasgow aneurysm score (GAS) and Hardman index in patients operated on because of ruptured abdominal aortic aneurysm (rAAA), and determining preoperative risk factors that affect in-hospital mortality. One hundred one patients operated on to repair a rAAA within the last 10 years were included. The GAS and Hardman index were calculated for each patient separately. The relation between in-hospital mortality and the Hardman index and GAS was analyzed by means of the receiver-operator characteristic (ROC) curve. Univariate and multivariate methods of analyses were used to determine preoperative risk factors. Average age was 69 ± 8, and in-hospital mortality rate was 51.5%. Analysis of the ROC curve showed that the Hardman index had an area under the curve (AUC) = 0.71 (95% confidence interval [CI], 0.593-0.800, P = 0.0002) for predicting in-hospital mortality. The GAS had an AUC = 0.77 (95% CI, 0.680-0.851, P < 0.0001). The results of multivariate analysis revealed the presence of the following preoperative risk factors: age more than 63 years (odds ratio [OR], 4.4; 95% CI, 1.17-16.49, P = 0.028); loss of consciousness (OR, 9.33; 95% CI, 1.94-44.86, P = 0.005); creatinine higher than 1.7 mg/dL (OR, 5.52; 95% CI, 1.92-15.85, P = 0.001); and pH lower than 7.31 (OR, 3.77; 95% CI, 1.18-11.99, P = 0.024). In conclusion, the Hardman index and GAS have a significant correlation with in-hospital mortality rates. Nevertheless, a high score does not necessarily correspond with a definite mortality. This is why scoring systems could not be considered as the sole criterion for choosing patients for this study. Clinical experience was still the leading factor in deciding against or in favor of surgery.

Effects of N-acetylcysteine on myocardial ischemia-reperfusion injury in bypass surgery.

Myocardial ischemia-reperfusion injury may complicate coronary artery bypass grafting (CABG) operations. N-Acetylcysteine (NAC) had antioxidant and microcirculatory effects, and inhibits neutrophil aggregation. The aim of this study was to determine the effects of NAC in limiting myocardial ischemia-reperfusion injury in CABG operations. Twenty patients undergoing elective coronary bypass operation with cardiopulmonary bypass were enrolled and randomly assigned to two groups: a control group operated with a routine CABG protocol, and one where NAC was administered intravenously during the operation (NAC group). Blood samples from coronary sinus for tumor necrosis factor-alpha assay, myocardial biopsy specimens for chemiluminescent luminol, and lucigenin measurements of reactive oxygen species were taken. The luminol (specific for (*)OH, H(2)O(2), and HOCl(-) radicals) and lucigenin (specific for O(2) (*-)) levels and the difference ratios after reperfusion were significantly lower in the NAC group. Tumor necrosis factor-alpha levels increased in the control group but, in contrast, a significant decrease was detected in the NAC group (P < 0.01). Creatine kinase-MB levels at 6 and 12 hours were significantly lower in the NAC group (P = 0.02). N-Acetylcysteine has potential effects to limit ischemia reperfusion injury during CABG operations. We believe that its effects on clinical outcome may be more apparent in patients prone to ischemia-reperfusion injury.