Predicting outcomes in patients with low ejection fraction undergoing coronary artery bypass graft.

Introduction: Reduced left ventricular ejection fraction (LVEF) is a well-known predictor of adverse events after cardiac surgery. We aimed to assess the outcomes in patients with low LVEF undergoing coronary artery bypass graft. Methods: In this retrospective cohort, we included all patients with left ventricular ejection fraction ≤ 40 who underwent coronary artery bypass grafting between March 2007 and March 2016 (with a median follow-up of nine years) at Tehran Heart Center. Demographics and clinical characteristics were extracted from the data registry. Akaike information criterion (AIC) was used. The univariate Cox regression was performed. We investigated the predictors of mortality and major adverse cardiac and cerebrovascular events (MACCE) using Cox multivariable regression. Results: In total, 5,532 cases (79 % male) with a mean age of 65.58 were included in the study. The nine-year overall survival was calculated at 68 %, and more than half of the patients had MACCE (55 %). In adjusted multivariable Cox regression analysis, moderate to severe mitral valve regurgitation, glomerular filtration rate ≤ 60, mild right ventricular dysfunction, and valvular heart disease independently predicted higher mortality. The abovementioned predictors and peripheral vascular disease significantly increased MACCE. Conclusion: Our study indicates the clinical significance of mitral regurgitation, valvular heart disease, and renal function in patients with low ejection fraction treated by coronary artery bypass grafting surgery. Identifying predictors of adverse events can help with clinical decision-making and risk stratification, ultimately improving patient outcomes.

Do adventitial mast cells contribute to the pathogenesis of ascending thoracic aorta aneurysm?

The precise pathogenesis of the ascending aortic aneurysm (AscAA) remains to be determined. Mast cells in the adventitia of human AscAA lesions may play a role in this pathogenesis. Adventitial mast cell density per 10 high-power fields (0.25 mm(2)) was assessed in multiple biopsy samples, from aneurysmal aortic sections (n = 41) and control (nondilated) aortic specimens (n = 50), stained by orcein-Giemsa method, an inexpensive (<$1) method. In a multivariable adjusted logistic regression model, using AscAA as the dependent variable, mast cell density was found to be an independent predictor of AscAA occurrence (odds ratio = 2.21; 95% confidence interval = 1.58-3.08; P < .001). Receiver operating characteristic curve analysis showed that the proposed cutoff value of ≥ 3 mast cells per 10 high-power fields was very sensitive to detect AscAA occurrence, yielding a sensitivity of 90% with a specificity of 80%. In conclusion, a significant increase in the number of mast cells in the adventitia of human ascending aortic lesions proposes a role for these cells in the pathogenesis of AscAA.

Perivascular nitric oxide delivery to saphenous vein grafts prevents graft stenosis after coronary artery bypass grafting: a novel sheep model.

OBJECTIVES: Graft stenosis is a major complication of coronary artery bypass grafting with autologous saphenous vein grafts. Nitric oxide (NO) is believed to prevent this phenomenon. We studied the effect of perivascular application of an NO donor on the degree of stenosis of such grafts in an ovine model. METHODS: Twenty white Iranian ewes were randomized to coronary artery bypass grafting using autologous saphenous vein grafts with application of an elastomer gel containing diethylenetriamine NO adduct in 0.9% sodium chloride solution around the grafted vessel (intervention group) or with the gel containing the saline solution alone (controls). Graft vessels were studied after 1 year using spot angiography and histological examination. RESULTS: The mean degree of stenosis was significantly lower in the intervention group than in the controls as found by histology (92.3 ± 5.5 vs. 80.9 ± 8.3%; p = 0.004). Although the difference in the angiographic score was not significant, the mean score was still lower in the intervention group (9.5 ± 11.3 vs. 12.0 ± 11.8). CONCLUSIONS: Perivascular application of an NO donor was, at least histologically, effective in reducing graft stenosis in our ovine model. This can be a step toward the development of drug-eluting coronary artery bypass grafts.

Screening of carotid artery stenosis in coronary artery bypass grafting patients.

BACKGROUND: We sought to evaluate the routine echo-Doppler screening of carotid artery stenosis in patients undergoing coronary artery bypass grafting. METHODS: A total of 2179 consecutive patients who underwent coronary artery bypass grafting alone or with other cardiac surgery at Tehran Heart Center, Tehran-Iran, between January 2005 and January 2006 were included in this retrospective study. Carotid Doppler was performed for 1604 (81.48%) of these patients. RESULTS: The patients' age ranged between 20 and 84 years (mean: 58.33, SD: 10.08 years). Of the 1604 patients studied, 1186 (73.9%) were men, 592 (36.9%) had diabetes, 598 (37.3%) were smokers, and 194 (12.1%) cases had significant left main stenosis. Twenty-one (1.3%) patients had significant carotid stenosis (> 60% stenosis), which constituted 0.9% of all the bypass surgery candidates. Post-operative cerebrovascular accident was not detected in any of the patients with significant carotid stenosis, but cerebrovascular accident occurred in 22 (1.4%) of the patients without carotid stenosis. Magnetic resonance angiography (MRA) was conducted in 15 patients. In our univariate analysis, female gender (p value = 0.023), hypertension (p value = 0.055), peripheral vascular disease (p value < 0.001), and age (p value = 0.001) were significant in the development of carotid stenosis. CONCLUSION: Pre-operative duplex carotid screening seems to be necessary in patients when there is hypertension, peripheral vascular disease, female gender, and advanced age.

Is severely left ventricular dysfunction a predictor of early outcomes in patients with coronary artery bypass graft?

BACKGROUND: Traditionally, the Coronary artery bypass grafting (CABG) surgery outcomes of patients with low ejection fraction (EF) have been worse compared to patients with moderate to good left ventricular function. During the past decade, despite improvements in surgical techniques, the trend in the outcomes of these patients remained unclear. AIM: We sought to determine the effect of left ventricular dysfunction on early mortality and morbidity and to specify predictors of early mortality of isolated CABG in a large group of patients EF≤35%. METHOD: We retrospectively analyzed data of 14 819 consecutive patients undergoing isolated CABG from February 2002 to March 2008 at Tehran Heart Center. Patients were divided into two groups based on their LVEF (EF≤35% and EF>35%). Differences in case-mix between patients with EF≤35% and those without were controlled by constructing a propensity score. RESULTS: Mean age of our patients was 58.7±9.5 years. EF≤35% was present in 1342 (9.1%) of patients. In-hospital mortality was significantly increased univariate in EF≤35%, while this association diminished after confounders were adjusted for by using the propensity score (p=0.242). Following adjustment it was demonstrated that renal failure, cardiac arrest, heart block, infectious complication, total ventilation time, and total ICU hours were more frequent in patients with EF≤35%. CONCLUSION: We demonstrated EF≤35% was not predictor of in-hospital mortality in patients underwent CABG. Careful preoperative patient selection remains essential in patients with EF≤35% undergoing CABG.

Traditional cardiac risk factors profile in Iranian patients undergoing coronary artery bypass surgery.

OBJECTIVE: It is well known that the traditional cardiac risk factors (TCRFs) affect short-term and long-term outcome following coronary artery bypass graft surgery (CABG). The objective of this study was to detect the prevalence of these risk factors i.e., hypertension, diabetes mellitus, hyperlipidaemia, smoking and family history of premature CAD in an Iranian population undergoing coronary artery bypass surgery. METHODS AND RESULTS: From March 2001 to September 2005, we retrospectively analysed prospectively collected data from our registry. Data were achieved regarding TCRFs in 10,622 consecutive patients undergoing elective CABG. Mean age of the patients was 58.75 +/- 9.72 years and 74.4% were men. The majority of the patients were overweight with a body mass index (BMI) > or = 25.0 kg/m2. Hyperlipidaemia was present in 63.9% of the patients. Over half of all the patients had hypertension and over one third diabetes. History of smoking was present in 37.7% of the patients and one third had a family history of CAD. Of all the patients, 91.6% had at least one of the TCRFs. As compared to men, women were more overweight or obese, and had a greater prevalence of hyperlipidaemia, hypertension, diabetes mellitus, and family history of CAD but smoking was much more common in men than in women. CONCLUSION: The current study revealed a high prevalence of most of TCRFs in an Iranian population that underwent CABG.

Determinant factors of renal failure after coronary artery bypass grafting with on-pump technique.

OBJECTIVE: The aim of the present study was to investigate the determinant factors of acute renal failure (ARF) after isolated on-pump coronary artery bypass grafting (CABG). SUBJECTS AND METHODS: This was a retrospective study of 13,315 adult patients who underwent isolated CABG with cardiopulmonary bypass (CPB) in Tehran Heart Center from May 2002 to May 2007. The exclusion criteria were age <18, concomitant cardiac and/or noncardiac surgical operations, history of renal failure before surgery, and chronic renal failure requiring dialysis. Preoperative and operative variables were measured, and a multivariate logistic regression model was constructed to identify the independent risk factors for developing renal failure after on-pump CABG. RESULTS: Of the 13,315 patients, 3,347 (25.4%) and 90,883 (74.6%) were females and males, respectively, with a mean age of 58.63 +/- 9.48 years. ARF was detected in 85 (0.6%) of the patients with isolated on-pump CABG. The mean age of the patients was 58.63 +/- 9.48 years, and 25.5% of them were female. The multivariate logistic regression analysis identified age (OR = 1.035; p = 0.002), female gender (OR = 1.622; p = 0.037), history of peripheral vascular disease (PVD) (OR = 2.579; p = 0.042), diabetes mellitus (OR = 1.918; p < 0.001), emergent and urgent surgery (OR = 1.744 and OR = 7.901, respectively; p = 0.003), CPB time >70 min (OR = 1.944; p = 0.007), and intra-aortic balloon pump (IABP) insertion (OR = 10.181; p < 0.001) as the independent risk factors for ARF. CONCLUSION: The data showed that age, female gender, positive history of diabetes and PVD, urgent and emergent surgery, CPB time >70 min, and need for IABP were the independent determinant factors of ARF after on-pump CABG.

Relationship between body mass index and left main disease: the obesity paradox.

BACKGROUND AND AIMS: Obesity is a well-known risk factor for development of diabetes, hypertension, and coronary artery disease. However, the obesity paradox shows that short-term outcome has been reported to be superior after revascularization in overweight patients. We conducted this study to examine this theory in patients who were candidates for coronary artery bypass graft and to determine if there is a relationship between obesity and the severity of coronary artery involvement and left main disease in Iranian patients. METHODS: A total of 15,550 patients who had undergone isolated coronary artery bypass graft were studied retrospectively. All medical records of the aforementioned patients were derived from our hospital surgery data bank. Preoperative angiography was used for angiographic data. RESULTS: After adjusting for confounding variables, we still found a significant relationship with higher BMI and lower prevalence of left main disease. CONCLUSIONS: We found that despite a higher prevalence of hypertension, diabetes mellitus, and dyslipidemia, overweight and obese patients who were candidates for coronary artery bypass graft surgery were significantly less likely to have left main disease according to preoperative angiography. This study suggests that obese patients are more likely to be referred for coronary artery bypass graft in earlier stages of coronary involvement.

The association of opium dependence and postoperative complications following coronary artery bypass graft surgery: a propensity-matched study.

OBJECTIVE: Opium is an overwhelming public health problem in some countries. Different studies have suggested this drug as a risk factor for cardiovascular disease. Although the effect of opium on immune system, lung disease, nephropathy, stroke, and cardiac arrhythmia has been found in different studies, its effect on postoperation complications is not clear yet. The authors conducted this study to assess the effect of opium on post operation in hospital complications among patients who underwent coronary artery bypass graft. DESIGN: The authors retrospectively analyzed the data in this study. SETTING: This study has been done at Tehran Heart Center. PATIENTS: A total of 4,398 patients who had undergone isolated CABG were studied. MAIN OUTCOME MEASURE: Patients who fulfilled the DSM-IV-TR criteria for opium dependence (by smoking) were enrolled as Opium Dependent Patients. Also outcome variables were: Perioperative MI, septicemia, UTI, TIA, continuous coma, prolonged ventilation, pulmonary embolism, renal failure, acute limb ischemia, heart block, AF, mortality. RESULTS: The prevalence of opium dependence was 15.6percent among patients. The authors used a propensity matched model to analyze the relationship between opium and post operation complications. The authors adjusted opium and non-opium dependent patients in all of the baseline preoperative risk factors, so all of the matched patients were same and there was no bias in assessment. CONCLUSION: Opium dependent patients had significantly longer resource utilization. However, no significant relationship was found between opium dependence and other cardiac and non cardiac in hospital complications.

Cardiac and great vessel involvement in "Behcet's disease".

Behcet's disease is a multisystem disorder and classified as "vasculitic syndrome with a wide variety of clinical manifestations." Cardiac involvement is very rare but can occur with different presentations including: pericarditis, cardiomyopathy, endocarditis, endomyocardial fibrosis, intracavitary thrombosis, and coronary artery disease. Great vessel involvement is more common. Recurrent Phlebitis, commonly involving large vessels (superior vena cava, inferior vena cava, hepatic veins) and cerebral veins are the sole presentation in this regard. Arterial involvement is expressed by aneurysm or pseudoaneurysmal formation. Due to the wide variety of cardiovascular manifestations and the resulting high mortality, cardiac surgeons should be familiar with this disease. In this paper we review the articles and introduce our four cases presenting with aneurysm of ascending aorta with free aortic insufficiency, aneurysm of descending aorta, pulmonary artery aneurysm, and pseudoaneurysm of aortic arch.

Mature cardiac myocyte hamartoma in the right atrium.

During coronary artery bypass grafting in a 58-year-old man, a mass was discovered incidentally in the right atrium, measuring 1.5 x 1 x 0.5 cm. It was composed of disorganized hypertrophic mature cardiac myocytes, and associated with focal fibrosis, mature adipocytes, and mild lymphocytic infiltration in peripheral areas, indicative of cardiac hamartoma. This type of hamartoma has been rarely reported as an isolated mass in the right atrium.

Factors affecting postoperative morbidity and mortality in isolated coronary artery bypass graft surgery.

PURPOSE: This study was conducted to investigate predictors of mortality before and after isolated coronary artery bypass grafting (CABG). METHODS: Single-institutional data on risk factors and mortality were collected for 8890 patients who underwent isolated CABG by the same group of surgeons. The relationship between risk factors and outcome was assessed using univariate and multivariate analyses in two risk models: a preoperative model (model 1) and then a pre-, intra-, and postoperative model (model 2). RESULTS: The mean age of the patients (25.4% women and 74.6% men) was 58.5 +/- 9.7 years. Fifty-five (0.6%) patients died after surgery. Hypercholesterolemia was the most common comorbidity factor (61.1%), followed by hypertension, a smoking habit, recent myocardial infarction (MI) <21 days, and diabetes. Postoperative tamponade, graft occlusion, and MI (0.01%) were the least common complications. The patients spent 39.7 +/- 33.9 h in the intensive care unit (ICU) postoperatively. Patients were followed up for a minimum of 30 days. The multivariate analysis of our preoperative risk model revealed that the best predictors of operative mortality were a history of diabetes, hypertension, previous CABG, the presence of angina, arrhythmia, Canadian Cardiovascular Society Classification (CCS) of grade III or IV, ejection fraction (EF) < or =30%, three-vessel disease, and left main disease. CONCLUSION: After surgery, and with the inclusion of all the pre-, intra-, and postoperative variables into model two, the following were revealed to be prognostic factors for in-hospital mortality: a history of diabetes, hypertension, the presence of angina, CCS grades III or IV, EF -30%, absence of internal mammary artery (IMA) use, prolonged cardiopulmonary bypass (CPB) time, and prolonged ICU stay.

Mortality in open heart surgery with intraaortic balloon pump support.

Mechanical circulatory assistance is frequently needed to support the failing heart. The aim of this study was to determine perioperative prognostic factors for hospital mortality in patients undergoing open heart surgery who required intraaortic balloon pump support. Between January 2002 and September 2006, 475 patients received an intraaortic balloon pump perioperatively. Hospital mortality was 21.89%. Risk factors for hospital death identified by multivariate logistic regression analysis were peripheral vascular disease, left main coronary artery disease, postoperative renal failure, postoperative cardiac arrest, and prolonged hospital stay. Minor and major intraaortic balloon pump-related complications were not significant in univariate and multivariate analysis; the incidence was 5.05%. It is suggested that the threshold for using balloon pump support is decreased in high-risk patients undergoing cardiac surgery.

Early outcomes of double-vessel coronary endarterectomy in comparison with single-vessel coronary endarterectomy.

Our goal was to investigate the safety of single- and double-vessel coronary endarterectomy as an adjunct to coronary artery bypass grafting in patients with diffuse coronary disease. In reviewing the records of 9,443 patients who underwent isolated coronary artery revascularization over a 4-year period, we found 310 patients (3.28%) who underwent concomitant coronary artery endarterectomy, 39 of whom (12.6%) required double endarterectomy (Group 2) and the rest of whom required single endarterectomy (Group 1). Variables of these groups were compared by means of univariate analysis. In Group 1, 76.3% were men, with a mean age of 58.73 +/- 9.36 yr. Regarding postoperative myocardial infarction as evaluated by electrocardiography and the MB isoenzyme of creatine kinase, 13% of the patients in Group 1 and 15.4% in Group 2 were so affected. The early mortality rate was 3.3% in Group 1 and 10.3% in Group 2 (P <0.05). In univariate analysis, the following variables were significant: 3-vessel disease, postoperative atrial fibrillation, dialysis, length of hospital stay, and death. In multivariate analysis of endarterectomized arteries, the vascular combinations most strongly associated with death were left anterior descending coronary artery + right coronary artery and right coronary artery + diagonal. There was no association between endarterectomy of particular vessels and perioperative myocardial infarction. Although coronary endarterectomy has become a safe procedure, adding a 2nd endarterectomy worsens the prognosis dramatically, and surgeons should be especially cautious about such an addition if the 1st endarterectomy is in left anterior descending coronary artery or right coronary artery territory.

Mesothelial/monocytic incidental cardiac excrescence.

Mesothelial/monocytic incidental cardiac excrescence (MICE) is a very uncommon lesion. Diagnosis is incidental and may simulate thrombotic lesions. One of the hypotheses with regard to the etiology of this lesion is a previous cardiac procedure especially mitral valve repair or commissurotomy. Herein, we describe a MICE incidentally found in a patient who underwent mitral valve replacement, as a thrombotic lesion on the left atrial auricle. Histopathologic examination suggested MICE lesions and immunohistochemical stains confirmed it.

Superficial and deep sternal wound infection after more than 9000 coronary artery bypass graft (CABG): incidence, risk factors and mortality.

BACKGROUND: Sternal wound infection (SWI) is an uncommon but potentially life-threatening complication of cardiac surgery. Predisposing factors for SWI are multiple with varied frequencies in different studies. The purpose of this study was to assess the incidence, risk factors, and mortality of SWI after coronary artery bypass grafting (CABG) at Tehran Heart Center. METHODS: This study prospectively evaluated multiple risk factors for SWI in 9201 patients who underwent CABG at Tehran Heart Center between January 2002 and February 2006. Cases of SWI were confirmed based on the criteria of the Centers for Disease Control and Prevention. Deep SWI (bone and mediastinitis) was categorized according to the Oakley classification. RESULTS: In the study period, 9201 CABGs were performed with a total SWI rate of 0.47 percent (44 cases) and deep SWI of 0.22 percent (21 cases). Perioperative (in-hospital) mortality was 9.1% for total SWI and about 14% for deep SWI versus 1.1% for non-SWI CABG patients. Female gender, preoperative hypertension, high functional class, diabetes mellitus, obesity, prolonged intubation time (more than 48 h), and re-exploration for bleeding were significant risk factors for developing SWI (p = 0.05) in univariate analysis. In multivariate analysis, hypertension (OR = 10.7), re-exploration (OR = 13.4), and female gender (OR = 2.7) were identified as significant predictors of SWI (p < 0.05 for all). The rate of SWI was relatively similar in 3 groups of prophylactic antibiotic regimen (Cefazolin, Cefazolin + Gentamycin and Cefazolin + Amikacin: 0.5%, 0.5%, and 0.34% respectively). CONCLUSION: Rarely reported previously, the two risk factors of hypertension and the female gender were significant risk factors in our study. Conversely, some other risk factors such as cigarette smoking and age mentioned as significant in other reports were not significant in our study. Further studies are needed for better documentation.

24-hour in-hospital mortality predictions in coronary artery bypass grafting patients.

BACKGROUND: The purpose of this study was to determine the factors that can help predict risk of mortality in the first 24 h of coronary artery bypass grafting (CABG), because mortality within a few hours of surgery is a disastrous event for surgeons and the patient's family. METHODS: The study population consisted of 120 in-hospital mortality cases (1.07%) from 11,183 patients who underwent CABG from February 2002 to February 2006 by the same group of surgeons in a referral center. One group consisted of 40/120 (about 33.3%) patients who died during the first 24 h after surgery. The second group consisted of 80/120 patients (66.7%) who died between the 2(nd) and 30(th) day postoperatively. A set of data was gathered from the surgery database of the hospital and analyzed in a univariate model. RESULTS: Among the studied variables, only the following factors proved to be significant: previous percutaneous transluminal coronary angioplasty (PTCA), previous cerebrovascular accident (CVA), cardiopulmonary bypass (CBP) time, and postoperative atrial fibrillation (AF) (p