Avaliação da função renal no pós-operatório de pacientes submetidos a revascularização do miocárdio com uso de dexmedetomidina

Pós-graduação em Anestesiologia - FMB

Effect of continuous and interval exercise training on the PETCO2 response during a graded exercise test in patients with coronary artery disease

OBJECTIVE: The purpose of this study was to evaluate the following: 1) the effects of continuous exercise training and interval exercise training on the end-tidal carbon dioxide pressure (PETCO2) response during a graded exercise test in patients with coronary artery disease; and 2) the effects of exercise training modalities on the association between PETCO2 at the ventilatory anaerobic threshold (VAT) and indicators of ventilatory efficiency and cardiorespiratory fitness in patients with coronary artery disease. METHODS: Thirty-seven patients (59.7 +/- 1.7 years) with coronary artery disease were randomly divided into two groups: continuous exercise training (n = 20) and interval exercise training (n = 17). All patients performed a graded exercise test with respiratory gas analysis before and after three months of the exercise training program to determine the VAT, respiratory compensation point (RCP) and peak oxygen consumption. RESULTS: After the interventions, both groups exhibited increased cardiorespiratory fitness. Indeed, the continuous exercise and interval exercise training groups demonstrated increases in both ventilatory efficiency and PETCO2 values at VAT, RCP, and peak of exercise. Significant associations were observed in both groups: 1) continuous exercise training (PETCO(2)VAT and cardiorespiratory fitness r = 0.49; PETCO(2)VAT and ventilatory efficiency r = -0.80) and 2) interval exercise training (PETCO(2)VAT and cardiorespiratory fitness r = 0.39; PETCO(2)VAT and ventilatory efficiency r = -0.45). CONCLUSIONS: Both exercise training modalities showed similar increases in PETCO2 levels during a graded exercise test in patients with coronary artery disease, which may be associated with an improvement in ventilatory efficiency and cardiorespiratory fitness.

The association between coronary artery calcification progression and loss of bone density in non-dialyzed CKD patients

Background: Coronary artery calcification (CAC) and low bone density are coexisting deleterious conditions commonly shared by chronic kidney disease (CKD) patients. In the present study, we aimed to investigate whether the progression of CAC was associated with overtime reduction in bone density in non-dialyzed CKD patients. Methods: This is a prospective study of 24 months including 72 non-dialyzed CKD patients Stages 2 - 4 (age 57.6 +/- 10.3 years, 62% male, 22% diabetics). CAC and vertebral bone density (VBD) were measured by computed tomography. Results: At baseline, 46% of the patients had CAC (calcified group) and calcification was not identified in 54% of the patients (non-calcified group). The calcified group was older, predominantly male, and had lower VBD in comparison to non-calcified group. CAC progression was observed only in the calcified group (91% of the patients increased calcium score). The multiple regression analysis revealed loss of VBD as the independent determinant of CAC progression in these patients. Conclusion: CAC progression was associated with loss of VBD in non-dialyzed CKD patients.

Coronary artery disease, nitric oxide and oxidative stress: the "Yin-Yang" effect--a Chinese concept for a worldwide pandemic

Prevention of coronary artery disease (CAD) and reduction of its mortality and morbidity remains a major public health challenge throughout the "Western world". Recent evidence supports the concept that the impairment of endothelial function, a hallmark of insulin resistance states, is an upstream event in the pathophysiology of insulin resistance and its main corollaries: atherosclerosis and myocardial infarction. Atherosclerosis is currently thought to be the consequence of a subtle imbalance between pro- and anti-oxidants that produces favourable conditions for lesion progression towards acute thrombotic complications and clinical events. Over the last decade, a remarkable burst of evidence has accumulated, offering the new perspective that bioavailable nitric oxide (NO) plays a pivotal role throughout the CAD-spectrum, from its genesis to the outcome after acute events. Vascular NO is a critical modulator of coronary blood flow by inhibiting smooth muscle contraction and platelet aggregation. It also acts in angiogenesis and cytoprotection. Defective endothelial nitric oxide synthase (eNOS) driven NO synthesis causes development of major cardiovascular risk factors (insulin resistance, arterial hypertension and dyslipidaemia) in mice, and characterises CAD-prone insulin-resistant humans. On the other hand, stimulation of inducible nitric oxide synthase (iNOS) and NO overproduction causes metabolic insulin resistance and characterises atherosclerosis, heart failure and cardiogenic shock in humans, suggesting a "Yin-Yang" effect of NO in the cardiovascular homeostasis. Here, we will present a concise overview of the evidence for this novel concept, providing the conceptual framework for developing a potential therapeutic strategy to prevent and treat CAD.

Aprotinin in cardiac surgery: a different point of view

Aprotinin is widely used in cardiac surgery to reduce postoperative bleeding and the need for blood transfusion. Controversy exists regarding the influence of aprotinin on renal function and its effect on the incidence of perioperative myocardial infarction (MI) and cerebrovascular incidents (CVI). In the present study, we analyzed the incidence of these adverse events in patients who underwent coronary artery bypass grafting (CABG) surgery under full-dose aprotinin and compared the data with those recently reported by Mangano et al [2006]. For 751 consecutive patients undergoing CABG surgery under full-dose aprotinin (>4 million kalikrein-inhibitor units) we analyzed in-hospital data on renal dysfunction or failure, MI (defined as creatine kinase-myocardial band > 60 iU/L), and CVI (defined as persistent or transient neurological symptoms and/or positive computed tomographic scan). Average age was 67.0 +/- 9.9 years, and patient pre- and perioperative characteristics were similar to those in the Society of Thoracic Surgeons database. The mortality (2.8%) and incidence of renal failure (5.2%) ranged within the reported results. The incidence rates of MI (8% versus 16%; P < .01) and CVI (2% versus 6%; P < .01) however, were significantly lower than those reported by Mangano et al. Thus the data of our single center experience do not confirm the recently reported negative effect of full-dose aprotinin on the incidence of MI and CVI. Therefore, aprotinin may still remain a valid option to reduce postoperative bleeding, especially because of the increased use of aggressive fibrinolytic therapy following percutaneous transluminal coronary angioplasty.

Coronary bypass surgery in patients treated with clopidogrel. Is it safe?

PURPOSE OF REVIEW: Current guidelines for the management of acute coronary syndrome clearly recommend that clopidogrel should be started before diagnostic coronary angiography. If patients undergo coronary artery bypass grafting (CABG) early after clopidogrel loading or during continued exposure, it seems reasonable to expect an increase in bleeding complications. RECENT FINDINGS: Earlier studies may have overestimated the risk of bleeding in patient undergoing CABG with prior clopidogrel exposure (5-10-fold increase). Some conflicting results are reported in literature. As reexploration because of excessive bleeding is concerned, a two to three-fold increase must be expected, which is demonstrated in actual trials properly matched to confounding factors. Discontinuation of clopidogrel for 5-7 days prior to urgent CABG as recommended by guidelines is not well adopted in clinical practice for several reasons. SUMMARY: There is a moderately elevated risk of bleeding complications after CABG due to prior clopidogrel exposure alone. However, in clinical practice this risk is added often to patients who carry already elevated surgical risks (urgent procedures, worse coronary anatomy, history of previous myocardial infarction and prior percutaneous intervention), and after bleeding complications singular patients may suffer from consecutive adverse outcome. Cessation of clopidogrel in patients before CABG clearly prolongs hospitalization time and has an estimated 1% risk of coronary events during the waiting period. Risk and benefit have to be balanced in every individual case.

Clinical outcomes after zotarolimus and everolimus drug eluting stent implantation in coronary artery bifurcation lesions: insights from the RESOLUTE All Comers Trial

OBJECTIVE We investigated clinical outcomes after treatment of coronary bifurcation lesions with second generation drug eluting stents (DES). DESIGN Post hoc analysis of a randomised, multicentre, non-inferiority trial. SETTING Multicentre study. PATIENTS All comers study with minimal exclusion criteria. INTERVENTIONS Patients were treated with either zotarolimus or everolimus eluting stents. The patient population was divided according to treatment of bifurcation or non-bifurcation lesions and clinical outcomes were compared between groups. MAIN OUTCOMES MEASURES Clinical outcomes within 2-year follow-up. RESULTS A total of 2265 patients were included in the present analysis. Two-year follow-up data were available in 2223 patients: 1838 patients in the non-bifurcation group and 385 patients in the bifurcation group. At 2-year follow-up the bifurcation and the non-bifurcation lesion groups showed no significant differences in terms of cardiac death (2.3 vs 2.1, p=0.273), target lesion failure (9.7% vs 13.8%, p=0.255), major adverse cardiac events (11.5% vs 15.1%, p=0.305), target lesion revascularisation (4.7% vs 6.0%, p=0.569), and definite or probable stent thrombosis (1.6% vs 1.8%, p=0.419). CONCLUSIONS The use of second generation DES for the treatment of coronary bifurcation lesions was associated with similar long term mortality and clinical outcomes compared with non-bifurcation lesions.

Coronary revascularization and TAVI: before, during, after or never?

Aortic valve stenosis and coronary artery disease (CAD) frequently coexist in elderly patients selected for transcatheter aortic valve implantation (TAVI). Therapeutic strategies to manage concomitant obstructive CAD are therefore an important consideration in the overall management of patients with severe aortic stenosis (AS) undergoing TAVI. Conventional surgical aortic valve replacement and coronary artery bypass grafting is the treatment of choice for low and intermediate risk patients with symptomatic severe AS and concomitant obstructive CAD. However, TAVI and percutaneous coronary intervention (PCI) are viable alternative options for high-risk or inoperable patients presenting with symptomatic severe AS. PCI has been shown to be feasible and safe in selected high-risk or inoperable patients with symptomatic severe AS. However, the optimal timing of PCI relative to the TAVI procedure has been a subject of debate. The most frequent approch is staged PCI typically performed a few weeks prior to TAVI. However, concomitant PCI has also been shown to be a feasible and safe approach, particularly in patients with a low level of CAD complexity and an absence of severe renal impairment. Conversely, staged PCI should be considered in patients with higher degrees of CAD complexity, particularly in the presence of severe renal impairment. The aim of the present review is to discuss the safety and feasibility of performing PCI in elderly patients with severe AS and the optimal timing of PCI relative to the TAVI procedure using the most up-to-date available evidence.

Early renal failure after domino hepatic transplantation using the liver from a compound heterozygous patient with primary hyperoxaluria.

BACKGROUND To cover the shortage of cadaveric organs, new approaches to expand the donor pool are needed. Here we report on a case of domino liver transplantation (DLT) using an organ harvested from a compound heterozygous patient with primary hyperoxaluria (PHO), who underwent combined liver and kidney transplantation. The DLT recipient developed early renal failure with oxaluria. The time to the progression to oxalosis with renal failure in such situations is unknown, but, based on animal data, we hypothesize that calcineurin inhibitors may play a detrimental role. METHODS A cadaveric liver and kidney transplantation was performed in a 52-year-old male with PHO. His liver was used for a 64-year-old patient with a non-resectable, but limited cholangiocarcinoma. RESULTS While the course of the PHO donor was uneventful, in the DLT recipient early post-operative, dialysis-dependent renal failure with hyperoxaluria developed. Histology of a kidney biopsy revealed massive calcium oxalate crystal deposition as the leading aetiological cause. CONCLUSIONS DLT using PHO organs for marginal recipients represents a possible therapeutic approach regarding graft function of the liver. However, it may negatively alter the renal outcome of the recipient in an unpredictable manner, especially with concomitant use of cyclosporin. Therefore, we suggest that, although DLT should be promoted, PHO organs are better excluded from such procedures.

Synchronous carotid and coronary bypass surgery using minimal extracorporeal circulation does not increase the risk of in-hospital stroke compared to isolated carotid endarterectomy under general anaesthesia

Gebiet: Chirurgie Abstract: Introduction: Carotid endarterectomy (CEA) and coronary artery bypass grafting (CABG) could be approached in a combined or a staged fashion. Some crucial studies have shown no significant difference in peri-operative stroke and death rate in combined versus staged CEA/CABG. At present conventional extracorporeal circulation (CECC) is regarded as the gold standard for performing on-pump coronary artery bypass grafting. On contrary, the use of minimized extracorporeal circulation (MECC) for CABG diminishes hemodilution, blood-air contact, foreign surface contact and inflammatory response. At the same time, general anaesthesia (GA) is a potential risk factor for higher perioperative stroke rate after isolated CEA, not only for the ipsilateral but also for the contralateral side especially in case of contralateral high-grade stenosis or occlusion. The aim of the study was to analyze if synchronous CEA/CABG using MECC (CEA/CABG group) allows reducing the perioperative stroke risk to the level of isolated CEA performed under GA (CEA-GA group). – Methods: A retrospective analysis of all patients who underwent CEA at our institution between January 2005 and December 2012 was performed. We compared outcomes between all patients undergoing CEA/CABG to all isolated CEA-GA during the same time period. The CEA/CABG group was additionally compared to a reference group consisting of patients undergoing isolated CEA in local anaesthesia. Primary outcome was in-hospital stroke. – Results: A total of 367 CEAs were performed, from which 46 patients were excluded having either off-pump CABG or other cardiac surgery procedures than CABG combined with CEA. Out of 321 patients, 74 were in the CEA/CABG and 64 in the CEA-GA group. There was a significantly higher rate of symptomatic stenoses among patients in the CEA-GA group (p<0.002). Three (4.1%) strokes in the CEA/CABG group were registered, two ipsilateral (2.7%) and one contralateral (1.4%) to the operated side. In the CEA-GA group 2 ipsilateral strokes (3.1%) occurred. No difference was noticed between the groups (p=1.000). One patient with stroke in each group had a symptomatic stenosis preoperatively. – Conclusions: Outcome with regard to mortality and neurologic injury is very good in both -patients undergoing CEA alone as well as patients undergoing synchronous CEA and CABG using the MECC system. Although the CEA/CABG group showed slightly increased risk of stroke, it can be considered as combined treatment in particular clinical situations.

Minimal invasive extracorporeal circulation should become the standard practice in coronary revascularization surgery†.

We read with great interest the large-scale network meta-analysis by Kowalewski et al. comparing clinical outcomes of patients undergoing coronary artery bypass grafting (CABG) operated on using minimal invasive extracorporeal circulation (MiECC) or off-pump (OPCAB) with those undergoing surgery on conventional cardiopulmonary bypass (CPB) [1]. The authors actually integrated into single study two recently published meta-analysis comparing MiECC and OPCAB with conventional CPB, respectively [2, 3] into a single study. According to the results of this study, MiECC and OPCAB are both strongly associated with improved perioperative outcomes following CABG when compared with CABG performed on conventional CPB. The authors conclude that MiECC may represent an attractive compromise between OPCAB and conventional CPB. After carefully reading the whole manuscript, it becomes evident that the role of MiECC is clearly undervalued. Detailed statistical analysis using the surface under the cumulative ranking probabilities indicated that MiECC represented the safer and more effective intervention regarding all-cause mortality and protection from myocardial infarction, cerebral stroke, postoperative atrial fibrillation and renal dysfunction when compared with OPCAB. Even though no significant statistical differences were demonstrated between MiECC and OPCAB, the superiority of MiECC is obvious by the hierarchy of treatments in the probability analysis, which ranked MiECC as the first treatment followed by OPCAB and conventional CPB. Thus, MiECC does not represent a compromise between OPCAB and conventional CPB, but an attractive dominant technique in CABG surgery. These results are consistent with the largest published meta-analysis by Anastasiadis et al. comparing MiECC versus conventional CPB including a total of 2770 patients. A significant decrease in mortality was observed when MiECC was used, which was also associated with reduced risk of postoperative myocardial infarction and neurological events [4]. Similarly, another recent meta-analysis by Benedetto et al. compared MiECC versus OPCAB and resulted in comparable outcomes between these two surgical techniques [5]. As stated in the text, superiority of MiECC observed in the current network meta-analysis, when compared with OPCAB, could be attributed to the fact that MiECC offers the potential for complete revascularization, whereas OPCAB poses a challenge for unexperienced surgeons; especially when distal marginal branches on the lateral and/or posterior wall of the heart need revascularization. This is reflected by a significantly lower number of distal anastomoses performed in OPCAB when compared with conventional CPB. Therefore, taking into consideration the literature published up to date, including the results of the current article, we advocate that MiECC should be integrated in the clinical practice guidelines as a state-of-the-art technique and become a standard practice for perfusion in coronary revascularization surgery.

Coronary bypass surgery in Illinois.

Description based on: 1993.

Prosthetic carotid bypass graft for in-stent restenosis performed for post-endarterectomy recurrent stenosis: technical details

Aim. Carotid artery stenting (CAS) is the treatment of choice for recurrent stenosis after carotid endarterectomy (CEA). However a significative incidence of in-stent restenosis could be occurred. Despite classical CEA leads to good results, in selective cases bypass graft may be the best treatment of in-stent restenosis. Case reports. We describe two cases of carotid bypass graft performed to treat a recurrent in-stent stenosis after CAS for post-CEA restenosis. No death and cardiac complication occurred and no cranial nerves impairment was detected. Conclusion. Prosthetic bypass graft is safe and effective in treatment of in-stent recurrent restenosis after CEA restenosis.

Double Coronary Artery Fistulae: Clinical and Imaging Concerns, and a Review of the Literature

Coronary artery fistulae (CAF) are a rare entity describing abnormal communication between a coronary artery and cardiac chamber or a large intrathoracic vessel and are seldom described in the literature[1]. These fistulae can be either congenital or acquired. Often incidental in finding, CAFs can have serious clinical sequelae, and should be duly reported and discussed with the cardiac team. More than 50% of patients with CAFs may be asymptomatic; 34% may report chest pain; 13% may have symptoms of heart failure, and a minority of 2% may suffer from endocarditis and arrhythmias[2]. The largest series to our knowledge was reported by the Cleveland Clinic, which found 225 patients with incidental CAF out of 126,595 coronary catheterizations (incidence of 0.18%), performed during a span of 28 years [3]. Multiple CAFs are an even rarer entity and only a handful of cases have been reported in the literature to date. Few cases of double CAFs have been reported that describe two different feeder coronary arteries giving rise to separate drainage sites[3]. In our report, however, we describe a new entity: a single-feeder coronary vessel communicated with two drainage sites. Our case is curiously unique, in which we report a single artery, originating from the right coronary artery (RCA) with double drainage sites – one to the left pulmonary artery and the second to the left bronchial artery.

Cognitive impairment in heart failure

The clinical syndrome of heart failure is one of the leading causes of hospitalisation and mortality in older adults. Due to ageing of the general population and improved survival from cardiac disease the prevalence of heart failure is rising. Despite the fact that the majority of patients with heart failure are aged over 65 years old, many with multiple co-morbidities, the association between cognitive impairment and heart failure has received relatively little research interest compared to other aspects of cardiac disease. The presence of concomitant cognitive impairment has implications for the management of patients with heart failure in the community. There are many evidence based pharmacological therapies used in heart failure management which obviously rely on patient education regarding compliance. Also central to the treatment of heart failure is patient self-monitoring for signs indicative of clinical deterioration which may prompt them to seek medical assistance or initiate a therapeutic intervention e.g. taking additional diuretic. Adherence and self-management may be jeopardised by cognitive impairment. Formal diagnosis of cognitive impairment requires evidence of abnormalities on neuropsychological testing (typically a result ≥1.5 standard deviation below the age-standardised mean) in at least one cognitive domain. Cognitive impairment is associated with an increased risk of dementia and people with mild cognitive impairment develop dementia at a rate of 10-15% per year, compared with a rate of 1-2% per year in healthy controls.1 Cognitive impairment has been reported in a variety of cardiovascular disorders. It is well documented among patients with hypertension, atrial fibrillation and coronary artery disease, especially after coronary artery bypass grafting. This background is relevant to the study of patients with heart failure as many, if not most, have a history of one or more of these co-morbidities. A systematic review of the literature to date has shown a wide variation in the reported prevalence of cognitive impairment in heart failure. This range in variation probably reflects small study sample sizes, differences in the heart failure populations studied (inpatients versus outpatients), neuropsychological tests employed and threshold values used to define cognitive impairment. The main aim of this study was to identify the prevalence of cognitive impairment in a representative sample of heart failure patients and to examine whether this association was due to heart failure per se rather than the common cardiovascular co-morbidities that often accompany it such as atherosclerosis and atrial fibrillation. Of the 817 potential participants screened, 344 were included in this study. The study cohort included 196 patients with HF, 61 patients with ischaemic heart disease and no HF and 87 healthy control participants. The HF cohort consisted of 70 patients with HF and coronary artery disease in sinus rhythm, 51 patients with no coronary artery disease in sinus rhythm and 75 patients with HF and atrial fibrillation. All patients with HF had evidence of HF-REF with a LVEF <45% on transthoracic echocardiography. The majority of the cohort was male and elderly. HF patients with AF were more likely to have multiple co-morbidities. Patients recruited from cardiac rehabilitation clinics had proven coronary artery disease, no clinical HF and a LVEF >55%. The ischaemic heart disease group were relatively well matched to healthy controls who had no previous diagnosis of any chronic illness, prescribed no regular medication and also had a LVEF >55%. All participants underwent the same baseline investigations and there were no obvious differences in baseline demographics between each of the cohorts. All 344 participants attended for 2 study visits. Baseline investigations including physiological measurements, electrocardiography, echocardiography and laboratory testing were all completed at the initial screening visit. Participants were then invited to attend their second study visit within 10 days of the screening visit. 342 participants completed all neuropsychological assessments (2 participants failed to complete 1 questionnaire). A full comprehensive battery of neuropsychological assessment tools were administered in the 90 minute study visit. These included three global cognitive screening assessment tools (mini mental state examination, Montreal cognitive assessment tool and the repeatable battery for the assessment of neuropsychological status) and additional measures of executive function (an area we believe has been understudied to date). In total there were 9 cognitive tests performed. These were generally well tolerated. Data were also collected using quality of life questionnaires and health status measures. In addition to this, carers of the study participant were asked to complete a measure of caregiver strain and an informant questionnaire on cognitive decline. The prevalence of cognitive impairment varied significantly depending on the neuropsychological assessment tool used and cut-off value used to define cognitive impairment. Despite this, all assessment tools showed the same pattern of results with those patients with heart failure and atrial fibrillation having poorer cognitive performance than those with heart failure in sinus rhythm. Cognitive impairment was also more common in patients with cardiac disease (either coronary artery disease or heart failure) than age-, sex- and education-matched healthy controls, even after adjustment for common vascular risk factors.