Atherosclerosis of the ascending aorta is an independent predictor of long-term neurologic events and mortality

Intimal aortic atherosclerosis in cardiac surgery: surgical strategies to prevent embolic stroke

 

OBJECTIVES

Although the incidence of perioperative stroke after cardiac surgery gradually decreased over the last decades, there is much variation between centres. This review aimed to create a concise overview of the evidence on possible surgical strategies to prevent embolic stroke in patients with intimal aortic atherosclerosis.

METHODS

The PubMed and EMBASE databases were searched for studies on surgical management of aortic atherosclerosis and the association with perioperative stroke in cardiac surgery, including specific searches on the most common types of surgery. Articles were screened with emphasis on studies comparing multiple strategies and studies reporting on the patients’ severity of aortic atherosclerosis. The main findings were summarized in a figure, with a grade of the corresponding level of evidence.

RESULTS

Regarding embolic stroke risk, aortic atherosclerosis of the tunica intima is most relevant. Although several strategies in general cardiac surgery seem to be beneficial in severe disease, none have conclusively been proven most effective. Off-pump surgery in coronary artery bypass grafting should be preferred with severe atherosclerosis, if the required expertise is present. Although transcatheter aortic valve replacement is used as an alternative to surgery in patients with a porcelain aorta, the risk profile concerning intimal atherosclerosis remains poorly defined.

CONCLUSIONS

A tailored approach that uses the discussed alternative strategies in carefully selected patients is best suited to reduce the risk of perioperative stroke without compromising other outcomes. More research is needed, especially on the perioperative stroke risk in patients with moderate aortic atherosclerosis.

Percutaneous coronary intervention versus coronary artery bypass grafting in patients with coronary heart disease and type 2 diabetes mellitus: Cumulative meta-analysis

Previous meta‐analyses showed that coronary artery bypass grafting (CABG) has lower all‐cause mortality than percutaneous coronary intervention (PCI) for the management of coronary heart disease (CHD), but the long‐term outcomes were not analyzed thoroughly in patients with type 2 diabetes mellitus (T2DM). To perform a meta‐analysis of randomized controlled trials (RCTs) to explore the long‐term effectiveness between CABG and PCI in patients with T2DM and study the temporal trends using a cumulative meta‐analysis. PubMed, Embase, Cochrane library, and Clinical Trials Registry for eligible RCTs published up to September 2020. The outcomes were all‐cause death, cardiac death, myocardial infarction, repeat revascularization, and stroke. Nine RCTs and 4566 patients were included. CABG resulted in better outcomes than PCI in terms of all‐cause death (RR = 1.41, 95%CI: 1.22–1.63, p < 0.001), cardiac death (RR = 1.56, 95%CI: 1.25–1.95, p < 0.001), and repeat revascularization (RR = 2.68, 95%CI: 1.86–3.85, p < 0.001), but with difference regarding the occurrence of myocardial infarction (RR = 1.20, 95%CI: 0.78–1.85, p = 0.414), while PCI was associated with better outcomes in terms of stroke occurrence (RR = 0.51, 95%CI: 0.34–0.77, p = 0.001). The cumulative meta‐analysis for all‐cause death showed that the differences between CABG and PCI started to be significant at 3 years of follow‐up, while the difference became significant at 5 years for cardiac death. In patients with CHD and T2DM, CABG results in better outcomes than PCI in terms of all‐cause death, cardiac mortality, and repeat revascularization, while PCI had better outcomes in terms of stroke. The differences are mainly observed over the long‐term follow‐up.

Antithrombotic Therapy for Stroke Patients with Cardiovascular Disease

Prevention of ischemic stroke relies on the use of antithrombotic medications comprising antiplatelet agents and anticoagulation. Stroke risk is particularly high in patients with cardiovascular disease. This review will focus on the role of antithrombotic therapies in the context of different types of cardiovascular disease. We will discuss oral antiplatelet medications and both IV and parental anticoagulants. Different kinds of cardiovascular disease contribute to stroke via distinct pathophysiological mechanisms, and the optimal treatment for each varies accordingly. We will explore the mechanism of stroke and evidence for antithrombotic therapy in the following conditions: atrial fibrillation, prosthetic heart values (mechanical and bioprosthetic), aortic arch atherosclerosis, congestive heart failure (CHF), endocarditis (infective and nonbacterial thrombotic endocarditis), patent foramen ovale (PFO), left ventricular assist devices (LVAD), and extracorporeal membrane oxygenation (ECMO). While robust data exist for antithrombotic use in conditions such as atrial fibrillation, optimal treatment in many situations remains under active investigation.

Novel Perspective for Antithrombotic Therapy in TAVI

:

While surgical aortic valve replacement (SAVR) was for years the only available treatment for symptomatic aortic stenosis, the introduction of transcatheter aortic valve implantation (TAVI) in 2002 and the improvement of its technical aspects in the following years, has holistically changed the synchronous therapeutic approach of aortic valve stenosis. Recent evidence has expanded the indication of TAVI from high to lower surgical risk populations with symptomatic aortic stenosis. The administration of antithrombotic therapy periprocedurally and its maintenance after a successful TAVI is crucial for the prevention of complications and affects postprocedural survival. Randomized controlled trials investigating the appropriate combination and the duration of antithrombotic treatment after TAVI are for the moment scarce. This review article sheds light on the underlying pathogenetic mechanisms contributing in periprocedural TAVI thrombotic complications and discuss the efficacy of current antithrombotic policies as evaluated in randomized trials.

Diagnosis and Treatment for embolic stroke of undetermined source: Consensus statement from the Taiwan stroke society and Taiwan society of cardiology

Cryptogenic stroke comprises about one-quarter of ischemic strokes with high recurrence rate; however, studies specifically investigating the features and treatment of this stroke subtype are rare. The concept of 'embolic stroke of undetermined source' (ESUS) may facilitate the development of a standardized approach to diagnose cryptogenic stroke and improve clinical trials. Since recent large randomized control trials failed to demonstrate a reduction in stroke recurrence with anticoagulants, anti-platelet agents remain the first-line treatment for ESUS patients. Nevertheless, patients with high risk of stroke recurrence (e.g., those with repeated embolic infarcts despite aspirin treatment) require a more extensive survey of stroke etiology, including cardiac imaging and prolonged cardiac rhythm monitoring. Anticoagulant treatments may still benefit some subgroups of high-risk ESUS patients, such as those with multiple infarcts at different arterial territories without aortic atheroma, the elderly, or patients with high CHA₂D₂-VASc or HOVAC scores, atrial cardiopathy or patent foramen ovale. Several important ESUS clinical trials are ongoing, and the results are anticipated. With rapid progress in our understanding of ESUS pathophysiology, new subcategorizations of ESUS and assignment of optimal treatments for each ESUS subgroup are expected in the near future.

Radiation-Associated Cardiac Disease: A Practical Approach to Diagnosis and Management

Radiation-associated cardiac disease (RACD) results in complex clinical presentations, unique management issues, and increased morbidity and mortality. Patients typically present years or even decades after radiation exposure, with delayed-onset cardiac damage sustained from high cumulative doses. Multimodality imaging is crucial to determine the manifestations and severity of disease because symptoms are often nonspecific. Comprehensive screening using a coordinated approach may enable early detection. However, timing of intervention should be carefully considered in these patients because surgery is often complex and high-risk second surgeries should be minimized in the long-term. This review aims to provide treating physicians with a comprehensive and clinically focused overview of RACD, including clinical/imaging manifestations, multi-modality screening recommendations, and management options.

Thoracic Aortic Calcification: Diagnostic, Prognostic, and Management Considerations

Thoracic aortic calcification (TAC) is associated with adverse cardiovascular outcomes, and for the cardiovascular imager, is predominantly encountered in 4 settings: 1) incidentally, for example, during a coronary artery calcium scan; 2) as part of dedicated screening; 3) in the evaluation of an embolic event; or 4) in procedural planning. This review focuses on TAC in these contexts. Within atherosclerosis, TAC is common, variable in extent, and begins in the intima with a patchy distribution. In metabolic disorders, aortitis, and radiation-associated cardiovascular disease, calcification preferentially involves the media and is often more concentric. As an incidental finding, atherosclerotic TAC provides limited incremental discriminative value, and current data do not support screening. After an embolic event, the demonstration of thoracic atheroma provides diagnostic clarity, but has limited treatment implications. Before any procedure, the plan often changes if the most severe form of TAC, a porcelain aorta, is discovered.

Cerebral Small Vessel, But Not Large Vessel Disease, Is Associated With Impaired Cerebral Autoregulation During Cardiopulmonary Bypass: A Retrospective Cohort Study

BACKGROUND

Impaired cerebral blood flow (CBF) autoregulation during cardiopulmonary bypass (CPB) is associated with stroke and other adverse outcomes. Large and small arterial stenosis is prevalent in patients undergoing cardiac surgery. We hypothesize that large and/or small vessel cerebral arterial disease is associated with impaired cerebral autoregulation during CPB.

METHODS

A retrospective cohort analysis of data from 346 patients undergoing cardiac surgery with CPB enrolled in an ongoing prospectively randomized clinical trial of autoregulation monitoring were evaluated. The study protocol included preoperative transcranial Doppler (TCD) evaluation of major cerebral artery flow velocity by a trained vascular technician and brain magnetic resonance imaging (MRI) between postoperative days 3 and 5. Brain MRI images were evaluated for chronic white matter hyperintensities (WMHI) by a vascular neurologist blinded to autoregulation data. "Large vessel" cerebral vascular disease was defined by the presence of characteristic TCD changes associated with stenosis of the major cerebral arteries. "Small vessel" cerebral vascular disease was defined based on accepted scoring methods of WMHI. All patients had continuous TCD-based autoregulation monitoring during surgery.

RESULTS

Impaired autoregulation occurred in 32.4% (112/346) of patients. Preoperative TCD demonstrated moderate-severe large vessel stenosis in 67 (25.2%) of 266 patients with complete data. In adjusted analysis, female sex (odds ratio [OR], 0.46; 95% confidence interval [CI], 0.25-0.86; P = .014) and higher average temperature during CPB (OR, 1.23; 95% CI, 1.02-1.475; P = .029), but not moderate-severe large cerebral arterial stenosis (P = .406), were associated with impaired autoregulation during CPB. Of the 119 patients with available brain MRI data, 42 (35.3%) demonstrated WMHI. The presence of small vessel cerebral vascular disease was associated with impaired CBF autoregulation (OR, 3.25; 95% CI, 1.21-8.71; P = .019) after adjustment for age, history of peripheral vascular disease, preoperative hemoglobin level, and preoperative treatment with calcium channel blocking drugs.

CONCLUSIONS

These data confirm that impaired CBF autoregulation is prevalent during CPB predisposing affected patients to brain hypoperfusion or hyperperfusion with low or high blood pressure, respectively. Small vessel, but not large vessel, cerebral vascular disease, male sex, and higher average body temperature during CPB appear to be associated with impaired autoregulation.

Cerebrovascular Events After Transcatheter Aortic Valve Implantation

Transcatheter aortic valve implantation (TAVI) has emerged as an alternative less invasive treatment for patients with symptomatic severe aortic stenosis. Despite the technological development and knowledge improvement in recent years, neurological complications remain a concern, especially with the expansion of the technique toward younger and lower risk patients. Clinical cerebrovascular events have an important impact on patients' morbidity and mortality with a multifactorial origin. While cerebral microembolizations during TAVI is a universal phenomenon and embolic protection devices have been developed in an attempt to reduce them, their clinical utility remains unclear. We review the current evidence on cerebrovascular events associated with TAVI and potential preventive strategies.

Meta-analysis study comparing percutaneous coronary intervention/drug eluting stent versus coronary artery bypass surgery of unprotected left main coronary artery disease: Clinical outcomes during short-term versus long-term (> 1 year) follow-up

BACKGROUND

Results on the safety and long-term efficacy of drug-eluting stent placement in unprotected left main coronary artery disease (ULMCAD) compared with those of coronary artery bypass surgery (CABG) remain inconsistent across randomized clinical trials and recent meta-analysis studies. We aimed to compare the clinical outcomes and safety over short- and long-term follow-ups by conducting a meta-analysis of large pooled data from randomized controlled trials and up-to-date observational studies.

METHODS

A systematic review of PubMed, Google Scholar, Medline, and reference lists of related articles was performed for studies conducted in the drug-eluting stent era, to compare percutaneous coronary intervention (PCI) with CABG in ULMCAD. The primary outcome was major adverse cardiovascular and cerebrovascular events (MACCE), myocardial infarction (MI), stroke, all-cause mortality, and revascularization after at least 1-year follow-up. In-hospital and 30-day clinical outcomes were considered secondary outcomes. Furthermore, a subgroup analysis of studies with ≥5 years follow-up was performed to test the sustainability of clinical outcomes.

RESULTS

A total of 29 studies were extracted with 21,832 patients (10,424 in PCI vs 11,408 in CABG). Pooled analysis demonstrated remarkable differences in long-term follow-up (≥1 year) MACCE (odds ratio [OR] 1.42, 95% CI 1.27-1.59), P < .00001), repeat revascularization (OR 3.00, 95% CI 2.41-3.73, P < .00001), and MI (OR 1.32, 95% CI 1.14-1.53, P = .0002), favoring CABG over PCI. However, stroke risk was significantly lower in the PCI group. Subgroup analysis of studies with ≥5 years follow-up showed similar outcomes except for the noninferiority outcome of MACCE in the PCI arm. However, the PCI group proved good safety profile after a minimum of 30-day follow-up with lower MACCE outcome.

CONCLUSION

PCI for ULMCAD can be applied with attentiveness in carefully selected patients. MI and the need for revascularization remain drawbacks and areas of concern among previous studies. Nonetheless, it has been proven safe during short-term follow-up.

Impact of Modified Transesophageal Echocardiography on Mortality and Stroke after Cardiac Surgery: A Large Cohort Study

The aim of this study was to investigate the impact of perioperative screening with modified transesophageal echocardiography (A-View method). We compared, in consecutive patients who underwent cardiac surgery between 2006 and 2014, 30-day mortality and in-hospital stroke incidence, operated either with perioperative modified TEE screening (intervention group) or only with conventional TEE screening (control group). Of the 8,605 study patients, modified TEE was applied in 1,391 patients (16.2%). Patients in the intervention group were on average older (71 versus 68 years, p < 0.001) and more often females (31.0% versus 28.0%, p < 0.001) and had a higher predicted mortality (EuroSCORE I: 5.9% versus 4.0%, p < 0.001). The observed 30-day mortality was 2.2% and 2.5% in both groups, respectively, with multivariable and propensity-score adjusted relative risks (RRs) of 0.70 (95% CI: 0.50–1.00, p = 0.05) and 0.67 (95% CI: 0.45–0.98, p = 0.04). In-hospital stroke was 2.9% and 2.1% in both groups, respectively, with adjusted RRs of 1.03 (95% CI: 0.73–1.45) and 1.01 (95% CI: 0.71–1.43). In patients undergoing cardiac surgery, use of perioperative screening for aortic atherosclerosis with modified TEE was associated with lower postoperative mortality, but not stroke, as compared to patients operated on without such screening.

Aortic Atheroma Increases the Risk of Long-Term Mortality in 20,000 Patients

BACKGROUND

The association between long-term survival and aortic atheroma in cardiac surgical patients has not been comprehensively investigated. In this study we determine the relation between grade of atheroma and the risk of long-term mortality in a retrospective cohort of more than 20,000 patients undergoing cardiac operation during a 20-year period.

METHODS

We included 22,304 consecutive intraoperative transesophageal and epiaortic ultrasound examinations performed at Brigham and Women's Hospital between 1995 and 2014, with long-term follow-up. The extent of atheromatous disease recorded in each examination was used for analysis. Mortality data were obtained from our institution's data registry. Mortality analyses were done using Cox proportional hazard regression models with follow-up as a time scale. We repeated the analysis in a subgroup of 14,728 patients with more detailed demographic characteristics, including postoperative stroke, queried from the institutional Society of Thoracic Surgeons database.

RESULTS

A total of 7,722 mortality events and 872 stroke events occurred. Patients with atheromatous disease demonstrated a significant increase in mortality across all grades of severity, both for the ascending and descending aorta. This relation remained unchanged after adjusting for additional covariates. Adjustments for postoperative stroke resulted in only minimal attenuation in the risk of postoperative mortality related to aortic atheroma.

CONCLUSIONS

Aortic atheromatous disease of any grade in the ascending and descending aorta is a significant long-term risk of long-term, all-cause mortality in cardiac operation patients. This association remains independent of other conventional risk factors and is not related to postoperative cerebrovascular accidents.

The Evolving Role and Use of Echocardiography in the Evaluation of Cardiac Source of Embolism

This report will review the role of echocardiography in the diagnosis of cardiac sources of embolism. Embolism of cardiac origin accounts for around 15%–30% of ischemic strokes. The diagnosis of a cardioembolic source of stroke is frequently uncertain and relies on the identification of a potential cardiac source of embolism in the absence of significant autochthonous cerebrovascular occlusive disease. Transthoracic and/or transesophageal echocardiography serves as a cornerstone in the evaluation, diagnosis, and management of these patients. This article reviews potential cardiac sources of embolism and discusses the role of echocardiography in clinical practice. Recommendations for the use of echocardiography in the diagnosis of cardiac sources of embolism are given including major and minor conditions associated with the risk of embolism.

Therapeutic alternatives after aborted sternotomy at the time of surgical aortic valve replacement in the TAVI Era-Five centre experience and systematic review

BACKGROUND

We aimed to analyze causes, management, and outcomes of the unexpected need to abort sternotomy in aortic stenosis (AS) patients accepted for surgical aortic valve replacement (SAVR) in the transcatheter aortic valve implantation (TAVI) era.

METHODS

Cases of aborted sternotomy (AbS) were gathered from 5 centers between 2009 and 2014. A systematic review of all published cases in the same period was performed.

RESULTS

A total of 31 patients (71% males, 74±8years, LogEuroSCORE 11.9±7.4%) suffered an AbS (0.19% of all sternotomies). Main reasons for Abs included previously unknown porcelain aorta (PAo) in 83.9%, mediastinal fibrosis due to radiotherapy in 12.9%, and chronic mediastinitis in 3.2%. Median time between AbS and next intervention was 2.3months (IQR: 0.7-5.8) with no mortality within this period. Only a case was managed with open surgery. In 30 patients (96.8%) TAVI was performed with a rate of success of 86.7%. Three patients (9.7%) presented in-hospital death and 17 (54.8%) had in-hospital complications including heart failure (9.6%), major bleeding (6.9%), and acute kidney injury (9.6%). Older patients (76±8 vs. 70±8years, p=0.045), previous cardiac surgery (60% vs. 15.4%, p=0.029), and shorter time from AbS to next intervention (5.1±5 vs. 1±0.7months, p=0.001) were related to higher six-month mortality (22.6%).

CONCLUSIONS

The main reason for AbS was PAo. This entity was associated to a higher rate of complications and mortality, especially in older patients and with prior cardiac surgery. A preventive strategy in these subgroups might be based on imaging evaluation. TAVI was the most extended therapy.

3-D Imaging for Aortic Plaque Assessment

Stroke and neurologic dysfunction continue to complicate cardiac surgery despite improvements in cardiopulmonary bypass. Intra-aortic plaque disrupted during aortic manipulation is a known risk factor contributing to neurologic complications; therefore, avoidance of these plaques during aortic manipulation is important. Intraoperative epiaortic echocardiography, with its high sensitivity and specificity, has become the modality of choice for detecting plaque within the aorta during cardiac surgery and is superior to either transesophageal echocardiography or aortic palpation for this purpose. Recently the matrix x4 three-dimensional (3D) ultrasound probe (Philps Medical Systems) was introduced allowing both real time 3D imaging and electrocardiography-gated “full volume” imaging, which essentially acquires a larger image but requires 8 cardiac cycles. Modification of our routine scanning technique was required, employing a saline (about 30 mL) filled sterile sheath secured with a sterile elastic band (creating a saline pocket). There appears little difference in the sensitivity of either 2D or 3D imaging to detect plaque within the aorta. We found that live 3D was superior to 2D imaging in identifying, localizing, and defining the true extent of plaque in the aorta.

Aortic Valve Replacement in a Patient with Takayasu's Disease without Cross-Clamping the Calcified Ascending Aorta

The case of a 42-year-old female requiring surgical management of aortic regurgitation, secondary to Takayasu's disease, with a co-existing heavily calcified ascending aorta is described. In order to address aortic valve surgery with such calcific disease affecting the ascending aorta and peripheral vessels, we present a simple and safe technique that allows aortic valve replacement using a vascular intra-aortic occlusion catheter.

Imaging Techniques for Diagnosis of Thoracic Aortic Atherosclerosis

The most severe complications after cardiac surgery are neurological complications including stroke which is often caused by emboli merging from atherosclerosis in the ascending aorta to the brain. Information about the thoracic aorta is crucial in reducing the embolization risk for both surgical open and closed chest procedures such as transaortic heart valve implantation. Several techniques are available to screen the ascending aorta, for example, transesophageal echocardiography (TEE), epiaortic ultrasound, TEE A-view method, manual palpation, computed tomography, and magnetic resonance imaging. This paper provides a description of the advantages and disadvantages of these imaging techniques.

Non-invasive volumetric assessment of aortic atheroma: a core laboratory validation using computed tomography angiography

Aortic atherosclerosis has been linked with worse peri- and post-procedural outcomes following a range of aortic procedures. Yet, there are currently no standardized methods for non-invasive volumetric pan-aortic plaque assessment. We propose a novel means of more accurately assessing plaque volume across whole aortic segments using computed tomography angiography (CTA) imaging. Sixty patients who underwent CTA prior to trans-catheter aortic valve implantation were included in this analysis. Specialized software analysis (3mensio Vascular™, Pie Medical, Maastricht, Netherlands) was used to reconstruct images using a centerline approach, thus creating true cross-sectional aortic images, akin to those images produced with intravascular ultrasonography. Following aortic segmentation (from the aortic valve to the renal artery origin), atheroma areas were measured across multiple contiguous evenly spaced (10 mm) cross-sections. Percent atheroma volume (PAV), total atheroma volume (TAV) and calcium score were calculated. In our populations (age 79.9 ± 8.5 years, male 52 %, diabetes 27 %, CAD 84 %, PVD 20 %), mean ± SD number of cross sections measured for each patient was 35.1 ± 3.5 sections. Mean aortic PAV and TAV were 33.2 ± 2.51 % and 83,509 ± 17,078 mm(3), respectively. Median (IQR) calcium score was 1.5 (0.7-2.5). Mean (SD) inter-observer coefficient of variation and agreement for plaque area among 4 different analysts was 14.1 (5.4), and the mean (95 % CI) Lin's concordance correlation coefficient was 0.79 (0.62-0.89), effectively simulating a Core Laboratory scenario. We provide an initial validation of cross-sectional volumetric aortic atheroma assessment using CTA. This proposed methodology highlights the potential for utilizing non-invasive aortic plaque imaging for risk prediction across a range of clinical scenarios.

Incidence of postoperative stroke using the Heartstring device in 1,380 coronary artery bypass graft patients with mild to severe atherosclerosis of the ascending aorta

BACKGROUND

Atherosclerotic disease of the ascending aorta during coronary artery bypass graft surgery (CABG) increases the risk for postoperative stroke. The objective of this study was to examine the incidence of postoperative stroke in CABG utilizing the Heartstring (Maquet Cardiovascular, San Jose, CA) proximal anastomotic device.

METHODS

Intraoperative epiaortic ultrasonography was used to grade atherosclerosis in CABG patients at Emory University from April 2003 to December 2012. The Heartstring device was utilized in 1,380 patients: 407 (29.5%) grade I (minimal atherosclerosis), 367 (26.6%) grade II, 437 (31.7%) grade III, 110 (8.0%) grade IV, and 59 (4.3%) grade V (severe atherosclerosis). Logistic regression analysis was used to estimate the effect of aortic grade on outcomes adjusted for Society of Thoracic Surgeons predicted risk of mortality and predicted risk of stroke scores.

RESULTS

The mean age of all patients was 66.7 ± 10.5 years, and 31.9% were female. An increasing risk profile was apparent with rising aortic grade. Most CABG was done off pump (n = 1,277, 92.5%). There was no significant association between aortic grade and frequency of postoperative stroke (p = 0.83). In all patients, use of the Heartstring device reduced the predicted risk of stroke by 44% (O:E risk 0.56). The benefit for postoperative stroke was least apparent in the grade I aorta patients (O:E 0.8) compared with patients having grade II and greater. There were no strokes among patients with severe atherosclerosis using the Heartstring device.

CONCLUSIONS

Compared with the Society of Thoracic Surgeons predicted risk for stroke, the Heartstring proximal anastomotic device can be safely used with all aortic grades. The most prominent benefit appears to be for patients with grade II disease and greater.

Impact of cardiovascular risk factors on vessel wall inflammation and calcified plaque burden differs across vascular beds: a PET-CT study

To evaluate the effect of age, gender and cardiovascular risk factors on vessel wall inflammation and the calcified plaque burden in different vascular beds as assessed by PET/CT. 315 patients (mean age: 57.8 years, 123 male and 192 female) who underwent whole body 18F-FDG PET/CT examinations were included in the study. Blood pool-corrected standardised uptake value (TBR) and the calcified plaque score (CPS, grade 0-4) were determined in the thoracic and abdominal aorta, both common carotid and both iliac arteries. The following cardiovascular risk factors were documented: Age ≥65 years (n = 114), male gender (n = 123), diabetes (n = 15), hyperlipidemia (n = 62), hypertension (n = 76), body mass index (BMI) ≥ 30 (n = 38), current smoker (n = 32). Effects of risk factors on TBR and CPS in different arterial beds were assessed using multivariate regression analysis. In the thoracic aorta TBR was independently associated with age ≥65 years and male gender, CPS was independently associated with age ≥65 years, male gender, hypertension and diabetes. In the abdominal aorta, TBR was independently associated with age ≥65 years and male gender, CPS with age ≥65 years, diabetes and smoking. Independent associations in the carotid arteries were found for age ≥65 years, male gender and BMI ≥ 30 in TBR and for age ≥65 and diabetes in CPS. In the iliac arteries, TBR was independently associated with age ≥65 and CPS with age ≥65, male gender, hypertension, diabetes and smoking. Findings of this PET/CT study demonstrate that the impact of cardiovascular risk factors on vessel wall inflammation and calcified plaque burden differs across vascular territories. Overall, CPS was more closely associated with cardiovascular risk factors compared to TBR.

Effects of medical treatment on the prognosis and risk of embolic events in patients with severe aortic plaque

AIM

The optimal treatment strategy for patients with aortic atheroma is not well established because data regarding medical treatment for such patients are lacking, especially with respect to the Japanese population. The purpose of this study was to clarify the effects of medical treatment on the risk of embolic events and mortality in patients with severe aortic plaque.

METHODS

We retrospectively investigated 75 consecutive patients with severe aortic plaque detected on transesophageal echocardiography (TEE) between 1995 and 2005. The occurrence of embolic events and all-cause death in the period after TEE was assessed. The cumulative incidence of subsequent embolic events and death was evaluated in relation to specific medical treatments, including statins, antiplatelet drugs and warfarin.

RESULTS

Embolic events occurred in 27 patients (36%) and death occurred in 37 patients (49%) during follow-up (5.6±3.0 years). The patients who experienced embolic events had a significantly higher prevalence of previous embolic events, atrial fibrillation and hemodialysis than the patients who did not experience embolic events. Univariate and multivariate analyses showed that the use of statins and/or antiplatelet drugs was significantly associated with a low incidence of death but not with a low incidence of embolic events. On the other hand, warfarin exhibited neither beneficial nor harmful effects on the incidence of embolic events or death.

CONCLUSIONS

Statin and antiplatelet drugs have beneficial effects on the prognosis of patients with severe aortic plaque diagnosed on TEE.

Replacement of the ascending aorta for severe atherosclerosis during coronary artery bypass surgery

BACKGROUND AND AIM

In the present study, we investigated the benefit of ascending aorta replacement in patients with severe aortic atherosclerosis who undergo coronary artery bypass surgery (CABG).

METHODS

From January 2001 to April 2011, 3842 patients underwent CABG and in 36 of these patients (31 male, 5 female) the ascending aorta was replaced due to severe atherosclerosis. Total circulatory arrest was used in 22 patients (61%). The patients were followed for 69 ± 36 months (1-133 months) and compared to a control group of patients. The control group consisted of patients who underwent CABG with or without a concomitant procedure (n = 3806).

RESULTS

For the study group, the mean additive and logistic Euroscores of the patients were nine and 20, respectively. One stroke (2.8%) was observed and this patient died in the early postoperative period. There were a total of four confirmed deaths (12%) at any time point over the length of the follow-up among the patients who were discharged from the hospital. Two of them died of malignancy (lung and gastric tumors) and the other two from cardiac reasons. No patients had a stroke during follow-up. For the control group the mean age was 61 ± 1, the stroke rate was 0.6%, and the mortality rate was 0.96%, and the mean logistic and additive Euroscores were 3.7 ± 4.4, and 3.5 ± 2.5, respectively.

CONCLUSIONS

Replacement of highly calcified ascending aortas during CABG can be safely performed in selected patients with good long-term outcomes.

Combined aortic valve replacement and coronary artery bypass grafting for a calcified ascending aorta

Although a severely calcified ascending aorta is encountered infrequently, it presents formidable problems during cardiac surgery. We describe a case of severe aortic valve stenosis and coronary artery disease combined with a severely calcified ascending aorta. The patient was an 80-year-old man with a calcified ascending aorta. He successfully underwent an aortic valve replacement and a single coronary artery bypass graft (CABG) using a saphenous vein graft with the proximal end connected on a Dacron patch, which was used for aortoplasty of the calcified plate along the aortotomy. These procedures were performed under moderate hypothermia with aortic clamping. This patch aortoplasty can be a useful alternative in cases that require aortotomy and proximal anastomoses of a CABG on a calcified ascending aorta.

Surgical experience of ascending aorta and aortic valve replacement in patient with calcified aorta

Background

The conventional method of aortic cross-clamping is very difficult and increases the risk of cerebral infarct due to embolism of the calcified aorta in these patients. Accordingly, we analyzed our experience with 11 cases of ascending aorta and aortic valve replacement with hypothermic circulatory arrest.

Materials and Methods

From January 2002 to December 2009, 11 patients had ascending aorta and aortic valve replacement with hypothermic arrest at our hospital. We performed a retrospective study.

Results

There were 5 males and 6 females, with a mean age of 68 years (range, 44 to 82 years). Eight patients had aortic stenosis, and 3 patients had aortic regurgitation. An aortic cannula was inserted into the right axillary artery in 3 patients and ascending aorta in 6 patients. Two patients with aortic regurgitation had a remote access perfusion catheter inserted though the right femoral artery. The mean cardiopulmonary bypass time was 180 minutes (range, 110 to 306 minutes) and mean hypothermic circulatory arrest time was 30 minutes (range, 20 to 48 minutes). The mean rectal temperature during hypothermic circulatory arrest was 21℃ (range, 19℃ to 23℃). No patient had any new onset of cerebral infarct or cardiovascular accident after surgery. There was no hospital mortality. Early complications occurred in 1 patient who needed reoperation due to postoperative bleeding. Late complications occurred in 1 patient who underwent a Bentall operation due to prosthetic valve endocarditis. The mean follow-up duration was 32 months (range, 1 month to 8 years) and 1 patient died suddenly due to unknown causes after 5 years.

Conclusion

Patients with a calcified aorta can be safely treated with a technique based on aorta and aortic valve replacement under hypothermic circulatory arrest.

Comparison of frequencies of patent foramen ovale and thoracic aortic atherosclerosis in patients with cryptogenic ischemic stroke undergoing transesophageal echocardiography

Studies have shown an association between the presence of a patent foramen ovale (PFO) and cryptogenic stroke (CS) in patients aged <55 years. In addition, protruding atheromatous plaques in the ascending aorta and aortic arch are an independent risk factor for ischemic stroke in patients aged ≥55 years. The aim of this study was to determine the association of CS in the 2 age groups with PFO and with atheromatous plaques in the ascending aorta and in the aortic arch. Transesophageal echocardiograms in 229 patients evaluated for CS were compared to those in 314 patients evaluated for cardiac disease other than PFO with no histories of stroke (the control group). The prevalence of PFO and the presence of complex atheromatous plaques in the ascending aorta and aortic arch were determined in all patients and compared between the CS and control patients in the 2 age groups. The prevalence of PFO was significantly higher in patients with CS than in control patients among those aged <55 years (31 of 114 [27%] vs 24 of 171 [14%], p = 0.006) and those aged ≥55 years (28 of 115 [24%] vs 21 of 143 [15%], p = 0.049). The incidence of atrial septal aneurysm was similar in the 2 groups irrespective of patient age, as was the prevalence of complex atheromatous plaques. Multivariate analysis showed that PFO was independently associated with CS, irrespective of patient age (<55 years: odds ratio 2.4, 95% confidence interval 1.3 to 4.5, p = 0.01; ≥55 years: odds ratio 1.9, 95% confidence interval 1.1 to 3.5, p = 0.03). In conclusion, PFO was significantly associated with CS in younger (aged <55 years) and older (aged ≥55 years) patients. Atrial septal aneurysm and complex atheromas in the ascending aorta and aortic arch do not appear to be associated with CS.

PET imaging of aortic atherosclerosis: Is combined imaging of plaque anatomy and function an amaranthine quest or conceivable reality?

Traditionally, blood vessels have been studied using contrast luminography to determine the site, extent and severity of luminal compromise by atherosclerotic deposits. Similar anatomical data can now be acquired non-invasively using ultrasound, computed tomography or magnetic resonance imaging. Plaque stability is an important determinant of subsequent vascular events and currently functional data on the stability of plaque is less well provided by these methods. The search for non-invasive techniques to image combined plaque anatomy and function has been pursued with visionary anticipation. This expectation may soon be realised as imaging with radionuclide-labelled atheroma-targeted contrast agents has demonstrated that plaque functional characteristics can now be shown. Increasingly positron emission tomography/computed tomography (PET/CT) imaging with (18)F fluorodexoyglucose (FDG) and other radionuclides is being used to determine culprit plaques in complex clinically scenarios. Clinically, this information may prove extremely valuable in the assessment of stable and unstable patients and its use in prime time medical practice is eagerly awaited. We will discuss the current clinical applications of functional atheroma imaging in the aorta and highlight the promising preclinical data on novel image biomarkers of plaque instability. If clinical science is able to successfully translate these advances in vascular imaging from the bench to the bedside, a new paradigm will be achieved in cardiovascular diagnostics.

Extent of thoracic aortic atheroma burden and long-term mortality after cardiothoracic surgery: a computed tomography study

OBJECTIVES

We hypothesized that the extent of aortic atheroma of the entire thoracic aorta, determined by pre-operative multidetector-row computed tomographic angiography (MDCTA), is associated with long-term mortality following nonaortic cardiothoracic surgery.

BACKGROUND

In patients evaluated for cardiothoracic surgery, presence of severe aortic atheroma is associated with adverse short- and long-term post-operative outcome. However, the relationship between aortic plaque burden and mortality remains unknown.

METHODS

We reviewed clinical and imaging data from all patients who underwent electrocardiographic-gated contrast-enhanced MDCTA prior to coronary bypass or valvular heart surgery at our institution between 2002 and 2008. MDCTA studies were analyzed for thickness and circumferential extent of aortic atheroma in 5 segments of the thoracic aorta. A semiquantitative total plaque-burden score (TPBS) was calculated by assigning a score of 1 to 3 to plaque thickness and to circumferential plaque extent. When combined, this resulted in a score of 0 to 6 for each of the 5 segments and, hence, an overall score from 0 to 30. The primary end point was all-cause mortality during long-term follow-up.

RESULTS

A total of 862 patients (71% men, 67.8 years) were included and followed over a mean period of 25 ± 16 months. The mean TPBS was 8.6 (SD: ±6.0). The TPBS was a statistically significant predictor of mortality (p < 0.0001) while controlling for baseline demographics, cardiovascular risk factors, and type of surgery including reoperative status. The estimated hazard ratio for TPBS was 1.08 (95% confidence interval: 1.045 to 1.12). Other independent predictors of mortality were glomerular filtration rate (p = 0.015), type of surgery (p = 0.007), and peripheral artery disease (p = 0.03).

CONCLUSIONS

Extent of thoracic aortic atheroma burden is independently associated with increased long-term mortality in patients following cardiothoracic surgery. Although our data do not provide definitive evidence, they suggest a relationship to the systemic atherosclerotic disease process and, therefore, have important implications for secondary prevention in post-operative rehabilitation programs.

Risks of Stroke After Coronary Artery Bypass Graft - Recent Insights and Perspectives

Stroke is one of the most devastating complications after coronary artery bypass graft (CABG) surgery, entailing permanent disability, a 3-6 fold increased risk of mortality, an incremental hospital resource consumption and a longer length of hospital stay. Notwithstanding advances in surgical, anaesthetic and medical management across the last 10 years, the risk of stroke after CABG has not significantly declined, likely because an older and sicker population is now deemed suitable to undergo CABG. The pathogenesis of stroke is multifactorial, but two variables are believed to play a major role - cerebral embolisation of atheromatous debris arising from the ascending aorta during surgical manipulation and hypoperfusion during surgery. Identification of vulnerable patients at increased risk of stroke before CABG is of paramount importance for the surgical decision-making approach and informed consent. Several models including demographic, clinical and procedural variables have been developed to risk-stratify the hazard of stroke in patients undergoing CABG, but identification of severe atherosclerosis of the ascending aorta and pre-existing cerebrovascular disease are key determinants for appropriate risk stratification and decision-making. Atherosclerotic disease of the ascending aorta can be identified before surgery using transoesophageal echocardiography, computed tomography and magnetic resonance imaging. However, intra-operative ultrasound scanning of the ascending aorta is the diagnostic tool with the best sensitivity and specificity for the detection of atheromatous debris in the ascending aorta. Although many investigators have advocated the use of off-pump CABG to minimise the risk of peri-operative stroke, results from randomised trials and meta-analyses have been inconsistent. Anaortic approaches, including total arterial revascularisation with in situ grafting of both mammary arteries, or the use of the HEARTSTRING® seal device avoid any manipulation of the aorta, thus potentially minimising the risk of stroke in high-risk patients. Assessment and treatment of severe carotid artery disease, and aggressive and prompt treatment of post-operative atrial fibrillation are other important strategies that should be routinely implemented to reduce the risk of stroke in patients undergoing CABG.

Improve morbidity and mortality in coronary artery bypass graft surgery for severe atherosclerosis

OBJECTIVES

Atherosclerosis has been identified as a risk factor for both morbidity and mortality in patients undergoing coronary artery bypass grafting (CABG). To investigate outcomes following CABG for severe atherosclerosis, and to determine whether different surgical techniques can reduce the risk of neurologic events in these patients.

METHODS

We studied 225 consecutive patients who underwent elective isolated CABG. Routine preoperative and intraoperative examinations identified patients with severe atherosclerosis. We compared the outcomes between patients with (group A; 42 ceses) and those without (group N; 183 cases) severe atherosclerosis.

RESULTS

36 patients (85.7%) in group A and 176 (96.2%) in group N underwent off-pump coronary artery bypass (OPCAB); 6 (14.3%) in group A and 7 (3.8%) in group N underwent on-pump beating CABG. Three patients in group A suffered deep sternal infection (7.1%), and one suffered stroke (2.4%) compared with none in group N. No cerebral infarction or neurologic events occurred in patients who underwent OPCAB (n = 212, 94.2%).

CONCLUSIONS

Prevalence of complications was significantly greater among patients with severe atherosclerotic disease who underwent OPCAB than in those without atherosclerotic disease. Careful selection of surgical strategies can prevent perioperative stroke and reduce mortality.

Aortic atheroma and adverse cerebral outcome: risk, diagnosis, and management options

Aortic atheromatous disease is a common finding in the patient presenting for cardiac surgery. Adverse neurologic outcome has been closely linked to the extent of aortic atherosclerosis. In order to optimize perioperative outcomes, the location and severity of disease needs accurate characterization using multimodal techniques. Although various preoperative radiographic techniques have variably identified patients with significant atheroma, intraoperative echocardiographic imaging has proven most useful in localizing and characterizing the degree of aortic atheroma. Epiaortic assessment of the ascending aorta has been utilized in guiding surgical modifications and interventions aimed at reducing the risk of neurologic injury. Although no particular technique has been definitely studied, avoidance of the identifiable atheromatous aortic region has been a main feature of the various modifications employed to optimize neurologic outcome after cardiac surgery.

Off-pump coronary artery revascularization in octogenarians: is it better?

PURPOSE OF REVIEW

Octogenarians are the fastest growing stratum of the population and have the highest prevalence of coronary artery disease. In the past, physicians have been reluctant to provide these patients with optimal care. Seniors are frequently excluded from large randomized trials and generally not included in published guidelines. The purpose of this review is to revisit the demography and epidemiology of coronary artery disease in this population as well as therapeutic strategies used.

RECENT FINDINGS

Recent publications have shown significant advancement in medical and invasive treatment of coronary artery disease in elderly, with special focus on the potential benefit of off-pump coronary artery bypass (OPCAB) surgery.

SUMMARY

Although OPCAB surgery has gained popularity over the past 15 years, its benefit regarding operative mortality and major complications has not been clearly defined in the general population. There is a body of literature supporting its benefit in the elderly population. OPCAB surgery has the potential of decreasing operative mortality and major postoperative complications such as stroke, delirium, atrial fibrillation, and decline in neurocognitive functions in these patients. Off-pump surgery is technically more demanding and has been blamed for providing less complete revascularization and lower graft patency rate, especially in less experienced hands. However, with the upcoming demographic explosion of senior citizens in western societies, OPCAB surgery has definitely to be a part of the armamentarium of modern cardiac surgeons.

“Beyond Beating Heart Surgery” Heartstring Device Protects against Perioperative Neurological Events

Objective

There is a growing body of evidence favoring off-pump coronary artery bypass surgery (OPCAB) over traditional coronary artery bypass surgery (CABG) with cardiopulmonary bypass as a method for reducing perioperative neurologic events. Aortic manipulation, whether with OPCAB or coronary artery bypass surgery with cardiopulmonary bypass, is strongly linked with adverse neurologic outcomes. Although the aortic “no-touch” technique has merit, most cardiac surgeons are reluctant to base entire myocardial revascularization exclusively on mammary pedicles. The purpose of this study was to analyze our experience with OPCAB combined with the use of a Heartstring proximal anastomotic device, as a strategy for reducing clinically evident cerebrovascular accidents.

Methods

Two hundred twenty-seven consecutive isolated OPCAB were performed without the use of a side-biting aortic clamp. In all these operations, a Heartstring device was used, permitting clampless hand-sutured proximal anastomoses. All patients were managed in this fashion regardless of the status of their ascending aorta. A mean of 3.4 bypasses were performed during each operation, with one or two mammary arteries harvested routinely. In 98% of patients, a single proximal anastomosis was performed; there was liberal use of sequential bypass grafts.

Results

Mean age was 69.3 years, with 17% octogenarians. Preexisting cerebrovascular disease was present in 22.4% of patients. There were no clinically evident perioperative neurologic events in any patients. There were no operative deaths.

Conclusions

This series suggests that OPCAB performed with a single, clampless, proximal aortic anastomosis, and with a Heartstring device may protect against perioperative strokes.

Cerebral Emboli Generation during Off-Pump Coronary Artery Bypass Grafting with a Clampless Device versus Partial Clamping of the Ascending Aorta

Objective

It is not known whether use of a clampless facilitating device during proximal graft anastamosis decreases intraoperative cerebral emboli in patients with mild atherosclerotic ascending aorta (AAA) having off-pump coronary artery bypass.

Methods

After intraoperative epiaortic ultrasound showed no more than mild (grade I–II) atherosclerotic ascending aorta, 20 patients were randomized to receive either partial clamping (PC, n = 10) or the HEARTSTRING clampless device (HS, n = 9) for proximal graft construction on the ascending aorta. Continuous transcranial Doppler monitoring, with capability to discern gaseous from solid particulates, was used intraoperatively to monitor high-intensity transient signals (HITS) in the middle cerebral arteries. Postoperative diffusion-weighted brain magnetic resonance imaging documented old and new ischemic brain lesions.

Results

There were no significant differences between the groups in the number of proximals (P = 0.14), distals (P = 0.4), or intraoperative cell saver transfusions (P = 0.69). The total number of HITS was not significantly different between the PC and HS groups (P = 0.2). However, the number of solid HITS was significantly lower in the HS than in the PC group (2.7 ± 2.6 versus 14.0 ± 8.1; P < 0.001). The number of gaseous emboli in the HS group was fourfold greater when a mister-blower rather than a suction device was used to clear blood away from the HS site. Postoperatively, there were no deaths, myocardial infarctions, or clinical strokes observed in either group. Diffusion-weighted cerebral magnetic resonance imaging revealed no statistical difference between groups for new infarct lesions.

Conclusions

Use of the HS device during off-pump coronary artery bypass was associated with significantly fewer intraoperative solid emboli in the middle cerebral artery than PC of the ascending aorta.

Influence of oscillating flow on LDL transport and wall shear stress in the normal aortic arch

Lipid accumulation in the aortic wall is an important factor in the development of atherosclerosis. The Low Density Lipoprotein (LDL) at the surface of the endothelium in relation to Wall Shear Stress (WSS) in the normal human aortic arch under unsteady, normal flow and mass conditions was computationally analysed. Concave sides of the aortic arch exhibit, relatively to the convex ones, elevated LDL levels at the surface of the endothelium for all time steps. At the peak systolic velocity, the LDL level reaches a value 23.0% higher than that at entrance in the ascending-descending aorta region. The corresponding LDL levels at the surface of the endothelium for the near minimum entrance velocity instant reaches 26.0%. During the cardiac cycle, the highest area averaged normalized LDL taken up as compared to the lowest one is 0.69%. WSS plays an important role in the lipid accumulation. Low WSS regions are exposed to high LDL levels at the surface of the endothelium. Regions of elevated LDL levels do not necessarily co-locate to the sites of lowest WSS. The near wall paths of the velocities might be the most important factor for the elevated LDL levels at the surface of the endothelium.

Intraoperative Epiaortic Ultrasound Scanning Guides Operative Strategies and Identifies Patients at High Risk during Coronary Artery Bypass Grafting

Objective

Epiaortic ultrasound (EU) reliably reveals ascending aortic atherosclerosis (AAA), allowing strategies to minimize the risk of embolization or plaque disruption during coronary artery bypass grafting. Our objective was to delineate if EU-guided intervention improved outcomes.

Methods

Patients undergoing coronary artery bypass grafting (2004–2007) were categorized by EU grade (grade 1–2 [mild] vs. 3–5 [moderate/severe]) and the use of an aortic clamp. A propensity score estimated probability of clamp use was based on 45 risk factors. Multiple logistic regression models measured the association between outcomes—death, stroke, myocardial infarction, and major adverse cardiac and cerebrovascular events (MACCE)—and the primary variables (grade and clamp use), adjusted for propensity score.

Results

Grade was available in 4278 patients. Patients with grade 3 to 5 AAA had an increased risk of death (adjusted odds ratios (AOR) 3.11; P < 0.001), stroke (AOR 2.12; P < 0.001), and MACCE (AOR 2.58; P < 0.001). Aortic clamping (any clamp, all grades) led to a higher risk of stroke (AOR 2.77; P = 0.032). EU altered aortic manipulation in 530 patients (12.4%). In this group, patients with high grade aortas had similar rates of death, stroke or MACCE, when compared with patients with low-grade aortas.

Conclusions

EU alters surgical strategy. Patients with grade 3 to 5 AAA are at increased risk of death, stroke, and MACCE compared with patients with grade 1 to 2 AAA. Clamping the aorta (any grade) increases the risk for stroke. Aortic clamping should be avoided in patients with grade 3 to 5 AAA, but EU may minimize morbidity and mortality if a clamp must be used.