Factors Associated With Presence of Ascending Aortic Atherosclerosis in CABG Patients

The Rationalisation of Intra-Operative Imaging During Cardiac Surgery: A Systematic Review

INTRODUCTION

One critical complication of cardiac surgery is cerebrovascular accidents (CVAs). Ascending aorta atherosclerosis poses a significant risk of embolisation to distal vessels and to cerebral arteries. Epi-aortic ultrasonography (EUS) is thought to offer a safe, high-quality accurate visualisation of the diseased aorta to guide the surgeon on the best surgical approach to the planned procedure and potentially improve neurological outcomes post-cardiac surgery.

METHOD

The authors conducted a comprehensive search of PubMed, Scopus and Embase. Studies that reported on epi-aortic ultrasound use in cardiac surgery were included. Major exclusion criteria were: (1) abstracts, conference presentations, editorials, literature reviews; (2) case series with <5 participants; (3) epi-aortic ultrasound in trauma or other surgeries.

RESULTS

A total of 59 studies and 48,255 patients were included in this review. Out of the studies that reported patient co-morbidities prior to cardiac surgery, 31.6% had diabetes, 59.5% had hyperlipidaemia and 66.1% had a diagnosis of hypertension. Of those that reported significant ascending aorta atherosclerosis found on EUS, this ranged from 8.3% of patients to 95.2% with a mean percentage of 37.8%. Hospital mortality ranged from 7% to 13%; four studies reported zero deaths. Long-term mortality and stroke rate varied significantly with hospital duration.

CONCLUSION

Current data have shown EUS to have superiority over manual palpation and transoesophageal echocardiography in the prevention of CVAs following cardiac surgery. Yet, EUS has not been implemented as a routine standard of care. Extensive adoption of EUS in clinical practice is warranted to aid large, randomised trials before making prospective conclusions on the efficacy of this screening method.

SYNTAX score may predict the severity of atherosclerosis of the ascending aorta

Background

The objective of this study was to investigate the association of the coronary SYNTAX score with the degree of atherosclerosis of the ascending aorta in patients who underwent coronary artery bypass grafting (CABG).

Methods

A total of 152 patients (mean age 65 years, 66% male) were analyzed who underwent isolated CABG with both SYNTAX score and the intraoperative 5-point scale grading of the severity of atherosclerosis in the ascending aorta available. The patient were stratified into low, intermediate, and high SYNTAX score groups [≤22 (n=36), 22-33 (n=42), and ≥33 (n=76)].

Results

The mean SYNTAX score was 31±11. Patient demographics and comorbidity were comparable in each group. The prevalence of severe atherosclerosis (Grade ≥III) in the ascending aorta was 17.5% (n=27) in the whole population and was different in each group with higher prevalence in higher score groups (8.3% vs. 9.5% vs. 26.3%, P=0.018). After adjusting for age, sex and other relevant comorbidity, SYNTAX score remained a predictor of severe atherosclerosis [adjusted OR 1.63, 95% CI: 1.01-2.62, P=0.046 (per 10 point increase); adjusted OR 5.20, 95% CI: 1.15-23.5, P=0.032 (high vs. low score)].

Conclusions

SYNTAX score was associated with the severity of atherosclerosis in the ascending aorta. Patients with high scores have a 5 times higher chance of severe disease compared to patients with low scores and should warrant preoperative and intraoperative comprehensive assessment of the ascending aorta.

Innovative approaches in the perioperative care of the cardiac surgical patient in the operating room and intensive care unit

Perioperative care for cardiac surgery is undergoing rapid evolution. Many of the changes involve the application of novel technologies to tackle common challenges in optimizing perioperative management. Herein, we illustrate recent advances in perioperative management by focusing on a number of novel components that we judge to be particularly important. These include: the introduction of brain and somatic oximetry; transesophageal echocardiographic hemodynamic monitoring and bedside focused ultrasound; ultrasound-guided vascular access; point-of-care coagulation surveillance; right ventricular pressure monitoring; novel inhaled treatment for right ventricular failure; new approaches for postoperative pain management; novel approaches in specialized care procedures to ensure quality control; and specific approaches to optimize the management for postoperative cardiac arrest. Herein, we discuss the reasons that each of these components are particularly important in improving perioperative care, describe how they can be addressed, and their impact in the care of patients who undergo cardiac surgery.

Clinical impact of computerised tomographic angiography performed for preoperative evaluation before coronary artery bypass grafting

OBJECTIVE

In our institution, computerised tomographic (CT) angiography has been performed as a near-routine test before coronary artery bypass grafting (CABG) to evaluate the aorta and its branches. We aimed to determine its impact on operative procedure and perioperative management.

METHODS

From January 2006 through December 2008, neck-to-leg systemic arteries were evaluated by 64-slice multidetector CT scan in 284 patients before CABG. For them, medical records and cardiac surgery database were retrospectively reviewed to investigate the incidence of pathologic lesions of the aorta and its major branches, other incidental lesions and procedure- or management-related decision affected by CT angiography.

RESULTS

In 36 patients (12.7%), cannulation and clamping of the ascending aorta were thought too dangerous because of severe atherosclerotic change. The use of cardiopulmonary bypass was inevitable in 10 of them, and postoperative mortality rate was significantly higher (3/10, 30%) than in the remaining patients (2/274, 0.7%). Conduit selection or grafting strategy was changed due to severe left subclavian artery stenosis or leg vein varicosity in 18 patients (6.3%). For the following problems, surgical interventions were performed in 34 patients (12.0%) concomitantly or during the same admission with CABG; > or = 90% stenosis in carotid (5.6%), iliofemoral (11.6%) or renal (4.6%) arteries, aortic aneurysm (14.4%, six of them met surgical indication) and incidental malignant neoplasm (2.8%). Counting all of the above, preoperative CT angiography affected risk assessment, CABG procedure itself, perioperative management or follow-up plan in 142 patients (50%).

CONCLUSIONS

Because preoperative CT angiography considerably affected management in one half of patients, we recommend its use as a routine test before CABG, unless contraindicated.

An Argument for Routine Ultrasound Screening of the Thoracic Aorta in the Cardiac Surgery Population

Stroke and neurological injury are among the most devastating and disabling complications associated with cardiac surgery. Transesophageal echocardiography and epiaortic ultrasound allow for sensitive, point-of-care diagnosis of thoracic aortic disease, which is especially common in patients with heart disease. Unlike other operative procedures, the manipulation of the ascending aorta is routine in cardiac surgery and often unavoidable. Dislodgement and embolization from the ascending and aortic arch atheromas have been clearly associated with manipulation during cardiac surgery. Epiaortic ultrasound and transesophageal echocardiography screening are more accurate and more accessible to the operative team than any other available modality to diagnose atherosclerosis of the aorta. The goal of this review is to review the rationale and scientific evidence that suggests that the routine use of ultrasound guidance in cardiac surgery may improve postoperative outcomes in this patient population.

Initial clinical experience with the Heartstring

OBJECTIVE

The Heartstring is one of the devices that enable proximal anastomosis without clamping the aorta. We have applied the device not only to low-risk patients with normal aortas but also to high-risk patients with diseased aortas. The purpose of this study was to investigate the initial outcomes of using this device.

METHODS

The Heartstring was used on 87 patients between January and December 2004. The patients comprised 62 men and 25 women 48-86 years old (mean 68.4 +/- 8.4 years). The ascending aorta was evaluated by computed tomography (CT) scanning before surgery. If a patient's aorta was severely calcified, epiaortic echocardiography was performed. The aortas were ranked into four grades, and the preoperative patient's status were evaluated by the EuroSCORE. Angiography was performed on the third postoperative day.

RESULTS

CT scanning revealed that 74 patients had no calcification in the ascending aorta, 10 patients had scattered calcification, and 3 patients had plate-like calcification. The EuroSCORE was 6.86 +/- 1.03. We performed 93 proximal anastomoses and 149 distal anastomoses. The average distal anastomosis was 1.6 +/- 0.6 sites per graft. Of the distal anastomoses, 74.2% were to the circumflex artery territory. Postoperative coronary angiography revealed that all grafts were patent.

CONCLUSION

The Heartstring facilitates safe proximal anastomosis, even in high-risk patients. Their short-term outcome was good. The device assists in bypassing circumflex artery territory. Long-term follow-up is necessary.

On-pump beating-heart mitral valve plasty without aortic cross-clamping

Patients with ischemic cardiomyopathy often have mitral regurgitation, which should be corrected for better long-term survival. Mitral valve surgery is usually performed during cardiopulmonary bypass under the arrested heart condition. The ascending aorta is cross-clamped and the heart is arrested using a cardioplegic solution. However, because ischemic cardiomyopathy patients often have a severely atherosclerotic ascending aorta and low cardiac function, aortic cross-clamping and cardiac arrest increase the risk of postoperative thromboemboli and low cardiac output syndrome. Under the on-pump beating-heart condition, we performed mitral valve plasty concomitant with coronary artery bypass grafting, tricuspid annuloplasty, left ventricular aneurysmectomy, and the maze procedure without aortic cross-clamping for a patient with ischemic dilated cardiomyopathy and bradycardial atrial fibrillation. The patient had no postoperative complications and re covered rapidly. Thus, to prevent serious postoperative complications, on-pump beating-heart mitral valve surgery without aortic cross-clamping may be a suitable surgical option for patients with ischemic cardiomyopathy.

Evaluation of Ascending Aortic Atherosclerosis with 16-Multidetector Computed Tomography Is Useful before Total Endoscopic Coronary Bypass Surgery

BACKGROUND

The purpose of this study was to investigate the assessment of ascending aortic atherosclerosis with 16-multidetector computed tomography (16-MDCT) angiography prior to total endoscopic coronary artery bypass (TECAB) surgery.

METHODS

Forty-five patients were examined with electrocardiogram-gated, 16-MDCT angiography. The presence of atherosclerosis at the ascending aorta was graduated as severe (>50% of circumference) or as mild (<50% of circumference). Ascending aortic plaque composition was evaluated based on CT densities expressed as Hounsfield units (HU). TECABs using the Da Vinci telemanipulator were performed either on the arrested heart (n = 39) with an intra-aortic cardiopulmonary bypass (CPB) perfusion device or on the beating heart (n = 6) in patients with severe atherosclerosis.

RESULTS

The presence of mild atherosclerosis at the ascending aorta (11/39) was associated with intra-aortic CPB perfusion device-related difficulties such as intra-aortic balloon migration (BM) or balloon rupture (P = .007) in arrested heart TECABs. The CT density of atherosclerotic plaque in patients with BM was mean 58 HU +/- 51 standard deviation (SD), suggesting noncalcifying plaque. In patients without BM, CT density of plaque was mean 526 HU +/- 306 SD corresponding to calcifying plaque (P < .001). Balloon rupture occurred in 2 patients who had calcifying plaque at the ascending aorta.

CONCLUSION

Evaluation of ascending aortic atherosclerosis with 16-MDCT angiography is useful prior to TECAB surgery. Even mild atherosclerosis of the ascending aorta is associated with intraoperative difficulties regarding the remote-access perfusion system that is used for arrested heart TECAB surgery.

Risk factors for late stroke after coronary artery bypass grafting

BACKGROUND

Postoperative stroke is a severe complication immediately after coronary artery bypass grafting, and it significantly deteriorates the postoperative quality of life if it occurs in the long term. It was the aim of our study to determine factors associated with the occurrence of new strokes during long-term follow-up after coronary artery bypass grafting.

METHODS

From 387 of 500 patients undergoing coronary artery bypass grafting (age, 67 years [33-84 years]; 76% male) who had intraoperative epiaortic ultrasonography for assessment of ascending aortic wall thickness, a complete follow-up regarding postoperative stroke was achieved. The median follow-up time was 52 months (9-74 months).

RESULTS

A stroke occurred in 26 (7%) of 387 patients, and the cumulative freedom from stroke was 99%, 95%, and 89% after 1, 3, and 5 years, respectively. A significantly lower freedom from stroke was present in patients with an age of 70 years or more (P = .007), preoperative unstable angina (P = .031), chronic obstructive pulmonary disease (P = .009), carotid artery disease (P < .001), preoperative history of neurologic events (P < .001), and a maximum ascending aortic wall thickness of 4 mm or more (P = .010). Multivariate analysis revealed preoperative history of neurologic events (P = .021) to be an independent risk factor.

CONCLUSION

Patients with ascending aortic atherosclerosis, older age (> or =70 years), preoperative unstable angina, chronic obstructive pulmonary disease, and carotid artery disease are at risk for late postoperative stroke after coronary artery bypass grafting. A history of neurologic events is of special predictive importance.