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Summary: Minimally invasive conduit harvesting techniques for coronary artery bypass grafting have developed over the past decade, aiming to reduce the morbidity and recovery time associated with the procedure, whilst preserving the quality of the conduit. Two types of commonly harvested free conduits include the great saphenous vein and the radial artery. Although much research has focussed on comparing less invasive and conventional harvest techniques, there is at present no consensus on the areas where one technique is superior to the other. Aspects of conduits that deserve appreciation when comparing minimally invasive and open harvesting techniques include wound healing at the harvest site, the macroscopic, histological and functional quality of the conduit, but perhaps most importantly its long-term angiographic patency. This paper aims to review the literature comparing minimally invasive and conventional conduit harvesting techniques for coronary artery bypass grafting, with regard to the previously mentioned factors. A literature search of Medline, Ovid, Embase and Cochrane databases was used to identify comparative studies published between 1997 and 2005. Outcomes of interest included: wound infection, non-infective healing disturbances, post-operative pain, neurological disturbance, mobility, patient satisfaction, conduit quality (macroscopic, histological and functional) and long-term conduit patency. A scoring system was applied and used to grade the quality of the evidence, based on which a recommendation of it being ‘good’ (Grade A), ‘fair’ (Grade B), or ‘insufficient’ (Grade C) was made. Results showed that there was ‘good’ evidence to suggest that wound infection and non-infective complications are reduced with minimally invasive harvest as compared to conventional vein harvest. The evidence suggesting that post-operative pain and mobilisation is reduced after minimally invasive vein harvest and that once harvested, the conduits are macroscopically comparable to conventional ones, is only ‘fair’. Finally, although initial reports are encouraging, there is at present insufficient evidence to comment on whether minimally invasive radial artery harvesting is better than that of conventional open surgery. Wounds from minimally invasively harvested venous conduits appear to be less prone to complications although more comparative evidence on conduit quality and long-term patency is eagerly awaited. [Copyright &y& Elsevier]

Systolic anterior motion (SAM) of the mitral valve (MV) can be a life-threatening condition. The SAM can result in severe left ventricular outflow tract obstruction and/or mitral regurgitation and is associated with an up to 20% risk of sudden death (which is substantially lower in hypertrophic cardiomyopathy (HCM)). The mechanisms of SAM are complex and depend on the functional status of the ventricle. The SAM can occur in the normal population, but is typically observed in patients with HCM or following MV repair. Echocardiography (2D, 3D and stress) has a central diagnostic role as the application of echocardiographic SAM predictors allows the incorporation of prevention techniques during surgery and post-operative SAM assessment. Cardiac magnetic resonance imaging has a special role in understanding the dynamic nature of SAM, especially in anatomically atypical hearts (including HCM). This article describes what the clinician needs to know about SAM ranging from pathophysiological mechanisms and imaging modalities to conservative (medical) and surgical approaches and their respective outcomes. A stepwise approach is advocated consisting of medical therapy, followed by aggressive volume loading and beta-adrenoceptor blockade. Surgery is the final option. The correct choice of surgical technique requires an understanding of the anatomical substrate of SAM. [ABSTRACT FROM AUTHOR]

Coronary artery bypass surgery can offer excellent results when performed with cardiopulmonary bypass (on pump) or without cardiopulmonary bypass (off pump). The debate as to which technique is superior remains unanswered. Intra-operative conversion from off- to on-pump coronary surgery is a relatively unexplored phenomenon, which cannot be assessed within randomised controlled trial design. We aimed to assess the effect of off-pump conversion on patient mortality. Medline, Embase, Cochrane and Google Scholar databases were systematically reviewed for studies published between 1980 and 2010 that compared the incidence of mortality between converted and non-converted off-pump patients. Publication bias and heterogeneity were assessed and data were extracted independently by multiple observers. We undertook a meta-analysis of these studies using random effects modelling. A total of 17 studies fulfilled our inclusion criteria, containing data for 18,870 off-pump coronary artery bypass operations spanning a decade (1998–2008), involving 920 cases of conversion. Overall, conversion increased mortality by an odds ratio of 6.18 (95% confidence interval 4.65–8.20), whereas emergency conversion further raised the odds ratio of mortality to 6.99 (95% confidence interval 5.18–9.45). The conversion from off- to on-pump cardiac surgery may significantly increase the chance of an adverse outcome, whereas emergency conversion confers a significant rise in mortality. The risk of conversion should be discussed when obtaining the patient’s informed consent and its prevention warrants serious consideration by cardiac surgeons and cardiac surgical training programmes. [ABSTRACT FROM AUTHOR]

Summary: Heparinization of the blood contact surface in cardiopulmonary bypass circuits has been promoted as an important step in the development of open heart surgery. As it decreases the inflammatory response resulting from the extracorporeal circulation, it may have a positive effect on clinical outcomes. This meta-analysis was carried out to examine if heparin-bonded circuits (HBCs) reduce the need for blood products and improve overall clinical outcome. A systematic literature search was performed to identify randomized controlled trials reporting outcomes of HBCs compared with non-HBCs. Primary outcomes assessed were postoperative blood/blood-product transfusion and blood loss. Secondary outcomes included all-cause mortality, acute postoperative myocardial infarction, stroke, re-sternotomy for postoperative bleeding, wound infection, atrial fibrillation, duration of ventilation, intensive care unit (ICU) and hospital-length of stay (LOS). Random effects meta-analytical techniques were applied to identify differences in outcomes between the two groups. Quality of the included studies and heterogeneity were assessed. From an initial review of 762-published studies, 41-randomized trials fulfilled the inclusion criteria, leaving 3434-patients’ data for analysis. HBCs significantly decreased the incidence of blood transfusion required (OR=0.8; 95% CI=0.6:0.9, P =0.004). It also significantly decreased re-sternotomy (OR=0.6; 95% CI=0.4:0.8, P =0.002), duration of ventilation (WMD=−1.3h; 95% CI=−1.9:−0.6, P <0.001), ICU-LOS (WMD=−9.3h; 95% CI=−14.7:−3.9, P < 0.001) and hospital-LOS (WMD=−0.5 day; 95% CI=−0.9:−0.1, P = 0.02). HBCs had no effect on other adverse events evaluated. Although HBCs showed a positive effect on some of the clinical outcomes, we identified only marginal differences for other outcomes. Further evaluation of the cost-effectiveness of this technology is required. [Copyright &y& Elsevier]

Summary: Multi-slice computed tomography technology is emerging as a realistic investigation in patients with suspected disease in native, stented or grafted coronary arteries. A non-invasive diagnostic tool is desirable as these patients are at high risk for complications of invasive angiography. A 64-slice CT may achieve the desired diagnostic accuracy, and overcome the limitations of spatial resolution, respiratory motion, artifacts from calcification and stents, and radiation dose considerations to produce reliable image quality. These advances, as well as the capacity for integrated functional cardiac assessment, may change the referral patterns in patients who have had previous bypass surgery or percutaneous intervention. This review outlines the debated issues about 64-slice cardiac CT in patients before and after coronary artery bypass surgery, as well as coronary stenting and functional assessment. A review of the recent literature on native coronary artery and bypass graft assessment by multi-slice CT is also performed. [Copyright &y& Elsevier]

Summary: The amount of literature published over the past decade comparing coronary angiography with transthoracic Doppler echocardiography assessment of internal thoracic artery graft patency after CABG is substantial. There has been no review of the available literature, and conflicting reports of diagnostic accuracy have prevented routine use of transthoracic Doppler in graft patency assessment. Thus, this article reviews the available literature on diagnostic accuracy of transthoracic Doppler echocardiography of coronary bypass grafts. Relevant studies were identified and meta-analysis of diagnostic accuracy was performed. Study quality was assessed. Quantitative data synthesis included calculation of sensitivity, specificity, summary receiver operating characteristic curve analysis, pooled analysis and meta-regression of accuracy against study quality, publication date, angina, probe frequency and diagnostic criteria. Twenty studies of 929 patients produced 26 results included for analysis. Grafts were not visualized in 93 (10%) patients. Pooled sensitivity (85%) and specificity (94%) and diagnostic odds ratio (100.7) were high. SROC analysis showed an area under the curve of 0.96. Heterogeneity of results was due to variations in diagnostic criteria and study size. Subgroup analysis showed best performance in patients with postoperative angina (p =0.014). Study quality did not affect results. Diastolic fraction less than 0.5 (sensitivity 89%, specificity 94%) was shown to be the best criterion for prediction of stenosis. Performance was lower using peak diastolic to systolic velocity ratio less than 1 (sensitivity 85%, specificity 86%). Transthoracic Doppler echography is effective in first-line assessment of left internal thoracic artery graft patency. It shows high specificity, prevents invasive investigations and improves in patients with postoperative angina. TDE is best used in combination with other non-invasive tests due to its inability to visualize the graft. The potential for use in postoperative coronary bypass patients is high. [Copyright &y& Elsevier]