Charles Ilsley

Temporary scaffolding of coronary arteries with bioabsorbable magnesium stents: a prospective, non-randomised multicentre trial

BACKGROUNDnCoronary stents improve immediate and late results of balloon angioplasty by tacking up dissections and preventing wall recoil. These goals are achieved within weeks after angioplasty, but with current technology stents permanently remain in the artery, with many limitations including the need for long-term antiplatelet treatment to avoid thrombosis. We report a prospective multicentre clinical trial of coronary implantations of absorbable magnesium stents.nnnMETHODSnWe enrolled 63 patients (44 men; mean age 61.3 [SD 9.5 years]) in eight centres with single de novo lesions in a native coronary artery in a multicentre, non-randomised prospective study. Follow-up included coronary angiography and intravascular ultrasound at 4 months and clinical assessment at 6 months and 12 months. The primary endpoint was cardiac death, non-fatal myocardial infarction, or clinically driven target lesion revascularisation at 4 monthsnnnFINDINGSn71 stents, 10-15 mm in length and 3.0-3.5 mm in diameter, were successfully implanted after pre-dilatation in 63 patients. Diameter stenosis was reduced from 61.5 (SD 13.1%) to 12.6 (5.6%) with an acute gain of 1.41 mm (0.46 mm) and in-stent late loss of 1.08 mm (0.49 mm). The ischaemia-driven target lesion revascularisation rate was 23.8% after 4 months, and the overall target lesion revascularisation rate was 45% after 1 year. No myocardial infarction, subacute or late thrombosis, or death occurred. Angiography at 4 months showed an increased diameter stenosis of 48.4 (17.0%). After serial intravascular ultrasound examinations, only small remnants of the original struts were visible, well embedded into the intima. Neointimal growth and negative remodelling were the main operating mechanisms of restenosis.nnnINTERPRETATIONnThis study shows that biodegradable magnesium stents can achieve an immediate angiographic result similar to the result of other metal stents and can be safely degraded after 4 months. Modifications of stent characteristics with prolonged degradation and drug elution are currently in development.

Does off-pump coronary artery bypass (OPCAB) surgery improve the outcome in high-risk patients?: a comparative study of 1398 high-risk patients

OBJECTIVEnAlthough there has been some evidence supporting the theoretical and practical advantages of off-pump coronary artery bypass (OPCAB) over the conventional coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB), it has not yet been determined which group of patients would benefit most from it. It has been advocated recently that high-risk patients could benefit most from avoidance of CPB. The aim of this retrospective study is to assess the efficacy of the OPCAB technique in multi-vessel myocardial revascularization in a large series of high-risk patients.nnnMETHODSnThe records of 1398 consecutive high-risk patients who underwent primary isolated CABG at Harefield Hospital between August 1996 and December 2001 were reviewed retrospectively. Patients were considered as high-risk and included in the study if they had a preoperative EuroSCORE of > or =5. Two hundred and eighty-six patients were operated on using the OPCAB technique while 1112 patients were operated on using the conventional CABG technique with CPB. The OPCAB patients were significantly older than the CPB patients (68.1+/-8.3 vs. 63.7+/-9.9 years, respectively, P<0.001). The OPCAB group included significantly more patients with poor left ventricular (LV) function (ejection fraction (EF) < or =30%) (P<0.001) and more patients with renal problems (P<0.001).nnnRESULTSnThere was no significant difference in the number of grafts between the groups. The CPB patients received 2.8+/-1.2 grafts per patient while OPCAB patients received 2.8+/-0.5 grafts per patient (P=1). Twenty-one (7.3%) OPCAB patients had one or more major complications, while 158 (14.2%) CPB patients (P=0.008) developed major complications. Thirty-eight (3.4%) CPB patients developed peri-operative myocardial infarction (MI) while only two (0.7%) OPCAB patients developed peri-operative MI (P=0.024). The intensive therapy unit (ITU) stay for OPCAB patients was 29.3+/-15.4 h while for CPB patients it was 63.6+/-167.1 h (P<0.001). There were ten (3.5%) deaths in the OPCAB patients compared to 78 (7%) deaths in the CPB patients (P=0.041) within 30 days postoperatively.nnnCONCLUSIONSnThis retrospective study shows that using the OPCAB technique for multi-vessel myocardial revascularization in high-risk patients significantly reduces the incidence of peri-operative MI and other major complications, ITU stay and mortality. Even though the OPCAB group included a significantly higher proportion of older patients with poor LV function (EF < or =30%) and renal problems, the beneficial effect of OPCAB was evident.

Use of radial artery graft reduces the morbidity of coronary artery bypass graft surgery in patients aged 65 years and older

BACKGROUNDnThe use of the radial artery graft in patients aged 65 years and older could prevent the occurrence of leg wound infection, which is known to increase the morbidity of coronary artery bypass grafting surgery.nnnMETHODSnWe reviewed, retrospectively, 261 patients aged 65 years and older (age range 65 to 93 years), who underwent coronary artery bypass grafting surgery between February 1998 and August 2001. All the patients received at least one radial artery graft in addition to either a left internal thoracic artery, right internal thoracic artery, or saphenous vein graft as required. Saphenous vein grafts were used in 141 (54.1%) patients (group 1), and these were compared to 120 (45.9%) patients (group 2) who received only arterial conduits. Angiography was performed on 26 consecutive patients. The aim of the study was to review the clinical and angiographic outcomes in this population.nnnRESULTSnThe mean number of distal anastomoses performed was 2.98. Mean global operating time was 204 minutes. This time dropped to 201 minutes in group 1 versus 231 minutes in group 2; p = 0.009. Sixteen (11.3%) patients receiving saphenous vein grafts had leg wound infection whereas only 1 (0.3%) patient of the global population had a forearm infection. The mean global hospital stay was 9.81 days; this duration increased to 13 days when leg wound infection occurred versus 9.1 days when infection did not occur; p = 0.008. Twenty-six (10%) patients underwent an early angiographic study. Twenty-four (92.3%) radial artery grafts were patent.nnnCONCLUSIONSnThe routine use of radial artery grafts in patients aged 65 years and older is feasible, safe, and does not increase mortality, morbidity, or the complexity of coronary artery bypass grafting surgery.

Economic Evaluation of Coronary Artery Bypass Grafting Surgery With and Without Cardiopulmonary Bypass: Cost-Effectiveness and Quality-Adjusted Life Years in a Randomized Controlled Trial

The objective of this study is to evaluate the costs and health benefits of coronary artery bypass grafting (CABG) surgery with and without cardiopulmonary bypass (CPB). Randomized controlled clinical trial is used as the design. The setting is in a single tertiary cardiothoracic center in Middlesex, UK. Participants were 168 patients (27 females) requiring primary isolated CABG surgery. Patients were randomized to have the procedure performed by a single surgeon either with CPB (n = 84) or by an off-pump coronary artery bypass (OPCAB) surgery (n = 84). Health-related quality of life was assessed at baseline, 6 weeks, and 6 months using the World Health Organization Quality-of-Life (WHOQOL-100) questionnaire. Mean total costs of patient management by either technique were calculated using different available key sources. A utility measure, derived from WHOQOL-100, was used to calculate quality-adjusted life year (QALY) gained in each group, on basis of which a cost-effectiveness analysis was performed. The mean total costs of an OPCAB patient was 5859 pounds , whereas for a CPB patient it was 7431 pounds with a mean difference of 1572 pounds (standard error [SE] 674 pounds ; P = 0.02). Three patients died in the CPB group and two in the OPCAB group during the 6-month follow-up period. Mean QALYs over 6 months was 0.379 in the OPCAB group and 0.362 in the CPB group, but the difference was not significant (mean difference 0.017; SE 0.016; P = 0.305). OPCAB surgery offered patients in this randomized trial similar health benefits to CPB over a 6-month period, but at a significantly less cost.

In vivo early and mid-termflow-mediated endothelial functionof the radial artery used as a coronary bypass graft

OBJECTIVESnWe sought to evaluate the in vivo endothelial function of the radial artery (RA) used as a coronary graft.nnnBACKGROUNDnThe RA is becoming a recognized alternative coronary bypass conduit. In vivo endothelial function is a possible predictor of long-term performance.nnnMETHODSnSixty consecutive patients underwent coronary artery bypass graft surgery (CABG); all received RA and left internal mammary artery (LIMA) grafts. Three weeks after CABG, 36 patients underwent angiography under basal conditions, during pacing and after intragraft injection of glyceryl trinitrate (GTN). Angiography was repeated at six months in 20 patients.nnnRESULTSnThe estimated mean difference of 66 segments of the radial graft on the first QCA study was 0.170 mm (95% confidence interval [CI] 0.101 to 0.258, p < 0.001) between baseline and pacing, and 0.310 mm (CI 0.225 to 0.401, p < 0.001) between baseline and GTN. At six months, the differences between baseline and pacing and baseline and GTN were 0.112 mm (CI 0.062 to 0.162, p < 0.001) and 0.274 (CI 0.192 to 0.353, p < 0.001), respectively. The difference between baseline values at three weeks and six months was 0.416 mm (CI 0.236 to 0.603, p < 0.001). In the LIMA segments, the difference between baseline and pacing and baseline and GTN were 0.206 mm (CI 0.136 to 0.278, p < 0.001) and 0.304 mm (CI 0.213 to 0.396, p < 0.001), respectively. At six months, the differences between baseline and pacing and baseline and GTN were 0.098 mm (CI 0.014 to 0.173, p < 0.001) and 0.218 mm (CI 0.130 to 0.298, p < 0.001). The difference between baseline values at three weeks and six months was 0.061 mm (CI 0.064 to 0.176, p > 0.05).nnnCONCLUSIONSnIn vivo flow-mediated dilation of the RA is comparable to that of pedicled LIMA. The increased dilation both at baseline and after pacing at six months represents a time-related improvement in the vasomotor function of the RA, which could have implications for its performance as a coronary conduit.

Can the Use of the Radial Artery Be Expanded to All Patients with Different Surgical Grafting Techniques? Early Clinical and Angiographic Results in 600 Patients

Abstractu2003 Objective: The use of the radial artery (RA) as a conduit for coronary artery bypass grafting (CABG) is gaining in popularity worldwide and is being increasingly adopted by many cardiac surgeons. Encouraged by our satisfactory early experience with the use of the RA conduit, we have expanded its use to more than 90% of all coronary surgery patients. The aim of the present study was to review our clinical and angiographic results when the use of the RA conduit was expanded to all patients including those aged 65 years and older and diabetics with different surgical grafting techniques. Methods: The records of 600 consecutive patients who underwent isolated CABG using the RA graft at Harefield Hospital between January 1999 and August 2002 were reviewed retrospectively. Ninety‐three (15.5%) patients consented and underwent angiography before discharge at the earliest on the fourth postoperative day, aiming to look at the quality of anastomoses and the patency of the RA grafts. Results: The 600 patients had 613 RA grafts to perform 652 distal RA anastomoses. The proximal ends of 515 (84%) RA grafts were anastomosed to the aorta, 98 (16%) RA grafts were constructed as Y‐grafts with 49 (8%) RA off a vein graft hood, and 49 (8%) RA grafts were constructed as T‐ or Y‐grafts off an internal thoracic artery (ITA) graft. The proximal ends of 19 (19/294 or 6.5%) vein grafts were constructed as Y‐grafts off the RA grafts. Two hundred and sixty‐one (43.5%) patients were above the age of 65 years and 111 (18.5%) patients were diabetics. There were four in‐hospital deaths (0.6%) among the study patients. Six (1%) patients developed forearm hematoma/seroma postoperatively. The operation time, the hospital stay, and the incidence of conduit harvest site infection for the patients who had vein grafts in addition to the RA grafts were significantly higher than those of patients who had RA grafts only. On postoperative angiography, 86 out of 93 (92.5%) RA grafts were found to be patent with good quality distal anastomoses. The maximum stenosis of the coronary arteries bypassed by the patent 86 RA grafts was 82.6 ± 6.2%, while it was 56.3 ± 15.4% for the coronary arteries bypassed by the occluded seven RA grafts, p < 0.001. Conclusion: The use of the RA can be expanded to all patients with different surgical grafting techniques and provides satisfactory clinical and angiographic outcomes.

Multivessel Off-Pump Coronary Artery Bypass Grafting Can Be Taught to Trainee Surgeons

Abstractu2003 Background: Although, Off‐Pump Coronary Artery Bypass (OPCAB) surgery is being increasingly explored and practised in many cardiac units worldwide, there have been only few reports documenting the training of surgeons in this new technique. The purpose of this study was to address the reproducibility of the OPCAB in a unit where this technique is used extensively. Methods: Registry data, notes, and charts of 64 patients who were operated on by four trainee cardiac surgeons over a period of thirteen months at Harefield Hospital, were reviewed retrospectively. These trainees were part of an accredited training program for cardiothoracic training and were trained by a single consultant trainer in a cardiac unit after it had an established recent experience in performing nonselective OPCAB for all in‐coming patients. Five (7.8%) patients (with 17 distal anastomoses) consented and underwent early postoperative angiography to check the quality of the grafts and anastomoses. Results: The mean age of the study patients was 65.6 and the mean Parsonnet score was 9.4. There was a mean of 2.9 grafts per patient and circumflex territory anastomoses were performed in 48 (75%) patients. No operation required conversion to Cardiopulmonary Bypass (CPB). Angiography of the five patients revealed 17 satisfactory (100%) distal anastomoses. Conclusion: With appropriate training, it is possible for trainees to learn OPCAB and perform multivessel revascularization in relatively high‐risk patients with good results.

Early Clinical and Angiographic Outcome of the Pedicled Right Internal Thoracic Artery Graft to the Left Anterior Descending Artery

BACKGROUNDnThe left internal thoracic artery (LITA) graft to the left anterior descending (LAD) artery became the gold standard graft in coronary surgery. Subsequently, the right internal thoracic artery (RITA) graft was increasingly used. However, there is still some debate about the optimal way of using this conduit. The aim of the present study was to assess our experience in grafting the pedicled RITA graft to LAD in 212 consecutive patients.nnnMETHODSnThe records of 212 consecutive patients who underwent isolated coronary artery bypass grafting with the pedicled RITA graft to the LAD artery at Harefield Hospital between January 1998 and May 2001 were retrospectively reviewed. We approached the last 35 consecutive patients to obtain an angiographic control group. All 35 patients (16.5%) consented and, before discharge, underwent angiography to look at the quality of anastomoses and the patency of grafts.nnnRESULTSnSuccessful catheterization and engagement of the RITA grafts was performed in 32 patients. Angiography showed that 32/32 (100%) of the RITA grafts were widely patent with excellent flow. The distal anastomoses of these RITA grafts were also satisfactory. There were no deaths among the study patients.nnnCONCLUSIONSnOur results show that the use of the pedicled RITA graft to the LAD artery provides a good early clinical and angiographic outcome, and suggests that the pedicled RITA graft to the LAD artery is a good alternative to the pedicled LITA graft to the LAD artery.

Differential response of coronary collateral channels to atrial pacing and balloon occlusion at angioplasty.

BackgroundCollateral channels can protect from infarction, even in the presence of a total or sub-total occlusion. Acute re-occlusion following restoration of flow may still lead to ischaemia or infarction. It is unclear whether collaterals respond differently to tachycardia-induced stress and balloon inflation. This study compared the response of collateral-dependent viable myocardium to repetitive atrial pacing with the response to multiple balloon occlusions during percutaneous transluminal coronary angioplasty (PTCA). Methods and resultsFifteen patients undergoing elective single vessel PTCA with well-developed collateral channels supplying the target vessel were recruited. Patients underwent two periods of incremental atrial pacing (P1; P2) followed by two 90-s balloon inflations (I1; I2). Collateral flow velocity was assessed by Doppler flow wire across the target lesion. Evidence of ischaemia was obtained from monitoring of surface ST-segments and by chest pain scores recorded on a visual analogue scale. Retrograde and ‘aggregate’ flow velocities were significantly lower during I1 and I2 than either P1 or P2. Reduction in flow velocity was most marked during I2 compared with P1 or P2. Chest pain score was lower during P2 than P1 (3.8u2009±u20093.5 versus 5.5u2009±u20093.0, Pu2009<u20090.02), although flow velocity was unchanged. ConclusionCollateral flow velocity is significantly higher during tachycardia-induced stress than balloon occlusion. Restoration of antegrade flow by balloon inflation results in a further reduction in flow during a second inflation, suggesting a functional down-regulation of the collateral channels. Ischaemic symptoms are attenuated with repetitive pacing independent of collateral flow, suggesting an additional preconditioning response.

A Technical Failure Changes a Y-graft into a C-conduit Causing Steal Syndrome

Y-grafting is a common coronary grafting technique for performing composite coronary grafts. The outcome and efficacy of this technique have not been studied in detail in the literature. We report a case of an occlusion in the proximal limb of a Y-graft, changing it into a C-shaped conduit and causing a steal syndrome. Our aim is to raise the level of caution when performing this type of composite graft and to suggest how this complication can be managed postoperatively.