Does a 'direct' transfer protocol reduce time to coronary angiography for patients with non-ST-elevation acute coronary syndromes? A prospective observational study.

OBJECTIVE: National guidelines recommend 'early' coronary angiography within 96 h of presentation for patients with non-ST elevation acute coronary syndromes (NSTE-ACS). Most patients with NSTE-ACS present to their district general hospital (DGH), and await transfer to the regional cardiac centre for angiography. This care model has inherent time delays, and delivery of timely angiography is problematic. The objective of this study was to assess a novel clinical care pathway for the management of NSTE-ACS, known locally as the Heart Attack Centre-Extension or HAC-X, designed to rapidly identify patients with NSTE-ACS while in DGH emergency departments (ED) and facilitate transfer to the regional interventional centre for 'early' coronary angiography. METHODS: This was an observational study of 702 patients divided into two groups; 391 patients treated before the instigation of the HAC-X pathway (Pre-HAC-X), and 311 patients treated via the novel pathway (Post-HAC-X). Our primary study end point was time from ED admission to coronary angiography. We also assessed the length of hospital stay. RESULTS: Median time from ED admission to coronary angiography was 7.2 (IQR 5.1-10.2) days pre-HAC-X compared to 1.0 (IQR 0.7-2.0) day post-HAC-X (p<0.001). Median length of hospital stay was 3.0 (IQR 2.0-6.0) days post-HAC-X v 9.0 (IQR 6.0-14.0) days pre-HAC-X (p<0.0005). This equates to a reduction of six hospital bed days per NSTE-ACS admission. CONCLUSIONS: The introduction of this novel care pathway was associated with significant reductions in time to angiography and in total hospital bed occupancy for patients with NSTE-ACS.

Case fatality rates for South Asian and Caucasian patients show no difference 2.5 years after percutaneous coronary intervention.

OBJECTIVE: To compare short and medium-term prognosis in South Asian and Caucasian patients undergoing percutaneous coronary intervention (PCI) to determine if there are ethnic differences in case death rates. DESIGN: Retrospective cohort study. SETTING: A cardiology referral centre in east London. PATIENTS: 9771 patients who underwent PCI from October 2003 to December 2007 of whom 7966 (81.5%) were Caucasian and 1805 (18.5%) were South Asian. MAIN OUTCOME MEASURES: In-hospital major adverse cardiac events (MACE; death, myocardial infarction, stroke and target vessel revascularisation), subsequent revascularisation rates (PCI and coronary artery bypass grafting; CABG) and all-cause mortality during a median follow-up of 2.5 years (range 1.5-3.6 years). RESULTS: South Asian patients were younger than Caucasian patients (59.69±0.27 vs 64.69±0.13 years, p<0.0001), and more burdened by cardiovascular risk factors, particularly type II diabetes mellitus (45.9%±1.2% vs 15.7%±0.4%, p<0.0001). The in-hospital rates of MACE were similar for South Asians and Caucasians (3.5% vs 2.8%, p=0.40). South Asians had higher rates of clinically driven PCI for restenosis and subsequent CABG, although Kaplan-Meier estimates of all-cause mortality showed no significant differences; this was regardless of whether PCI was performed post-acute coronary syndrome or as an elective procedure. The adjusted hazard of death for South Asians compared with Caucasians was 1.00 (95% CI 0.81 to 1.23). CONCLUSION: In this large PCI cohort, the in-hospital and longer-term mortality of South Asians appeared no worse than that of Caucasians. South Asians had higher rates of restenosis and CABG during follow-up. Data suggest that the excess coronary mortality for South Asians compared with Caucasians is not explained by differences in case-fatality rates.

Recommendations on percutaneous coronary intervention for the reperfusion of acute ST elevation myocardial infarction.

Little information is currently available from the various societies of cardiology on primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI). Since primary PCI is the main method of reperfusion in AMI in many centres, and since of all cardiac emergencies AMI represents the most urgent situation for PCI, recommendations based on scientific evidence and expert experience would be useful for centres practising primary PCI, or those looking to establish a primary PCI programme. To this aim, a task force for primary PCI in AMI was formed to develop a set of recommendations to complement and assist clinical judgment. This paper represents the product of their recommendations.

Coronary artery brachytherapy.

Coronary artery disease is the leading cause of mortality in the West with over 1.2 million angioplasties performed annually. Despite the introduction of stents, restenosis occurs in 30-40% of vessels, which until recently has only been treated effectively by coronary artery bypass surgery. Coronary artery brachytherapy appears to provide an alternative, less invasive remedy. The mechanisms of restenosis and how these are inhibited by radiation are described here. The practicalities of radiation delivery and the history of the development of intravascular radiation as an effective clinical tool are outlined. Finally, the pitfalls of the current technology and the areas in which future research must be targeted for the field to develop are discussed.

Suitability of the Cordis Stabilizer marker guide wire for quantitative coronary angiography calibration: an in vitro and in vivo study.

Catheters usually are used for calibration purposes in quantitative coronary angiography (QCA). The systematic and random errors in these calibration factors (CFs) are dependent on the size and quality of the catheters and limited by out-of-plane magnification (OPM). Theoretically, a guide wire with evenly spaced marker bands would solve many of these potential problems. For this reason, we tested the Cordis Stabilizer marker wire, featuring 10 radiopaque platinum marker bands 15 mm apart, in in vitro and in vivo studies. To assess the effect of foreshortening, wires were positioned in a tube phantom; a centimeter grid was used as the gold standard. Radiographic images were acquired at 5-inch and 7-inch image-intensifier sizes, 512(2) and 1,024(2) matrix sizes and angulations from 0 degrees to 70 degrees in steps of 10 degrees. It was concluded that the relative errors in CFs are less than 7% if the foreshortening angles remain less than 20 degrees. In DICOM images of 15 patients, 65 measurements were taken after calibration on an 8F catheter and on a guide wire positioned in the coronary lesion. In all but two cases, the wire CFs were larger than the catheter CFs (relative difference, 24.7 +/- 19.6%). The measurements were divided into four groups: (I) no apparent OPM or foreshortening (n = 7), (II) only OPM (n = 4), (III) only foreshortening (n = 10), and (IV) the combination of both (n = 44). In group I (no OPM or foreshortening) the QCA results were similar using the guide wire or catheter as the calibration device (relative CF difference, 2.9% only). In group III the diameters were overestimated using the guide wire (obstruction diameter difference, 0.22 +/- 0.11 mm; reference diameter difference, 0.35 +/- 0.06 mm). For only OPM (group II) and the combination of OPM and foreshortening (group IV), the lesion length was underestimated on average by 2.4 mm using the catheter instead of the guide wire. In conclusion, if accurate assessment of the lesion length is important, the marker wire should be used for calibration purposes. For vessel diameter measurements, the conventional catheter calibration approach is the method of choice.

Effect of direct thrombin inhibition with Bivalirudin (Hirulog) on restenosis after coronary angioplasty.

The direct antithrombin, bivalirudin, did not reduce angiographic restenosis measured either as the dichotomous restenosis rate of 62% for bivalirudin and 58% for heparin (p = 0.70), or as the late loss in lumen diameter of 0.44 +/- 0.47 mm for bivalirudin and 0.39 +/- 0.53 mm for heparin (p = 0.62). Direct thrombin inhibition with bivalirudin neither reduces angiographic restenosis nor alters the impact of several established risk factors for restenosis.

Differences between amlodipine and lisinopril in control of clinic and twenty-four hour ambulatory blood pressures.

The anti-hypertensive efficacy of once-daily amlodipine (up to 10 mg) and lisinopril (up to 20 mg) were compared in terms of clinic and ambulatory blood pressure (BP) control, in an observer-blind, two-period crossover study. Following a 4-week placebo run-in period, patients underwent two active treatment phases each lasting 12 weeks and separated by a 4-week washout period. Sixty patients with a supine diastolic BP between 90 and 120 mm Hg were included, irrespective of whether or not they had received previous anti-hypertensive medication. Amlodipine reduced supine systolic and diastolic clinic BP significantly more than lisinopril (-20+/-2/-14+/-1 vs -11 3/-7+/-1 mm Hg; P=0.02/ P=0.001) 24 h post-dose. Clinic standing diastolic BP was also significantly reduced with amlodipine compared with lisinopril (P=0.05). Both drugs produced control of mean ambulatory BP relative to baseline over 24 h. Amlodipine showed more consistent control of BP over the 24-h period in contrast to lisinopril which exerted its greatest effect during the daytime.

The role of signal averaged P wave duration and serum magnesium as a combined predictor of atrial fibrillation after elective coronary artery bypass surgery.

OBJECTIVE: To investigate the role of low serum magnesium as a trigger for atrial fibrillation in patients with a substrate for the arrhythmia (assessed by signal averaged P wave duration). DESIGN: A case-control study. SETTING: A regional referral cardiac centre. PATIENTS AND INTERVENTIONS: 105 consecutive patients undergoing elective coronary artery bypass surgery had signal averaged P wave recordings before operation. Serum electrolytes were analysed preoperatively and on days 1, 2, and 5 after surgery. MAIN OUTCOME MEASURES: Any episode of electrocardiographically recorded atrial fibrillation was taken as a study end point. RESULTS: Of 102 patients discharged, 27 (26%) had documented episodes of atrial fibrillation at a mean of 2.7 days after surgery. A combination of P wave duration > 155 ms and serum magnesium on the first postoperative day of < 0.7 mmol/l had a sensitivity of 75% and specificity of 80% for predicting atrial fibrillation. Duration of hospital stay (7.9 v 6.8 days) was longer in the atrial fibrillation group (P < 0.01). Stepwise regression showed age, serum magnesium < 0.7 mmol/l on the first postoperative day (both P < 0.001), angiotensin converting enzyme inhibitor withdrawal (P < 0.02), and signal averaged P wave duration (P = 0.04) to be independent predictors. CONCLUSIONS: The combination of signal averaged P wave duration and low serum magnesium on the first postoperative day identified the majority of patients with atrial fibrillation after coronary artery bypass surgery. Early identification and pharmacological treatment for selected patients may reduce the incidence of postoperative atrial fibrillation.

Planning for coronary angioplasty: guidelines for training and continuing competence. British Cardiac Society (BCS) and British Cardiovascular Intervention Society (BCIS) working group on interventional cardiology.

The following recommendations are made: 1 Existing centres undertaking angioplasty should increase their activity, and the target figure of 400 PTCA procedures per million of the United Kingdom population should be achieved by the end of 1996-97, or immediately thereafter. 2 Angioplasty centres should be appropriately equipped to undertake PTCA safely and effectively and provide a reliable emergency service. They should have a minimum of two trained PTCA operators jointly undertaking a minimum of 200 procedures per year at that centre, and have regular meetings to share experience. 3 Angioplasty operators should ensure that where the need arises patients undergoing PTCA can receive immediate attention from a trained operator at any time until discharge from hospital. 4 Trained operators should undertake at least 1-2 PTCA procedures per week (> 60 procedures per year) to maintain competence, and those undertaking so few procedures should increase their activity over the next three years to more than 100 a year. 5 Trainers should have performed at least 500 procedures before formally training others and should undertake a minimum of 125 procedures a year to maintain accreditation as a trainer. 6 Surgical cover for PTCA procedures should be mandatory and on site cover remains the strongly preferred option. Where surgical cover is provided off site, this should be at a centre less than 30 minutes away by road. Whether provided on or off-site it should be possible to establish cardiopulmonary bypass within 90 minutes of the decision being made to refer the patient for surgery. 7 All operators and interventional centres should audit their activity and results, review these data locally with colleagues, and provide regular audit returns to the national database run by BCIS. This will allow future recommendations concerning standards to take more account of risk stratification and actual outcomes, and not place such emphasis merely on volumes of activity. 8 These recommendations should be reviewed in three years.

Emergency surgical revascularisation for coronary angioplasty complications.

OBJECTIVES: To evaluate trends in referrals for emergency operations after percutaneous transluminal coronary angioplasty (PTCA) complications; to analyse morbidity and mortality and assess the influence of PTCA backup on elective surgery. DESIGN: A retrospective analysis of patients requiring emergency surgical revascularisation within 24 hours of percutaneous transluminal coronary angioplasty. PATIENTS: Between January 1980 and December 1990, 75 patients requiring emergency surgery within 24 hours of percutaneous transluminal coronary angioplasty. SETTING: A tertiary referral centre and postgraduate teaching hospital. RESULTS: 57 patients (76%) were men, the mean age was 55 (range 29-73) years, and 30 (40%) had had a previous myocardial infarction. Before PTCA, 68 (91%) had severe angina, 59 (79%) had multivessel disease, and six (8%) had a left ventricular ejection fraction of less than 40%. A mean of 2.1 grafts (range one to five) were performed; the internal mammary artery was used in only one patient. The operative mortality was 9% and inhospital mortality was 17%. There was a need for cardiac massage until bypass was established in 19 patients (25%): this was the most important outcome determinant (P = 0.0051) and was more common in those patients with multivessel disease (P = 0.0449) and in women (P = 0.0388). In 10 of the 19 cases a vacant operating theatre was unavailable, the operation being performed in the catheter laboratory or anaesthetic room. These 19 patients had an operative mortality of 32% and inhospital mortality of 47%, compared with 2% and 7% respectively for the 56 patients who awaited the next available operating theatre. Complications included myocardial infarction, 19 patients (25%); arrhythmias, 10 patients (3%); and gross neurological event, two patients (3%). The mean intensive care unit stay was 2.6 days (range 1 to 33 days) and the mean duration of hospital admission was 13 days (range 5-40 days). CONCLUSIONS: Patients undergoing emergency surgery after PTCA complications have a substantially increased inhospital mortality and morbidity. PTCA in this unit continues to require surgical cover. Delays in operating on stable patients in centres which operate a "next available theatre" backup policy may not differ from some units performing PTCA with offsite cover for PTCA complications. Particularly in the presence of multivessel disease, however, PTCA complications may be associated with the need for "crash" bypass and such patients are unlikely to survive hospital transfer. The proportion of patients requiring "crash" bypass has increased during the period reviewed because of the extent of disease in the emergency surgical group increased. These results indicate that surgery should not be denied to these patients.

Failure of epoprostenol (prostacyclin, PGI2) to inhibit platelet aggregation and to prevent restenosis after coronary angioplasty: results of a randomised placebo controlled trial.

OBJECTIVE: To study the effect of epoprostenol (prostacyclin, PGI2) given before, during, and for 36 h after coronary angioplasty on restenosis at six months and to evaluate the transcardiac gradient of platelet aggregation before and after percutaneous transluminal coronary angioplasty (PTCA) in treated and placebo groups. DESIGN: Double blind placebo controlled randomised study. PATIENTS: 135 patients with successful coronary angioplasty. METHODS: Intravenous infusion of PGI2 (4 ng/kg/ml) or buffer was started before balloon angioplasty and continued for 36 hours. Platelet aggregation was measured in blood from the aorta and coronary sinus before and after PTCA in each group. Routine follow up was at six months with repeat angiography and there was quantitative assessment of all angiograms (those undertaken within the follow up period and at routine follow up). PRESENTATION OF RESULTS: Restenosis rates in treated and placebo groups determined according to the National Heart, Lung and Blood Institute definition IV. Comparison at follow up between the effect of treatment on mean absolute luminal diameter and mean absolute follow up diameter in the placebo group. Comparison of acute gain and late loss between groups. RESULTS: Of 125 patients available for assessment 23 were re-admitted because of angina within the follow up period. Quantitative angiography showed restenosis in 15 (10 in the PGI2 group and five in the placebo group). Of 105 patients evaluated at six month angiography there was restenosis in nine more in the PGI2 group and 18 more in the placebo group. Total restenosis rates (for patients) were 29.2% for PGI2 and 38.3% for placebo (NS). The mean absolute gain in luminal diameter was 1.84 (0.76) mm in the PGI2 group and 1.58 (0.56) mm in the placebo group (p = 0.04); the late loss in the PGI2 group was also greater (0.65 (0.94) mm vs 0.62 (0.89) mm (NS) and there was no significant difference in final luminal diameter at follow up between the two groups (1.83 (0.88) mm v 1.59 (0.60) mm). The transcardiac gradient of quantitative platelet aggregation increased after PTCA in both groups, indicating that PGI2 in this dose did not affect angioplasty-induced platelet activation. Mean (SD) platelet activation indices in the PGI2 group were pre PTCA aorta 8.4 (4.1) v coronary sinus 8.8 (4.0) (p = 0.001) and post PTCA aorta 8.9(3.0) v coronary sinus 12.9 (5.7) (p = 0.001). In the placebo group the values were pre PTCA aorta 7.6 (3.3) v coronary sinus 7.4 (3.6) (p = 0.001) and post PTCA aorta 7.6(2.8) v coronary sinus 11.2(4.3) (p = 0.001). CONCLUSION: The dose of PGI2 given was designed to limit side effects and as a short-term infusion did not significantly decrease the six month restenosis rate after PTCA. The sample size, which was determined by the original protocol and chosen because of the potency of the agent being tested, would have detected only a 50% reduction in restenosis rate. There was, however, no effect in the treated patients on the increased platelet aggregation seen in placebo group as a result of angioplasty. Angioplasty is a powerful stimulus to blood factor activation. Powerful agents that prevent local platelet adhesion and aggregation are likely to be required to reduce restenosis.

Intravascular ultrasound to assess left main stem coronary artery lesion.

A man of 70 underwent coronary arteriography for the assessment of angina. The appearance of the left coronary main stem was slightly abnormal but no definite stenosis could be delineated. Intracoronary ultrasound examination with a 4.8 French intravascular ultrasound probe showed an extensive plaque in the distal left main stem and proximal left anterior descending coronary artery, with a shelf-like projection causing 60% narrowing at one point in the distal left main stem. Since coronary bypass surgery the patient has been free of angina.

Stenting of the arterial duct: a new approach to palliation for pulmonary atresia.

OBJECTIVE: To assess the possibility of maintaining ductal patency in neonates with complex pulmonary atresia by percutaneous implantation of balloon expandable stents. PATIENTS: Two duct-dependent neonates with long segment pulmonary atresia, right sided aortic arch, and left sided arterial duct. RESULTS: Stents with final diameter of 3.5 or 4 mm and initial length of 7 or 15 mm were successfully positioned in the arterial duct. Two stents were required in one child and four in the other in order to stent the entire length of the duct. After the procedures the ducts remained widely patent and arterial oxygen saturations remained above 80%. Complications of the procedures included perforation of a peripheral pulmonary artery and cardiac perforation, both caused by guide wire manipulation. Both babies died suddenly, one at five weeks, and the other at nine days after successful stenting of the duct. Both ducts were patent at necropsy; the exact cause of one death was not clearly defined, but the second seemed to be caused by pneumococcal septicaemia. CONCLUSIONS: Stenting of the arterial duct is technically feasible. It provides adequate palliation for neonates with pulmonary atresia at least in the short term and it seems to result in balanced, central perfusion of both pulmonary arteries. This preliminary report suggests that this previously untried technique may prove to be a promising and attractive alternative to neonatal aortopulmonary shunt operation.

Ambulatory blood pressure monitoring evaluation of a semi-automated device.

The accuracy of a semi-automated ambulatory blood pressure monitoring device (the Instrumedix 'Personal Blood Pressure Transmitter') was assessed in 36 patients undergoing diagnostic cardiac catheterisation. Blood pressure readings measured by the device and by a standard manual sphygmomanometer were compared with simultaneous intra-aortic pressure measured directly via the catheter. No measurement size trends were identified for either of the two comparisons. Compared to direct intra-aortic pressure measurement, the manual sphygmomanometer gave lower systolic (p less than 0.05), and higher diastolic readings (p less than 0.01), while the semi-automated device gave slightly higher readings for both systolic (not significant: p greater than 0.05) and diastolic (p greater than 0.05) pressure. In this assessment the semi-automated device provided at least as accurate a reflection of intra-aortic pressure as did standard manual sphygmomanometry. This device is an accurate tool for the ambulatory assessment of blood pressure where adequacy of treatment or correctness of the diagnosis is in question.