Patient and hospital determinants of primary percutaneous coronary intervention in England, 2003-2013.

OBJECTIVE: Primary percutaneous coronary intervention (PPCI) for ST-elevation myocardial infarction (STEMI) is insufficiently implemented in many countries. We investigated patient and hospital characteristics associated with PPCI utilisation. METHODS: Whole country registry data (MINAP, Myocardial Ischaemia National Audit Project) comprising PPCI-capable National Health Service trusts in England (84 hospital trusts; 92 350 hospitalisations; 90 489 patients), 2003-2013. Multilevel Poisson regression modelled the relationship between incidence rate ratios (IRR) of PPCI and patient and trust-level factors. RESULTS: Overall, standardised rates of PPCI increased from 0.01% to 86.3% (2003-2013). While, on average, there was a yearly increase in PPCI utilisation of 30% (adjusted IRR 1.30, 95% CI 1.23 to 1.36), it varied substantially between trusts. PPCI rates were lower for patients with previous myocardial infarction (0.95, 0.93 to 0.98), heart failure (0.86, 0.81 to 0.92), angina (0.96, 0.94 to 0.98), diabetes (0.97, 0.95 to 0.99), chronic renal failure (0.89, 0.85 to 0.90), cerebrovascular disease (0.96, 0.93 to 0.99), age >80 years (0.87, 0.85 to 0.90), and travel distances >30 km (0.95, 0.93 to 0.98). PPCI rates were higher for patients with previous percutaneous coronary intervention (1.09, 1.05 to 1.12) and among trusts with >5 interventional cardiologists (1.30, 1.25 to 1.34), more visiting interventional cardiologists (1-5: 1.31, 1.26 to 1.36; ≥6: 1.42, 1.35 to 1.49), and a 24 h, 7-days-a-week PPCI service (2.69, 2.58 to 2.81). Half of the unexplained variation in PPCI rates was due to between-trust differences. CONCLUSIONS: Following an 8 year implementation phase, PPCI utilisation rates stabilised at 85%. However, older and sicker patients were less likely to receive PPCI and there remained between-trust variation in PPCI rates not attributable to differences in staffing levels. Compliance with clinical pathways for STEMI is needed to ensure more equitable quality of care.

Automated cardiopulmonary resuscitation using a load-distributing band external cardiac support device for in-hospital cardiac arrest: a single centre experience of AutoPulse-CPR.

BACKGROUND: Poor quality cardiopulmonary resuscitation (CPR) predicts adverse outcome. During invasive cardiac procedures automated-CPR (A-CPR) may help maintain effective resuscitation. The use of A-CPR following in-hospital cardiac arrest (IHCA) remains poorly described. AIMS & METHODS: Firstly, we aimed to assess the efficiency of healthcare staff using A-CPR in a cardiac arrest scenario at baseline, following re-training and over time (Scenario-based training). Secondly, we studied our clinical experience of A-CPR at our institution over a 2-year period, with particular emphasis on the details of invasive cardiac procedures performed, problems encountered, resuscitation rates and in-hospital outcome (AutoPulse-CPR Registry). RESULTS: Scenario-based training: Forty healthcare professionals were assessed. At baseline, time-to-position device was slow (mean 59 (±24) s (range 15-96s)), with the majority (57%) unable to mode-switch. Following re-training time-to-position reduced (28 (±9) s, p<0.01 vs baseline) with 95% able to mode-switch. This improvement was maintained over time. AutoPulse-CPR Registry: 285 patients suffered IHCA, 25 received A-CPR. Survival to hospital discharge following conventional CPR was 28/260 (11%) and 7/25 (28%) following A-CPR. A-CPR supported invasive procedures in 9 patients, 2 of whom had A-CPR dependant circulation during transfer to the catheter lab. CONCLUSION: A-CPR may provide excellent haemodynamic support and facilitate simultaneous invasive cardiac procedures. A significant learning curve exists when integrating A-CPR into clinical practice. Further studies are required to better define the role and effectiveness of A-CPR following IHCA.

Comparison of cardiac troponin I and creatine kinase ratios in the detection of myocardial injury after aortic surgery.

BACKGROUND: Perioperative myocardial infarction may not be diagnosed correctly because World Health Organization criteria are often not met and creatinine kinase myocardial fraction (creatinine kinase/creatinine kinase MB isoenzyme; CK/CK-MB) ratios can be difficult to interpret. Cardiac troponin (cTn) I and cTnT are the most sensitive and specific markers of myocardial cell necrosis currently available but are not widely used in surgical practice. The aim was to compare cTnI and CK/CK-MB ratios in the detection of myocardial injury following aortic surgery. METHODS: This was a prospective study of 59 patients undergoing elective (n = 28) or ruptured (n = 24) abdominal aortic aneurysm repair or elective aortofemoral bypass (n = 7). cTnI level was measured before operation and at 6, 24 and 48 h after surgery. The CK/CK-MB ratio was measured where cTnI was detectable. RESULTS: Some 14 of 24 emergency and ten of 35 elective patients had detectable cTnI (greater than 0.5 ng/ml) at one or more time-points. The CK/CK-MB ratio was greater than 5 per cent in only four of 24 patients having an emergency operation and in none of the elective patients with detectable cTnI. CONCLUSION: Over half of patients undergoing emergency operation and more than a quarter of those having elective aortic surgery suffered myocardial necrosis as determined by detectable cTnI levels. This was accompanied by a raised CK/CK-MB ratio in less than one-fifth of patients.

Myocardial injury and systemic fibrinolysis in patients undergoing repair of ruptured abdominal aortic aneurysm: a preliminary report.

BACKGROUND: ruptured abdominal aortic aneurysm (AAA) is associated with inhibition of systemic fibrinolysis. Hypofibrinolysis is a risk factor for ischaemic myocardial injury, one of the commonest complications of ruptured AAA repair. Cardiac troponin I (cTnI) is one of the most sensitive and specific marker of myocardial injury currently available. OBJECTIVE: To examine, for the first time, the relationship between fibrinolytic activity and myocardial injury in patients operated for ruptured AAA. METHODS: Twenty patients (18 men and 2 women of median age 74, range 65-86 years) undergoing repair of ruptured AAA were prospectively studied. Plasma tissue plasminogen activator (t-PA) and plasminogen activator inhibitor (PAI-1) activity were measured pre-operatively, immediately before and five minutes following aortic clamp release. Serum cTnI was measured pre-operatively, 6 and 24 h following clamp release. Results cTnI was detectable at one or more sample points in 13 (65%) patients, and in 7 out of 8 patients who suffered major cardiac complications. There was a significant negative correlation between pre-operative t-PA activity and cTnI before operation (r =-0.55, p = 0.01) and 6 h ( r =-0.51, p =0.02) after clamp release. There was a significant positive correlation between pre-operative PAI activity and cTnI before operation (r =+0.50, p =0.03), 6 h ( r =+0.47, p =0.04) and 24 h ( r =+0.50, p =0.03) after clamp release. There was no correlation between pre- and intra-operative hypotension or blood transfusion requirement and cTnI release. CONCLUSIONS: Hypofibrinolysis during ruptured AAA repair is associated with the development of peri-operative myocardial injury. The causal mechanisms underlying this state are not clear but treatment of this prothrombotic/hypofibrinolytic diathesis may help to limit myocardial cell necrosis.

Balloon mitral valvuloplasty: comparison of haemodynamic and echocardiographic assessment of mitral stenosis at different heart rates in the catheterisation laboratory.

AIMS: To compare echo-Doppler, Gorlin equation and haemodynamic methods of measuring mitral valve stenosis during right ventricular pacing-induced tachycardia before and after Inoue balloon mitral valvuloplasty to determine which method gave the most consistent results. METHODS AND RESULTS: Measurements were made before and after valvuloplasty at: baseline heart rates, paced at 115 and then 145 beats/min. Mitral valve area by echo-Doppler was 1.1(+/-0.1) cm2 (mean +/- S.E.) before and 1.8(+/-0.2) cm2 after valvuloplasty; and by Gorlin equation: 0.9(+/-0.1) cm2 before and 1.5(+/-0.1) cm2 after. Echo-Doppler measurements were heart rate dependent but those by Gorlin measurements were not. At baseline, cardiac index was 2.08(+/-0.2) l min(-1), left atrial pressure 23.3(+/-7.9) mm Hg and mean mitral diastolic gradient 16.9(+/-9.9) mm Hg. After valvuloplasty, cardiac index was 2.31(+/-0.1) l min(-1), left atrial pressure fell to 19.2(+/-5.6) mm Hg and mean diastolic gradient was reduced to 8.5(+/-1.8) mm Hg. CONCLUSIONS: The Gorlin mitral valve area appeared to be the most heart rate independent indicator of success following valvuloplasty.

Incidence and clinical relevance of coronary calcification detected by electron beam computed tomography in heart transplant recipients.

BACKGROUND: Patients treated by cardiac transplantation who survive beyond one year are at significant risk from fatal coronary artery disease. The development of coronary artery calcification in these patients is discussed and methods available to detect it are reviewed. OBJECTIVES: To assess the clinical importance of coronary artery calcium in heart transplant recipients. METHODS: In a cohort of 102 cardiac transplant recipients, electron beam computed tomography was used to measure calcium in the coronary arterial wall 63 days to 9.1 years (median 4.6 years) after transplantation. The results were compared with angiographic findings and with conventional coronary disease risk factors. The patients were followed for a mean of 2.12 years (1.2-4.02 years) to assess the relationship between these findings and future cardiac events. RESULTS: Forty-one (40.2%) had a stenosis of > 24% in one or more major coronary artery at angiography. Forty-six (45%) had a coronary calcium score > 0. The absence of calcium had a negative predictive value with respect to angiographic disease in any vessels of 87.5%. Logistic regression revealed that dyslipidaemia, systemic hypertension and organ ischaemic time were significant predictors of calcification. At follow-up, both an abnormal coronary angiogram and coronary calcium were found to be the only significant predictors of late events. Multivariate analysis suggested that the detection of coronary calcium did not offer any additional predictive information over that provided by the angiogram itself. CONCLUSION: Electron beam computed tomography is well suited to the assessment of calcium in the coronary arteries of heart transplant recipients, although the mechanisms of this calcification remain poorly understood. Calcium is detected more frequently than would be suggested by studies using intravascular ultrasound. It is associated with the presence of angiographic disease, and with some conventional risk factors for coronary disease. At follow-up the presence of coronary calcium was associated with an adverse clinical outcome, as it is in conventional ischaemic heart disease.

Coronary angiography from the radial artery--experience, complications and limitations.

AIMS: to assess the outcomes, complications and limitations of coronary angiography performed via percutaneous radial artery puncture. METHODS AND RESULTS: two hundred and fifty patients underwent diagnostic coronary angiography from the radial artery, 182 (72.8%) of whom had contraindications to the femoral approach, for example due to peripheral vascular disease (n=85), therapeutic anticoagulation (29), or failed femoral approach (17). Procedural success in this high-risk population was achieved in 231 patients (92.4%). Principle reasons for failure were unsuccessful radial access (5) and arterial spasm (5). Procedure duration (SD) for an operator's first 20 cases compared with cases thereafter (min) was 47.7 (16.7) vs. 41.5 (14.6), P=0.0004; fluoroscopy time (min) 9.7 (7.1) vs. 6.6 (5.1), P=0.0001 and procedural success 89.6% vs. 94.1%, P=ns. Complications included two deaths associated temporally with catheterisation, three cases of arterial dissection without ischaemic sequelae and one transient ischaemic attack. CONCLUSIONS: coronary angiography can be performed successfully from the radial artery, but this approach has limitations, which include the need to demonstrate dual palmar vascular supply, the prolonged learning phase, the procedural failure rate, patient discomfort and a demonstrable incidence of vascular and haemodynamic complications. We believe that radial coronary angiography should only be undertaken when there is a contraindication to the femoral approach.

Comparison of radial versus brachial approaches for diagnostic coronary angiography when the femoral approach is contraindicated.

One hundred patients with contraindications to the femoral approach were randomized to undergo diagnostic coronary angiography via percutaneous radial puncture or brachial artery cutdown. Procedure duration, fluoroscopy time, and total radiation dose were significantly less via the radial route, whereas procedural success, complication rates, and pain scores were comparable; we conclude that the radial technique should be the arm approach of choice for new trainees, although there will be occasions when radial access fails and a brachial approach is required.

Late complications following permanent pacemaker implantation or elective unit replacement.

OBJECTIVE: To determine the rate of late complications following first implantation or elective unit replacement of a permanent pacemaker system. DESIGN: Analysis of pacemaker data and complications prospectively acquired on a computerised database. Complications were studied over an 11 year period from January 1984 to December 1994. SETTING: Tertiary referral cardiothoracic centre. PATIENTS: Records of 2621 patients were analysed retrospectively. MAIN OUTCOME MEASURES: Complications requiring repeat procedures occurring more than six weeks after pacemaker implantation or elective unit replacement. RESULTS: The overall rate of late complications was significantly lower after first implantation of a permanent pacemaker (34 cases, complication rate 1.4%, 95% confidence interval 0.9% to 1.9%) than after elective unit replacement (16 cases, complication rate 6.5% (3.3% to 9.7%). There were 20 cases of erosion, 18 infections, five electrode problems, and seven miscellaneous problems. Complications were more common with inexperienced operators (18.9% (6.0% to 31.8%)) than with experienced operators (0.9% (0.3% to 1.5%). CONCLUSIONS: The incidence of late complications following pacemaker implantation is low and compares favourably with early complication rates. The majority are caused by erosion and infection. Patients who have undergone elective unit replacement are at particular risk.

Transient ST-segment changes associated with mitral valvuloplasty using the Inoue balloon.

We describe unexplained transient inferior ST-segment elevation on the electrocardiogram during Inoue mitral valvuloplasty in 8 patients from a series of 108. Electrocardiographic changes were associated with chest pain in 7 patients, and although the clinical features were suggestive of myocardial ischemia, no cause for this could be found.

Radial versus femoral approach for diagnostic coronary angiography in stable angina pectoris.

We compared coronary angiography of the radial artery using 6Fr catheters in 116 patients with that of the femoral artery in 100 case controls. We showed that transradial coronary angiography offers a useful alternative to the femoral route and can be performed without resorting to 5Fr catheters.

Changing from intensive anticoagulation to treatment with aspirin alone for coronary stents: the experience of one centre in the United Kingdom.

OBJECTIVE: To investigate whether an elective change in the anticoagulation protocol for patients with coronary stents affected clinical outcomes and length of hospital stay. DESIGN: Retrospective observational study of a consecutive series of patients treated with coronary stents over an 18 month period from April 1994 to October 1995. BACKGROUND: Intensive anticoagulation regimens are used in many UK centres to reduce the risk of coronary stent thrombosis. Recent data have called into question the necessity for full anticoagulation and favourable results have been reported with antiplatelet agents alone. The results from a tertiary referral centre were investigated during a period where an elective change in policy was made: an initial 70 patients were treated intensively with intravenous heparin and with warfarin and aspirin; subsequently 94 were treated with aspirin and deployment of a high pressure balloon only. METHODS: Review of case notes, angiograms, and a database of intervention procedures and telephone interview. Classic epidemiological techniques, as well as linear regression and logistic regression, were used to model the outcomes of major procedural complications and length of hospital stay. PATIENTS: 164 patients treated with 196 coronary stents. RESULTS: There were 22 (13.4%) major complications (coronary bypass grafting 11, subacute thrombosis 6, tamponade 2, myocardial infarction 1, death 2). With logistic regression, the risk of major complication was shown not to be affected by anticoagulation (relative risk (RR) 1.03; P = 0.97). Significant determinants of risk included acute vessel closure as an indication for stenting (RR = 80.6; P < 0.001) and sex (male: female RR = 0.19; P = 0.02). The median length of stay (LOS) was 5 days (1-45). Use of a linear regression model showed that anticoagulation added 4.5 days and a major complication added a further 4.5 days to a baseline length of stay of 3.2 days (R2 = 0.32; P < 0.001). CONCLUSION: This is a report of coronary stenting as part of usual clinical practice in one British tertiary referral centre. In this experience, treatment with aspirin alone is probably as safe as intensive anticoagulation, and has the benefit of reducing length of stay by more than 50% to 3.2 days in an uncomplicated case.

Maze 3 for atrial fibrillation: two cuts too few?

The Maze procedure has been developed as a surgical approach to the management of patients with atrial fibrillation refractory to medical treatment. The recent modification of the technique (Maze 3) achieves good rate control with coordinated AV contractions. However, the procedure involves cuts that completely isolate a block of left atrial (LA) wall, including the four ostia of the pulmonary veins. The electrical and mechanical activity of this isolated LA block are dissociated from the rest of the atrium, and the area may, in fact, continue to fibrillate. This may provide a nidus for the development of mural thrombus. The weight and endocardial surface area of the LA block and of the entire LA were estimated in ten formalin fixed hearts from trauma victims with no evidence of cardiac disease. In these samples, the LA block represented 35% of the endocardial surface area of the entire LA and 29% of the weight. The LA block is of sufficient size to allow macroreentrant circuits to form and has the potential to fibrillate if isolated from the rest of the atrium. We modified the Maze 3 procedure to recruit the otherwise isolated LA block by using two additional cuts around each pair of pulmonary veins as they enter the LA. The first patient who underwent the modified procedure demonstrated sinus rhythm on Holter monitoring postoperatively and remained in sinus rhythm following burst atrial pacing at 300 and 420 beats/min each for 30 seconds. In addition, atrial contractions were found to contribute 19% of the cardiac output.(ABSTRACT TRUNCATED AT 250 WORDS)