Abstract
Enhanced communication via gap junctions protects the endothelium from ischaemia-reperfusion injury in vivo in man
S Venkatasubramanian*, C M Pedersen*†, J P Langrish*, G Barnes*, C Mei Cheong* and N L Cruden*
*Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK; †Department of Cardiology, Aarhus University Hospital Skejby, Aarhus, Denmark
Endothelial dysfunction is the hallmark of ischaemia-reperfusion (IR) injury. Animal studies have demonstrated a role for gap junctions in this process. Rotigaptide (ZP-123) is a novel antiarrhythmic agent that increases intercellular communication via gap junctions. We tested the hypotheses that rotigaptide protects the human forearm arterial circulation from IR-induced endothelial dysfunction. Healthy male subjects (n = 21) were recruited into a randomized, double-blinded, crossover study. IR injury (upper arm cuff inflated to 200 mmHg for 20 minutes) was induced in the presence of intraarterial rotigaptide (25 nmol/minute) or saline placebo on separate visits. Using venous occlusion plethysmography, forearm arterial blood flow was measured during intraarterial infusion of acetylcholine (ACh; 5–20 μg/minute) or sodium nitroprusside (SNP; 2–8 μg/minute) before and after IR injury. Resting blood flow remained unchanged throughout (P = NS). ACh and SNP caused arterial vasodilation (P < 0.01) that was not affected by rotigaptide (P = NS). IR injury caused substantial impairment of ACh-induced vasodilation (P = 0.005). This effect was abolished by rotigaptide. Endothelium-independent vasodilation evoked by SNP was unaffected by IR injury, both in the presence and the absence of rotigaptide (P = NS). IR injury impairs endothelium-dependent vasomotion and is reversed by rotigaptide. This is the first clinical study to demonstrate that enhanced communication via gap junctions protects the endothelium from IR injury.
DOI: 10.1258/SMJ.2011.011037
Glycaemic control and the development of heart failure in diabetic patients with left ventricular systolic dysfunction on echocardiography
D Elder, L Donnelly, A F Wong, A Doney, A M Choy, A D Struthers and C C Lang
Ninewells Hospital, University of Dundee, Dundee, UK
There is controversy regarding the importance of glycaemic control in patients with type 2 diabetes mellitus (T2DM) and chronic heart failure (CHF), with recent evidence suggesting that tight glycaemic control may be associated with worse survival. The aim of this study was to examine the relationship between HBAlc and the risk of incident CHF and to examine the relationship between HbAlc and outcome in T2DM with established CHF. This study was carried out in the population (~400,000) of Tayside in Scotland, using data from the Go-DARTS study, the echocardiography database (~120,000 scans) and the dispensed prescribing database maintained by the Health Informatics Centre of the University of Dundee. The incidence date of new CHF was determined during the study period (January 1991 to June 2008). CHF was defined as impaired left ventricular systolic function on echocardiography together with prescription of loop diuretic and/or the presence of a hospital discharge code for CHF. A prospective case-control study was performed with each case of CHF matched with up to five controls, for gender and age at date of diagnosis with diabetes. Development of CHF was modelled using conditional logistic regression using mean HBA1c during the study period, number of HbA1c measures, standard deviation and thiazolidinediones prescribing as covariates. Subsequently, a proportional hazards model was used to consider the impact of HbA1c on survival of the cases. Out of 9172 diabetic individuals, there were 1135 incident cases of CHF (mean age at diagnosis of 60.3 ± 13.8 years, 61.9% men). The adjusted hazard ratio (HR) of developing CHF for each 1% increase in HbA1c was 1.31 (95% CI 1.20, 1.44), P = 1.43 × 10-9. In the cases there were 726 deaths. Death occurred in 38% of patients in Q1 (HBA1c ≤ 6.5%), 28% in Q2 (6.5 < HBA1c ≤ 7.2), 34% in Q3 (7.2 < HBA1c ≤ 7.9), 36% in Q4 (7.9 < HBA1c < 8.6) and 38% in Q5 (HBA1c ≥ 8.6). Using Q1 as the reference group, Q4 and Q5 had increased mortality (risk-adjusted HR 1.287 [95% CI 1.0.980–1.690, P = 0.07] and HR 1.628 [95% CI 1.216–2.179, P = 0.001] respectively). These data suggest that glycaemic control is an independent risk factor for incident CHF in persons with T2DM. In diabetic patients with established CHF, a tight glycaemic control is associated with a better outcome.
DOI: 10.1258/SMJ.2011.011038
The impact of metformin in non-diabetic insulin-resistant chronic heart failure
A K F Wong, R Symon, M A AlZadjali, DSC Ang, A Choy, J R Petrie, A D Struthers and C C Lang
Centre for Cardiovascular and Lung Biology, Division of Medical Sciences, University of Dundee and Medical School, Dundee, UK
Chronic heart failure (CHF) is now recognized as an insulin-resistant (IR) state. IR is associated with reduced exercise capacity in CHF. Metformin had been perceived as being relatively contraindicated in CHF, although mounting evidence indicates that it may be beneficial. The aim of the study was to determine the impact of metformin on cardiopulmonary exercise (CPET) parameters and glycemic control in non-diabetic insulin-resistant CHF. In a randomized, double-blind, placebo-controlled trial, 62 non-diabetic insulin-resistant CHF patients (mean age, 65.2 ± 8.0 years; male, 90%; left ventricular ejection fraction, 32.6 ± 8.3%; NYHA I/II/III/IV 11/45/6/0) were randomized to receive four months of metformin (2 g/day) or matching placebo. IR was defined by fasting insulin resistance index (FIRI) of ≥2.7. CPET, biomarkers, endothelial function were assessed at baseline and after four months of intervention. Compared with placebo, four months of metformin treatment significantly improved FIRI (from 5.8 ± 3.8 to 4.0 ± 2.5, P < 0.001), reduced fasting insulin (from 26.8 ± 14.3 to 20.2 ± 10.4 mU/L, P < 0.001) and reduced serum HbA1c (from 5.7 ± 0.3% to 5.5 ± 0.3%, P = 0.002). These correlate with significant improvement in VE/VCO2 slope (from 32.9 ± 15.9 to 28.1 ± 8.8, P = 0.05), ventilatory class (from 1.9 ± 0.9 to 1.6 ± 0.9, P = 0.021) and NYHA functional class (from 1.89 ± 0.5 to 1.75 ± 0.5, P = 0.046). Although peak exercise parameters and endothelial function did not differ between treatment groups, serum leptin is significantly reduced in the metformin arm (from 16.6 ± 23.3 to 12.1 ± 16.5 ng/mL, P < 0.05) and associated with a significant weight loss of 1.9 kg (P < 0.001). This novel study has shown that metformin treatment improved glucose homeostasis and weight loss, and resulted in significant improvement in submaximal exercise parameters and NYHA functional class. Reversing IR may represent a new target for treatment in CHF.
DOI: 10.1258/SMJ.2011.011039
T2 weighted magnetic resonance imaging has high diagnostic accuracy for myocardial haemorrhage in myocardial infarction: a preclinical validation study in swine
A R Payne*†, P Kellman*, R Anderson*, M Y Chen*, A R McPhaden†, S Watkins†, W Schenke*, V Wright*, R J Lederman*, A H Aletras*, A E Arai* and C Berry*†
*National Heart, Blood and Lung Institute, National Institutes of Health, Bethesda, MD, USA; †BHF Glasgow Cardiovascular Research Centre, University of Glasgow, Glasgow, UK
Myocardial haemorrhage after myocardial infarction (MI) frequently goes undetected. Since the paramagnetic effects of oxidized iron may result in signal loss on T2*-and T2-weighted magnetic resonance imaging (MRI), we investigated the diagnostic accuracy of T2-weighted MRI in experimental MI. Acute MI was created in swine (43 ± 9.5 kg) by occluding the left anterior descending coronary artery (n = 10) or circumflex (n = 5) for 90 minutes, followed by reperfusion for ≤3 days (n = 2), 10 days (n = 7) or 60 days (n = 6). Cardiac MRI was performed at 1.5 T using T2-prepared steady-state free-precession (T2P-SSFP) and gadolinium-enhanced (CE) MRI. Left ventricular (LV) sections were visually inspected, photographed and stained for histology. Gross images and histology were scored for myocardial haemorrhage by an experienced cardiac pathologist blinded to all other data. Regions of low signal intensity on T2-weighted and CE-MRI were independently determined by three cardiologists blinded to the pathology results. Eighty ventricular slices of pathology were matched with MRI (n = 68 for first-pass CE-CMR). All pathological sections with evidence of MI (n = 63 [79%]) also exhibited hyperintense zones consistent with oedema on T2-weighted, and infarct on CE-MRI. Myocardial haemorrhage occurred in 49 LV sections (61%) and corresponded with signal voids on 48 T2-weighted (98%) and 26 CE-MRI (53%). Alternatively, signal voids occurred in the absence of haemorrhage in three T2-weighted (90% specificity) and five CE-MRI (84% specificity). On first-pass CE-MRI, 27/43 perfusion defects corresponded with haemorrhage (63% sensitivity), while 5/25 defects occurred in the absence of haemorrhage (80% specificity). The positive and negative predictive values for pathological evidence of haemorrhage were 94% and 96% for T2-weighted, 84% and 53% for CE-MRI, and 84% and 56% for first-pass perfusion. T2-weighted MRI has high diagnostic accuracy for myocardial haemorrhage. Heterogeneity of signal intensity associated with acute MI on T2-weighted MRI, is partially due to intra-myocardial haemorrhage.
DOI: 10.1258/SMJ.2011.011040
Implications of extending the indication for cardiac-resynchronization therapy-defibrillator to patients with mild heart failure
R Duncan, C Dospinescu, G Padfield, A Hannah and P Broadhurst
Cardiology Department, Aberdeen Royal Infirmary, Aberdeen, UK
NICE acknowledges that insertion of the implantable cardioverter-defibrillator (ICD), prolongs survival in patients at risk from sudden cardiac death and that cardiac-resynchronization therapy (CRT) reduces the risk of heart failure and death in patients with poor left ventricular (LV) function, broad QRS and NYHA class III or IV symptoms. Recent studies, including the MADIT-CRT trial, have shown that patients with an indication for ICD therapy and who have poor LV function, QRS prolongation but with only mild (NYHA I-II) symptoms of heart failure, experienced significantly fewer heart failure events if a CRT-D is implanted rather than an ICD. This retrospective case review in Aberdeen Royal Infirmary assessed the impact of potentially extending the indications for CRT-D to patients who would otherwise receive an ICD. The hospital records of all patients who received an ICD in ARI between January 2009 and April 2010 were reviewed. Information collected included epidemiological data, indications for ICD, NYHA class, QRS duration, LV function, medication and cardiac risk factors. Criteria for patients to have been considered potentially suitable for CRT-Ds were those of the MADIT-CRT trial and included a QRS duration > 130 ms, NYHA class I-II in patients with ischaemic heart disease and NYHA II in non-ischaemic heart disease, IV EF <30% (or severe IV systolic impairment) and sinus rhythm immediately prior to ICD insertion. None had a prior implant of any type. Fifty-one patients were identified, six were excluded as notes were unavailable. Median age was 64 (range 16–90), 69% were men and 33% received an ICD for primary prevention. Applying MADIT-CRT criteria, four patients (9%) would have qualified for a CRT-D rather than an ICD (i.e. 3 patients per year). Four patients were excluded on the basis of atrial fibrillation. Should these indications be implemented, our results suggest a Scotland-wide yearly additional cost of at least £75,000 and 30 extra cath lab hours. If the NICE criteria for CRT-D were to include the results of the MADIT-CRT trial, the extra resource necessary would have to be balanced against the decreased cost of treatment and re-admission.
DOI: 10.1258/SMJ.2011.011041
Right ventricular outflow tract pacing as an alternative to left ventricular pacing in cardiac resynchronization therapy
H Alhous, A Hannah, G Small, G Hillis and P Broadhurst
Cardiology Department, Aberdeen Royal Infirmary, Aberdeen, UK
Left ventricular (LV) lead placement can be difficult in patients undergoing cardiac resynchronization therapy (CRT). Pacing from right ventricular mid-interventricular septum (RV mIVS) or RV outflow tract (RVOT) may be an acceptable alternative if LV lead placement is unsuccessful. There are few data assessing the effects of alternate RV pacing sites on LV function in this setting. Thus we studied 22 patients [13 male (59%), mean age 70.3 years], with standard indications for CRT and performed temporary dual-chamber pacing prior to CRT implantation. The RV pacing lead was placed at the RV apex (RVA), RV mIVS and RVOT in random order. Detailed echocardiographic studies, including measurements of ventricular dyssnchrony (interventricular mechanical delay [IVMD] and ‘dyssynchrony index’ [Ts-SD]), were undertaken at baseline, at each RV lead position and after CRT. Continuous data are expressed as median values and compared using the Wilcoxon's signed-ranks test. All patients had severe LV systolic impairment, inter- and intra-ventricular dyssynchrony at baseline and these were not significantly changed by RVA pacing. RV mIVS or RVOT resulted in significant improvement in all the assessed parameters. Incremental improvement was achieved by CRT. RV septal or outflow tract pacing may be a useful alternative strategy to try when LV pacing is unobtainable.
DOI: 10.1258/SMJ.2011.011042
Identifying patients with chronic heart failure for palliative care: a comparison of the gold standards framework with a clinical prognostic model
K K Haga*, S A Murray†, J Reid‡, A Ness‡, M O'Donnell‡, D Yellowlees‡ and M A Denvir§
*School of Medicine and Veterinary Medicine, University of Edinburgh; †Heart Failure Nursing Service, NHS Lothian; ‡Primary Palliative Care Research Group, University of Edinburgh; §Centre for Cardiovascular Science, Edinburgh, UK
Heart failure has a worse survival rate than many common cancers, yet few patients receive any palliative care input during the course of their illness. The aim of this study was to compare the ‘Gold Standards Framework’ (GSF) criteria, which were developed to determine the need for palliative care in non-cancer patients, with the patient's mean life expectancy, assessed using the ‘Seattle Heart Failure (SHF) Model’. Chronic heart failure patients, in NYHA class III or IV, who were being managed in the specialist, heart failure nursing service were identified from a clinical heart failure database. GSF criteria were assessed by interviewing the specialist nurse responsible for each patient's care. Clinical data required for the SHF model were obtained from two, online databases and were used to estimate mean life expectancy and predicted mortality at 1, 2 and 5 years. One hundred and thirty-eight NYHA III-IV patients were identified from a total of 368 patients, currently managed within the specialist nurse service; 66% were male, and the mean age was 77 years. GSF criteria, identified 119/138 (86%) patients that met the minimum requirement for palliative care input. However, the SHF model predicted that only 26/138 patients (19%) had a predicted life expectancy of less than one year. Patients who met GSF criteria for palliative care had significantly more hospital admissions (P = 0.001) and had significantly lower predicted survival rates at one year (P = 0.038) than those patients who did not meet GSF criteria. The GSF identifies the majority of NYHA III-IV CHF patients as qualifying for palliative care input. However, only one-fifth of these patients have a predicted life-expectancy of less than one year. This clear discrepancy between palliative criteria, developed for non-cancer patients, and clinical prognostic models for CHF, highlights the difficulties in developing models of care for CHF patients near the end-of life.
DOI: 10.1258/SMJ.2011.011043
Ventricular premature beats: a suitable case for (ablative) treatment
D H J Elder, R Good, J C Patel, C Redfern, J Affolter and P Broadhurst
Department of Cardiology, Aberdeen Royal Infirmary, Aberdeen, UK
Ventricular premature beats (VPBs) are common and, in the context of a structurally normal heart, generally considered benign. Occasionally, patients remain highly symptomatic despite lifestyle advice and reassurance and some may develop heart failure. Medical therapy is not always effective. We report our experience in managing such patients by radiofrequency ablation (RFA), a therapy probably underutilized. Patient's undergoing ablation of VPBs were identified from our local RFA database. Clinical notes, the ablation procedure and outcome were reviewed and patient's were contacted by telephone to ascertain their current symptoms. Ten patients out of 605 (1.6%) were scheduled to undergo electrophysiological study and ablation for symptomatic VPBs, although two did not receive RF ablation due to arrhythmia quiescence. Mean age was 36.3 (range 28–69) years, four men, with patients experiencing symptoms (including palpitations, presyncope, syncope and dyspnoea) for six months to five years prior to RFA. One patient with dyspnoea had moderately impaired left ventricular (LV) systolic dysfunction on echocardiography prior to the procedure, otherwise function was normal. All patients had failed medical therapy. Navigational systems were utilized during RFA in five patients with non-contact mapping required in two. The patients who exhibited frequent VPBs were identified as arising from the right ventricular (RV) outflow tract (5 patients), RV basal free wall (1 patient) and the floor of the right coronary cusp (2 patients); one patient exhibited two foci within the RV and another also underwent RFA for atrioventricular nodal re-entrant tachycardia at the same sitting. All VPBs were successfully ablated though early recurrence, in one case, required re-ablation within the LV outflow tract. One patient experienced transient heart block during RFA. The patient with moderately impaired LV function underwent repeat echocardiography, which demonstrated normal LV function at 14 (2–50) months. All patients experienced abolition of their symptoms and remain well after a mean follow-up of 18 (range 1–52) months. RFA for individuals with highly symptomatic, drug refractory VPBs is effective and may be curative. Not infrequently, these VPBs originate from sites outside of the right ventricular tract. Ablation may lead to improved LV systolic function where this is depressed by frequent ectopy. Few patients, however, appear to be referred for this procedure.
DOI: 10.1258/SMJ.2011.011044
Nurse-led early triage of chest pain patients: an observational study to evaluate a service development aimed at improving the management of patients with non-ST-elevation acute coronary syndromes
L O'Neill, P Currie and C C Lang
Acute Coronary Syndrome Specialist Nurse, Ninewells Hospital, NHS Tayside, Dundee, UK; Cons. Cardiologists, Ninewells Hospital, NHS Tayside, Dundee, UK
Patients presenting with non-ST-elevation acute coronary syndromes (NSTE-ACS) are at risk of early death. This may be reduced by prompt assessment and therapeutic intervention. The objectives of the study were to evaluate if nurse-led chest pain triage can improve time to assessment and the management of ACS patients, and to re-evaluate if any benefits are sustained several years later, when established as routine care. In NET-1 study, initial data on 79 consecutive chest pain patients admitted before the introduction of chest pain triage and on 103 patients admitted in the first six months of the service, were re-examined. The primary outcome measure was time to 12-lead ECG. In NET-2 study, data were gathered on 92 patients admitted to the current CCU triage service and on 22 patients admitted to acute admissions, who were denied access to CCU triage. End-points were compared between all groups and differences analysed by the χ2 -test for categorical variables and the Mann-Whitney U test to compare median times. In NET-1, nurse-led early triage resulted in statistically significant improvements in the number of chest pain patients who had their 12-lead ECG performed within 10 minutes of admission (94% versus 32%, P < 0.001) and the number of high-risk NSTE-ACS patients receiving Clopidogrel (72% versus 42%, P < 0.05) and being managed in CCU (82% versus 34%, P < 0.001). The completion of NET-2 and comparison of current triage with NET-1 non-triage (baseline control), demonstrated that these measurable benefits were sustained with P values of P < 0.001 for comparative ECG times, Clopidogrel prescribing and whether managed in CCU. There were no significant differences in outcomes between NET-2 triage and NET-1 triage, demonstrating that current triage is as effective as it was when the service was introduced. Comparison of the current triage group with the current non-triage group (of relatively smaller sample number) revealed that there were no significant differences between the number of high-risk NSTE-ACS patients prescribed clopidogrel or referred for angiography; however, patients in triage received these drugs more promptly and the difference in median time was significant (1 hour 37 minutes versus 9 hours 50 minutes, P < 0.05). The current study demonstrated the positive impact of nurse-led early triage on the management of patients with non ST-elevation ACS, admitted to a district general hospital and that initial benefits seen when the service was first introduced have been sustained.
DOI: 10.1258/SMJ.2011.011045
Feasibility and utility of cardiac magnetic resonance imaging for early risk assessment after acute ST elevation myocardial infarction
A R Payne*, R M McGeoch*, T Steedman†, R Woodward†, A Saul†, J Gilchrist†, C Clark†, C J Payne†, H Eteiba*, M M Lindsay*, K J Hogg*, S Hood*, E Peat*, A P Davie*, M C Pétrie*, S D Robb*, A P Rae*, N Tzemos*, K G Oldroyd* and C Berry*†
*West of Scotland Heart and Lung Institute, Golden jubilee National Hospital, Clydebank, Glasgow, UK; †BHF Glasgow Cardiovascular Research Centre, University of Glasgow, Glasgow, UK
Imaging of the heart is recommended for risk assessment after ST elevation myocardial infarction (STEMI) and the usual method is echocardiography. Cardiac magnetic resonance imaging (MRI) has higher diagnostic accuracy but is not normally performed after STEMI, and if it is, the scan is usually deferred for at least three days post-MI for medical stabilization. We prospectively studied the feasibility and clinical utility of cardiac MRI in STEMI. Cardiac MRI was performed at 1.5 T in two different hospital settings. Consecutive STEMI patients underwent MRI after invasive management and other routine investigations. The MRI protocol included HASTE black-blood sequences, retrospective cine imaging, T2-weighted oedema imaging and contrast-enhanced MRI with first-pass perfusion and early (2–5 minutes) and late (>10 minutes) gadolinium enhancement imaging. Two hundred STEMI patients (mean ± SD age 57.9 ± 10.5; 78.5% men; 26 [13%] Killip class 2–4; haemodynamic instability 45 [22%]) underwent early inpatient contrast-enhanced MRI. Of these, 128 (64%) patients underwent MRI ≤24 hours of hospital admission and 72 (36%) underwent MRI > 24 hours from admission. The MRI scan was completed in 191 (96%) patients, with the reasons for an incomplete MRI examination being claustrophobia (8 [4%] patients) and back pain (1 [0.5%] patient). The mean ± SD MRI scan duration was 44 ± 10 minutes. The mean ± SD left ventricular ejection fraction (LVEF) was 52 ± 11% and 14 (7%), 49 (24%) and 122 (61%) patients had an LVEF of <35%, <45% and <55%, respectively. Incidental findings were reported in 60 (42%) patients. Incidental findings were systematically reported in one hospital only, n = 143. In all cases, MRI was uncomplicated and no adverse events occurred. Even though one-quarter of patients had a history of haemodynamic instability or heart failure, MRI was completed in almost all patients without complication. Cardiac MRI is increasingly available, especially in primary PCI centres. Our findings support the emerging role of MRI in early risk assessment of STEMI survivors.
DOI: 10.1258/SMJ.2011.011046
Angiotensin-Converting enzyme inhibitors in patients with aortic stenosis and their impact on survival
M A Nadir, R Libianto, D Elder, L Wei, T K Lim, S D Pringle, A Doney, A D Struthers, M Pauriah, A Choy and C C Lang
Ninewells Hospital, University of Dundee, Dundee, UK
Angiotensin-Converting enzyme inhibitors (ACEIs) had been perceived to be relatively contraindicated in aortic stenosis (AS) because of their vasodilatory properties. However, there is emerging evidence that ACEI may actually be beneficial in AS. We hypothesized that ACEI therapy in patients with AS, is associated with lower all-cause mortality and better cardiovascular (CV) outcome in a large population-based cohort. The Health Informatics Centre (HIC) dispensed prescribing database for the population of Tayside, Scotland (~400,000 people) was linked to a large echocardiogram database (> 110,000 scans) by a unique patient identifier that records all healthcare events in the region. Patients with incident AS (defined as peak aortic gradient > 20 mmHg) between 1993 and 2008 were identified. Cox regression analysis was used to assess differences in all-cause mortality and CV events (CV death or hospitalizations) between those treated with and without ACEI, adjusted for multiple con-founders including age, left ventricular function, peak aortic valve gradient, co-morbidities and concurrent therapy. A total of 2621 subjects with varying degree of AS (aged 72.8 ± 12.5, 47% males) were identified. Mean follow-up was 4.7 ± 4.0 years. Eight hundred thirty-six (32%) patients received ACEI. There were 1185 (45%) all-cause deaths and 1282 (49%) CV events. Those treated with ACEI had significantly lower all-cause mortality and fewer CV events. The adjusted hazard ratio (HR) was 0.68 (95% CI 0.54–0.87) for all-cause mortality and 0.74 (95% CI 0.60–0.93) for CV events in patients treated with ACEI. For a propensity score-matched cohort analysis, the adjusted HR for CV events was 0.77 (95% CI 0.61–0.97). This is the largest retrospective data on the use of ACEI in AS. Our results suggest that ACEI therapy may be associated with improved mortality and CV outcome in patients with AS.
DOI: 10.1258/SMJ.2011.011047
Single centred comparison of off pump (OPCAB) versus on-pump coronary artery bypass grafting operated by same surgeon
M A Nawaz and F W H Sutherland
Cardiothoracic Surgery, Golden jubilee National Hospital NHS Glasgow, Glasgow, UK
Since last two decades, beating heart surgery has become more popular and has revolutionarized coronary surgery with better outcome. We describe our experience with off-pump coronary artery surgery and short-term outcome. Between 2008 and 2009, 150 coronary artery bypass grafting (CABG) operations were performed by consultant at our institution. One hundred and fifteen underwent on-pump CABG, while the remaining 35 had off-pump CABG for coronary revascularization. We reviewed records of all patients who underwent CABG with either technique, operated by the same surgeon and analysed results. Standard techniques were followed for OPCAB and conventional CABG. The two groups were comparable in terms of preoperative characteristics. Mean operative time taken by OPCAB was 3.2 hours, while for on-pump CABG, it was 3.8 hours. Average chest tube drainage for OPCAB was 335 mL, which was double (604 mL) for on-pump. Blood transfusion and ventilation time was significantly higher for on-pump CABG as compared with OPCAB median of 9 (range 1–917.72 hours) and 7.5 (range 0.0–384.5 hours), respectively. OPCAB complications were also much less, revealing five (4.3%) postoperative renal impairment in CABG, while 0.74% in OPCAB. Similarly, 21 (15.5%) patients developed cardiac complications but only four (2.9%) had only atrial fibrillation in OPCAB. Our study shows that OPCAB is associated with comparable early survival, less organ damage, lower incidence of reopening, shortened intensive care unit and hospital stay.
DOI: 10.1258/SMJ.2011.011048
Percutaneous coronary intervention in the elderly: changes in case-mix and peri-procedural outcomes in 31,758 patients treated between 2000 and 2007
C Johnman, K G Oldroyd and J P Pell
NHS Greater Glasgow & Clyde, Glasgow, UK
Percutaneous coronary intervention (PCI) is the most common method of revascularization in the elderly. We examined whether the risk of peri-procedural complications following PCI was higher among elderly (≥75 years) patients and whether it has changed over time. The Scottish Coronary Revascularisation Register was used to undertake a retrospective cohort study on all 31,758 patients undergoing non-emergency PCI in Scotland, between April 2000 and March 2007 inclusive. There was an increase in the number and percentage of PCIs undertaken in elderly patients, from 196 (8.7%) in 2000, to 752 (13.9%) in 2007. Compared with younger patients, the elderly were more likely to have multivessel disease, multiple comorbidity and a past history of myocardial infarction or coronary artery bypass grafting (χ2 tests, all P < 0.001). The elderly had a higher risk of major adverse cardiovascular events within 30 days of PCI (4.5% versus 2.7%, χ2 test P < 0.001). Over the seven years, there was a significant increase in the proportion of elderly patients who had multiple comorbidity (χ2 test for trend, P < 0.001). In spite of this, the underlying risk of complications did not change significantly over time either among the elderly (χ2 test for trend, P = 0.142) or overall (χ2 test for trend, P = 0.083). Elderly patients have a higher risk of peri-procedural complications and account for an increasing proportion of PCIs. Despite this, the risk of complications following PCI has not increased over time.
DOI: 10.1258/SMJ.2011.011049
A preoperative 12-lead ECC: can it predict postoperative complications and long-term outcome?
C J Payne*, A R Payne†, S C Gibson*, A R Jardinet†, D B Kingsmore* and C Berry†
*Department of General and Vascular Surgery, Gartnavel General Hospital; Glasgow Cardiovascular Research Centre, University of Glasgow, Glasgow, UK
A 12-lead electrocardiogram (ECG) is a standard preoperative investigation for patients undergoing major surgery. There is often debate over the usefulness of this test in stratifying postoperative cardiac risk. The aim of this study is to investigate the correlation between an abnormal ECG and the postoperative cardiac event rate. A single-centre observational study in patients undergoing major non-cardiac surgery between January 2004 and August 2006, was performed. Written consent was obtained and patients had standard preoperative assessment, including a 12-lead ECG. ECGs were analysed at the end of the study for the presence of abnormalities (left ventricular hypertrophy, strain, Q-waves, atrial fibrillation [AF], axis deviation and bundle branch block). An ECG was considered abnormal if one or more abnormalities were present. Screening for cardiac events was performed (days 2, 5, 42) using clinical criteria, cardiac troponin and serial ECGs. The primary outcome was major adverse cardiac event (MACE), defined as non-fatal myocardial infarction or cardiac death. Three hundred and forty-five patients were included in the study. Of these, 276 (80.0%) patients underwent a vascular procedure (aortic surgery 25.8%, lower limb bypass 29.8% and amputation 25.2%) and 69 (20.0%) patients underwent laparotomy. An abnormal ECG was present in 153 (44.4%) patients. MACE was observed in 46 (13.23%) cases. Patients with an abnormal ECG had a significantly higher incidence of MACE (21.6% versus 8.3%, P < 0.001). Univariate analysis shows that strain and AF also predict postoperative events. This study confirms that a preoperative ECG remains a useful adjunct in predicting perioperative cardiac events.
DOI: 10.1258/SMJ.2011.011050
The prevalence and predictors of left ventricular hypertrophy in patients with rheumatoid arthritis
M A Nadir, J George, G Mackle, M Pauriah and A Struthers
Ninewells Hospital, University of Dundee, Dundee, UK
Patients with rheumatoid arthritis (RA) have high cardiovascular risk. In these patients, the increased levels of vascular inflammation and oxidative stress lead to endothelial dysfunction and therefore vascular stiffness. Left ventricular hypertrophy (LVH) is a natural consequence of increased vascular stiffness and an established independent cardiac risk factor. We hypothesized that patients with RA may have increased the prevalence of LVH, owing to increased levels of underlying vascular inflammation and oxidative stress. We recruited 60 consecutive patients with RA from our local rheumatology outpatients clinic and 31 age- and sex-matched healthy volunteers through local advertisements. Each patient attended for a single visit. Baseline demographic data and blood samples for C-reactive protein (CRP), B-type natriuretic peptide and vitamin D were collected. Office blood pressures, electrocardiogram and echocardiogram were performed as well as 24-hour ambulatory blood pressure monitoring. LVH was defined according to The American Society of Echocardiography criteria, corrected for body surface area (left ventricular mass index, LVMI). The study was approved by the Local Regional Ethics Committee. The prevalence of LVH in patients (mean age 60.1 ± 10.8, 77% women) with RA was 33% compared with 23% (P < 0.001) in healthy volunteers (mean age 59.3 ± 11, 80% women). Among RA patients, those with LVH on echocardiography were older, more likely to be hypertensive and had higher baseline CRP levels than those without LVH. When corrected for age, gender, BMI and blood pressure, only CRP (P < 0.01) was an independent predictor of LVMI in patients with RA. LVH is highly prevalent in patients with RA and CRP correlates significantly with the presence of LVH in this population. This suggests that underlying vascular inflammation seen in RA may result in augmented CV risk, due to an increased prevalence of LVH. Larger studies are required to confirm these findings.
DOI: 10.1258/SMJ.2011.011051