Mark Mason

Importance of rate control or rate regulation for improving exercise capacity and quality of life in patients with permanent atrial fibrillation and normal left ventricular function: a randomised controlled study

OBJECTIVE To determine the importance of rhythm regulation or rate control in patients with permanent atrial fibrillation (AF) and normal left ventricular function. PATIENTS AND INTERVENTIONS Thirty six patients with a mixed fast and slow ventricular response rate to their AF were randomised to either His bundle ablation (HBA) and VVIR pacemaker (HBA group) or VVI pacemaker and atrioventricular modifying drugs (Med group). Outcomes assessed at one, three, six, and 12 months included exercise duration and quality of life. RESULTS Exercise duration significantly improved from baseline in both groups. There was no difference in outcome between the groups (Med +40%v HBA +20%, p = NS). The heart rate profile on exercise was similarly slowed in both groups compared to baseline. Quality of life significantly improved in both treatment arms for the modified Karolinska questionnaire (KQ) (Med +50%v HBA +50%, p = NS) and the Nottingham health profile (NHP) (Med +40% v HBA +20%, p = NS). However, for the individual symptom scores of each questionnaire more were improved in the Med group (KQ-Med 6 improvedv HBA 4, NHP-Med 3 vHBA 1). Left ventricular function was equally preserved by both treatments during follow up. CONCLUSION In these patients control of ventricular response rate with either HBA + VVIR pacemaker or atrioventricular modifying drugs + VVI pacemaker will lead to a significant improvement in exercise duration and quality of life. Rhythm regulation by HBA did not confer additional benefit, suggesting rate control alone is necessary for the successful symptomatic treatment of these patients in permanent AF.

A Randomized Optical Coherence Tomography Study of Coronary Stent Strut Coverage and Luminal Protrusion With Rapamycin-Eluting Stents

OBJECTIVES We used optical coherence tomography, which has a resolution of <20 microm, to analyze thin layers of neointima in rapamycin-eluting coronary stents. BACKGROUND Lack of neointimal coverage has been implicated in the pathogenesis of drug-eluting coronary stent thrombosis. Angiography and intracoronary ultrasound lack the resolution to examine this. METHODS We conducted a randomized trial in patients receiving polymer-coated rapamycin-eluting stents (Cypher, Cordis, Johnson & Johnson, Miami, Florida) and nonpolymer rapamycin-eluting stents (Yukon, Translumina, Hechingen, Germany) to examine neointimal thickness, stent strut coverage, and protrusion at 90 days. Twenty-four patients (n = 12 for each group) underwent stent deployment and invasive follow-up at 90 days with optical coherence tomography. The primary end point was binary stent strut coverage. Coprimary end points were neointimal thickness and stent strut luminal protrusion. RESULTS No patient had angiographic restenosis. For polymer-coated and nonpolymer rapamycin-eluting stents, respectively, mean (SD), neointimal thickness was 77.2 (25.6) microm versus 191.2 (86.7) mum (p < 0.001). Binary stent strut coverage was 88.3% (11.8) versus 97.2% (6.1) (p = 0.030). Binary stent strut protrusion was 26.5% (17.5) versus 4.8% (8.6) (p = 0.001). CONCLUSIONS Mean neointimal thickness for the polymer-coated rapamycin-eluting stent was significantly less than the nonpolymer rapamycin-eluting stent but as a result coverage was not homogenous, with >10% of struts being uncovered. High-resolution imaging allowed development of the concept of the protrusion index, and >25% of struts protruded into the vessel lumen with the polymer-coated rapamycin-eluting stent compared with <5% with the nonpolymer rapamycin-eluting stent. These findings may have important implications for the risk of stent thrombosis and, therefore, future stent design. (An optical coherence tomography study to determine stent coverage in polymer coated versus bare metal rapamycin eluting stents. ORCA 1, from the Optimal Revascularization of the Coronary Arteries group; ISRCTN42475919).

Initial evidence for the return of coronary vasoreactivity following the absorption of bioabsorbable magnesium alloy coronary stents.

AIMS To investigate the endothelium independent coronary smooth muscle vasomotor function four months after implantation of magnesium alloy absorbable metal stents (AMS) as part of the Progress-AMS clinical trial (n = 5), compared with a control group of patients implanted with permanent metal stents (PMS) (n = 10) undergoing follow-up angiography, but who were free from angiographic restenosis. METHODS AND RESULTS Quantitative coronary angiogram (QCA) using an automated edge detection system was performed before and after the administration of 2 mg intracoronary isosorbide dinitrate (ISDN). The vessel diameter was measured at 0.2 mm intervals throughout the stented segments and a 1 cm proximal reference segment. The cross sectional area (CSA) was calculated before and after the ISDN, averaged and the percentage change measured. Reference segments demonstrated preserved vasomotor function in all cases: +13.28% (AMS) versus +17.15% (PMS), p = 0.39. The mean percentage increase in CSA for the stented segment was +6.78% for the AMS versus -1.30% for PMS, p = 0.003. CONCLUSION These data demonstrate that four months after AMS implantation vasomotor function in reference segments is no different to that observed with PMS. However in contrast to PMS, within the AMS-stented segments there is demonstrable vasodilatation. These observations may have important implications for future stent design.

Stabilisation of medically refractory ventricular arrhythmia by intra-aortic balloon counterpulsation

OBJECTIVE To review the efficacy of intra-aortic balloon counterpulsation (IABCP) in medically refractory ventricular arrhythmia. DESIGN Retrospective analysis of the outcome of patients with ventricular arrhythmia treated with IABCP after transfer between 1992 and 1997. SETTING Tertiary cardiac referral centre. PATIENTS 21 patients (mean age 58 years) who underwent IABCP for control of ventricular arrhythmia. All had significant left ventricular impairment (mean ejection fraction 28.6%); 18 had coronary artery disease. RESULTS Before IABCP, 10 patients had incessant monomorphic ventricular tachycardia and 11 had paroxysmal ventricular tachycardia and/or ventricular fibrillation (VT/VF). IABCP resulted in suppression of ventricular arrhythmia in 18 patients, of whom 13 were weaned from IABCP. After stabilisation of ventricular arrhythmia, 10 patients were maintained on medical treatment alone and one underwent endocardial resection. IABCP was maintained until cardiac transplantation in five patients. One patient had a fatal arrest before discharge and one died from progressive heart failure. IABCP failed to control ventricular arrhythmia in three patients and was subsequently discontinued. A cardiac assist device was employed in one of these until cardiac transplantation; the other two were eventually stabilised on medical treatment. Nineteen patients were discharged from hospital. Overall survival was 95% at mean follow up of 25.7 months. CONCLUSIONS IABCP can be an effective means of controlling refractory ventricular arrhythmia, allowing time for the institution of more definitive treatment.

Cardiac iodine-123 metaiodobenzylguanidine imaging predicts ventricular arrhythmia in heart failure patients receiving an implantable cardioverter-defibrillator for primary prevention

Objective To assess the prognostic value of cardiac iodine-123 metaiodobenzylguanidine (123I-MIBG) scintigraphy to predict ventricular arrhythmias in patients with heart failure (HF) listed for implantable cardioverter-defibrillator (ICD) devices as primary prevention. Design, setting and patients A prospective cohort study in 27 patients with HF referred for ICD implantation (alone or in combination with cardiac resynchronisation therapy) at a tertiary cardiac centre. Methods Cardiac 123I-MIBG scintigraphy was performed with calculation of early and late heart-to-mediastinum (H:M) ratios, washout rate, and summed defect score from single photon emission computed tomography (SPECT) acquisition. Resting myocardial perfusion SPECT using 99mTc-tetrofosmin was also performed and a summed score calculated. Innervation-perfusion mismatch was evaluated by comparing SPECT scores. Main outcome measure Ventricular arrhythmia requiring ICD therapy. Results At 16 months median follow-up, 10 (37%) patients experienced a significant arrhythmic event. Compared with patients who suffered no event, these individuals had lower early and late H:M ratio and higher 123I-MIBG SPECT defect scores: 1.83±0.43 versus 2.34±0.33 (p<0.001); 1.54±0.38 versus 1.96±0.38 (p=0.005); 37.0±9.4 versus 25.5±7.7 (p=0.001). Mismatch scores were also higher: 18.5±8.5 versus 8.4±5.0 (p<0.01). Optimal thresholds for predicting arrhythmia were <1.94 for early H:M ratio (sensitivity 70%, specificity 88%); <1.54 for late H:M ratio (sensitivity 60%, specificity 88%); 123I-MIBG SPECT defect score ≥31 (sensitivity 78%, specificity 77%). Conclusions In HF patients without prior ventricular arrhythmia, 123I-MIBG imaging strongly predicts future arrhythmic risk. This may inform the process of case selection for ICD therapy on an individual basis, although no single measurement provides sufficient reassurance to obviate device implantation if otherwise clinically indicated.

Radiation dose reduction without compromise of image quality in cardiac angiography and intervention with the use of a flat panel detector without an antiscatter grid

Objective: To test the hypothesis that replacing the antiscatter grid with an air gap will reduce patient radiation exposure without significant compromise of image quality. Methods: 457 patients having either uncomplicated diagnostic studies or a single vessel angioplasty (percutaneous transluminal coronary angioplasty (PTCA)) on a flat plate system (GE Innova) were studied. For two months their total dose–area product score was recorded on standard gridded images and then for two months on images made with the grid out, with an air gap used to reduce scatter. Detector magnification was reduced one step when an air gap was used to achieve the same final image size. A sample set of studies was reviewed blind by five observers, who scored sharpness and contrast on a non-linear scale. Results: The average dose–area product was significantly reduced, both in the diagnostic group (n  =  276), from a mean (SD) of 26.2 (14.7) Gy·cm2 with the grid in to 16.1 (12) Gy·cm2 with the grid out (p  =  0.01), and in the PTCA group (n  =  181), from 48.2 (36.2) to 37 (27.5) (p  =  0.01). The mean image quality scores of the gridless cohort were not significantly different from those of the gridded cohort. Conclusion: With the use of a flat plate detector, air gap gridless angiography reduces the radiation dose to the patient and, in consequence, to the operator without significantly affecting image quality. It is proposed that gridless imaging should be the default technique for adults and children and in most installations.

Brachial artery low-flow-mediated constriction is increased early after coronary intervention and reduces during recovery after acute coronary syndrome: characterization of a recently described index of vascular function

AIMS The endothelium plays a role in regulating vascular tone. Acute and dynamic changes in low-flow-mediated constriction (L-FMC) and how it changes with regard to traditional flow-mediated dilatation (FMD) have not been described. We aimed to investigate the changes in brachial artery L-FMC following percutaneous coronary intervention (PCI) and during recovery from non-ST-segment elevation myocardial infarction (NSTEMI). METHODS AND RESULTS FMD was performed in accordance with a previously described technique in patients before and after PCI and in the recovery phase of NSTEMI, but in addition, L-FMC data were acquired from the last 30 s of cuff inflation. About 135 scans were performed in 96 participants (10 healthy volunteers and 86 patients). Measurement of brachial L-FMC was reproducible over hours. L-FMC was greater among patients with unstable vs. stable coronary atherosclerosis (-1.33 ±1.09% vs. -0.03 ± 1.26%, P < 0.01). Following PCI, FMD reduced (4.43 ± 2.93% vs. 1.66 ± 2.16%, P < 0.01) and L-FMC increased (-0.33 ± 0.76% vs. -1.63 ± 1.15%, P = 0.02). Furthermore, during convalescence from NSTEMI, L-FMC reduced (-1.37 ± 1.19% vs. 0.01 ± 0.82%, P = 0.02) in parallel with improvements in FMD (2.54 ± 2.19% vs. 5.15 ± 3.07%, P < 0.01). CONCLUSION Brachial L-FMC can be measured reliably. Differences were observed between patients with stable and unstable coronary disease. L-FMC was acutely increased following PCI associated with reduced FMD and, in the recovery from NSTEMI, L-FMC reduced associated with increased FMD. These novel findings characterize acute and subacute variations in brachial L-FMC. The pathophysiological and clinical implications of these observations require further study.

Culprit Vessel Versus Multivessel Intervention at the Time of Primary Percutaneous Coronary Intervention in Patients With ST-Segment–Elevation Myocardial Infarction and Multivessel Disease: Real-World Analysis of 3984 Patients in London

Background—It is estimated that up to two thirds of patients presenting with ST-segment–elevation myocardial infarction have multivessel disease. The optimal strategy for treating nonculprit disease is currently under debate. This study provides a real-world analysis comparing a strategy of culprit-vessel intervention (CVI) versus multivessel intervention at the time of primary percutaneous coronary intervention in patients with ST-segment–elevation myocardial infarction. Methods and Results—We compared CVI versus multivessel intervention in 3984 patients with multivessel disease undergoing primary percutaneous coronary intervention between 2004 and 2011 at all 8 tertiary cardiac centers in London. Multivariable-adjusted models were built to determine independent predictors for in-hospital major adverse cardiovascular events (MACEs) and all-cause mortality at 1 year. To reduce confounding and bias, propensity score methods were used. CVI was associated with reduced in-hospital MACE (4.6% versus 7.2%; P=0.010) and mortality at 1 year (7.4% versus 10.1%; P=0.031). CVI was an independent predictor for reduced in-hospital MACE (odds ratio, 0.49; 95% confidence interval [CI], 0.32–0.75; P<0.001) and survival at 1 year (hazard ratio, 0.65; 95% CI, 0.47–0.91; P=0.011) in the complete cohort; and in 2821 patients in propensity-matched cohort (in-hospital MACE: odds ratio, 0.49; 95% CI, 0.32–0.76; P=0.002; and 1-year survival: hazard ratio, 0.64; 95% CI, 0.45–0.90; P=0.010). Inverse probability treatment weighted analyses also confirmed CVI as an independent predictor for reduced in-hospital MACE (odds ratio, 0.38; 95% CI, 0.15–0.96; P=0.040) and survival at 1 year (hazard ratio, 0.44; 95% CI, 0.21–0.93; P=0.033). Conclusions—In this observational analysis of patients with ST-segment–elevation myocardial infarction undergoing primary percutaneous coronary intervention, CVI was associated with increased survival at 1 year. Acknowledging the limitations with observational analyses, our findings support current recommended practice guidelines.

Influence of clinical and angiographic factors on development of collateral channels.

Background The degree of coronary collateralization is believed to be related to several clinical and angiographic factors. The duration and frequency of angina may be important factors in determining development of collateral channels. Objective To assess these factors for a consecutive series of patients suspected to have coronary artery disease. Methods Patients without at least one stenosis of <50% and patients who had previously undergone bypass surgery were excluded from our study. Severity of stenosis was quantified by digital analysis, antegrade flow in terms of TIMI grade, and collaterals using the Rentrop classification. Results We reviewed 106 patients [mean age 61 years (range 35–84), 77.6% men]. Of these, 22 (21%) had presented with an acute coronary syndrome on this admission, whilst 46 patients (43%) had previously had an acute coronary syndrome. Collaterals were more likely in patients with stenoses of >90% (Spearman correlation 0.65, P  < 0.001) in patients with lower than normal TIMI flow grade (Spearman correlation 0.86, P  < 0.01) and were related to regions of hypokinesis (Spearman correlation 0.35, P  < 0.01). Significant collaterals were present in 14 patients (13%) despite their having TIMI grade II/III flow. Two of these patients had grade 2/3 collaterals with TIMI grade II/III antegrade flow. Degree of collateralization was not related to chronicity and frequency of symptoms, age, risk factors for atherosclerosis and nature of presentation (i.e. acute or stable symptoms). Conclusion The likelihood of coronary collateralization cannot be prospectively predicted from clinical history alone, but appears to be largely a function of severity of stenosis and level of antegrade flow. A few patients develop high-grade collateral channels despite the presence of good antegrade flow.

Schwartz Rounds: reviving compassion in modern healthcare

Expectations of modern healthcare are extremely high. Medicine can achieve wonders hardly dreamt of 50 years ago. Technology and the accelerated pace of change threaten to displace compassion. That old phrase which used to resonate when used by consultants on ward rounds, ‘lots of TLC, Sister’ is rarely heard now. Healthcare is expensive and every nation wrestles with its priorities and problems. The urge to measure is understandable and necessary and has led to positive results such as the marked reduction in waiting times for treatment in hospital within the NHS. And yet, much of what is really valuable to our patients is difficult to measure. Prompted by our Director of Nursing and supported by Kings Fund we have embarked on the Schwartz Rounds.1 The Royal Brompton and Harefield are the third hospital Trust in the UK to do so after Cheltenham and Gloucester and the Royal Free Hospitals. As a postgraduate teaching institution, the Royal Brompton and Harefield NHS Foundation Trust aspires to care, at the highest level, for patients with heart and lung disease. We endeavour to manage difficult clinical problems that others cannot. In this process it is easy to get lost in the logistics of efficiency and innovation and to ignore the human relationships that develop between both staff and their patients and between different staff members. Ken Schwartz was a successful American lawyer in his early 40s when he was struck down with lung cancer. He was treated at the Brigham and Womens Hospital, Boston some 11 years ago. Despite all attempts at treatment he died 11 months after the initial diagnosis was made. He and his family had nothing but praise for the care he received at an internationally renowned centre. They realized also the importance of their relationships with the caregivers. Indeed, in an essay in the Boston Globe, Ken Schwartz wrote that ‘the smallest acts of kindness made the unbearable bearable’. The family set up a legacy to enable monthly meetings, Schwartz Rounds, to take place where individual staff members could feel free and safe to express and understand their feelings about the care of a particular patient. The Rounds aim to nurture the relationships between patients and all members of staff within an institution. Everyone is welcomed to the Schwartz Rounds – porters, catering staff, pharmacists, librarians, scientists, managers and administrators. It is not just for doctors, nurses and therapists. Many of us were brought up in an age when the metaphorical stiff upper lip still held sway. While we were allowed to have ‘feelings’ we were discouraged from ‘wearing them on our sleeve’. As busy practising physicians, anaesthetists and surgeons, we inevitably have taken on the treatment of extremely sick patients whose time in hospital, despite very high levels of effort, ended with the death of the patient. Delivering bad news to relatives and loved ones is never easy but is very important and, in a way, helps to lighten the load on oneself. In the past, we might slink away, sleep uneasily for the next few nights and be somewhat withdrawn with our friends, partners and spouses. Alternatively, we may have debriefed with colleagues over a drink after the work day had ended – a situation now less common with the loosening of work ties associated with the reduced hours necessitated by the European Working Time Directive. But, showing compassion towards oneself is crucial if we are to continue showing compassion towards patients and their families. By taking time to debrief as a team and discuss what the experience of caring for a critically-ill patient was like, we can guard against the long-term effects of the stress of such challenging situations.2 Schwartz Rounds are one-hour meetings held in the middle of the day, preceded by a buffet lunch, a principle laid down by Ken Schwartz himself. A story is told by three or four people, of whom only one is a doctor. Each person speaks for three to four minutes about the care of a particular patient. There is no formal presentation. The rest of the room are invited to join the discussion by a facilitator, who is a senior nurse, and the lead clinician, a senior doctor. The presentation and discussion are confidential, and strenuous efforts are made to ensure that we preserve the anonymity of the patient. The Rounds stop promptly after 60 minutes. We have noticed that many of the audience linger afterwards to continue the discussions in smaller groups. We take this as one indicator that these Rounds are helpful. Preliminary analysis of the evaluation forms also suggests that there is considerable enthusiasm for these sessions. A few hours of preparation are required in the weeks leading up to the round and we have found that a ‘dress rehearsal’ on the morning of the Round is very helpful. It helps to highlight the key issues and provides leads to the subsequent discussion. We are about to embark on a prospective study to assess the impact of these Rounds not only on the panel members but on the audience, the hospital at large, and the patients. Meetings of this type are an effective way of providing the care team with an outlet to share their feelings with each other. This can help staff to understand that they are supported, their feelings are mirrored by others and that they are not isolated. It helps them to continue providing quality care even in highly emotional cases. Moreover, several participants have remarked that the process of preparation for these sessions has helped them to achieve closure on a troubling experience that had been niggling in their consciousness for many months. Six months into our Schwartz Rounds we are learning fast and have been helped enormously by the skill of a professional psychologist who acts both as our coach and quality controller. In any meeting of medical people the overwhelming desire is to try to solve the problem and focus entirely on the patient. These Rounds are different. We seek to bring problems of care into the fresh air, a process which requires a great deal of courage on the part of the participants. This process is not sterile but leads those in a position of power in the hospital to re-think the way we organize ourselves and seek to find better solutions. The true heroes of our hospitals are not the nurses or the doctors but the patients. Most patients are just ordinary people thrust into extraordinary circumstances and part of what enables them to be courageous is the compassion of those caring for them. It behoves us then to care for ourselves so that we can better care for our patients.