Impact of COVID-19 on cardiac procedure activity in England and associated 30-day mortality

Background

The COVID-19 pandemic had a significant impact on the quality of healthcare provision across all specialities and disciplines. However, there are limited data on the scale of its disruption to cardiac procedure activity from a national perspective and whether procedural outcomes different before and during the COVID-19 pandemic.

Methods

Major cardiac procedures (n=374,899) performed between 1st January and 31st May for the years 2018, 2019 and 2020 were analysed, stratified by procedure type and time-period (pre-COVID: January-May 2018 and 2019 and January-February 2020 and COVID: March-May 2020). Multivariable logistic regression modelling was undertaken to examine the odds ratio (OR) of 30-day mortality for procedures performed in the COVID period (vs. pre-COVID).

Results

There was a deficit of 45,501 procedures during the COVID period compared to the monthly averages (March-May) in 2018–2019. Cardiac catheterisation and cardiac electronic device implantations were the most affected in terms of numbers (n=19,637 and n=10,453) while surgical procedures including mitral valve replacement, other valve replacement/repair, atrial and ventricular septal defect repair, and CABG were the most affected as a relative percentage difference (D) to previous years' averages. TAVR was the least affected (D-10.6%). No difference in 30-day mortality was observed between pre-COVID and COVID time-periods for all cardiac procedures except cardiac catheterisation (OR 1.25 95% confidence interval (CI) 1.07–1.47, p=0.006) and cardiac device implantation (OR 1.35 95% CI 1.15–1.58, p<0.001).

Conclusion

There was a significant decline in national cardiac procedural activity in England during the COVID-19 pandemic, with a deficit in excess of 45000 procedures over the study period. However, there was no increase in risk of mortality for most cardiac procedures performed during the pandemic. While health service pressures are gradually easing given the increased roll out of vaccination and decline in infection rates, there is a need for major restructuring of cardiac services deal with this significant backlog of procedures, which would inevitably impact longer-term morbidity and mortality.

Funding Acknowledgement

Type of funding sources: None.

High-sensitivity troponin is a biomarker of medium term mortality in 20,000 consecutive hospital patients undergoing a blood test for any reason

Introduction

High sensitivity troponin (hs-cTn) concentrations above the manufacturer recommended upper limit of normal (ULN) are frequently seen in patients without a clinical presentation consistent with type 1 myocardial infarction. There is increasing evidence that these concentrations may act as a marker of prognosis in a range of conditions. However, previous studies have been limited because they have only included patients in whom the clinician has requested the test. The aim of this study was to assess the relationship between medium term mortality and hs-cTn concentration in a large consecutive hospital population undergoing a blood test, regardless of whether there was a clinical indication for performing the hs-cTn.

Method

This single centre study included 20,000 consecutive patients undergoing a blood test for any reason, in whom hs-cTnI was added, regardless of the clinical indication (CHARIOT population). Mortality data up to 2.25 years was obtained via NHS Digital. The association between hs-cTnI concentration and one year mortality was evaluated using Kaplan-Meier plots (with log-rank test) and Cox proportional hazards analyses. After the cohort was considered as a whole, each of the clinical areas (inpatient (IPD), outpatient (OPD), emergency department (ED)) were considered separately. Furthermore, in the IPD and ED populations, a landmark analysis was performed excluding those patients who died within 30 days to assess whether any longer term relationship was driven by short term mortality.

Results

Overall, 2825 (14.1%) patients had died at 2.25 years. The mortality at 2.25 years was significantly higher if the hs-cTnI concentration was above the ULN (45.3% versus 12.3%, p<0.001 (log rank) in the entire cohort (Figure 1). Multivariable Cox regression analysis demonstrated that the log10hs-cTnI concentration was independently associated with 2.25 year mortality (hazard ratio (HR) 1.69 (95% confidence interval (CI): 1.59–1.80)). This relationship was demonstrated for patients in each of the clinical areas (IPD HR 1.46 (95% CI: 1.33–1.60), OPD HR 2.19 (95% CI: 1.84–2.60), ED HR 1.87 (95% CI: 1.68–2.07)). Further analysis by excluding those patients that died within 30 days demonstrated that the relationship between hs-cTnI concentration and mortality persisted and it was not driven by short term mortality.

Conclusion

In a large, unselected hospital population of both in- and out-patients, the majority of whom there was no clinical indication for testing, hs-cTnI concentration was independently associated with medium term mortality. These data suggest that hs-cTnI may have a role as a biomarker of future risk.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Beckman Coulter

Incidence and one year outcome of periprocedural myocardial infarction following cardiac surgery: are the universal definition and SCAI criteria fit for purpose?

Introduction

The diagnosis and clinical implication of periprocedural myocardial infarction (PPMI) following coronary artery bypass grafting (CABG) is contentious, especially given its importance in the interpretation of trial data. Two accepted definitions of PPMI yield discrepant results. Little is known about the association between the diagnosis of PPMI, using high sensitivity troponin (hs-cTn), and medium term mortality in patients who undergo CABG, either alone or in conjunction with another procedure. In addition, there are currently no criteria for the diagnosis of PPMI following non-CABG surgery.

Method

Consecutive patients admitted to a cardiothoracic critical care unit (CCCU) over a six month period following open cardiac surgery had hs-cTnI assay performed on admission and every day for forty-eight hours, regardless of whether there was a clinical indication. Patients were categorised as PPMI using both the Universal Definition of MI (UDMI) and Society of Cardiovascular Angiography and Interventions (SCAI) criteria. Comorbidity data, surgical details and clinical progress in CCCU were recorded. One year mortality data were obtained from NHS Digital.

Results

There were 245 CABG patients, of whom 20.4% met criteria for UDMI PPMI and 87.6% for SCAI UDMI (figure 1). The diagnosis of UDMI PPMI was independently associated with one year mortality (hazard ratio 4.175 (95% confidence interval 1.281 – 13.608)), whereas there was no association between SCAI PPMI and one year mortality (figure 2). Of the 243 patients who had non CABG cardiac surgery, 11.4% met criteria for UDMI PPMI and 85.2% for SCAI PPMI (figure1) but neither was associated with one year mortality.

Conclusions

The incidence of SCAI PPMI in a real world cohort of cardiac surgery patients is so high as to be of limited clinical value. By contrast, a diagnosis of UDMI PPMI post CABG is independently associated with one year mortality, so may have clinical utility.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Beckman Coulter - supplied the assays used in the study but had no role in the study Figure 1. Frequency of PPMIFigure 2. Kaplan Meier curves

The relationship between high-sensitivity troponin taken on admission to critical care, regardless of whether there was a clinical indication for testing, and one year mortality

Introduction

High-sensitivity troponin (hs-cTn) assays now form a key component of the diagnostic pathways for patients presenting to emergency medical services with chest pain. However, hs-cTn concentrations above the manufacturer-provided upper limit of normal (ULN) are now frequently reported in patients presenting with conditions not traditionally associated with type 1 myocardial infarction (T1MI). This is particularly true of severe illness states. We investigated the possible association between hs-cTn and 1 year mortality in critical care patients.

Method

Consecutive patients admitted to two adult critical care units (general critical care unit (GCCU) and neuroscience critical care unit (NCCU)) over a six month period had hs-cTnI assay performed on admission, regardless of whether there was a clinical indication, and the results nested unless a clinical request had been made. Comorbidity data, illness severity and critical care outcome were recorded and have been previously reported. One year mortality data were obtained from NHS Digital.

Results

After excluding patients diagnosed with T1MI by the clinical team, there were 1,033 patients remaining. At one year a total of 253 (24.5%) patients had died. The Kaplan-Meier curves in figure 1 demonstrate a positive association between mortality and increasing hs-cTnI concentrations relative to the ULN. Specifically, using the log-rank test, the mortality at one year was significantly higher (p<0.001) in patients with hs-cTnI concentrations above the ULN. Furthermore, on multivariable Cox regression analysis, the log(10) hs-cTnI concentration was independently associated with the hazard of one year mortality (hazard ratio 1.587 (95% confidence interval 1.358–1.856).

Conclusions

These data suggest that admission hs-cTnI is a biomarker for one year mortality in critical care patients. Further work is now required to assess whether any medical intervention can alter this risk.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Beckman Coulter provided the assays for the tests used in this study. They had no other involvement in the study

Fractional flow reserve derived from computed tomography coronary angiography in the assessment and management of stable chest pain: the FORECAST randomized trial

Aims 

Fractional flow reserve (FFR_CT) using computed tomography coronary angiography (CTCA) determines both the presence of coronary artery disease and vessel-specific ischaemia. We tested whether an evaluation strategy based on FFR_CT would improve economic and clinical outcomes compared with standard care.

Methods and results 

Overall, 1400 patients with stable chest pain in 11 centres were randomized to initial testing with CTCA with selective FFR_CT (experimental group) or standard clinical care pathways (standard group). The primary endpoint was total cardiac costs at 9 months. Secondary endpoints were angina status, quality of life, major adverse cardiac and cerebrovascular events, and use of invasive coronary angiography. Randomized groups were similar at baseline. Most patients had an initial CTCA: 439 (63%) in the standard group vs. 674 (96%) in the experimental group, 254 of whom (38%) underwent FFR_CT. Mean total cardiac costs were higher by £114 (+8%) in the experimental group, with a 95% confidence interval from −£112 (−8%) to +£337 (+23%), though the difference was not significant (P = 0.10). Major adverse cardiac and cerebrovascular events did not differ significantly (10.2% in the experimental group vs. 10.6% in the standard group) and angina and quality of life improved to a similar degree over follow-up in both randomized groups. Invasive angiography was reduced significantly in the experimental group (19% vs. 25%, P = 0.01).

Conclusion 

A strategy of CTCA with selective FFR_CT in patients with stable angina did not differ significantly from standard clinical care pathways in cost or clinical outcomes, but did reduce the use of invasive coronary angiography.

New onset left bundle branch block after transcatheter aortic valve implantation and the effect on long-term survival – a UK wide experience

Introduction

New onset left bundle branch block (LBBB) is the most common conduction disturbance associated with transcatheter aortic valve implantation (TAVI). It has been shown to adversely affect cardiac function and increase re-hospitalisation, although its impact on mortality remains contentious.

Methods

We conducted an observational cohort analysis of all TAVI procedures performed by 13 heart teams in the United Kingdom from inception of their structural programmes until 31st July 2013. The primary outcome was 1-year all-cause mortality. Secondary outcomes included left ventricular ejection fraction (LVEF) at 30 days and need for a post-TAVI permanent pacemaker (PPM).

Results

1785 patients were eligible for inclusion to the study. The primary analysis cohort was composed of 1409 patients with complete electrocardiographic (ECG) data pre- and post-TAVI. Pre-existing LBBB was present in 200 (14.2%) patients. New LBBB occurred in 323 (22.9%) patients post TAVI, which resolved in 99 (7%) patients prior to discharge. A balloon-expandable device was implanted in 968 (69%) patients, whilst 421 (30%) patients received a self-expandable valve. New LBBB was observed in 120 (12.4%) and 192 (45.6%) patients receiving a balloon- or self-expandable prosthesis respectively.

Overall 1-year all-cause mortality post TAVI was 18.7%. New onset LBBB was not associated with an increase in 1-year all-cause mortality (p=0.416). Factors that were associated with mortality included an increasing logistic EuroScore (p=0.05), history of previous balloon aortic valvuloplasty (p=0.001), renal impairment (p=0.003), previous myocardial infarction with pre-existing LBBB (p=0.028) and atrial fibrillation (p=0.039). Lower baseline peak and mean AV gradients were also associated with greater mortality at 1 year (p=0.001), likely reflecting underlying left ventricular dysfunction.

In the majority of patients, LVEF remained unchanged following TAVI. Interestingly, the presence or absence of new onset LBBB did not affect LVEF improvement at 30 days. 10% of patients required a PPM post TAVI. Predictors of PPM included new LBBB (OR 2.6, p<0.001), pre-TAVI left ventricular systolic impairment (OR 1.2, p=0.037), a self-expandable device (p<0.001), and pre-existing RBBB (OR 4.0, p<0.001).

Conclusions

These findings suggest that new onset LBBB post TAVI does not increase mortality at 1 year or adversely affect LVEF at 30 days.

Funding Acknowledgement

Type of funding source: None

Distribution of high sensitivity troponin taken without conventional clinical indications in critical care patients and its association with mortality

Background

High sensitivity troponin (hs-cTn) concentrations above the manufacturer's upper limit of normal (ULN) are frequently seen outside the context of MI, particularly in critical care units. The current evidence regarding the prognostic value of hs-cTn in critical care settings is discrepant.

Purpose

To describe the distribution of hs-cTn in a consecutive cohort of patients in critical care units, regardless of whether there is a conventional clinical indication, and the association of this distribution with clinical outcomes.

Methods

Consecutive patients admitted to three adult critical care units (cardiothoracic (CCU), general (GCU), neuroscience (NCU)) over a six month period had hs-cTnI tests performed serially throughout the admission, regardless of whether the supervising team felt there was a clinical indication. The results were nested and not revealed to patients or clinicians unless they were requested as part of routine care. The hs-cTnI results were correlated with parameters of clinical outcome.

Results

After excluding those diagnosed with a type 1 MI, there were 1,563 patients remaining in the study cohort (CCU 530, GCU 750, NCU 283). The median hs-cTnI was 77ng/L (IQR 11–1932ng/L, with 1081 (69.2%) patients above the manufacturer-provided ULN. Overall there was a bimodal distribution; GCU and NCU were positively skewed and CCU negatively skewed. Hs-cTnI concentrations above the ULN were associated with age, comorbidity, illness severity and need for organ support (table 1). The degree by which the hs-cTnI concentration was above the ULN remained an independent predictor of critical care mortality (figure 1) in NCU and GCU.

Conclusion

Hs-cTnI elevation taken outside the context of conventional clinical indications is common in the critically ill and is associated with age, comorbidity and illness severity. Admission hs-cTnI is an independent predictor of mortality and provides additional discriminative ability to the APACHE II score alone. This assay may represent a novel prognostic biomarker on admission in non-CCU critical care settings.

Mortality relative to ULN

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Beckman Coulter

P6510Frailty and in-hospital outcomes in percutaneous coronary interventions

Background

Frailty may be an important marker for poor outcomes in percutaneous coronary intervention (PCI) and there is limited literature on outcomes based on frailty from national cohorts.

Purpose

This study evaluates the prevalence of frailty, changes in frailty over time and outcomes associated with frailty in a national American cohort of patients who underwent PCI.

Methods

The study included adults who underwent PCI in the National Inpatients Sample between 2004 and 2014. Frailty risk was determined using a validated Hospital Frailty Risk Score (HFRS) using the cutoffs <5, 5–15 and >15 corresponding to low, intermediate and high HFRS.

Results

There were 7,306,007 PCI admissions in this cohort. A total of 94.58%, 5.39% and 0.03% of admissions were for low HFRS, intermediate HFRS and high HFRS, respectively. The proportion of intermediate or high frailty risk patients increased over time from 1.9% in 2004 to 11.7% in 2014. In-hospital death increased from 1.0% with low HFRS to 13.9% with high HFRS and average length of stay increased from 2.9±3.3 days to 17.1±15.5 days from low to high HFRS. Greater frailty risk was associated with greater average inpatient cost which was $17,743±11,059, $38,824±34,809 and $56,119±49,772 for low, intermediate and high HFRS, respectively. There were increased adverse outcomes with high frailty including greater in-hospital death (OR 9.91 95% CI 7.17–13.71), in-hospital bleeding complications (OR 4.99 95% CI 3.82–6.51), in-hospital vascular complications (OR 3.96 95% CI 3.00–5.23) and in-hospital stroke (OR 10.49 95% CI 8.28–13.29) comparing high to low HFRS.

Conclusions

More than 1 in 20 patients who undergo PCI have intermediate or high risk of frailty which has significantly increased over time. There are poor outcomes and increased inpatient costs associated with greater frailty. Improvements in education of healthcare workers and increased awareness of frailty could facilitate frailty-tailored care to minimise risk of adverse outcomes and its associated costs.

Acknowledgement/Funding

Research and Development Department at the Royal Stoke Hospital, Keele University and Biosensors International

Determinants of excess mortality following unprotected left main stem percutaneous coronary intervention

OBJECTIVE

For percutaneous coronary intervention (PCI) to the unprotected left main stem (UPLMS), there are limited long-term outcome data. We evaluated 5-year survival for UPLMS PCI cases taking into account background population mortality.

METHODS

A population-based registry of 10 682 cases of chronic stable angina (CSA), non-ST-segment elevation acute coronary syndrome (NSTEACS), ST-segment elevation myocardial infarction with (STEMI+CS) and without cardiogenic shock (STEMI-CS) who received UPLMS PCI from 2005 to 2014 were matched by age, sex, year of procedure and country to death data for the UK populace of 56.6 million people. Relative survival and excess mortality were estimated.

RESULTS

Over 26 105 person-years follow-up, crude 5-year relative survival was 93.8% for CSA, 73.1% for NSTEACS, 77.5% for STEMI-CS and 28.5% for STEMI+CS. The strongest predictor of excess mortality among CSA was renal failure (EMRR 6.73, 95% CI 4.06 to 11.15), and for NSTEACS and STEMI-CS was preprocedural ventilation (6.25, 5.05 to 7.75 and 6.92, 4.25 to 11.26, respectively). For STEMI+CS, the strongest predictor of excess mortality was preprocedural thrombolysis in myocardial infarction (TIMI) 0 flow (2.78, 1.87 to 4.13), whereas multivessel PCI was associated with improved survival (0.74, 0.61 to 0.90).

CONCLUSIONS

Long-term survival following UPLMS PCI for CSA was high, approached that of the background populace and was significantly predicted by co-morbidity. For NSTEACS and STEMI-CS, the requirement for preprocedural ventilation was the strongest determinant of excess mortality. By contrast, among STEMI+CS, in whom survival was poor, the strongest determinant was preprocedural TIMI flow. Future cardiovascular cohort studies of long-term mortality should consider the impact of non-cardiovascular deaths.

Does the response to aspirin and clopidogrel vary over 6 months in patients with ischemic heart disease?

BACKGROUND

Dual-antiplatelet therapy (DAPT) with aspirin and a P2Y12 inhibitor, mostly clopidogrel, is the default therapy in both acute coronary syndrome (ACS) and after intracoronary stents. It is well established that responses to antiplatelet therapy (APT), particularly clopidogrel, are subject to considerable interindividual variability.

OBJECTIVES

We investigated whether responses to APT in individuals vary significantly over time.

METHODS

Simultaneous assay with VerifyNow(™) and short thrombelastography (s-TEG) was performed before and at four time points over 6 months after hospital discharge in 40 patients receiving DAPT. Serum thromboxane B2 levels were also measured.

RESULTS

While aspirin response units (ARU) by VerifyNow(™) and serum thromboxane B2 levels remained stable over time, arachidonic acid (AA)-mediated platelet aggregation with s-TEG (i.e. area under the curve at 15 min in AA channel, AUC15AA ) increased at 1 week compared with predischarge (P < 0.008). In addition, platelet reactivity units (PRU) by VerifyNow(™) (P = 0.046) and adenosine diphosphate (ADP)-mediated platelet aggregation with s-TEG (i.e. AUC15ADP ) also increased at 1 week compared with predischarge (P = 0.026). There were no significant changes in either platelet reactivity or rates of high on-treatment platelet reactivity while receiving clopidogrel beyond 1 week.

CONCLUSIONS

This study demonstrates important variability in responses to APT within individuals between predischarge and 1 week but not thereafter. The use of a single early (predischarge) platelet function assay as an indicator of future response may therefore be flawed. The design of future strategies to assess individual responses for tailored therapy needs to take this into account.

Transapical perfusion for peri-arrest salvage during transcutaneous aortic valve implantation

An 80-year-old man developed severe haemodynamic instability during a transapical aortic valve implantation. He was not suitable for a conventional surgical approach due to comorbidities and patent aortocoronary bypass grafts also limited further stabilizing actions. As a bail-out procedure, we demonstrate the feasibility of transapical arterial cannulation by crossing a newly implanted TAVI valve in order to establish an emergency bypass circuit

Troponin-positive chest pain with unobstructed coronary arteries: definitive differential diagnosis using cardiac MRI

OBJECTIVE

The purpose of this study was to assess the outcome of cardiac MRI (CMRI) with late gadolinium enhancement (LGE) at outpatient follow-up in a consecutive series of patients with troponin-positive chest pain but unobstructed coronary arteries at the index admission.

METHODS

The study group comprised 91 consecutive patients who presented to our institution with cardiac chest pain, elevated troponin I and unobstructed coronary arteries on coronary angiography. All patients underwent an outpatient CMRI with LGE imaging in order to establish a definitive diagnosis.

RESULTS

The average time from coronary angiography to LGE-CMRI was 2 months. 73% of patients had no abnormality on their LGE-CMRI, 16% of patients had patchy late enhancement consistent with myocarditis and 11% had focal subendocardial or full thickness late enhancement consistent with myocardial infarction. There were no deaths in this cohort during a mean follow-up of 21 months.

CONCLUSION

LGE-CMRI is a useful tool for establishing whether such patients have definitive evidence of non-ST-segment elevation myocardial infarction (NSTEMI), and can make an important contribution to the long-term management strategy of these patients as an inappropriate diagnosis of NSTEMI carries important medical, social and financial implications.

Individualised assessment of response to clopidogrel in patients presenting with acute coronary syndromes: a role for short thrombelastography?

INTRODUCTION

There is considerable interindividual variation in response to the antiplatelet agent clopidogrel. Hyporesponse predicts negative outcomes in patients presenting with a variety of ischemic cardiac conditions and following intracoronary stent placement. Many tests of clopidogrel activity are time consuming and complex. Short thromboelastography (s-TEG) allows rapid measurement of platelet clopidogrel response.

AIMS

We initiated this study to investigate the utility of s-TEG in assessing the response to clopidogrel in patients presenting with acute coronary syndromes (ACS) and to compare these results with established clopidogrel monitoring techniques.

METHODS

Patients admitted with unstable angina (UA) or Non ST elevation myocardial infarction (NSTEMI) undergoing coronary angiography were recruited. After routine loading with clopidogrel, all patients were tested with s-TEG and Accumetrics Verify-Now rapid platelet function analyzer (VN-RPFA). We used the modified TEG technique of measuring area under the curve at 15 min (AUC15), which allows a rapid estimation of antiplatelet response. Vasodilator-stimulated phosphoprotein phosphorylation (VASP) was also tested in a subgroup of patients. Clinical follow-up was obtained at 1 year. s-TEG results were correlated with VN-RPFA and VASP findings.

RESULTS

A total of 49 patients (33 male, mean age 63) were recruited and tested with s-TEG and VN-RPFA and a total of 39 patients were also assessed with VASP. s-TEG readings correlated well with VN-RPFA (r(2)= 0.54, P < 0.0001) and VASP (r(2)= 0.26, P= 0.001).

CONCLUSION

s-TEG provides timely results which compare to current tests of clopidogrel activity. This technique can also be used to measure a variety of other clotting parameters and as such could develop into a valuable near patient test for the interventional cardiologist.

Screening for carotid artery disease before cardiac surgery: is current clinical practice evidence based?

BACKGROUND

There is no clear consensus as to the correct screening procedure to identify patients undergoing cardiac surgery and who are at greatest risk of stroke because of the presence of significant carotid artery stenosis. Such screening is important because some patients benefit from combined carotid and cardiac surgery and, regardless of this, the information gained puts the cardiac surgeon in a position to provide an accurate assessment of surgical risk. Our objective was to examine current clinical practice of carotid artery investigation prior to urgent cardiac surgery and to review this illustrative practice in the context of the world literature.

HYPOTHESIS

The study aimed to establish that current typical practice for screening cardiac surgical patients for carotid artery disease is illogical according to the evidence in the world literature.

METHODS

The study consisted of a retrospective assessment of all patients undergoing urgent cardiac surgery and a Medline-derived literature review, and included all patients undergoing urgent cardiac surgery at a tertiary cardiothoracic center between January 1 and December 31, 1997.

RESULTS

Of 529 patients undergoing urgent cardiac surgery, 44 (8%) were screened preoperatively by duplex Doppler ultrasonography for carotid disease. The indications for screening were asymptomatic carotid bruit in 24 patients, history of stroke or transient ischemic attack (TIA) in 12 patients, and neither stroke, TIA, or bruit in 7 patients. The tests were requested either by the attending cardiologists or by the cardiac surgeon to whom they were referred. One patient had already been diagnosed as having carotid artery disease in the past. Thirteen patients underwent additional carotid investigations. Eleven patients were demonstrated to have internal carotid artery stenosis > or = 60% and 3 patients underwent combined cardiac and carotid surgery. Review of the literature revealed the following groups to be at increased risk of future stroke unrelated to surgery, and of postoperative stroke: those with a history of stroke or TIA, those with carotid bruits, and, of importance, all patients with significant carotid stenosis. Recent data suggest that symptomatic patients and the elderly are at greatest risk.

CONCLUSIONS

Only 8% of patients undergoing urgent cardiac surgery in a 1-year period were screened for carotid artery disease. We suggest that screening should definitely be performed in all patients with a history of stroke or TIA, all patients with a bruit, and all patients aged > 65 years. The literature suggests, however, that significant reductions in stroke rate could be achieved by screening the whole cardiac surgical population, although there is a paucity of data that are specifically pertinent to this patient subgroup. Further data are therefore required for the construction of a scientifically valid and medicolegally sound policy.

Atherogenesis: the role of inflammation and infection

Atherosclerosis is no longer considered a disorder of lipid accumulation, but a disease process characterized by the dynamic interaction between endothelial dysfunction, subendothelial inflammation and the 'wound healing response' of the vascular smooth muscle cells. Prospective epidemiological studies have unequivocally demonstrated increased vascular risk in individuals with elevated levels of (i) cytokines such as interleukin-6 and tumour necrosis factor-alpha, (ii) cell adhesion molecules such as intercellular adhesion molecule-1 and P-selectin, and (iii) acute-phase proteins such as C-reactive protein, fibrinogen and serum amyloid A. Furthermore, evidence from clinical trials have demonstrated that risk reduction achieved with anti-inflammatory agents such as statins is significantly greater in patients with evidence of inflammation. A number of risk factors for atherogenesis, including infectious agents, have been shown to exert their influence via inflammatory mechanisms. However, despite compelling experimental evidence, clinical studies looking at the role of infection in atherogenesis have lacked consistency. The clinical product of this dynamic process is variable and unpredictable between individuals, even those with apparently similar risk profiles.

Reducing transfer times for coronary angiography in patients with acute coronary syndromes: one solution to a national problem

BACKGROUND

Patients with acute coronary syndrome (ACS) are at high risk of further cardiac events and benefit from early intervention, as reflected by international guidelines recommending early transfer to interventional centres. The current average waiting time of up to 21 days contravenes evidence based early intervention, creates geographical inequity of access, wastes bed days, and is unsatisfactory for patients.

METHODS

A regional transfer unit (RTU) was created to expatriate access of ACS patients referred from other centres to the revascularisation service. By redesigning the care pathway patients arriving on the RTU undergo angiography within 24 hours, and then leave the RTU the following day, allowing other ACS patients to be treated.

RESULTS

During the first six months of the RTU, the mean waiting time from referral to procedure decreased from 20 (SD 15) days (range 0-51) to 8 (SD 3) days (range 0-21) for 365 patients transferred from a district general hospital. Ninety seven per cent of patients underwent angiography within 24 hours, 61% having undergone percutaneous coronary intervention at the same sitting, and 78% were discharged home within 24 hours.

CONCLUSIONS

Delivering standards laid out in the National Service Framework, reducing inequalities of care across the region, and facilitating evidence based strategies of care represents a challenging and complex issue. For high risk patients suffering ACS who need early invasive investigation, a coordinated network wide approach together with the creation of an RTU resulted in a 62% reduction in waiting times for no extra resources. Further improvements can be expected through increased capacity of this verified strategy.

Non-clinical factors influencing the selection of patients with acute coronary syndromes for angiography

OBJECTIVE

To analyse clinical and non-clinical factors determining the selection for coronary angiography in patients with acute coronary syndromes (ACS).

DESIGN

Single centre, prospective cohort study.

PARTICIPANTS

Eighty consecutive patients admitted with a diagnosis of ACS during the period 21 May 2001 to 4 July 2001.

SETTING

Coronary care unit of a tertiary referral centre, the Manchester Royal Infirmary.

DATA COLLECTION

Information concerning baseline patient characteristics, clinical presentation, and the selection for angiography was collected from the patient notes.

DATA COLLECTION

Windows SPSS version 9.0 using cross tabulations with chi(2) estimation and binomial logistic regression analysis.

MAIN OUTCOME MEASURE

Selection for angiography in ACS.

RESULTS

Cross tabulations with chi(2) analysis and logistic regression analysis identified significant non-clinical factors predicting the use of angiography. Although clinical factors such as recurrent ischaemia (odds ratio 5.11) influenced the decision to undergo coronary angiography, non-clinical factors such as young age (odds ratio 6.88 for <65 years old), gender (odds ratio 3.81 for males), admission on a weekday (odds ratio 0.2488 for admission on the weekend), and consultant in charge (odds ratio 0.111 for consultant "2") independently predicted the use of angiography in ACS.

CONCLUSION

The selection of patients for angiography in ACS is not based purely on clinical criteria. Awareness of the apparent sources of bias among clinical decision makers may improve management of these patients.

Recurrent stent thrombosis associated with lupus anticoagulant due to renal cell carcinoma

A case is presented of recurrent stent thrombosis unexplained by angiographic appearance, which subsequently revealed a diagnosis of antiphospholipid syndrome secondary to renal cell carcinoma.

Are district general hospital patients with unstable angina at a disadvantage?

OBJECTIVE

To determine whether patients with non-ST elevation acute coronary syndromes requiring coronary angiography and revascularisation have inferior access to these services if admitted to district general hospitals (DGHs) compared with similar patients admitted to a base hospital containing a tertiary cardiac centre.

DESIGN

Prospective, consecutive monitoring of all patients with acute coronary syndromes accepted by the tertiary cardiac centre for angiography and revascularisation over a three month period (1 April to 30 June 2002).

PARTICIPANTS

All patients accepted for angiography from DGHs and from within the base hospital with a diagnosis of acute coronary syndromes.

SETTING

Tertiary cardiac facility (Manchester Heart Centre at Manchester Royal Infirmary (MRI)).

MAIN OUTCOME MEASURE

Time waited from referral to angiography and revascularisation.

RESULTS

A total of 184 patients with a diagnosis of non-ST elevation acute coronary syndromes underwent angiography with a view to revascularisation. Of these, 89 (48%) were admitted initially to MRI and 95 (52%) were admitted to a feeder DGH. DGH patients waited significantly longer from admission to angiography than MRI patients (median 13 days (25th-75th percentiles 7-19) v 5 days (3-8) respectively; p<0.0005). DGH patients therefore also waited longer from admission to revascularisation (15 days (6-20) v 6 days (3-9) respectively). Once transferred into the Manchester Heart Centre, DGH patients underwent angiography within a median of 1 day (1-2). More DGH patients than those from MRI underwent both coronary artery bypass grafting (21 (22%) v 8 (9%) respectively; p=0.015) and percutaneous coronary intervention (44 (46%) v 32 (36%) respectively; p=NS).

CONCLUSION

Patients admitted to feeder DGHs with non-ST elevation acute coronary syndromes wait significantly longer for access to invasive coronary assessment and revascularisation than similar patients admitted in the hospital that incorporates the tertiary cardiac centre. This inequity of access is determined by postcode rather than clinical priority.

A national Survey of Acute Myocardial Infarction and Ischaemia (SAMII) in the U.K.: characteristics, management and in-hospital outcome in women compared to men in patients under 70 years

AIMS

To assess the clinical characteristics, management and outcome of women compared to men with acute myocardial infarction or ischaemia.

DESIGN

A prospective clinical survey was made in a random sample of 94 District General Hospitals in the U.K. 1064 patients, <70 years of age, comprising six consecutive females and six consecutive males from each hospital, diagnosed on admission as acute coronary syndromes (myocardial infarction or myocardial ischaemia) were studied. Outcome measures included: admission and final diagnosis, time to delivery of care, inpatient management, complications and clinical outcome.

RESULTS

Five hundred and three women and 561 men were admitted with a diagnosis of acute myocardial infarction or myocardial ischaemia. Women were older, waited longer between seeking and receiving advice, and much less likely to have infarction than men. After adjustment for age, diagnosis and past medical history there were no gender differences in initial and subsequent hospital management, in complications (recurrent ischaemia, arrhythmias, temporary pacing, heart failure), any routine procedure or outcome. Of all patients, 3.4% died in a District General Hospital, 12.2% were transferred to Specialist Cardiac Centres and 84.4% discharged home. Prophylactic medication on discharge was similar for men and women.

CONCLUSION

After adjustment for age, diagnosis and past medical history, although women waited longer between seeking and receiving medical advice, in hospital their assessment, management, complications, outcome and follow-up arrangements were the same as for men. In hospital, management and outcomes were mainly influenced by age, diagnosis (infarction or ischaemia), a past history of coronary disease, but not by gender. This large, nationally representative, survey has found no evidence of important gender difference in the hospital management of acute ischaemic syndromes.

Increased binding of fibrinogen to glycoprotein IIIa-proline33 (HPA-1b, PlA2, Zwb) positive platelets in patients with cardiovascular disease

AIMS

The GPIIb-IIIa complex on the platelet membrane plays an important part in thrombosis as it is the receptor for fibrinogen. The gene for platelet membrane glyco-protein IIIa has multiple alleles one of which, the GPIIIa-Proline33 (HPA-1b, PlA2, Zwb) allele has been reported in some, but not all studies, to be associated with an increased risk of myocardial infarction. We investigated whether the presence of the Pro33 form of GPIIIa on the platelet membrane is associated with increased fibrinogen binding.

METHODS AND RESULTS

Blood samples from 70 patients (54 male) with stable angina of whom 22 (18 male) had a history of previous myocardial infarction, were analysed for the GPIIIa-Leu-Pro33 polymorphism at the genomic level, and for whole blood flow cytometric measurement of platelet fibrinogen binding. The GPIIIa-Pro33 form was present in 20 (28.6%) patients (1 homozygous) representing an allele frequency of 0.85 and 0.15 (GPIIIa-Leu33:Pro33). The incidence of myocardial infarction was higher (40.0%) in patients positive for GPIIIa-Pro33 than in those without (32.0%) but this was not significant (P=0.58). Fibrinogen binding to ADP-stimulated platelets was significantly higher in the GPIIIa-Pro33 positive group at all ADP concentrations (<0.0001; two way ANOVA). There was no association between fibrinogen binding and the level of expression of the GPIIb-IIIa complex, platelet volume or platelet count. Fibrinogen binding in response to thrombin stimulation was not different between the groups (P>0.05).

CONCLUSIONS

The increased tendency of platelets from patients with the Pro33 form of GPIIIa may predispose patients with this allele to a higher risk of acute thrombotic events, and argues for selective use of therapeutic agents that inhibit ADP-mediated platelet activation in occlusive vascular disease states.

Concrete induced cardiac contusion

A previously fit 22 year old man was struck in the chest by a concrete block dropped through the windscreen of his car while he was driving on the motorway. He suffered extensive chest wall trauma and lung contusion, which subsequently precipitated acute respiratory distress. On admission ECG showed right bundle branch block and left axis deviation. Three days later QRS duration was normal but there was anterior ST segment elevation and subsequent T wave change. There was a large rise in creatine kinase, and echocardiography revealed septal and apical hyokinesis as well as a mobile mass attached to the left side of the interventricular septum, which had the echogenic texture of myocardium. The patient had fixed perfusion defects in the areas of hypokinesis on thallium scanning but the coronary arteries were unobstructed at angiography. He was treated with warfarin in the short term and an angiotensin converting enzyme inhibitor in the longer term and has made an asymptomatic recovery. Outpatient echocardiography two months after the injury demonstrated some recovery in overall left ventricular systolic function and no evidence of the intracardiac mass. This case illustrates some of the typical features of non-fatal cardiac contusion associated with non-penetrating cardiac trauma, and was complicated by partial thickness avulsion of a strip of the myocardium in the interventricular septum.

Women with chest pain: is exercise testing worthwhile?

OBJECTIVE

To determine the diagnostic value of the exercise tolerance test (ETT) in women presenting with chest pain.

DESIGN

Prospective study of all women presenting to a centre with chest pain between 1987 and 1993 who were assessed by an ETT and coronary angiography.

SETTING

The outpatient clinic of one consultant cardiologist in a tertiary referral centre.

PATIENTS

All women referred to this outpatient clinic with chest pain were screened. For inclusion, patients had to perform ETT and undergo coronary angiography. Of the 347 referred during this period, 142 were excluded because they were unable to perform ETT or because of Q waves or other abnormalities on their resting electrocardiogram.

RESULTS

Overall the sensitivity of the ETT was 68% and the specificity was 61%, with a positive predictive value of 0.61 and a negative predictive value of 0.68. There were 42 false positive and 31 false negative ETT results (36% of the study group). The predictive value of a negative test was higher in younger women (< 52 years) than in the older group (> or = 52 years) (P = 0.004), but the positive predictive value in the two groups was not significantly different. The predictive value of a negative test was also higher in those with two or fewer risk factors than in those with three or more risk factors (P = 0.001). The negative predictive value for those women above 52 years with three or more risk factors (24% of the study group) was only 0.25. Lack of chest pain during ETT was associated with a higher negative predictive value in the younger group than in the older women (P = 0.006).

CONCLUSIONS

In women with chest pain use of the ETT was a misleading predictor of the presence or absence of coronary disease in 36% of these patients. In particular, a negative test in older women with three or more risk factors had a very low predictive value. The inclusion of risk factors and division by age can, however, be used to identify a population at intermediate risk for coronary artery disease in whom the ETT result has the highest diagnostic utility.

Detection of ambulatory ischaemia is not of practical clinical value in the routine management of patients with stable angina. A long-term follow-up study

It has been reported that medically treated patients with stable angina and positive exercise test for ischaemia have an adverse 1-2 year outlook if they are shown also to have transient, and predominantly silent, ischaemic episodes detected by ambulatory ST segment monitoring during their daily activities: it has been suggested that this investigation could be used to identify patients more likely to benefit from early investigation and treatment. We assessed the long-term (up to 65 months) prognostic significance of transient ischaemic episodes during daily activities in 172 patients routinely attending cardiac outpatients with medically treated stable angina who had undergone exercise testing and 48 h of ambulatory ST segment monitoring between February 1988 and August 1989 for this purpose. A positive exercise test for ischaemia was not a prerequisite for inclusion. One hundred and four patients (60.5%) had a positive exercise test for ischaemia and 72 (42%) had transient ischaemia during daily activities (63 had both tests positive). Over a median 50-month follow-up period 54 patients suffered at least one cardiac event (primary event: cardiac death n = 7; non-fatal myocardial infarction n = 11; unstable angina n = 18; elective CABG/PTCA n = 18). Two further patients suffered non-cardiac death. Cardiac events, either objective (cardiac death or non-fatal myocardial infarction) or subjective (unstable angina or revascularisation) were no more likely to occur in those with transient ischaemia during daily life when compared with those without, at follow-up times up to 65 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Value of physical signs in the diagnosis of ventricular tachycardia

BACKGROUND

Although the use of physical signs for the diagnosis of ventricular tachycardia (VT) was described in the early 1900s, their value in this role has never been systematically assessed.

METHODS AND RESULTS

Using a blinded, randomized protocol, we examined the ability of 26 clinicians to detect ventriculoatrial (VA) dissociation during cardiac pacing in 21 patients with both atrial and ventricular pacing wires in situ after successful ablation of accessory pathways. In protocol 1 (10 patients), pacing was randomized to either ventricular pacing alone (simulating VT) or to atrioventricular sequential pacing (simulating supraventricular tachycardia or VT with intact VA conduction) at rates of 150 or 180 beats per minute. Each patients was examined by four clinicians blinded to the pacing mode. Clinicians were asked to make a diagnosis of "VA association" or "VA dissociation" after examining the patient for variability of the arterial pulse, jugular venous pulse (JVP), and first heart sound. In protocol 2 (11 patients), randomization of pacing mode was performed between examination of each of the three physical signs so that the value of each sign was assessed individually. In protocol 1, a diagnosis of VA dissociation (VT) was made in 21 of 40 observations, with a specificity of 75%, sensitivity of 70%, and a positive predictive value (PPV) of 71%. In protocol 2, from a total of 132 observations (44 for each sign), the sensitivity, specificity, and PPV for a diagnosis of VT were as follows: arterial pulse, 61%, 71%, 70%; JVP, 96%, 75%, 82%; and first heart sound, 58%, 100%, 100%.

CONCLUSIONS

It is concluded that, in patients with a regular tachycardia of uncertain origin, clinically detectable variations in the first heart sound and JVP are highly specific and sensitive indicators, respectively, of a diagnosis of VT. Assessment of the arterial pulse is of little value in this role.

Prognostic significance of transient ST segment changes after coronary artery bypass surgery: a long-term (4-10 year) follow up study

OBJECTIVE

To assess the long-term (four to 10 years) prognostic significance of transient ST segment changes on ambulatory ST segment monitoring after coronary artery bypass grafting (CABG).

PATIENTS AND METHODS

76 patients (67 men, nine women) underwent CABG between 1982 and 1984 (n = 31) and between 1987 and 1988 (n = 45) and at a mean age of 57. All underwent 48 hours of ambulatory ST segment monitoring at a mean of 19 weeks after surgery. The results were available for assessment. All general practitioners were contacted and patients' notes reviewed. Patients were contacted by telephone. Details were recorded of intervening events (acute myocardial infarction, unstable angina, need for further revascularisation, and deaths). Event free survival curves were produced for those with and without transient ST segment changes during routine postoperative ambulatory ST segment monitoring.

RESULTS

During 3213 hours of monitoring after CABG, 21 (27.6%) of 76 patients had transient ST segment changes, of which 70% were silent. Over a mean 70 month follow up period, patients with such ischaemic changes were no more likely to have either an objective (myocardial infarction or cardiac death) or subjective (unstable angina or another revascularisation) event than those patients without ischaemic changes. This finding was the same in patients operated on between 1987 and 1988 and between 1982 and 1984.

CONCLUSIONS

Although ambulatory ST segment monitoring is becoming increasingly popular in some countries as a routine investigation for ischaemia in various coronary subgroups, the findings of such an investigation, when performed after CABG, do not help to identify a subgroup more likely to have an adverse outcome during up to 10 years of follow up. There seems to be no reason to perform this investigation after surgery, and particularly to refer patients for reinvestigation because of the detection of predominantly silent ST segment changes of uncertain relevance.

Obstructive sleep apnoea associated with syringomyelia

We present a case of obstructive sleep apnoea in association with syringomyelia. We describe the successful treatment of the respiratory obstruction by continuous positive airway pressure and then by surgical means. This rare combination of conditions and the management is reviewed.