Heart valve service provision in the United Kingdom and the effect of the COVID 19 pandemic; improved but must do better. A British Heart Valve Society national survey

BACKGROUND

Outpatient care for patients with heart valve disease (HVD) is best provided by valve clinics delivered by specialists. Modern day practice in the United Kingdom (UK) is currently poorly understood and has not been evaluated for nearly a decade. Furthermore, the COVID 19 pandemic changed the management of many chronic diseases, and how this has impacted patients with heart valve disease is unclear.

METHODS

A British Heart Valve Society survey was sent to 161 hospitals throughout the UK.

RESULTS

There was a general valve clinic in 46 of the 68 hospitals (68%), in 19 of 23 Heart Centres (83%) and 29 of 45 DGHs (64%). Across all settings, 3824 new patients and 17,980 follow up patients were seen in valve clinics per annum. The mean number of patients per hospital were 197 (median 150, range 48-550) for new patients and 532 (median 400, range 150-2000) for follow up. On the day echocardiography was available in 55% of valve clinics. In patients with severe HVD, serum brain natriuretic peptide (BNP) was measured routinely in 39% of clinics and exercise testing routinely performed in 49% of clinics. A patient helpline was available in 27% of clinics. 78% of centres with a valve clinic had a valve multidisciplinary team meeting (MDT). 45% centres had an MDT co-ordinator and MDT outcomes were recorded on a database in 64%. COVID-19 had a major impact on valve services in 54 (95%) hospitals.

CONCLUSIONS

There has been an increase in the number of valve clinics since 2015 from 21 to 68% but the penetration is still well short of the expected 100%, meaning that valve clinics only serve a small proportion of patients requiring surveillance for HVD. COVID-19 had a major impact on the care of patients with HVD in the majority of UK centres surveyed.

P2650Antihypertensive treatment with calcium channel blockers in patients with moderate or severe aortic stenosis: relationship with all-cause mortality

Background

Hypertension is prevalent in patients with aortic stenosis (AS) and optimal blood pressure (BP) control is advised to reduce arterial load and avoid cardiovascular events. Whether calcium channel blockers (CCB) are safe is not known.

Methods

A total of 314 patients (age 65±12 y, 68% men) with moderate or severe asymptomatic AS were included.

Results

The prevalence of hypertension was 73.6%, and 65% took antihypertensive treatment. Patients who used a CCB (25%) (CCB+) were older, had higher clinic systolic BP, were more likely to have hypercholesterolemia and coronary artery disease (CAD), and to use a diuretic or alpha blocker compared to CCB- patients (all p<0.05) (Table). During the baseline ETT, patients who used a CCB achieved a lower peak heart rate, a shorter exercise time and were more likely to have a blunted BP response compared to those who did not use a CCB (all p<0.05) (Table). Event-free survival was significantly lower in CCB+ than CCB- patients (Fig) (all-cause mortality 16 [20.3%] versus 13 (5.6%); p<0.001). In a multivariable Cox regression model, CCB+ was associated with a 6.8-fold increased hazard ratio (HR) for all-cause mortality (HR 6.77 95% CI 1.66–27.54, p=0.008), independent of age, gender, systolic BP, hypertension, diabetes, CAD, hypercholesterolemia and aortic valve area.

Table 1. Baseline characteristics of patients CCB− (n=234) CCB+ (n=80) p Age, y 64±12 70±10 <0.001 CAD, % 45 66 0.006 Hypercholesterolemia, % 62 78 0.015 Clinic systolic BP, mmHg 139±19 150±17 <0.001 Left atrial diameter, cm 3.7±0.7 3.9±0.6 0.007 LV end-diastolic diameter, cm 4.5±0.7 4.8±0.6 0.002 LV mass index, g/m2.7 50±17 57±17 0.007 Aortic valve area, cm2 0.94±0.22 0.93±0.22 0.716 LV stroke work, g-m/bmp 155±46 175±69 0.046 Peak HR at baseline ETT, bmp 138±24 120±25 <0.001 Blunted BP response, % 33 49 0.013 Exercise duration, min 10.1±4.5 8.3±3.7 0.001 Double Product, mmHg·bmp 1.85±0.43 2.08±0.54 <0.001

Figure 1

Conclusion

The use of calcium channel blockers was associated with an adverse effect on treadmill exercise and reduced survival in apparently asymptomatic patients with moderate or severe AS.

Acknowledgement/Funding

None

Longitudinal hemodynamics in acute phase of treatment with labetalol in hypertensive pregnant women to predict need for vasodilatory therapy

OBJECTIVE

Hypertensive pregnant women who do not respond to treatment with labetalol to control blood pressure (BP), but require vasodilatory therapy, progress rapidly to severe hypertension. This could be delayed by early recognition and individualized treatment. In this study, we sought to create prediction models from data at presentation and at 1 h and 24 h after commencement of treatment to identify patients who will not have a sustained response to labetalol and therefore need vasodilatory therapy.

METHODS

The study population comprised 134 women presenting with hypertension at a UK hospital. Treatment with oral labetalol was administered when BP was > 150/100 mmHg or > 140/90 mmHg with systemic disease. BP and hemodynamic parameters were recorded at presentation and at 1 h and 24 h after commencement of treatment. Labetalol doses were titrated to maintain BP around 135/85 mmHg. Women with unresponsive BP, despite labetalol dose maximization (2400 mg/day), received additional vasodilatory therapy with nifedipine. Binary logistic and longitudinal (mixed-model) data analyses were performed to create prediction models anticipating the likelihood of hypertensive women needing vasodilatory therapy. The prediction models were created from data at presentation and at 1 h and 24 h after treatment, to assess the value of central hemodynamics relative to the predictive power of BP, heart rate and demographic variables at these intervals.

RESULTS

Twenty-two percent of our cohort required additional vasodilatory therapy antenatally. These women had higher rates of severe hypertension and delivered smaller babies at earlier gestational ages. The unresponsive women were more likely to be of black ethnicity, had higher BP and peripheral vascular resistance (PVR), and lower heart rate and cardiac output (CO) at presentation. Those who needed vasodilatory therapy showed an initial decrease in BP and PVR, which rebounded at 24 h, whereas BP and PVR in those who responded to labetalol showed a sustained decrease at 1 h and 24 h. Stroke volume and CO did not decrease during the acute phase of treatment in either group. The best model for prediction of the need for vasodilators was provided at 24 h by combining ethnicity and longitudinal BP and heart rate changes. The model achieved a detection rate of 100% for a false-positive rate of 20% and an area under the receiver-operating characteristics curve of 0.97.

CONCLUSION

Maternal demographics and hemodynamic changes in the acute phase of labetalol monotherapy provide a powerful tool to identify hypertensive pregnant patients who are unlikely to have their BP controlled by this therapy and will consequently need additional vasodilatory therapy. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

RESUMEN OBJETIVO

Las embarazadas hipertensas que no responden al tratamiento con labetalol para el control de la presión arterial (PA), pero que requieren terapia vasodilatadora, evolucionan rápidamente hacia una hipertensión severa. Ésta se puede retrasar mediante un diagnóstico precoz y un tratamiento individual. En este estudio se ha tratado de crear modelos de predicción a partir de datos al inicio del tratamiento y al cabo de 1 hora y de 24 horas después del mismo, para identificar a las pacientes que no mostrarán una respuesta constante al labetalol y que por lo tanto necesitarán terapia vasodilatadora. MÉTODOS: La población de estudio incluyó 134 mujeres con hipertensión en un hospital del Reino Unido. El tratamiento con labetalol por vía oral se administró cuando la PA fue >150/100 mm de Hg o >140/90 mm de Hg con enfermedad multisistémica. Se registró la PA y los parámetros hemodinámicos tanto al inicio como al cabo de 1 h y de 24 h después del inicio del tratamiento. Las dosis de Labetalol se ajustaron para mantener la PA en torno a los 135/85 mm de Hg. Las mujeres cuya PA no produjo respuesta, a pesar de haberles administrado la dosis máxima de labetalol (2400 mg/día), recibieron terapia vasodilatadora adicional con nifedipino. Se realizaron análisis de datos mediante logística binaria y longitudinal (modelo mixto), para crear modelos de predicción con los que pronosticar la probabilidad de la necesidad de terapia vasodilatadora en mujeres hipertensas. Los modelos de predicción se crearon a partir de datos al inicio y al cabo de 1 hora y 24 horas del tratamiento, para evaluar el valor de los parámetros hemodinámicos principales con respecto a la capacidad predictiva de la PA, la frecuencia cardíaca y las variables demográficas en estos intervalos.

RESULTADOS

El 22 % de la cohorte necesitó terapia vasodilatadora adicional antes del parto. Estas mujeres tuvieron tasas más altas de hipertensión grave y neonatos más pequeños en edades gestacionales más tempranas. Las mujeres que no respondieron al tratamiento fueron con más frecuencia de raza negra, tuvieron la PA y la resistencia vascular periférica (RVP) más alta, y la frecuencia cardíaca y el gasto cardíaco (GC) más bajos al inicio del tratamiento. Aquellas que necesitaron terapia vasodilatadora mostraron un descenso inicial de la PA y la RVP, que se recuperó al cabo de 24 h, mientras que la PA y la RVP en las que respondieron al labetalol mostraron una disminución constante al cabo de 1 h y de 24 h. El volumen sistólico y el GC no disminuyeron durante la fase aguda del tratamiento en ninguno de los grupos. El mejor modelo para la predicción de la necesidad de vasodilatadores se obtuvo a las 24 h mediante la combinación de la etnia con los cambios longitudinales de la PA y la frecuencia cardíaca. El modelo alcanzó una tasa de detección del 100% para una tasa de falsos positivos del 20% y un área bajo la curva de características operativas del receptor de 0,97. CONCLUSIÓN: Los datos demográficos maternos y los cambios hemodinámicos en la fase aguda de la monoterapia con labetalol constituyen una herramienta poderosa para identificar a las pacientes embarazadas hipertensas con pocas probabilidades de que se les pueda controlar su PA mediante esta terapia y que por lo tanto necesitarán terapia vasodilatadora adicional. : 、(blood pressure,BP),。。,1 h24 h,。 : 134。BP>150/100 mmHgBP>140/90 mmHg。1 h24 hBP。,BP135/85 mmHg。BP,()。logistic(),。1 h24 h,,BP、。 : 22%。。,BP(peripheral vascular resistance,PVR),(cardiac output,CO)。BPPVR,24 h,1 h24 hBPPVR。CO。24hBP。100%,20%,0.97。 : ,BP。.

Maternal ethnicity and its impact on the haemodynamic and blood pressure response to labetalol for the treatment of antenatal hypertension

Objective

Blood pressure (BP) control outside pregnancy is associated with a reduction in adverse cardiovascular events, and in pregnancy with improved outcomes. Outside pregnancy, there is evidence β-blockers are less effective in controlling BP in black populations. However, in pregnancy, labetalol is recommended as a universal first-line treatment, without evidence for the impact of ethnicity on its efficacy. We sought to compare haemodynamic responses to labetalol in black and white pregnant patients.

Methods

This was a prospective observational cohort study in a London teaching hospital. Maternal haemodynamics were assessed in 120 pregnant women treated with labetalol monotherapy. Measurements were taken at presentation, 1 and 24 h after treatment. Participants were monitored regularly until delivery. Statistical analysis was performed by multilevel modelling.

Results

Both groups exhibited similar temporal trends in haemodynamic changes over the first 24 h following labetalol. Both showed a reduction in BP and peripheral vascular resistance within 1 h and in heart rate after 24 h. There was no change in cardiac output and stroke volume in either group. BP control (<140/90) was achieved at 1 h in 79.7% of the white and 77% of the black cohort. At 24 h, control was achieved among 83.1% and 63.9%, and up to the immediate intrapartum period control was achieved in 89.8% and 70.4% of white and black patients, respectively.

Conclusions

There is no difference in the acute haemodynamic changes and hypertension can be controlled throughout pregnancy with labetalol monotherapy in excess of 70% pregnant black and white patients.

A multidisciplinary, biopsychosocial treatment for non-cardiac chest pain

BACKGROUND

Non-cardiac chest pain (NCCP) affects up to 80% of patients attending chest pain clinics, but its treatment is suboptimal.

AIM

To describe the outcomes of a pilot, stepped care, biopsychosocial management programme in terms of improvements in chest pain, psychosocial scores and use of healthcare resources.

METHODS

Of 198 referrals, 77 patients were suitable for the clinic and received a one hour biopsychosocial assessment. Stepped care consisted of assessment only, low intensity Cognitive Behaviour Therapy (CBT), or high intensity CBT.

RESULTS

The proportion with pain occurring more than once monthly fell from 100% at baseline to 61% at 3 months (p < 0.001). Pain interference reduced significantly (p < 0.001) from 5.9 [SD 2.2] at baseline to 3.2 [SD 2.6] at 3 months. Depression scores improved from a mean 8.8 to 5.4 (p < 0.05) and anxiety from 6.9 to 4.6 (p < 0.05). Use of healthcare resources improved with a fall in consultations for chest pain over 6 months from a mean 2.6 to 0.1 (p < 0.05). The impact on work and social functioning reduced from 10.4 [SD 10.4] to 3.9 [SD 7.5]: [t (70) = 6.3, p < 0.001). Further improvements occurred at 6 months for chest pain frequency (which fell to 51%, p = 0.003), interference (2.6 [SD 2.1], p < 0.05) and avoidance of exercise (p = 0.03). Otherwise improvements were maintained between 3 and 6 months.

CONCLUSION

A stepped-care biopsychosocial approach to NCCP is effective in reducing chest pain frequency and improving behaviour and wellbeing. It can be delivered in part by a nurse allowing integration into any chest pain clinic.

Provision, organization and models of heart valve clinics within The United Kingdom

BACKGROUND

Specialist clinics are recommended for the assessment and follow-up of patients with heart valve disease. We sought to identify the current provision of specialist valve clinics in UK.

METHODS

A database of all UK National Health Service hospitals was created. An online survey was distributed to each hospital to examine the model of heart valve clinic, patient population, provision of advanced imaging modalities and biochemical markers and provision of patient information services.

RESULTS

Valve clinics were run in 48/228 (21%) hospitals, in 27/45 (60%) tertiary centres and 21/183 (11%) district hospitals. The survey was completed by 34 (71%). A consultant cardiologist ran the clinic in 19 (56%), a cardiac sonographer in 8 (24%), a nurse specialist in 3 (9%) and a hybrid model was used in 4 (12%). Patients with native valve disease were seen in 32 (94%), after heart valve surgery in 19 (56%), pre-/post-transcatheter valve intervention in 10 (29%) and with Marfan syndrome in 9(26%). Stress echocardiography, cardiac magnetic resonance imaging, computed tomography and positron emission tomography were available in 21 (62%), 19 (56%), 22 (65%) and 6 (18%) hospitals, respectively.

CONCLUSION

There is an underprovision of specialist heart valve clinics within the UK, and there is a 5-fold difference between cardiac centres and district general hospitals.

The rapid access chest pain clinic: unmet distress and disability

AIMS

To determine the characteristics, clinical needs and level of health-care use of patients with non-cardiac (NCCP) and cardiac-chest pain (CCP) attending a Rapid Access Chest Pain Clinic in an inner-London Hospital.

METHODS

A cross-sectional comparison of NCCP and CCP patients on measures of pain, mood, beliefs, somatic symptoms and use of services completed by patients attending the Rapid Access Chest Pain Clinic over an 18-month period.

RESULTS

There were no significant differences between NCCP and CCP patients in terms of chest pain frequency, duration or severity or associated distress; however, NCCP were younger (53 vs. 60, OR = 1.05) and reported 'atypical' pain more frequently (82% vs. 50%, OR = 3.72). The NCCP group reported more panic-type beliefs about chest pain (5.8 vs. 4.3, P < 0.05) and lower 'illness coherence' (a patient's belief that the illness 'makes sense') (3.5 vs. 4.7, P < 0.05). Anxiety and depression scores were similar in both groups. Both groups had similar levels of health-care use but patients with NCCP saw more types of health-care worker (mean 1.7) than those with CCP (mean 1.4, P < 0.05).

CONCLUSION

Patients with NCCP are as disabled and distressed as patients with CCP however current services fail to meet their needs. We suggest that a biopsychosocial approach should be explored.

Non-cardiac chest pain: time to extend the rapid access chest pain clinic?

Non-cardiac chest pain is common. It has a low risk of coronary events, but causes considerable physical and social disability and inappropriate health-care usage. It is a heterogeneous condition, which may be caused by or associated with gastro-oesophageal, musculoskeletal or psychiatric abnormalities and sustained by psychological factors including catastrophisation, avoidance behaviour and abnormal help-seeking. These may coexist and their relative contributions may vary in different patients or at different times in an individual patient. The absence of a unitary cause probably explains why treatment studies show only moderate success. An individualised biopsychosocial approach takes account of all causative and sustaining processes and has been shown to work in pain syndromes at other sites. We suggest that this approach should be tried for chest pain using a multidisciplinary clinic model including cardiologists, psychologists and nurses linked with a Rapid Access Chest Pain Clinic.

NICE guidance on antibiotic prophylaxis to prevent infective endocarditis: a survey of clinicians' attitudes

BACKGROUND

Since the introduction of the National Institute for Health and Clinical Excellence (NICE) guideline (CG064) in 2008 recommending cessation of antibiotic prophylaxis (AP) against infective endocarditis (IE), low level prescribing persists in the UK and is a potential reason why there has been no significant change in the general upward trend in cases of IE.

AIM

To undertake a survey of dentists (Ds), cardiologists and cardiothoracic surgeons (C/CTSs) and infection specialists (ISs) to determine why this might be the case.

DESIGN

Internet questionnaire-based survey.

METHODS

A questionnaire was distributed by email to specialists via UK national societies.

RESULTS

A total of 1168 responses were received. All the specialist groups are aware of the guideline (99%). Ds are broadly satisfied, whereas C/CTSs are not. Most Ds follow the NICE guidance (87%), whereas many C/CTSs (39%) do not; ISs adopt a middle course (56%). Even amongst Ds, a significant proportion believe that patients with a prosthetic heart valve (25%) or previous history of IE (38%) should receive AP. A total of 36% of Ds have prescribed AP since March 2008 and many have undertaken procedures where AP has been prescribed by someone else. The majority of respondents (65%) feel that more evidence is required, preferably in the form of a randomized controlled trial.

CONCLUSION

Many patients perceived to be at high risk of IE are still receiving AP in conflict with current NICE guidance.

Maternal cardiac function in normotensive and pre-eclamptic intrauterine growth restriction

OBJECTIVES

To compare maternal cardiac function between pregnancies complicated by normotensive and pre-eclamptic intrauterine growth restriction (IUGR).

METHODS

Two-dimensional Doppler echocardiography and Doppler tissue imaging (DTI) were used to examine 19 pregnant women with IUGR and 17 with pre-eclampsia complicated by IUGR at 20-38 weeks of gestation. Indices were converted into differences in SDs from the expected normal mean for gestation (Z-scores) and compared.

RESULTS

With respect to normal pregnancy, in the normotensive IUGR compared with the pre-eclamptic IUGR group, there were similar reductions in maternal cardiac output (Z-score, - 1.71 vs. - 1.37, P = 0.26) and heart rate (Z-score, - 3.67 vs. - 9.43, P = 0.1) and a similar increase in total vascular resistance (Z-score, 2.91 vs. 3.93, P = 0.05). There was also a greater decrease in stroke volume (Z-score, - 1.72 vs. - 0.69, P = 0.01), a smaller increase in mean arterial pressure (Z-score, 0.73 vs. 2.94, P < 0.01) and a smaller decrease in DTI systolic velocity at the lateral mitral margin (Z-score, - 0.4 vs. - 1.42, P = 0.02). In terms of diastolic function, there was a smaller transmitral late diastolic velocity (Z-score, 0.04 vs. 0.93, P = 0.03) and a greater DTI early diastolic velocity at the lateral mitral margin (Z-score, - 0.17 vs. - 1.6, P < 0.01).

CONCLUSIONS

In normotensive IUGR and pre-eclamptic IUGR there is a similar alteration in maternal left ventricular systolic function, but there is greater impairment in maternal diastolic function in pre-eclamptic IUGR.

Reference ranges for tissue Doppler measures of maternal systolic and diastolic left ventricular function

OBJECTIVES

Tissue Doppler imaging (TDI) is an echocardiographic technique that evaluates longitudinal myocardial tissue velocities during left ventricular systolic and diastolic function, relatively independently of loading conditions. Limited data are available regarding maternal cardiac function using TDI. The aim of this study was to construct reference charts for TDI indices in normal pregnancy.

METHODS

This was a cross-sectional study on 104 pregnant women at 11-38 weeks of gestation and 19 non-pregnant controls. Doppler echocardiography was used to assess transmitral inflow velocities during diastole (peak velocity of early (E) and late (A) atrial filling), whilst TDI at the septal and lateral margins of the mitral annulus measured diastolic velocities (peak velocity of early (E') and late (A') diastolic filling) and peak systolic velocity (S'). The left ventricular filling index (E : E' ratio) was derived. The Tei index (ratio of isovolumetric time to ejection time) was measured.

RESULTS

Systolic function assessed by TDI S' velocity was unaltered at the septal and lateral margins, although S' velocity at the lateral margin was higher (12%, P = 0.028) in the first two trimesters, compared to non-pregnant controls. Diastolic function was modified as demonstrated by an increase in A velocity (P P = 0.024). Similarly, A' increased at the septal and lateral margins ( P < 0.001 and P = 0.02, respectively), resulting in a decrease in E' : A' ratios at the septal and lateral mitral margins ( P = 0.001 and P = 0.001, respectively). E : E' at both mitral margins and Tei index were unaltered.

CONCLUSION

This study gives normal ranges for TDI indices in pregnancy. TDI demonstrated modified longitudinal systolic and diastolic function. Future studies will evaluate the potential of this technique in pregnancies complicated by hypertension and cardiac disease. Published by John Wiley & Sons, Ltd.

Maternal cardiac function in fetal growth-restricted and non-growth-restricted small-for-gestational age pregnancies

OBJECTIVE

To compare maternal cardiac function in women with intrauterine growth restriction (IUGR) to those with small-for-gestational age (SGA) pregnancies (non-IUGR).

METHODS

This was a cross-sectional study involving maternal echocardiography and uterine, umbilical and fetal middle cerebral artery Doppler assessment in 52 normotensive women at 20-36 weeks' gestation with SGA fetuses (26 IUGR and 26 non-IUGR).

RESULTS

In the IUGR (compared to the non-IUGR) group, maternal cardiac output (CO) was lower (4.7 vs. 6.1 L/min, P<0.001) and total vascular resistance (TVR) was higher (1444 vs. 1088 dynes/s/cm5, P<0.001). The lower CO was due to a lower preload, demonstrated by a reduced stroke volume (59.9 vs. 73.6 mL, P<0.01) and smaller left atrial diameter (LAD) (31.5 vs. 34.1 mm, P=0.01). Mean arterial pressure and diastolic function were similar between the groups. Logistic regression and receiver-operating characteristics curve analysis for detection of IUGR demonstrated that a model using TVR, LAD, fetal middle cerebral artery pulsatility index and gestational age, had a sensitivity of 96.2% and a specificity of 84.6%.

CONCLUSIONS

Maternal echocardiography can provide a very sensitive tool for identifying IUGR pregnancies.

Is antibiotic prophylaxis ever necessary before transoesophageal echocardiography?

Evidence strongly suggests that antibiotic prophylaxis should not be used routinely for transoesophageal echocardiography for any indication.

A simple score for predicting coronary artery disease in patients with chest pain

BACKGROUND

We have previously derived a chest pain score by comparing those with and without coronary artery disease on angiography, which was subsequently validated in patients attending coronary angiography.

AIM

To test the predictive validity of the score prospectively in a more varied out-patient population, and to determine whether it had predictive validity in addition to exercise testing.

DESIGN

Prospective clinical study.

METHODS

The score was applied to 405 out-patients with chest pain who subsequently underwent coronary angiography. Framingham risk analysis and exercise testing were performed in 155.

RESULTS

The score had a sensitivity of 91.4% and specificity of 28% for coronary artery disease, which was found in 31.8%, 51%, 63%, and 82% of those with scores of 0, 1, 2, and 3, respectively. Gender (p < 0.001), age (p < 0.001), and chest pain score (p = 0.009) independently predicted coronary artery disease on multivariate Poisson regression analysis. The chest pain score had additive predictive value with Framingham risk analysis and Duke's score.

DISCUSSION

This simple chest pain score can predict coronary anatomy with similar sensitivity to exercise testing, and can be used in conjunction with exercise testing and other measures. Further validation of the chest pain score in the primary care setting will be useful.

Diet-induced obesity and cardiovascular regulation in C57BL/6J mice

1. In the present study, we determined the effect of diet-induced obesity on cardiovascular and metabolic regulation in mice at standard laboratory temperatures (ambient temperature (Ta) = 22 degrees C) and during exposure to thermoneutrality (Ta = 30 degrees C). 2. Male C57BL/6J (B6) mice fed a high-fat diet (HFF; n = 17) or chow (CHW; n = 14) for 15 weeks were surgically instrumented with telemetry devices, housed in metabolic chambers and assigned to either control or atenolol treatment (25 mg/kg per day in drinking water) to determine the effects of obesity on baseline cardiovascular function and on the responses to thermoneutrality and 24 h fasting. Mean arterial pressure (MAP), heart rate (HR), arterial pressure and HR variability (time and frequency domain), oxygen consumption (VO2) and locomotor activity were determined. 3. The HFF mice exhibited increased bodyweight (+10.6 +/- 4.1 g), moderate light period hypertension (+8.6 +/- 2.6 mmHg), no difference in HR and increased HR variability at standard laboratory temperature compared with CHW controls. Atenolol produced less of a decrease in HR in HFF mice (-42 +/- 10 b.p.m.) compared with CHW controls (-73 +/- 15 b.p.m.). Acute exposure to thermoneutrality (Ta = 30 degrees C) reduced HR similarly in both HFF and CHW mice (approximately 175 b.p.m.), but reduced MAP less in HFF than in CHW mice (-7.3 +/- 2.5 and -15.2 +/- 1.0 mmHg), respectively. Atenolol treatment had only minor effects on the HR response to thermonuetrality (-114 +/- 13 and -129 +/- 8 b.p.m. in HFF and CHW mice, respectively). The HFF mice displayed greater fasting-induced reductions in light period MAP than did CHW mice (-10.0 +/- 1.1 vs-3.1 +/- 3.5 mmHg, respectively), whereas HR was decreased equally in both groups. Fasting-induced increases in HR variability were attenuated in HFF mice. 4. We conclude that diet-induced obesity produced generally minor changes in cardiovascular regulation in B6 mice at baseline, some of which are distinct from the effects of diet-induced obesity in larger animal models. In contrast, acute variations in Ta or caloric availability produce pronounced alterations in cardiovascular function in either lean or obese mice, which are generally evident after atenolol and, thus, presumably not due exclusively to variation in cardiac sympathetic activity. Interestingly, the degree of obesity induced hypertension was augmented when mice were studied at thermonuetrality. The results suggest an important unrecognized role for vagal tone in the regulation of cardiovascular function in mice and support the need for considerable caution when using mouse models of obesity to examine regulation of cardiovascular function. We argue that mouse physiology studies should be performed in thermoneutral conditions.

Cardiovascular and metabolic responses to fasting and thermoneutrality in Ay mice

Several lines of evidence support a role for reduced melanocortin signaling in the regulation of metabolic rate and cardiovascular function during negative energy balance. We tested the hypothesis that agouti yellow (B6.Cg-A(y)) mice would exhibit blunted physiologic responses to fasting and thermoneutrality. Male B6.Cg-A(y) mice (A(y); n=11, 34+/-2 g) and lean B6 littermates (B6; n=7, 26+/-2 g) were implanted with telemetry devices and housed in metabolic chambers (T(a)=23 degrees C) to determine the effects of a 24-h fasting and exposure to thermoneutrality (T(a)=30 degrees C) on mean arterial pressure (MAP), heart rate (HR), AP and HR variability (time and frequency domain), oxygen consumption (VO(2)), and locomotor activity. A(y) mice exhibited elevated baseline light-period MAP (A(y): 113+/-4; B6: 99+/-3 mm Hg) and VO(2) (A(y): 1.82+/-0.08 vs. B6: 1.45+/-0.13 ml/min) with no difference in HR (A(y): 530+/-12 vs. B6: 548+/-19 bpm). At 12-24 h after food removal, A(y) mice displayed normal fasting-induced bradycardia (A(y): -106+/-12; B6: -117+/-19 bpm) and reduction in VO(2) (A(y): -0.19+/-0.04 vs. B6: -0.28+/-0.05 ml/min), but with augmented hypotension (A(y): -9+/-2 vs. B6: -0.5+/-2 mm Hg) and blunted hyperactivity (A(y): 27+/-23 vs. B6: 122+/-42 m/11 h). Fasting was associated with increased HR variability in both time and frequency domain in B6 but not A(y) mice. Exposure to thermoneutrality produced comparable reductions in MAP, HR, and VO(2) in both strains. We conclude that inhibition of melanocortin signaling is not requisite for, but participates in, the metabolic and cardiovascular responses to negative energy balance.

Cardiovascular responses to caloric restriction and thermoneutrality in C57BL/6J mice

We utilized variations in caloric availability and ambient temperature (T(a)) to examine interrelationships between energy expenditure and cardiovascular function in mice. Male C57BL/6J mice (n = 6) were implanted with telemetry devices and housed in metabolic chambers for measurement of mean arterial pressure (MAP), heart rate (HR), O(2) consumption (VO(2)), and locomotor activity. Fasting (T(a) = 23 degrees C), initiated at the onset of the dark phase, resulted in large and transient depressions in MAP, HR, VO(2), and locomotor activity that occurred during hours 6-17, which suggests torporlike episodes. Food restriction (14 days, 60% of baseline intake) at T(a) = 23 degrees C resulted in progressive reductions in MAP and HR across days that were coupled with an increasing occurrence of episodic torporlike reductions in HR (<300 beats/min) and VO(2) (<1.0 ml/min). Exposure to thermoneutrality (T(a) = 30 degrees C, n = 6) reduced baseline light-period MAP (-14 +/- 2 mmHg) and HR (-184 +/- 12 beats/min). Caloric restriction at thermoneutrality produced further reductions in MAP and HR, but indications of torporlike episodes were absent. The results reveal that mice exhibit robust cardiovascular responses to both acute and chronic negative energy balance. Furthermore, we conclude that T(a) is a very important consideration when assessing cardiovascular function in mice.

A comparison of wall motion analysis and systolic left ventricular long axis function during dobutamine stress echocardiography

AIMS

To compare long-axis function and wall motion analysis for the detection of significant coronary artery stenoses in patients with single and multivessel disease.

METHODS AND RESULTS

We performed dobutamine stress echocardiography in 67 subjects, 14 with normal coronary anatomy, and 53 with significant coronary disease. A blunted increase in mean long-axis shortening of <0.25 cm was the best discriminator for coronary artery disease (sensitivity 85%, specificity 81%). Using this threshold, long axis function gave a sensitivity of 88% and specificity 89% for the detection of coronary artery disease in patients with normal resting wall motion while wall motion abnormality analysis had a sensitivity 73% and specificity 94%. Of 26 patients with a resting wall motion abnormality, 14 (54%) had multivessel disease. Long axis function detected multivessel disease in 12 of these (sensitivity 86%) compared with nine (sensitivity 64%) for wall motion analysis.

CONCLUSION

Long axis function provides a promising, quantitative adjunct to wall motion analysis for the detection of coronary ischaemia using dobutamine stress echocardiography in patients with single and multivessel disease and with resting wall motion abnormalities.

Coronary bypass grafting in South Thames: the correlation between clinical scores and waiting times

To determine waiting times before surgery and their correlation with clinical need, we examined the files of 1049 patients on the waiting list for coronary bypass grafting in 1996. The total waiting time to bypass grafting was 279 (SD 209) days (range 1-1579 days). Waiting time to specialist consultation was 36 (SD 43) days, and time on the waiting list for coronary angiography was 85 (SD 89) days. The mean time on the surgical waiting list was 133 (SD 134) days. Patients with a Birmingham clinical score below 10 waited between 27 and 879 days, and patients with scores above 35 waited between 3 and 282 days. Total waiting time was weakly associated with the priority score (Pearson correlation = -0.51). We conclude that waiting times were long with wide variation at every stage between referral and coronary bypass grafting. There was little correlation between clinical scores and waiting times.

A chest pain score for stratifying the risk of coronary artery disease in patients having day case coronary angiography

'Typical' or 'atypical' are universally used descriptions of chest pain, but they are limited by subjectivity. This study tested the ability of a semi-objective chest pain score to predict the likelihood of coronary disease. A chest pain questionnaire was given to 250 patients with stable chest pain attending coronary angiography. The answers to three questions were defined as 'typical' or 'atypical' and summed to give a 'typical' score between 0 and 3. Logit analysis was performed based on an age cut-off of 55 years and 'typical' score. There were 96 (38%) patients with normal coronary arteries and 154 (62%) with coronary disease. In patients aged under 55 years, the likelihood of coronary disease by 'typical' score was 11% (score 0), 30% (score 1), 40% (score 2), 53% (score 3). Similar figures for age 55 years were 39% (score 0), 45% (score 1), 77% (score 2), and 85% (score 3). There is a direct relationship between 'typical' chest pain score and the likelihood of coronary artery disease. This scoring system may be useful in the clinical characterization of patients for research, for guiding referral to a cardiologist or for aiding the decision to perform coronary angiography.

Cardiovascular and metabolic responses to fasting and thermoneutrality are conserved in obese Zucker rats

The primary purpose of the study was to test the hypothesis that reduced leptin signaling is necessary to elicit the cardiovascular and metabolic responses to fasting. Lean (Fa/?; normal leptin receptor; n = 7) and obese (fa/fa; mutated leptin receptor; n = 8) Zucker rats were instrumented with telemetry transmitters and housed in metabolic chambers at 23 degrees C (12:12-h light-dark cycle) for continuous (24 h) measurement of metabolic and cardiovascular variables. Before fasting, mean arterial pressure (MAP) was higher (MAP: obese = 103 +/- 3; lean = 94 +/- 1 mmHg), whereas oxygen consumption (VO(2): obese = 16.5 +/- 0.3; lean = 18.6 +/- 0.2 ml. min(-1). kg(-0.75)) was lower in obese Zucker rats compared with their lean controls. Two days of fasting had no effect on MAP in either lean or obese Zucker rats, whereas VO(2) (obese = -3.1 +/- 0.3; lean = -2.9 +/- 0.1 ml. min(-1). kg(-0.75)) and heart rate (HR: obese = -56 +/- 4; lean = -42 +/- 4 beats/min) were decreased markedly in both groups. Fasting increased HR variability both in lean (+1.8 +/- 0.4 ms) and obese (+2.6 +/- 0.3 ms) Zucker rats. After a 6-day period of ad libitum refeeding, when all parameters had returned to near baseline levels, the cardiovascular and metabolic responses to 2 days of thermoneutrality (ambient temperature 29 degrees C) were determined. Thermoneutrality reduced VO(2) (obese = -2.4 +/- 0.2; lean = -3.3 +/- 0.2 ml. min(-1). kg(-0.75)), HR (obese = -46 +/- 5; lean = -55 +/- 4 beats/min), and MAP (obese = -13 +/- 6; lean = -10 +/- 1 mmHg) similarly in lean and obese Zucker rats. The results indicate that the cardiovascular and metabolic responses to fasting and thermoneutrality are conserved in Zucker rats and suggest that intact leptin signaling may not be requisite for the metabolic and cardiovascular responses to reduced energy intake.

Clinical safety of SonoVue, a new contrast agent for ultrasound imaging, in healthy volunteers and in patients with chronic obstructive pulmonary disease

RATIONALE AND OBJECTIVES

To evaluate the safety profile of SonoVue, a new echo-contrast agent based on stabilized sulfur hexafluoride (SF6) microbubbles, in healthy volunteers and in patients with chronic obstructive pulmonary disease (COPD).

METHODS

Safety and tolerability of SonoVue were evaluated in 66 healthy volunteers during two placebo-controlled phase I studies (a single intravenous ascending-dose study in 36 volunteers given SonoVue doses of 0.003 to 0.12 mL/kg and a multiple-dose study in 30 subjects given cumulative doses of 0.15 to 0.6 mL/kg) and in 12 patients with COPD of various degrees of clinical severity, who were given SonoVue at a dosage of 4 mL (corresponding to 0.057 mL/kg in a 70-kg patient). Adverse events were monitored up to 48 to 72 hours after administration. All volunteers underwent extensive safety assessments (monitoring of vital signs, electrocardiogram, blood oxygen saturation, laboratory assessments, and Mini-Mental test) up to 24 to 72 hours after administration. In addition, patients with COPD underwent specific lung function tests, such as forced expiratory volume, forced vital capacity, and forced midexpiratory flow.

RESULTS

No serious adverse events occurred throughout the study. All nonserious adverse events were minor, mild, and rapidly self-resolving. No difference in the incidence of adverse events was observed among the various dosages of SonoVue and between SonoVue and placebo. There were no clinically significant changes in any of the safety assessments. No statistically significant differences between SonoVue and placebo were observed in mean forced expiratory volume, forced vital capacity, or forced midexpiratory flow levels. No substantial changes from baseline in blood oxygen saturation were observed for either study agent at any postinjection time point.

CONCLUSIONS

SonoVue showed a good safety profile both in healthy subjects and in patients with COPD.

Central leptin infusion attenuates the cardiovascular and metabolic effects of fasting in rats

The role of reduced leptin signaling in the regulation of cardiovascular responses to negative energy balance is not known. We tested the hypothesis that central infusion of leptin would attenuate the cardiovascular and metabolic responses to fasting. Male Sprague-Dawley rats, instrumented with telemetry devices and intracerebroventricular cannulas, were housed in metabolic chambers for continuous (24 hours) measurement of dark-phase (active) and light-phase (inactive) mean arterial pressure, heart rate, oxygen consumption, and respiratory quotient. Rats received central infusions of either saline (0.5 microL/h) or leptin (42 ng/h) for 6 days through osmotic pumps and were either fed ad libitum or were fasted for 48 hours followed by refeeding for 4 days. In ad lib animals, continuous intracerebroventricular leptin infusion significantly reduced caloric intake, body weight, and respiratory quotient compared with saline controls while having no effect on mean arterial pressure or heart rate. Fasting reduced mean arterial pressure, heart rate, oxygen consumption, and respiratory quotient in rats receiving saline infusions. Fasting-induced reductions in mean arterial pressure were specific to the active phase and were not attenuated by central leptin infusion. In contrast, intracerebroventricular leptin, at a dose that had no cardiovascular effects in ad lib control animals, completely prevented fasting-induced decreases in light-phase heart rate and oxygen consumption and blunted fasting-induced reductions in dark-phase heart rate and oxygen consumption. The results are consistent with the hypothesis that reductions in central leptin signaling contribute to the integrated cardiovascular and metabolic responses to acute caloric deprivation.

Cardiovascular and metabolic responses of hypertensive and normotensive rats to one week of cold exposure

Challenges to energy homeostasis, such as cold exposure, can have consequences for both metabolic and cardiovascular functioning. We hypothesized that 1-wk cold exposure (4 degrees C) would produce concurrent increases in metabolic rate (VO(2); indirect calorimetry), heart rate (HR), and mean arterial blood pressure (MAP) measured by telemetry. In the initial hours of change in ambient temperature (T(a)), both spontaneously hypertensive rats (SHRs) and normotensive Sprague-Dawley rats showed rapid increases (in cold) or decreases (in rewarming) of VO(2), HR, and MAP, although the initial changes in MAP and HR were more exaggerated in SHRs. Throughout cold exposure, HR, VO(2), food intake, and locomotor activity remained elevated but MAP decreased in both strains, particularly in the SHR. During rewarming, all measures normalized quickly in both strains except MAP, which fell below baseline (hypotension) for the first few days. The results indicate that variations of T(a) produce rapid changes in a suite of cardiovascular and behavioral responses that have many similarities in hypertensive and normotensive strains of rats. The findings are consistent with the general concept that the cardiovascular responses to cold exposure in rats are closely related to and perhaps a secondary consequence of the mechanisms responsible for increasing heat production.

Retrospective review of osteoarticular infections in a pediatric sickle cell age group

Patients with sickle cell disease have been documented to be particularly susceptible to osteoarticular infections. Controversy exists concerning the bacteriology, etiology, and clinical presentation in differentiating osteoarticular infections from bone infarct. We retrospectively reviewed all cases from our institution over the past 22 years of osteoarticular infections in children who carry the diagnosis of sickle cell disease. Two thousand consecutive patient charts of children enrolled in the Pediatric Sickle Cell Clinic of our institution between 1973 and 1995 were evaluated. There were 14 cases of bone or joint infections (10 osteomyelitis, four septic arthritis). There was one case of multicentric osteomyelitis and one case of meningitis complicating the septic arthritis. There were nine male and five female patients with ages ranging from 6 months to 17 years (mean, 8.0). All patients were noted to have hemoglobin SS. The predominant presenting symptoms were pain (79% of cases) and swelling (71% of cases). The most frequent physical findings were fever >38.2 degrees C (71% of cases) and tenderness (86% of cases). Ninety-three percent of the children had a white blood count exceeding 15,000/mm3 (range, 7,900-32,300). Westergren sedimentation rates ranged from 14 to 89 mm/h with 93% of the children exceeding the normal value in our hospital. Cultures were positive in 75% of tissue biopsies, 58% of the blood cultures, and 70% of the bone or joint aspirates. The most common offending organism found in osteomyelitis was Salmonella (eight of 10 cases); however, no predominant organism found was identified in cases of septic arthritis. Radiographs and bone scans were of limited value in the differential diagnosis between osteoarticular infections and bone infarction. Early diagnosis and treatment of osteoarticular infections is key to satisfactory outcome. This study suggests that an ill-appearing patient with a fever >38.2 degrees C, pain, and swelling should prompt the physician to aspirate or biopsy the area and not rely on diagnostic studies that we found to be unreliable.

Concurrent reductions in blood pressure and metabolic rate during fasting in the unrestrained SHR

Fasting produces multiple cardiovascular, metabolic, and behavioral responses. To examine the interrelationship between these responses, male spontaneously hypertensive rats (SHR; n = 8) implanted with cardiovascular telemetry devices were housed in metabolic chambers at 23 degrees C for 22-h daily measurements of physiological variables. The experimental apparatus was designed so that ingestive behavior was detected by photobeams and locomotion was detected by a load sensor. Cardiovascular and metabolic status were determined as both a function of the circadian cycle (12-h dark and 10-h light), as well as during periods of inactivity (no ingestion and minimal locomotion) within the dark and light phases. Data were obtained during baseline, 48-h of caloric deprivation, and 6 days of refeeding. Fasting produced significant reductions in mean arterial pressure (dark: -9.2+/-1.3 from 143.7+/-3.7 mm Hg; light: -8.6+/-1.8 from 140.1+/-3.7 mm Hg), heart rate (dark: -43.4+/-5.2 from 330.0+/-5.2 beats/min; light: -27.4+/-5.2 from 294.0+/-5.2 beats/min), and oxygen consumption (dark: -5.0+/-0.6 from 20.6+/-0.3 ml x min(-1) x kg (0.75); light: -2.7+/-0.2 from 14.9 +/-0.2 ml x min(-1) x kg(0.75)). Analysis of inactive periods during both light and dark phases revealed that these reductions were not dependent on behavioral effects. We conclude that fasting produces concurrent and interrelated reductions in cardiovascular and metabolic function in the SHR. The merging of cardiovascular telemetry, indirect calorimetry, and behavioral monitoring provides a powerful approach for investigation of the integrative physiological responses to energetic challenges.

Plasma sialic acid and coronary artery atheromatous load in patients with stable chest pain

Serum or plasma sialic acid and C-reactive protein have recently been shown to be cardiovascular risk factors. Our aim was to determine whether plasma sialic acid or C-reactive protein concentration correlate with atheromatous load on coronary angiography. Plasma sialic acid concentration and plasma C-reactive protein concentration were determined in 128 consecutive patients attending day case coronary angiography. Patients were excluded for previous coronary angioplasty, coronary artery bypass grafting, recent myocardial infarction, acute or chronic inflammatory disease and proximal occlusions precluding analysis of distal coronary anatomy. Total cholesterol, triglyceride, HDL cholesterol and glucose concentrations were assayed on fasting samples of venous blood. Angiograms were graded according to a semisubjective scoring system. There was no significant correlation between plasma sialic acid (r = 0.19, P = 0.07), or C-reactive protein concentration (r = 0.17, P = 0.13) and atheromatous load. There was no significant correlation between sialic acid (P = 0.13), or C-reactive protein concentration (P = 0.32) and the number of diseased coronary vessels. The difference in plasma sialic acid concentration between those with normal coronary angiograms and those with coronary artery disease did not reach significance (P = 0.08). Plasma sialic acid concentration correlated with C-reactive protein (r = 0.58, P = 0.0001), serum triglyceride (r = 0.32, P = 0.002), and blood cholesterol concentration (r = 0.22, P = 0.04). Plasma sialic acid concentration does not correlate with atheromatous load on coronary angiography in patients with stable angina.

Gender differences in the treatment of patients with acute myocardial ischemia and infarction in England

We conducted a retrospective cohort study based on a case note review to determine whether there are differences in the treatment pathways followed for men and women admitted with acute myocardial ischemia and infarction after adjusting for differences in case mix. Women were as likely as men to receive thrombolysis, but were less likely subsequently to undergo exercise testing (adjusted odds ratio, 0.58; 95% CI, 0.40-0.84) or angiography (adjusted odds ratio, 0.62; 95% CI, 0.39-0.99). Coronary anatomy was the strongest predictor of revascularization regardless of sex. Women with diagnosed cardiac pain are less likely than men to be placed on the investigative pathways that lead to revascularization. Those women who are investigated are as likely as men to undergo revascularization. These findings are independent of the effects of age, angina grade, comorbidity, or cardiac risk factors. Clinicians' and patients' beliefs and preferences about treatment require investigation.

A prospective study of oesophageal function in patients with normal coronary angiograms and controls with angina

AIMS

To compare the incidence of oesophageal abnormalities and their correlation with chest pain in patients with normal coronary angiograms, and in controls with angina.

PATIENTS

Sixty one patients with normal coronary angiograms (NCA group) referred to a single cardiac centre between March 1990 and April 1991; 25 matched controls with confirmed coronary artery disease (CAD group).

SETTING

Cardiac referral centre and oesophageal function testing laboratory.

MAIN OUTCOME MEASURES

Oesophageal manometry, provocation tests, and 24 hour ambulatory pH monitoring.

RESULTS

Simultaneous contractions were more common (6.7% versus 0.8%, p < 0.01), and the duration of peristaltic contractions was longer (2.9 versus 2.4 seconds, p < 0.01) in the NCA group than in the CAD group. There were no group differences in the amplitude of peristaltic contractions, and none had nutcracker oesophagus. Ten (16%) patients with NCA and no patients with CAD had diffuse spasm (p = 0.03). Twenty one (34%) patients with NCA, and five (20%) patients with CAD had abnormal gastro-oesophageal reflux (p > 0.05). There was no significant difference between the groups in the number of patients whose pain was temporally related to pH events. Particular chest pain characteristics, or the presence of additional oesophageal symptoms, were not predictive of an oesophageal abnormality.

CONCLUSION

Oesophageal function tests commonly implicate the oesophagus as a source of pain in patients with normal coronary angiograms. With the exception of simultaneous contractions during manometry however, the incidence of abnormalities and in particular the correlation of pH events with chest pain are as common in patients with normal coronary angiograms as in controls with angina. The oesophagus may often be an unrecognised source of pain in both groups of patients.