Contribution of NOTCH1 genetic variants to bicuspid aortic valve and other congenital lesions

INTRODUCTION

Bicuspid aortic valve (BAV) affects 1% of the general population. NOTCH1 was the first gene associated with BAV. The proportion of familial and sporadic BAV disease attributed to NOTCH1 mutations has not been estimated.

AIM

The aim of our study was to provide an estimate of familial and sporadic BAV disease attributable to NOTCH1 mutations.

METHODS

The population of our study consisted of participants of the University of Leicester Bicuspid aoRtic vAlVe gEnetic research-8 pedigrees with multiple affected family members and 381 sporadic patients. All subjects underwent NOTCH1 sequencing. A systematic literature search was performed in the NCBI PubMed database to identify publications reporting NOTCH1 sequencing in context of congenital heart disease.

RESULTS

NOTCH1 sequencing in 36 subjects from 8 pedigrees identified one variant c.873C>G/p.Tyr291* meeting the American College of Medical Genetics and Genomics criteria for pathogenicity. No pathogenic or likely pathogenic NOTCH1 variants were identified in 381 sporadic patients. Literature review identified 64 relevant publication reporting NOTCH1 sequencing in 528 pedigrees and 9449 sporadic subjects. After excluding families with syndromic disease pathogenic and likely pathogenic NOTCH1 variants were detected in 9/435 (2.1%; 95% CI: 0.7% to 3.4%) of pedigrees and between 0.05% (95% CI: 0.005% to 0.10%) and 0.08% (95% CI: 0.02% to 0.13%) of sporadic patients. Incomplete penetrance of definitely pathogenic NOTCH1 mutations was observed in almost half of reported pedigrees.

CONCLUSIONS

Pathogenic and likely pathogenic NOTCH1 genetic variants explain 2% of familial and <0.1% of sporadic BAV disease and are more likely to associate with tetralogy of Fallot and hypoplastic left heart.

Short-term adverse remodeling progression in asymptomatic aortic stenosis

OBJECTIVES

Aortic stenosis (AS) is characterised by a long and variable asymptomatic course. Our objective was to use cardiovascular magnetic resonance imaging (MRI) to assess progression of adverse remodeling in asymptomatic AS.

METHODS

Participants from the PRIMID-AS study, a prospective, multi-centre observational study of asymptomatic patients with moderate to severe AS, who remained asymptomatic at 12 months, were invited to undergo a repeat cardiac MRI.

RESULTS

Forty-three participants with moderate-severe AS (mean age 64.4 ± 14.8 years, 83.4% male, aortic valve area index 0.54 ± 0.15 cm2/m2) were included. There was small but significant increase in indexed left ventricular (LV) (90.7 ± 22.0 to 94.5 ± 23.1 ml/m2, p = 0.007) and left atrial volumes (52.9 ± 11.3 to 58.6 ± 13.6 ml/m2, p < 0.001), with a decrease in systolic (LV ejection fraction 57.9 ± 4.6 to 55.6 ± 4.1%, p = 0.001) and diastolic (longitudinal diastolic strain rate 1.06 ± 0.2 to 0.99 ± 0.2 1/s, p = 0.026) function, but no overall change in LV mass or mass/volume. Late gadolinium enhancement increased (2.02 to 4.26 g, p < 0.001) but markers of diffuse interstitial fibrosis did not change significantly (extracellular volume index 12.9 [11.4, 17.0] ml/m2 to 13.3 [11.1, 15.1] ml/m2, p = 0.689). There was also a significant increase in the levels of NT-proBNP (43.6 [13.45, 137.08] pg/ml to 53.4 [19.14, 202.20] pg/ml, p = 0.001).

CONCLUSIONS

There is progression in cardiac remodeling with increasing scar burden even in asymptomatic AS. Given the lack of reversibility of LGE post-AVR and its association with long-term mortality post-AVR, this suggests the potential need for earlier intervention, before the accumulation of LGE, to improve the long-term outcomes in AS.

KEY POINTS

• Current guidelines recommend waiting until symptom onset before valve replacement in severe AS. • MRI showed clear progression in cardiac remodeling over 12 months in asymptomatic patients with AS, with near doubling in LGE. • This highlights the need for potentially earlier intervention or better risk stratification in AS.

Comparison of exercise testing and CMR measured myocardial perfusion reserve for predicting outcome in asymptomatic aortic stenosis: the PRognostic Importance of MIcrovascular Dysfunction in Aortic Stenosis (PRIMID AS) Study

Aims

To assess cardiovascular magnetic resonance (CMR) measured myocardial perfusion reserve (MPR) and exercise testing in asymptomatic patients with moderate-severe AS.

Methods and results

Multi-centre, prospective, observational study, with blinded analysis of CMR data. Patients underwent adenosine stress CMR, symptom-limited exercise testing (ETT) and echocardiography and were followed up for 12-30 months. The primary outcome was a composite of: typical AS symptoms necessitating referral for AVR, cardiovascular death and major adverse cardiovascular events. 174 patients were recruited: mean age 66.2 ± 13.34 years, 76% male, peak velocity 3.86 ± 0.56 m/s and aortic valve area index 0.57 ± 0.14 cm2/m2. A primary outcome occurred in 47 (27%) patients over a median follow-up of 374 (IQR 351-498) days. The mean MPR in those with and without a primary outcome was 2.06 ± 0.65 and 2.34 ± 0.70 (P = 0.022), while the incidence of a symptom-limited ETT was 45.7% and 27.0% (P = 0.020), respectively. MPR showed moderate association with outcome area under curve (AUC) = 0.61 (0.52-0.71, P = 0.020), as did exercise testing (AUC = 0.59 (0.51-0.68, P = 0.027), with no significant difference between the two.

Conclusions

MPR was associated with symptom-onset in initially asymptomatic patients with AS, but with moderate accuracy and was not superior to symptom-limited exercise testing. ClinicalTrials.gov (NCT01658345).

Symptom Onset in Aortic Stenosis: Relation to Sex Differences in Left Ventricular Remodeling

OBJECTIVES

The aim of this study was to establish sex differences in remodeling and outcome in aortic stenosis (AS) and their associations with biomarkers of myocardial fibrosis.

BACKGROUND

The remodeling response and timing of symptoms is highly variable in AS, and sex plays an important role.

METHODS

A total of 174 patients (133 men, mean age 66.2 ± 13.3 years) with asymptomatic moderate to severe AS underwent comprehensive stress cardiac magnetic resonance imaging, transthoracic echocardiography, and biomarker analysis (matrix metalloproteinase [MMP]-2, -3, -7, -8, and -9; tissue inhibitor matrix metalloproteinases-1 and -4; syndecan-1 and -4; and N-terminal pro-B-type natriuretic peptide), and were followed up at 6-month intervals. A primary endpoint was a composite of typical AS symptoms necessitating referral for aortic valve replacement, cardiovascular death, or major adverse cardiovascular events.

RESULTS

For a similar severity of AS, male patients demonstrated higher indexed left ventricular (LV) volumes and mass, more concentric remodeling (higher LV mass/volume), a trend to more late gadolinium enhancement (present in 51.1% men vs. 34.1% women; p = 0.057), and higher extracellular volume index than female patients (13.27 [interquartile range (IQR): 11.5 to 17.0] vs. 11.53 [IQR: 10.5 to 13.5] ml/m², p = 0.017), with worse systolic and diastolic function and higher MMP-3 and syndecan-4 levels, whereas female patients had higher septal E/e'. Male sex was independently associated with indexed LV mass (β = 13.32 [IQR: 9.59 to 17.05]; p < 0.001). During median follow-up of 374 (IQR: 351 to 498) days, a primary outcome, driven by spontaneous symptom onset, occurred in 21.8% of male and 43.9% of female patients (relative risk: 0.50 [95% confidence interval: 0.31 to 0.80]; p = 0.004). Measures of AS severity were associated with the primary outcome in both sexes, whereas N-terminal pro-B-type natriuretic peptide, MMP-3, and mass/volume were only associated in men.

CONCLUSIONS

In AS, women tolerate pressure overload with less concentric remodeling and myocardial fibrosis but are more likely to develop symptoms. This may be related to higher wall stress and filling pressures in women.

Point-of-care cardiac ultrasound in acute medicine--the quick scan

The optimum management of acute medical patients requires prompt and accurate diagnosis, monitoring and treatment. The clinical history and physical examination remain central to diagnosis, but often need supplementation by laboratory testing or imaging. Echocardiographic assessment of cardiac structure and function provides valuable information that can aid diagnosis and assess clinical progress. It has many advantages as an imaging modality, and recent technological advances have resulted in hand-held, battery-powered ultrasound devices that provide high-quality images. Three broad applications of cardiac ultrasound now exist: conventional echocardiography, focussed echocardiography and the quick-scan. A quick-scan using a hand-held ultrasound device is readily integrated into the bedside clinical assessment, providing information that can be used immediately in diagnostic reasoning; it can also guide pericardiocentesis. Hand-held ultrasound devices can also be used in acute situations, as well as geographically remote areas or special situations (eg disaster zones) where other imaging is not available. However, the diagnostic yield of echocardiography is user dependent, and training is required for its benefits to be realised, adding to the hardware costs. More data are needed on the incremental value of hand-held ultrasonography and a quick-scan over conventional methods of assessment, their impact on clinical outcomes, and cost effectiveness.

A study of role expansion: a new GP role in cardiology care

BACKGROUND

The National Health Service is reconfiguring health care services in order to meet the increasing challenge of providing care for people with long-term conditions and to reduce the demand on specialised outpatient hospital services by enhancing primary care. A review of cardiology referrals to specialised care and the literature on referral management inspired the development of a new GP role in Cardiology. This new extended role was developed to enable GPs to diagnose and manage patients with mild to moderate heart failure or atrial fibrillation and to use a range of diagnostics effectively in primary care. This entailed GPs participating in a four-session short course with on-going clinical supervision. The new role was piloted in a small number of GP practices in one county in England for four months. This study explores the impact of piloting the Extended Cardiology role on the GP's role, patients' experience, service delivery and quality.

METHODS

A mixed methods approach was employed including semi-structured interviews with GPs, a patient experience survey, a quality review of case notes, and analysis on activity and referral data.

RESULTS

The participating GPs perceived the extended GP role as a professional development opportunity that had the potential to reduce healthcare utilisation and costs, through a reduction in referrals, whilst meeting the patient's wishes for the provision of care closer to home. Patient experience of the new GP service was positive. The standard of clinical practice was judged acceptable. There was a fall in referrals during the study period.

CONCLUSION

This new role in cardiology was broadly welcomed as a model of care by the participating GPs and by patients, because of the potential to improve the quality of care for patients in primary care and reduce costs. As this was a pilot study further development and continuing evaluation of the model is recommended.

Successful low-dose thrombolysis of submassive pulmonary embolus in a pregnant patient

Low-dose thrombolysis was effective and safe in a pregnant woman with acute pulmonary embolism causing severe right ventricular dysfunction.

This is the first reported case of successful thrombolysis for pulmonary embolus in pregnancy in the absence of shock.

Developing a rapid access chest pain clinic: qualitative studies of patients' needs and experiences

OBJECTIVE

The aims of this study are to understand the needs and experiences of rapid access chest pain clinic attenders and to determine the acceptability and effectiveness of simple procedural changes.

METHODS

Two qualitative studies of clinic attenders before and after procedural changes which were guided by the first study.

RESULTS

Study 1: Patients wanted to be reassured, by knowing what was causing their pain, understanding the cause, and feeling able to help themselves. Often, these needs were not met, and uncertainties left some patients feeling ill-equipped to help themselves. Communication problems were identified. Study 2: The changes were acceptable to patients, and almost all were reassured. Most valued receiving extra verbal and written advice and information. Many felt more aware of cardiac risk factors and intended to change their lifestyle.

CONCLUSION

There were clear opportunities for improvements in care. Changes in procedures helped patients to understand their pain, to practice self-management, and to consider altering their lifestyle.

Characteristics of patients presenting to a cardiac clinic with palpitation

BACKGROUND

Palpitation is a very common presenting symptom in primary care and in cardiac clinics, associated with marked disability. Although serious arrhythmias are uncommon causes, treatment of persistent palpitation is difficult.

AIM

To describe the cardiological, behavioural and psychological characteristics of consecutive patients presenting to a cardiac clinic with the main complaint of palpitation.

DESIGN

Prospective evaluation of consecutive out-patients.

METHODS

Participants were 184 consecutive patients with the complaint of palpitation referred to an out-patient cardiac clinic. Three assessments were used. Three to four weeks prior to clinic attendance, measures of symptoms, distress and disability were gathered, and a heart rate perception test was conducted. At the out-patient clinic, a routine clinical assessment was made. Three months later, patients received a questionnaire which included baseline measures of symptoms, distress and disability.

RESULTS

Palpitation was associated with arrhythmias in 62 patients (34%), extrasystoles in 75 patients (41%) and awareness of sinus rhythm in 47 patients (26%). Distress and disability were common and persistent. There were significant differences in the characteristics of the three groups.

DISCUSSION

Most patients presenting to secondary care with palpitation do not have serious underlying cardiovascular conditions. Concurrent psychological problems are common and persistent. Aetiology may be seen as an interaction of pathology, awareness of normal physiology, and psychological variables. Few patients require specialist cardiological treatment, but simple reassurance is of limited effectiveness. A stepped care approach may improve outcomes and needs rigorous evaluation.

A randomized controlled trial of a brief educational and psychological intervention for patients presenting to a cardiac clinic with palpitation

BACKGROUND

We sought to determine whether a brief psycho-educational intervention reduced disability in patients with benign palpitation.

METHOD

In a pragmatic randomized controlled trial within a cardiology clinic at a district general hospital, 80 consecutive patients diagnosed as having benign palpitation--either palpitation due to awareness of extrasystoles or sinus rhythm--with associated distress or disability were randomized to an intervention group (usual care plus nurse-delivered intervention based on cognitive-behavioural principles) or to a control group (usual care). Principal outcome was difference in proportion of participants with good or excellent researcher-rated activity levels at 3 months. Subsidiary outcomes were self-rated symptoms, distress and disability, researcher-rated unmet treatment needs.

RESULTS

The principal outcome showed a statistically and clinically significant benefit for the intervention group, with a number needed to treat of 3 (95% CIs 2 to 7). All but one subsidiary outcomes also showed a difference in favour of the intervention group, and several differences reached statistical significance. Significantly more of the control group had unmet treatment needs at 3 months.

CONCLUSIONS

A brief, nurse-delivered, psycho-educational intervention, was an effective treatment for benign palpitation. Further evaluation, including assessment of cost-effectiveness, is needed. The findings have application to the care of patients presenting with other types of 'unexplained' medical symptoms.

Patients with palpitations referred for 24-hour ECG recording

Palpitations are one of the most common reasons for referral to cardiologists; most are assessed as being medically benign. Eighty consecutive subjects referred for 24-hour ECG recording completed a questionnaire at the time of assessment and a follow-up self-report questionnaire at 18 months. Many of those with and without abnormal hearts reported distress, concern about their symptoms, and limitation of everyday activities. There were few differences between these groups at assessment or at follow-up. There was little change in mental state or in disability in either group over 18 months. Present symptomatic treatment is largely ineffective and there is a need to evaluate psychological and behavioral interventions.

"Not clinically indicated": patients' interests or resource allocation?

The decision that a particular intervention is not clinically indicated may conceal two quite different ethical assumptions. The first assumption is that the intervention is not of overall benefit to this patient. The second is that limited resources should not be used for this patient. These issues are discussed with reference to cardiac surgery in elderly patients with reference to the main theories of allocation: QALYs, needs theories, the sanctity of life theory, the lottery theory, and market forces.

Intraventricular septal hypertrophy in type 1 diabetic patients with microalbuminuria or early proteinuria

To investigate whether the slightly increased blood pressure that occurs in early diabetic renal disease is associated with hypertensive left ventricular hypertrophy, M-mode echocardiograms were recorded in 11 non-diabetic control subjects and four groups of Type 1 diabetic patients. These were 15 patients without microvascular complications, 10 with microalbuminuria, 12 with early persistent proteinuria, and 8 with established renal impairment. Mean blood pressure was 133/80 mmHg (uncomplicated patients), 143/85 mmHg (microalbuminuria), 147/92 mmHg (early proteinuria) and 158/85 mmHg (renal impairment). Mean intraventricular septal width in the uncomplicated diabetic patients was 9.8 (SE 1.2) mm which did not differ from non-diabetic control subjects. Mean septal width was significantly greater in the other groups (microalbuminuria, 12.7 (1.1) mm, p less than 0.02; proteinuria, 12.0 (0.7) mm, p less than 0.05; renal impairment, 15.5 (1.8) mm, p less than 0.001). Left ventricular mass increased progressively between groups and was significantly increased in those with renal impairment (140 (21) vs 103 (5) g m-2 in uncomplicated patients, p less than 0.05). Septal width in the diabetic population not receiving antihypertensives (n = 37) was significantly correlated with systolic blood pressure (r = 0.45, p less than 0.005) which was the only variable independently related to septal width and ventricular mass. It appears that the slight increase in blood pressure that occurs in microalbuminuria and early proteinuria is frequently associated with hypertensive left ventricular hypertrophy.

Observations on the warm up phenomenon in angina pectoris

Adaptation to exercise was investigated in 14 men aged 34-69 years (mean 51) with stable exertional angina caused by occlusive coronary artery disease. All underwent exercise electrocardiography to symptom limitation according to the Bruce protocol (first effort), and exercise to the onset of angina (warm up) followed by four minutes' rest, followed by exercise to symptom limitation (second effort). This protocol was repeated after sequential treatment for one month each with nifedipine 10 mg three times a day and with timolol 10 mg twice a day. Warm up significantly increased walking time to the onset of angina by 34.5% and to maximal exercise by 29.5%. The heart rate and rate-pressure product were significantly higher on second effort both at the onset of angina (by 7.0% and 11.1% respectively) and at maximal exercise (by 10.5% and 15.4% respectively). ST segment displacement was not significantly different after warm up. The effect of warm up on walking time to the onset of angina was markedly reduced after treatment with nifedipine but little influenced by timolol. Mean (SE) walking time after warm up on no treatment was 10.1 (0.7) min; after treatment with nifedipine it was 10.0 (0.6) min and after treatment with timolol it was 9.7 (0.4) min. These data demonstrate a substantial improvement in exercise performance after warm up and are consistent with the hypothesis that submaximal exercise in angina pectoris facilitates myocardial oxygen uptake by coronary vasodilatation.