Ethnicity-specific myocardial remodelling in hypertensive heart disease by multi-parametric cardiovascular magnetic resonance

Background

Patients with systemic hypertension (HTN) of African ancestry (Afr-a) are at greater risk of incident heart failure (HF), hospitalisation and death than those of European ancestry (Eu-a). This has been related to higher prevalence of HTN-related target organ damage, including high level of circulating cardiac troponins, which is not fully explained by blood pressure level. Thus, one may speculate that Afr-a hypertensives have a higher tendency to develop myocardial damage in response to arterial afterload. However, myocardial composition differences between Afr-a and Eu-a hypertensives remain speculative.

Purpose

To investigate ethnic-specific differences in myocardial tissue composition in Eu-a and Afr-a hypertensives by multi-parametric cardiovascular magnetic resonance (CMR).

Methods

This cross-sectional study included 63 Afr-a and 47 Eu-a hypertensive patients. All patients underwent multi-parametric CMR (1.5-Tesla Aera, Siemens-Healthcare, Erlangen-Germany). Left (LV) and right ventricular (RV) volumes, mass and function, atrial dimensions, and myocardial tissue characterisation (including T1- and T2-mapping) were measured using a standardised imaging protocol, and post-processing recommendations from international scientific societies. Analysis was completed using a commercially available cardiac-software (CVI-42, Calgary-Canada). Central pulse-wave-velocity (PWV) between the ascending and proximal descending thoracic aorta was measured by high-temporal, resolution 2D phase-contrast velocity-encoded parasagittal cine images, using in-house MATLAB software.

Results

Although Afr-a were 5 years older than Eu-a hypertensives, cardiovascular risk factors, anthropometric, body composition and haemodynamic measures were similar between the two groups (Figure 1). Segmental PWV was greater in Afr-a than Eu-a patients (8.16±2.71 vs 6.97±2.82 m/s, P=0.044), underlying higher aortic stiffness in Afr-a hypertensives. Afr-a hypertensives also had greater LV mass and LV-mass/end-diastolic volume ratio than Eu-a (Figure 2), whilst no difference was observed in LV systolic/diastolic function. Native T1 relaxation time and synthetic extracellular volume were also similar between the two ethnicities, though T2 relaxation time was significantly higher in Afr-a hypertensives. Late gadolinium enhancement (LGE), a well-established metric of replacement fibrosis (scarring), was more prevalent in Afr-a than Eu-a hypertensives (14% vs 4%, P=0.001). In patients with LGE, the extent of LGE was higher in Afr-a than Eu-a hypertensives (Figure 2).

Conclusion

Afr-a hypertensives have higher arterial afterload, LV mass and remodelling than Eu-a, despite comparable mean blood pressure, body-mass-index, and body composition. These changes in LV structure and geometry were associated with higher T2 relaxation time, likely reflecting low-grade inflammation, as well as higher prevalence and extent of replacement myocardial fibrosis.

Funding Acknowledgement

Type of funding sources: None.

Racial differences of right ventricular remodelling in systemic hypertension unveiled by multiparametric cardiovascular magnetic resonance

Background

Patients with systemic hypertension (HTN) of African ancestry (Afr-a) are at greater risk of heart failure (HF), hospitalisation and death than those of European ancestry (Eu-a). Compelling evidence suggests that left ventricular (LV) remodelling and hypertrophy are more prevalent in Afr-a than Eu-a hypertensives due to either a high clustering of cardiovascular risk-factors and/or a difference in genetic background. Prior studies in Eu-a subjects have shown that uncomplicated HTN is associated with right ventricular (RV) hypertrophy and remodelling which may contribute to development of HF. However, the impact of ethnicity on RV remodelling in HTN remains speculative.

Purpose

To investigate the influence of ethnicity on RV remodelling/hypertrophy in patients with HTN using cardiovascular magnetic resonance (CMR).

Methods

In this cross-sectional study we included 16 Afr-a and 32 Eu-a age- and sex-matched healthy-volunteers, and 63 Afr-a and 47 Eu-a hypertensives. All participants underwent a CMR exam (1.5-Tesla, Aera, Siemens-Healthcare, Erlangen-Germany). LV and RV volumes, masses and function were measured according to the current recommendations. Blood pressure was recorded during the CMR.

Results

Age- and sex-matched Afr-a and Eur-a healthy-volunteers (37±10 vs 37±12 years, P=0.975; male 53% vs 44%; P=0.539) exhibited closely comparable LV and RV volumes, masses, and end-diastolic volume/mass ratios. In the HTN group, despite Afr-a hypertensives being roughly 5 years older than Eu-a, baseline characteristics including cardiovascular risk factors, mean blood pressure, body-mass-index, and body composition metrics were similar between the two groups (Figure 1). Afr-a hypertensives also had greater LV and RV masses and mass/end-diastolic volume ratios than Eur-a hypertensives (Figure 2). RV mass correlated with LV mass in both ethnic groups (r=0.593 in Eu-a and r=0.569 in Afr-a; both P<0.001). Multivariable linear regression analysis showed that RV mass was independently associated with African descendance after correction for major confounders including LV mass, biventricular volumes, and body composition.

Conclusion

Our findings support the notion that Afr-a and Eur-a healthy-volunteers have comparable left and right ventricular geometry and masses, arguing against genetic-determinate ventricular geometry and myocardial mass in this population. However, Afr-a individuals exhibit higher sensitivity to myocardial hypertrophy in response to HTN which translates into greater biventricular masses and remodelling, compared to Eu-a hypertensives.

Funding Acknowledgement

Type of funding sources: None.

In-depth phenotyping by cardiovascular magnetic resonance uncovering differences between ethnic groups in hypertensive heart disease

Background

Black African/African-Caribbean individuals with hypertension (BH) are at greater risk of heart failure than those of white European ethnicity (WH). The mechanisms underlying this dissimilarity remain poorly understood.

Purpose

To investigate the influence of ethnicity on left ventricular (LV) remodelling using multi-parametric cardiovascular magnetic resonance (CMR).

Methods

BH (n=44), WH (n=38) and healthy-volunteers (HV; n=25, 5 of black ethnicity) underwent comprehensive CMR. The exam included: i) Arterial Stiffness/Afterload pulse-wave-velocity (PWV), aortic elastance (Ea) and systemic vascular resistance (SVR) by phase-contrast velocity-encoding imaging; ii) Ventricular remodelling/Function LV and right ventricular (RV) volumes, mass, ejection fraction (EF), LV peak-filling rate by short-axis cine images; myocardial strains were measured by feature tracking; iii) Left atrial (LA) remodelling/Function volumes and functions by long-axis cine images; iv) Tissue characterisation: extracellular volume by pre/post-contrast T1-mapping and late gadolinium enhancement (LGE) for interstitial and replacement myocardial fibrosis, respectively. Multivariate linear regression models were developed to investigate how LV remodelling associates with ethnicity, arterial afterload, including elastance (Ea) and stiffness [PW], and SVR. Models were adjusted for age, gender, body-mass-index, LV volumes or function and LA volumes.

Results

Subject characteristics are summarised in the Table. PWV and Ea and SVR were greater in hypertensives, particularly in BH, than HV; this was paralleled by higher LV mass, interventricular septum thickness (IVS), LA volumes but lower LV-EF. These findings were confirmed after adjusting for age.

On the Model-1, IVS was associated with Ea (β=0.335, P=0.008) and black ethnicity (β=0.226, P=0.019) but not with SVR or PWV. For each increment of Ea there was a similar increase of IVS in BH and WH (P=0.602 for interaction), however BH had greater IVS than WH at each Ea value (Figure, fully-adjusted Model-1). On Model-2, LV end-diastolic volume was associated with Ea (β=−0.268, P=0.001), SVR (β=−0.319, P=0.019) but not with PWV or ethnicity. However, the inverse relation between LV size and Ea was significantly attenuated in BH (P=0.039 for interaction), (Figure, fully-adjusted Model-2). On model-3, LV-EF was associated with Ea (β=0.223, P=0.009) but not with ethnicity, PWV or SVR. LV-EF reduction for each Ea increment was similar for BH and WH (P=0.597 for interaction).

Conclusion

BH and WH show a distinctive LV remodelling phenotype. BH had a greater susceptibility to hypertrophy and an attenuated reduction of chamber size in response to arterial afterload. Further research to disentangle the genetic and environmental factors underlying these ethnic group-specific differences is utterly required.

Funding Acknowledgement

Type of funding sources: None. Figure 1Table 1

Unravelling racial differences in hypertensive heart disease by multiparametric cardiovascular magnetic resonance: a phenotype-wide association study

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): Dr Georgiopoulos was supported by the Onassis Foundation under the special grant & support program for scholars" association members

Introduction – Black Afro-Caribbean hypertensives (BAHs) are exposed to a higher risk of heart failure (HF) than white hypertensives (WHs). Arterial afterload is higher in BAHs due to increased arterial stiffness and vascular volume; BAHs develop more often left ventricular (LV) hypertrophy, dilatation and systolic dysfunction than WHs. However, it is unclear whether other racial differences concur to the more pronounced LV remodelling in BAHs.

Methods – This cross-sectional study included hypertensive patients undergoing cardiovascular magnetic resonance for their clinical work-up (1.5T Aera Siemens-Healthcare). Clinical history and haemodynamic parameters were collected in all participants; a subset of patients had complete bio-humoral assay of the renin-angiotensin-aldosterone system (RAAs). Arm cuff pressure was measured during CMR. The CMR protocol included: i) Arterial afterload / LV arterial-coupling - pulse-wave-velocity (PWV), aortic (Ea) and LV elastance (Ees) by aorta anatomic and phase-contrast velocity-encoding imaging; ii) ventricular remodelling and function - LV and right ventricular (RV) volumes, mass, EF, LV peak-filling rate by short-axis cine images; global circumferential and longitudinal strains by cine feature tracking; iii) left atrial (LA) remodelling volumes and reservoir, conduit and booster functions by long-axis cine images; iv) tissue characterisation: T2 and pre/post-contrast T1 relaxation times, extracellular volume (ECV) by single mid-ventricular short-axis T1/T2-mapping.

Results – 34 BAHs and 35 WHs (52 ± 12 vs 45 ± 14 years, P < 0.05; 61% vs 65% males P = NS) were included in the study. Baseline features are summarised in the Table. LV systolic dysfunction was more prevalent in BAH than WHs (P = 0.038). Of note, BAHs tended to have greater LV volumes and significantly higher LV mass and septal thickness than WHs. In BAHs, but not in WHs, PWV was associated with increased septal thickness after correction for blood pressure and age (β-value: 0.447, P = 0.02). Normalised RV mass was greater in BHA than WHs; RV mass suits for the identification of racial or circulating factors predisposing to hypertrophy being largely unaffected by systemic afterload. In our study LV diastolic function and LA volumes were similar between BAHs and WHs, and none of the subjects had conditions associated with pre-capillary pulmonary hypertension. Hence, higher RV-mass in BAHs pinpoints a racial susceptibility to myocardial hypertrophy. Finally, in a subset of patients with RAAs assays (n = 43), the aldosterone/renin ratio was higher in BAHs than WHs (67.04 [IQR: 19.37-209.73] vs 13.77 [IQR: 7.47-40.43], P = 0.01).

Conclusion – BAHs have heightened LV remodelling than WHs because of racial predisposition to develop hypertrophy which also encompasses derangements in RAAs. Altogether, these findings may account for the greater risk for HF in BAHs than WHs.

ESC 2019 guidelines on chronic coronary syndromes: can calcium scoring improve the risk underestimation associated with the updated pre-test probability risk score?

Funding Acknowledgements

Type of funding sources: None.

Introduction

The European Society of Cardiology (ESC) published an updated stable chest pain guideline in 2019. It recommends the use of an updated pre-test probability (PTP) risk score (RS) to assess the likelihood of coronary artery disease (CAD), to try and reduce the risk overestimation associated with previous risk scores. We sought to assess the performance of the 2019 PTPRS in a contemporary cohort of patients undergoing CT coronary angiography (CTCA). Furthermore, we focussed on patients with PTPRS <15%, and assessed the utility of CT calcium scores as a discriminator of risk.

Methods

652 patients who were investigated with CTCA for stable chest pain between January 2017 and May 2018 were included in a retrospective analysis. CTCA reported CAD degree of stenosis as normal/minimal stenosis, mild (30-50%), moderate (50-70%), or severe (>70%). ESC 2019 pre-test probability risk scores were retrospectively calculated and compared.

Results

A total of 652 patients underwent CTCA between 01 January 2017 and 31 May 2018, of which 330 were male and 322 were female, with an average age of 55 years ±11 years.

Using the ESC 2019 PTPRS there were no patients with PTPRS >85%. 2 patients had PTPRS 50-85%; one patient had moderate stenosis and one mild stenosis on CTCA. 

There were 267 patients with PTPRS 15-50%; 23 (9%) patients had severe CTCA stenosis, 37 (14%) a moderate stenosis, and 34 (13%) a mild stenosis.

A further 379 patients had PTPRS <15%; 11 (3%) had severe stenosis and 20 (5%) moderate stenosis. A further 27 (7%) patients had mild CTCA stenosis. 

A total of 357 of 379 patients with PTPRS <15% based on ESC 2019 had a CT calcium score. 236 patients were found to have a calcium score of zero, and 121 patients had a score greater than zero, with a range between 1 and 930. Of patients with zero calcium score, only 1 (0.4%) patient had severe stenosis, 2 (0.8%) moderate stenoses and 6 (2.5%) mild stenosis. In contrast, in patients with positive calcium scores, 10 (8%) had severe stenosis, 18 (15%) moderate stenosis, and 22 (18%) mild stenosis.

Conclusions

The ESC 2019 PTPRS classified this as an overall low risk cohort. The downward risk modification of PTPRS has led to a large number of patients being classified as low risk with PTPRS <15%. No or deferred investigation is recommended by the ESC in this cohort. However, the use of CT calcium scores  in patients with PTPRS <15%, detected the majority of patients with any degree of CAD. CT calcium scores are a simple and low cost risk modifier, and may help identify patients who may benefit from primary prevention as per SCOT-Heart. Patients with calcium score greater than zero could be investigated with CTCA.

ESC 2019 guidelines on chronic coronary syndromes: could calcium scoring improve detection of coronary artery disease in patients with low risk score. Findings from a retrospective cohort of patients in a district general hospital

BACKGROUND

The European Society of Cardiology (ESC) published an updated stable chest pain guideline in 2019, recommending the use of an updated pre-test probability (PTP) risk score (RS) to assess the likelihood of coronary artery disease (CAD). We sought to compare the 2019 and 2013 PTPRS in a contemporary cohort of patients.

METHODS

612 patients who were investigated with computed tomography coronary angiography (CTCA) for stable chest pain were included in a retrospective analysis.

RESULTS

There were 255 patients with 2019 PTPRS 15-50% with a 9% yield of severe CAD on CTCA, compared with 402 patients and a 4% yield using the 2013 PTPRS (p = 0.01). 355 patients had a 2019 PTPRS of <15%, with 3% found to have severe CAD, compared with 67 patients and none with severe CAD using the 2013 PTPRS (p = 0.14). 336 of patients with 2019 PTPRS of <15% had a calcium score as part of the CTCA. 223 of these had a zero calcium score and only one had severe CAD. In comparison, 113 patients had a positive calcium score, and 10 (9%) had severe CAD (p < 0.001).

DISCUSSION

The ESC 2019 PTPRS classifies more patients as at lower risk of CAD and hence reduces the risk overestimation associated with the 2013 PTPRS. However, in patients with a 2019 PTPRS of <15%, who would not be investigated, the use of the calcium score detected the majority of patients with significant CAD, who may benefit from secondary prevention and an associated mortality benefit as per the SCOT-Heart trial.

P1589 Yield of invasive coronary angiography following the UK NICE 2016 guideline expansion of CT coronary angiography

Results

In total 652 patients underwent CTCA (mean age 55 yrs; 330 male). 92 patients were found to have moderate or severe stenosis. 69 of them were referred directly to ICA, with 63 undergoing ICA and confirming severe CAD in 40 patients, a yield of 63%. 18 patients with moderate stenosis were referred for stress echo (SE) with one positive result. In total 35 patients went on to be revascularised.

62 patients were found to have mild stenosis. The majority of patients (n = 462) had normal/minimal stenosis. There were 36 inconclusive studies.

The ESC RS was calculated retrospectively with the following results:

70 patients had an ESC RS &lt;15% and 2 (3%) were found to have moderate stenosis. 427 patients had an ESC RS 15-50%; 17 (4%) had severe stenosis and 32 (8%) moderate stenosis. 149 patients had an ESC RS 50-85%; 17 (11%) were found to have severe stenosis and 23 (15%) moderate stenosis. Lastly 2 patients had an ESC RS &gt;85% and one had moderate stenosis.

Conclusions

Our results demonstrate that CTCA is an effective first line test for most patients with new stable chest pain as the majority were found to have normal/minimal disease. In the patients that went on to have ICA, CTCA had a relatively high yield of detecting severe CAD (63%). This was achieved with some use of SE as a gatekeeper to ICA, particularly in patients with moderate CTCA stenosis. SE should be used more after CTCA in patients with moderate stenosis, as a gatekeeper to ICA.

The ESC RS was predictive of significant CAD but overestimated the likelihood of CAD.

Abstract P1589 Figure. Severe CTCA stenosis of the LAD

P1487 Anomalous right coronary artery from mid left anterior descending artery

55-year-old male with history of transient ischaemic attack, excised gastro-intestinal stromal tumour, and osteoarthritis presented to rapid access chest pain clinic with history of atypical chest pain. There were no resting electrocardiographic changes. In accordance with NICE stable chest pain guidelines, a CT coronary angiogram was requested to further assess for any underlying coronary artery disease. This showed normal origin of left main stem (LMS) from left coronary sinus of aorta, however there was an anomalous origin of the right coronary artery (RCA) as a branch from the mid portion of left anterior descending artery (LAD). This was deemed to be an incidental finding with a benign course and not the cause of his symptoms.

Coronary anomalies have a reported incidence of 1.3% at invasive coronary angiography (1), and a reported incidence of 0.014-0.066% of single coronary artery (2). Anomalous RCA usually courses from the LMS and courses between the aorta and pulmonary artery. We present an extremely rare variant of single coronary artery arising from the mid LAD without any associated congenital or structural abnormality, on CT coronary angiography (the gold standard for demonstrating coronary anatomy). This is rarely reported in the literature and is a benign coronary anomaly.

Abstract P1487 Figure.

Effect of a common X-linked angiotensin II type 2-receptor gene polymorphism (-1332 G/A) on the occurrence of premature myocardial infarction and stenotic atherosclerosis requiring revascularization

OBJECTIVES

To assess the association of the angiotensin II type 2 (AT2) receptor (-1332 G/A) gene polymorphism with premature coronary artery disease (CAD) and investigate for a further role in both myocardial infarction and predominantly stenotic atherosclerosis requiring revascularisation.

METHODS AND RESULTS

We investigated 885 families, which consisted of at least one sibling affected with premature CAD and at least one unaffected sibling. Genotyping of subjects was performed using a restriction enzyme digestion of an initial 310 bp PCR fragment that included the AT2 (-1332 G/A) locus. The mean age of the 1143 individuals affected by premature CAD at the time of event was 50.6+/-9.1 years. The genetic data were analyzed for these families using the X-linked sibling transmission disequilibrium test (XS-TDT). We observed significant evidence for an association for the AT2 (-1332 G) locus and premature CAD (p-exact value=0.028). This was driven by a highly significant result in men (p-exact value=0.005). We performed further analyses to investigate for an association with myocardial infarction (Group 1) and stenotic atherosclerosis that was of sufficient severity as to require revascularization (Group 2). We found an increase in the frequency of the G/GG genotype in both Groups 1 and 2, being most marked in Group 2 (XS-TDT, p-exact value=0.0134); logistic regression (p=0.033, OR 1.38; 95% CI of 1.212-1.507).

CONCLUSION

We have observed evidence of association between the X-linked AT2 (-1332 G/A) polymorphism and premature CAD with further evidence of a statistically significant association with stenotic atherosclerosis requiring revascularization.

Cost-effectiveness of alternative strategies for the initial medical management of non-ST elevation acute coronary syndrome: systematic review and decision-analytical modelling

OBJECTIVES

To identify and prioritise key areas of clinical uncertainty regarding the medical management of non-ST elevation acute coronary syndrome (ACS) in current UK practice.

DATA SOURCES

Electronic databases. Consultations with clinical advisors. Postal survey of cardiologists.

REVIEW METHODS

Potential areas of important uncertainty were identified and 'decision problems' prioritised. A systematic literature review was carried out using standard methods. The constructed decision model consisted of a short-term phase that applied the results of the systematic review and a long-term phase that included relevant information from a UK observational study to extrapolate estimated costs and effects. Sensitivity analyses were undertaken to examine the dependence of the results on baseline parameters, using alternative data sources. Expected value of information analysis was undertaken to estimate the expected value of perfect information associated with the decision problem. This provided an upper bound on the monetary value associated with additional research in the area.

RESULTS

Seven current areas of clinical uncertainty (decision problems) in the drug treatment of unstable angina patients were identified. The agents concerned were clopidogrel, low molecular weight heparin, hirudin and intravenous glycoprotein antagonists (GPAs). Twelve published clinical guidelines for unstable angina or non-ST elevation ACS were identified, but few contained recommendations about the specified decision problems. The postal survey of clinicians showed that the greatest disagreement existed for the use of small molecule GPAs, and the greatest uncertainty existed for decisions relating to the use of abciximab (a large molecule GPA). Overall, decision problems concerning the GPA class of drugs were considered to be the highest priority for further study. Selected papers describing the clinical efficacy of treatment were divided into three groups, each representing an alternative strategy. The strategy involving the use of GPAs as part of the initial medical management of all non-ST elevation ACS was the optimal choice, with an incremental cost-effectiveness ratio (ICER) of 5738 pounds per quality-adjusted life-year (QALY) compared with no use of GPAs. Stochastic analysis showed that if the health service is willing to pay 10,000 pounds per additional QALY, the probability of this strategy being cost-effective was around 82%, increasing to 95% at a threshold of 50,000 pounds per QALY. A sensitivity analysis including an additional strategy of using GPAs as part of initial medical management only in patients at particular high risk (as defined by age, ST depression or diabetes) showed that this additional strategy was yet more cost-effective, with an ICER of 3996 pounds per QALY compared with no treatment with GPA. Value of information analysis suggested that there was considerable merit in additional research to reduce the level of uncertainty in the optimal decision. At a threshold of 10,000 pounds per QALY, the maximum potential value of such research in the base case was calculated as 12.7 million pounds per annum for the UK as a whole. Taking account of the greater uncertainty in the sensitivity analyses including clopidogrel, this figure was increased to approximately 50 million pounds.

CONCLUSIONS

This study suggests the use of GPAs in all non-ST elevation ACS patients as part of their initial medical management. Sensitivity analysis showed that virtually all of the benefit could be realised by treating only high-risk patients. Further clarification of the optimum role of GPAs in the UK NHS depends on the availability of further high-quality observational and trial data. Value of information analysis derived from the model suggests that a relatively large investment in such research may be worthwhile. Further research should focus on the identification of the characteristics of patients who benefit most from GPAs as part of medical management, the comparison of GPAs with clopidogrel as an adjunct to standard care, follow-up cohort studies of the costs and outcomes of high-risk non-ST elevation ACS over several years, and exploring how clinicians' decisions combine a normative evidence-based decision model with their own personal behavioural perspective.

Perindopril

Perindopril is a third-generation ACE inhibitor that is characterised as a small, lipophilic molecule with a therapeutically active carboxyl side group. These and other features combine to make this a unique member of a very well-established class of drugs that have proven efficacy in a wide range of cardiovascular diseases. The Perindopril Protection Against Recurrent Stroke Study (PROGRESS) demonstrated benefit in the secondary prevention of patients with stroke, whereas the Perindopril and Remodelling in Elderly with Acute Myocardial Infarction (PREAMI) trial supports extended routine use after myocardial infarction. The most recent evidence from the European Trial on Reduction of Cardiac Events with Perindopril in Stable Coronary Artery Disease (EUROPA) and the Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT) show that perindopril is able to improve the prognosis of patients with a relatively low global cardiovascular risk, denoted either by the presence of stable coronary artery disease or of essential hypertension in conjunction with at least three other risk factors. The fact that major relative risk reductions have been reported for these two studies is matched by the significance of the findings to modern clinical practice. Both studies were conducted in the context of advance concomitant care that is typically better in clinical trials than in routine practice. In particular, the benefits observed were seen to be of a similar magnitude, and also independent of those resulting from statin therapy. Of particular interest is the likely complimentary action of these treatment strategies with regard to the stabilisation of atheromatous plaques. Perindopril is a well-established drug, the full value of which is only now becoming fully apparent.