Sex-specific lifetime risk of cardiovascular events: the European Prospective Investigation into Cancer-Norfolk prospective population cohort study

AIMS

Better understanding of sex differences in cardiovascular disease (CVD) is essential in tailoring appropriate preventative strategies. Using a large population-based study with follow-up >25 years, we aimed to determine sex-specific lifetime risks of incident CVD and cardiovascular (CV) mortality amongst populations with and without prevalent CVD.

METHODS AND RESULTS

Participants were drawn from the European Prospective Investigation into Cancer-Norfolk and followed up for a median of 26.2 years. Sex-specific lifetime risks were ascertained accounting for the competing risk of death. Models were adjusted for ethnicity and time-updated covariates: material deprivation, CV risk factors, lifestyle factors, comorbidities, and medication. A total of 23 859 participants [54.5% women; mean age (standard deviation) 59.2 (9.3) years at baseline] were included. Adjusted lifetime risks of incident CVD were higher in men than in women (69.1 vs. 57.7% at age 75): cause-specific hazard ratio (cHR) (99% confidence interval)-1.49 (1.41-1.57), while the risks of CV mortality at age 75 were 4.4% (men) and 3.1% (women): cHR-1.42 (1.31-1.54). Myocardial infarction was the predominant first presentation in men until the eighth decade. In women, the first CVD manifestations after their sixth decade were predominantly atrial fibrillation and stroke. The male-associated excess relative risks of incident CVD and CV mortality were halved in people with prevalent CVD.

CONCLUSION

We characterized the sex-specific lifetime CV risks in a large cohort. Men had substantially higher risk of incident CVD and CV mortality than women, which was attenuated amongst people with prevalent CVD. Our findings provide an evidence base for sex-specific CV prevention.

Manganese-Enhanced Magnetic Resonance Imaging in Takotsubo Syndrome

BACKGROUND

Takotsubo syndrome is an acute cardiac emergency characterized by transient left ventricular systolic dysfunction typically following a stressful event. Despite its rapidly rising incidence, its pathophysiology remains poorly understood. Takotsubo syndrome may pass unrecognized, especially if timely diagnostic imaging is not performed. Defective myocardial calcium homeostasis is a central cause of contractile dysfunction and has not been explored in takotsubo syndrome. We aimed to investigate myocardial calcium handling using manganese-enhanced magnetic resonance imaging during the acute and recovery phases of takotsubo syndrome.

METHODS

Twenty patients with takotsubo syndrome (63±12 years of age; 90% female) and 20 volunteers matched on age, sex, and cardiovascular risk factors (59±11 years of age; 70% female) were recruited from the Edinburgh Heart Centre between March 2020 and October 2021. Patients underwent gadolinium and manganese-enhanced magnetic resonance imaging during index hospitalization with repeat manganese-enhanced magnetic resonance imaging performed after at least 3 months.

RESULTS

Compared with matched control volunteers, patients had a reduced left ventricular ejection fraction (51±11 versus 67±8%; P<0.001), increased left ventricular mass (86±11 versus 57±14 g/m2; P<0.001), and, in affected myocardial segments, elevated native T1 (1358±49 versus 1211±28 ms; P<0.001) and T2 (60±7 versus 38±3 ms; P<0.0001) values at their index presentation. During manganese-enhanced imaging, kinetic modeling demonstrated a substantial reduction in myocardial manganese uptake (5.1±0.5 versus 8.2±1.1 mL/[100 g of tissue ·min], respectively; P<0.0001), consistent with markedly abnormal myocardial calcium handling. After recovery, left ejection fraction, left ventricular mass, and T2 values were comparable with those of matched control volunteers. Despite this, native and postmanganese T1 and myocardial manganese uptake remained abnormal compared with matched control volunteers (6.6±0.5 versus 8.2±1.1 mL/[100 g of tissue ·min]; P<0.0001).

CONCLUSIONS

In patients with takotsubo syndrome, there is a profound perturbation of myocardial manganese uptake, which is most marked in the acute phase but persists for at least 3 months despite apparent restoration of normal left ventricular ejection fraction and resolution of myocardial edema, suggesting abnormal myocardial calcium handling may be implicated in the pathophysiology of takotsubo syndrome. Manganese-enhanced magnetic resonance imaging has major potential to assist in the diagnosis, characterization, and risk stratification of patients with takotsubo syndrome.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT04623788.

Renin-angiotensin and endothelin systems in patients post takotsubo syndrome

Background

We investigate if renin-angiotensin and endothelin-1 response pathways follow the same pattern of recovery as left ventricular ejection fraction in patients with takotsubo syndrome.

Purpose

To provide better insight into the pathophysiology underlying this condition.

Methods

Ninety takotsubo syndrome patients [n=30 in each of “acute”, “convalescent” (3–5 months) and “recovered” (&gt;1 year) groups] who were on minimal or no medication and were free of any significant cardiac/metabolic co-morbidities, and 30 healthy controls were studied. Serum concentrations of renin, angiotensin converting enzyme, angiotensin II, big endothelin-1, endothelin-1 were measured using commercially available ELISA, and BNP was measured using an immunoassay.

Results

Left ventricular ejection fraction was 38±1.6% in acute, 63±2.0% in convalescent and 64±2.6% in recovered takotsubo syndrome patients. As shown in Figure 1, serum renin concentrations are persistently elevated after a takotsubo episode (p=0.03 vs controls). Angiotensin converting enzyme levels are significantly depressed during the acute phase compared to convalescent (p=0.004), recovered takotsubo (p=0.02) or controls (p=0.03). Angiotensin II is increased in takotsubo patients (p&lt;0.001 vs controls) remaining persistently elevated long-term in the recovered group (p=0.03 vs controls). B-type natriuretic peptide concentrations remain elevated after a Takotsubo episode compared to controls (p=0.003). Big endothelin-1 levels are unchanged, but endothelin-1 is significantly lower after takotsubo syndrome compared to controls (p=0.03).

Conclusions

Despite “normalisation” of the left ventricular ejection fraction, there is long-term maladaptive activation of renin-angiotensin system in takotsubo syndrome patients. This suggests therapy aimed at modulating this pathway may be beneficial in the long-term.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): British Heart Foundation

Transaortic flow rate to predict short and long term outcomes in individuals with asymptomatic aortic stenosis

Background

Echocardiographic derived transaortic flow rate (TFR), defined as stroke volume over left ventricular ejection time, has been shown to be associated with increased mortality in asymptomatic mild to severe aortic stenosis (AS) and superior to stroke volume index (SVi) in individuals with symptomatic discordant AS undergoing aortic valve replacement. However, TFR has not been explored alongside SVi in asymptomatic moderate to severe AS, who are a group of interest in risk stratifying for early intervention. Moreover, there is no data where TFR is indexed to body surface area (TFRi).

Purpose

We explored the prognostic value of TFR, TFRi and SVi in a homogenous cohort of asymptomatic patients with moderate to severe AS.

Methods

Subjects with asymptomatic moderate to severe AS were prospectively recruited to the Prognostic Importance of Microvascular Dysfunction in asymptomatic patients with AS (PRIMID) study, a multi-centre observational study in the UK conducted between April 2012 and November 2014. All subjects underwent extensive phenotyping with transthoracic echocardiography, bicycle exercise testing and cardiovascular magnetic resonance (CMR) imaging, with blinded core-lab analysis. Patients were followed up in person for a minimum of 12 months, and through health records thereafter. The composite outcome of interest was: cardiovascular mortality, AVR for symptoms and major adverse cardiovascular events (hospitalisation with heart failure, myocardial infarction, syncope and arrhythmia) at one-year and at five years. A cox proportional hazards model was used to calculate a hazard ratio (HR) and 95% confidence intervals (95% CI). Known co-variables associated with the composite outcome were added into the multivariable model.

Results

Overall, 173 individuals were included with a mean age of 66.3—-±13.3 years and 76.4% were male. Most individuals had severe AS (71.1%, n=123). There were 47 (64.4%) primary outcome events at one-year and 110 (63.6%) events at five-years. Age, sex, N-terminal pro brain natriuretic peptide (NT-pro-BNP), peak aortic velocity (AV Vmax), a positive exercise tolerance test (ETT), myocardial perfusion reserve and right ventricular ejection fraction measured on cardiac magnetic resonance were included in the multivariable model in addition to TFR or TFRi or SVi. Decreasing TFR and TFRi remained independently associated with one-year and five-year composite outcome (Figure 1). However, SVi was only associated with the composite outcome at five-years. AV Vmax (HR: 4.36, 95% CI: 2.59, 7.34, p&lt;0.01) and a positive ETT (HR: 1.87, 95% CI: 1.03, 3.37, p=0.04) were independently associated with the primary outcome at one-year.

Conclusion

Both TFR and TFRi have a potential role in risk stratifying asymptomatic patients with AS and identifying those for earlier intervention, and may be superior to SVi. However, further prospectively designed studies are needed before this becomes part of the routine clinical practice.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Independent research from a Post-Doctoral Fellowship supported by the National Institute for Health Research (NIHR-PDF 2011-04-51 Geral P McCann).

Manganese-enhanced magnetic resonance imaging in Takotsubo syndrome

Background

Takotsubo syndrome is an increasingly common acute cardiac emergency characterised by profound transient left ventricular systolic dysfunction following a stressful event. Its pathophysiology remains poorly understood and a third of patients will have a major adverse cardiac or cerebrovascular event by 5 years [1]. Defective myocardial calcium homeostasis is central to contractile dysfunction and may be implicated in its pathophysiology. Manganese-enhanced magnetic resonance imaging is a novel non-invasive imaging technique that assesses myocardial manganese uptake as a measure of myocardial calcium handling [2]. Our aim was to investigate myocardial calcium handling using manganese-enhanced magnetic resonance imaging during the acute and recovery phase of takotsubo syndrome.

Methods

This single centre case-controlled observational longitudinal cohort study was conducted in accordance with the Declaration of Helsinki and ethical committee approval with written informed consent. Twenty patients with takotsubo syndrome and 20 age, sex and cardiovascular risk factor matched volunteers were recruited between March 2020 and September 2021. Patients underwent gadolinium and manganese-enhanced magnetic resonance imaging during the index event with repeat manganese-enhanced magnetic resonance imaging after 3 months. Myocardial manganese uptake was characterised by Patlak modelling.

Results

During the acute presentation, most patients had an “apical” pattern of takotsubo syndrome with reduced left ventricular ejection fraction (51±11 versus 67±8%, P&lt;0.001, Figure 1), elevated left ventricular mass (89±11 versus 57±14 g/m2, P&lt;0.01) and native T1 (1358±49 versus 1211±28 ms, P&lt;0.001) and T2 (60±7 versus 38±3 ms, P&lt;0.001) values compared to matched volunteers. Patlak modelling demonstrated reduced myocardial manganese uptake (5.1±0.5 versus 8.0±1.0 mL/100g of tissue/min, P&lt;0.0001) consistent with a major abnormality of myocardial calcium handling. Reduced myocardial manganese uptake attributable to apical takotsubo syndrome could be seen in one patient, scanned 18 days after symptom onset despite apparent resolution of cardiac function. Beyond 3 months of convalescence, left ventricular mass, ejection fraction, native T1 and T2 values were comparable to matched volunteers. Despite this, myocardial calcium handling remained abnormal compared to matched volunteers (6.7±0.7 versus 8.0±1.0 mL/100 g of tissue/min, P&lt;0.001, Figure 2).

Conclusions

In patients with takotsubo syndrome, there is a profound perturbation of myocardial calcium handling which is most marked acutely but persists after apparent recovery of left ventricular ejection fraction and resolution of myocardial oedema. Abnormal myocardial calcium handling is implicated in the pathophysiology of takotsubo syndrome and manganese-enhanced magnetic resonance imaging could play a major role in the diagnosis and risk stratification of patients with takotsubo syndrome.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Medical Research CouncilBritish Heart Foundation

OUES from submaximal cardiopulmonary exercise

Introduction

Cardiopulmonary exercise testing (CPEX) provides valuable diagnostic and prognostic cardiopulmonary function data. However, in clinical setting a maximal test is not always achievable. The Oxygen Efficiency Uptake Slope (OUES) has been proposed as a possible submaximal measure of cardiopulmonary function as it remains relatively stable during the final quartile of the exercise test. This study explored the validity of OUES as a surrogate marker for cardiopulmonary function in the event of a submaximal test.

Methods

Four groups of subjects [128 healthy controls (73 M), 44 asymptomatic hypertensive (HT) patients (26 M), 67 adult cardiac congenital heart disease (ACHD) patients (44 M) and 35 Heart Failure with preserved Ejection Fraction (HFpEF) (10M) patients] were recruited after informed consent. All subjects underwent clinical assessment, resting ECG, blood pressure and spirometry prior to a treadmill CPEX to volitional exhaustion and a respiratory exchange ratio (RER) of at least 1.1 using the same testing protocol. Peak VO2 (ml/min) was recorded from the last 5s of the maximal test (RER=1.1) and OUES was calculated from complete (RER=1.1) and truncated (RER=0.9) gas exchange data. The linear relationships between absolute peak VO2 and OUES from complete and truncated gas exchange data were assessed using Pearson's correlation coefficient. Subsequently, the two correlations obtained in each patient group were compared. Statistical significance was set at p&lt;0.01.

Results

Mean and 95% confidence intervals of the peak VO2 for males and females in each decile of life examined in the 4 subject groups are shown in the Figure. Peak VO2 values achieved in each of the patient groups were significantly lower when matched for age and sex compared to healthy participants (HT p=0.006, ACHD patients p&lt;0.001 and HFpEF patients p&lt;0.001).

In all 4 groups there was a good correlation between absolute peak VO2 and the OUES at RER 1.1 (healthy volunteers r=0.910, p&lt;0.001, HT r=0.899, p&lt;0.001, ACHD r=0.816, p&lt;0.001 and HFpEF r=0.846, p&lt;0.001). Correlations were inferior for absolute peak VO2 and OUES at RER 0.9 (healthy volunteers r=0.74, p&lt;0.001, HT r=0.780, p&lt;0.001, ACHD r=0.651, p&lt;0.001 and HFpEF r=0.817, p&lt;0.001). Correlations between absolute peak VO2 vs OUES at RER of 1.1 and 0.9 were significantly different only for healthy controls (p=0.001, Z-score = −4.649), but not for HT (p=0.05, Z-score = −1.909), ACHD (p=0.04, Z-score = −2.080) or HFpEF (p=0.7, Z-score = −0.377) patients.

Conclusion

Our data support the use of submaximal OUES at an RER of 0.9 as a surrogate marker for absolute peak VO2 obtained at an RER of 1.1, especially in patients, in whom it can often be difficult to achieve maximal exercise.

Funding Acknowledgement

Type of funding sources: None.

Renin-Angiotensin and Endothelin Systems in Patients Post-Takotsubo Cardiomyopathy

Background We investigate if renin-angiotensin and endothelin-1 response pathways follow the same pattern of recovery as left ventricular ejection fraction in patients with takotsubo cardiomyopathy. Methods and Results Ninety patients with takotsubo cardiomyopathy (n=30 in each of "acute," "convalescent" [3-5 months] and "recovered" [>1 year] groups) who were on minimal or no medication and were free of any significant cardiac/metabolic comorbidities, and 30 controls were studied. Serum concentrations of renin, angiotensin-converting enzyme, angiotensin II, big endothelin-1, endothelin-1 were measured using commercially available ELISA, and B-type natriuretic peptide was measured using an immunoassay. Mean left ventricular ejection fraction was <40% during the acute phase in all groups, but recovered to 63% in convalescent and 64% in the recovered groups, respectively. Serum renin concentrations remain persistently elevated after a episode of takotsubo cardiomyopathy (P=0.03 versus controls). Angiotensin converting enzyme levels are significantly depressed during the acute phase compared with convalescent (P=0.004), recovered takotsubo cardiomyopathy (P=0.02) or controls (P=0.03). Angiotensin II is increased in patients with takotsubo cardiomyopathy (P<0.001 versus controls) remaining persistently elevated in the chronically recovered group alone (P=0.03 versus controls). Big endothelin-1 levels are unchanged, but endothelin-1 is significantly lower after takotsubo cardiomyopathy compared with controls (P=0.03). Conclusions Despite "normalization" of the left ventricular ejection fraction, there is long-term maladaptive activation of renin-angiotensin system in patients with takotsubo cardiomyopathy. Registration URL: https://www.clinicaltrials.gov; Unique identifiers: NCT02897739, NCT02989454.

Psilocybin-induced takotsubo cardiomyopathy

We present a case of takotsubo cardiomyopathy following recreational ingestion of Psilocybe semilanceata (known as ‘magic mushrooms’). The patient presented with respiratory distress and pulmonary oedema responding to standard medical measures. Investigations included: echocardiogram, cardiac MRI and angiogram. Based on our search, we suggest this is only the second recognised case in the published literature.

The unspoken benefit of participation in a clinical trial

BACKGROUND

Publicly funded trials do not usually offer financial incentives to volunteers. An intensive level of medical care could act as an additional motivator for participation. Our aim was to establish whether patients may draw any clinical benefit from volunteering in a clinical trial.

METHODS

We analysed the recruitment process of a phase II randomised controlled trial, the Inorganic Nitrate in Angina Study.

RESULTS

Two-hundred and thirteen patients with a history of stable angina and who had been under at least annual primary care review were screened for participation by history taking, examination, 12-lead electrocardiography, treadmill test and echocardiography. Thirty-five (16.4%) patients were found to have significant unstable or new clinical pathology, requiring urgent clinical attention. We identified 17 (7.9%) patients with unstable angina. Furthermore, we found new undiagnosed pathologies: amyloidosis in two (0.9%), hypertrophic cardiomyopathy in two (0.9%), left ventricular systolic dysfunction (ejection fraction <45%) in three (1.4%), left ventricular thrombus in one (0.4%), significant valvular disease in five (2.4%) and arrhythmias in six (2.8%).

CONCLUSION

Compared with routine care, patients screened for a clinical trial may come under an increased level of scrutiny that may affect their clinical management. This may act as additional motivator to attract patients to future studies.

Predictors of Major Atrial Fibrillation Endpoints in the National Heart, Lung, and Blood Institute HCMR

OBJECTIVES

This study sought to identify predictors of major clinically important atrial fibrillation endpoints in hypertrophic cardiomyopathy.

BACKGROUND

Atrial fibrillation (AF) is a common morbidity associated with hypertrophic cardiomyopathy (HCM). The HCMR (Hypertrophic Cardiomyopathy Registry) trial is a prospective natural history study of 2,755 patients with HCM with comprehensive phenotyping.

METHODS

All patients received yearly telephone follow-up. Major AF endpoints were defined as requiring electrical cardioversion, catheter ablation, hospitalization for >24 h, or clinical decisions to accept permanent AF. Penalized regression via elastic-net methodology identified the most important predictors of major AF endpoints from 46 variables. This was applied to 10 datasets, and the variables were ranked. Predictors that appeared in all 10 sets were then used in a Cox model for competing risks and analyzed as time to first event.

RESULTS

Data from 2,631 (95.5%) patients were available for analysis after exclusions. A total of 127 major AF endpoints events occurred in 96 patients over 33.3 ± 12.4 months. In the final model, age, body mass index (BMI), left atrial (LA) volume index, LA contractile percent (active contraction), moderate or severe mitral regurgitation (MR), and history of arrhythmia the most important. BMI, LA volume index, and LA contractile percent were age-dependent. Obesity was a stronger risk factor in younger patients. Increased LA volume, reduced LA contractile percent, and moderate or severe MR put middle-aged and older adult patients at increased risk.

CONCLUSIONS

The major predictors of major AF endpoints in HCM include older age, high BMI, moderate or severe MR, history of arrhythmia, increased LA volume, and reduced LA contractile percent. Prospective testing of a risk score based on these parameters may be warranted.

Sex Differences in Ischemic Stroke Outcomes in Patients With Pulmonary Hypertension

Background The association between systemic hypertension and cerebrovascular disease is well documented. However, the impact of pulmonary hypertension (PH) on acute ischemic stroke outcomes is unknown despite PH being recognized as a risk factor for acute ischemic stroke. We aimed to determine the association between PH and adverse in-hospital outcomes after acute ischemic stroke, as well as whether there are sex differences in this association. Methods and Results Acute ischemic stroke admissions from the US National Inpatient Sample between October 2015 and December 2017 were included. The relationship between PH and outcomes (mortality, prolonged hospitalization >4 days, and routine home discharge) was analyzed using logistic regressions adjusting for demographics, comorbidities, and revascularization therapies. Interaction terms between PH and sex and age groups were also included. A total of 221 249 records representative of 1 106 045 admissions were included; 2.9% of patients had co-morbid PH, and 35.34% of those were male. PH was not associated with in-hospital mortality (odds ratio [OR], 0.96; 95% CI, 0.86-1.09) but was associated with increased odds of prolonged hospitalization (OR, 1.15; 95% CI, 1.09-1.22) and decreased odds of routine discharge (OR, 0.87; 95% CI, 0.81-0.94) for both sexes. Older patients with PH were significantly less likely to be discharged routinely (P=0.028) than their younger counterparts. Compared with female patients with PH, men were 31% more likely to die in hospital (P=0.024). Conclusions PH was not significantly associated with in-hospital mortality but was associated with prolonged hospitalization and adverse discharge status. Male patients with PH were more likely to die in hospital than female patients.

Metabolic alterations in a rat model of Takotsubo syndrome

AIMS

Cardiac energetic impairment is a major finding in takotsubo patients. We investigate specific metabolic adaptations to direct future therapies.

METHODS AND RESULTS

An isoprenaline-injection female rat model (versus sham) was studied at day-3; recovery assessed at day-7. Substrate uptake, metabolism, inflammation and remodelling were investigated by 18F-FDG-PET, metabolomics, qPCR and WB. Isolated cardiomyocytes were patch-clamped during stress protocols for redox states of NAD(P)H/FAD or [Ca2+]c, [Ca2+]m and sarcomere length. Mitochondrial respiration was assessed by seahorse/Clark electrode (glycolytic and β-oxidation substrates).Cardiac 18F-FDG metabolic rate was increased in takotsubo (p = 0.006), as were expression of GLUT4-RNA/GLUT1/HK2-RNA and HK activity (all p < 0.05), with concomitant accumulation of glucose- and fructose-6-phosphates (p > 0.0001). Both lactate and pyruvate were lower (p < 0.05) despite increases in LDH-RNA and PDH (p < 0.05 both). β-oxidation enzymes CPT1b-RNA and 3KAT were increased (p < 0.01) but malonyl-CoA (CPT-1 regulator) was upregulated (p = 0.01) with decreased fatty acids and acyl-carnitines levels (p = 0.0001-0.02). Krebs cycle intermediates α-ketoglutarate and succinyl-carnitine were reduced (p < 0.05) as was cellular ATP reporter dihydroorotate (p = 0.003). Mitochondrial Ca2+ uptake during high workload was impaired on day-3 (p < 0.0001), inducing oxidation of NAD(P)H and FAD (p = 0.03) but resolved by day-7. There were no differences in mitochondrial respiratory function, sarcomere shortening or [Ca2+] transients of isolated cardiomyocytes, implying preserved integrity of both mitochondria and cardiomyocyte. Inflammation and remodelling were upregulated - increased CD68-RNA, collagen RNA/protein and skeletal actin RNA (all p < 0.05).

CONCLUSION

Dys-regulation of glucose and lipid metabolic pathways with decreases in final glycolytic and β-oxidation metabolites and reduced availability of Krebs intermediates characterises takotsubo myocardium. The energetic deficit accompanies defective Ca2+ handling, inflammation and upregulation of remodelling pathways, with preservation of sarcomeric and mitochondrial integrity.

TRANSLATIONAL PERSPECTIVE

The simultaneous dysregulation in the glycolytic and beta-oxidation pathways which underlies the energetic deficit of the takotsubo heart supports further testing of currently available metabolic modulators as possible candidates for successful therapy, as well as targeting the inflammatory and remodelling pathways.

Effect of the 2017 European Guidelines on Reclassification of Severe Aortic Stenosis and Its Influence on Management Decisions for Initially Asymptomatic Aortic Stenosis

BACKGROUND

The 2017 European Society of Cardiology guidelines for valvular heart disease included changes in the definition of severe aortic stenosis (AS). We wanted to evaluate its influence on management decisions in asymptomatic patients with moderate-severe AS.

METHODS

We reclassified the AS severity of the participants of the PRIMID-AS study (Prognostic Importance of Microvascular Dysfunction in Asymptomatic Patients With AS), using the 2017 guidelines, determined their risk of reaching a clinical end point (valve replacement for symptoms, hospitalization, or cardiovascular death) and evaluated the prognostic value of aortic valve calcium score and biomarkers. Patients underwent echocardiography, cardiac magnetic resonance imaging, exercise tolerance testing, and biomarker assessment.

RESULTS

Of the 174 participants, 45% (56/124) classified as severe AS were reclassified as moderate AS. This reclassified group was similar to the original moderate group in clinical characteristics, gradients, calcium scores, and remodeling parameters. There were 47 primary end points (41 valve replacement, 1 death, and 5 hospitalizations-1 chest pain, 2 dyspnea, 1 heart failure, and 1 syncope) over 368±156 days follow-up. The severe and reclassified groups had a higher risk compared with moderate group (adjusted hazard ratio 4.95 [2.02-12.13] and 2.78 [1.07-7.22], respectively), with the reclassified group demonstrating an intermediate risk. A mean pressure gradient ≥31 mm Hg had a 7× higher risk of the primary end point in the reclassified group. Aortic valve calcium score was more prognostic in females and low valve area but not after adjusting for gradients. NT-proBNP (N-terminal pro-brain-type natriuretic peptide) and myocardial perfusion reserve were associated with the primary end point but not after adjusting for positive exercise tolerance testing. Troponin was associated with cardiovascular death or unplanned hospitalizations.

CONCLUSIONS

Reclassification of asymptomatic severe AS into moderate AS was common using the European Society of Cardiology 2017 guidelines. This group had an intermediate risk of reaching the primary end point. Exercise testing, multimodality imaging, and lower mean pressure gradient threshold of 31 mm Hg may improve risk stratification. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01658345.

Recurrent spontaneous coronary artery dissection in a middle-aged male athlete patient: a case report

BACKGROUND

Spontaneous coronary artery dissection (SCAD) is a rare condition, mainly affecting young women. Cases in male patients are rare, especially with recurrence.

CASE SUMMARY

A 59-year-old male non-elite athlete presented as an ST-elevation myocardial infarction following a 5-km run. Urgent coronary angiogram was normal, but cardiac magnetic resonance showed a myocardial infarction. Four years later, he experienced similar chest pain with no ST-elevation on electrocardiogram and a mild troponin rise. Urgent coronary angiogram was initially thought normal but subsequent close inspection confirmed a Type 2b SCAD. Cardiac magnetic resonance showed a small additional myocardial infarction contained within an area of acute myocardial oedema.

DISCUSSION

Spontaneous coronary artery dissection is more common in young women compared to men and recurrent dissection has been rarely reported in the literature. Cohort studies have shown the rate of recurrent dissection to be 13-16%, but most of the patients in these cohorts are female. Poor data exists on the best treatment of SCAD in men, but given the presence of intramural thrombus, dual antiplatelet therapy was discontinued on the presumption that it may exacerbate an intramural bleeding process.

Diastolic Ventricular Interaction in Heart Failure With Preserved Ejection Fraction

Background

Exercise‐induced pulmonary hypertension is common in heart failure with preserved ejection fraction (HFpEF). We hypothesized that this could result in pericardial constraint and diastolic ventricular interaction in some patients during exercise.

Methods and Results

Contrast stress echocardiography was performed in 30 HFpEF patients, 17 hypertensive controls, and 17 normotensive controls (healthy). Cardiac volumes, and normalized radius of curvature (NRC) of the interventricular septum at end‐diastole and end‐systole, were measured at rest and peak‐exercise, and compared between the groups. The septum was circular at rest in all 3 groups at end‐diastole. At peak‐exercise, end‐systolic NRC increased to 1.47±0.05 (P<0.001) in HFpEF patients, confirming development of pulmonary hypertension. End‐diastolic NRC also increased to 1.54±0.07 (P<0.001) in HFpEF patients, indicating septal flattening, and this correlated significantly with end‐systolic NRC (ρ=0.51, P=0.007). In hypertensive controls and healthy controls, peak‐exercise end‐systolic NRC increased, but this was significantly less than observed in HFpEF patients (HFpEF, P=0.02 versus hypertensive controls; P<0.001 versus healthy). There were also small, non‐significant increases in end‐diastolic NRC in both groups (hypertensive controls, +0.17±0.05, P=0.38; healthy, +0.06±0.03, P=0.93). In HFpEF patients, peak‐exercise end‐diastolic NRC also negatively correlated (r=−0.40, P<0.05) with the change in left ventricular end‐diastolic volume with exercise (ie, the Frank‐Starling mechanism), and a trend was noted towards a negative correlation with change in stroke volume (r=−0.36, P=0.08).

Conclusions

Exercise pulmonary hypertension causes substantial diastolic ventricular interaction on exercise in some patients with HFpEF, and this restriction to left ventricular filling by the right ventricle exacerbates the pre‐existing impaired Frank‐Starling response in these patients.

Fast field-cycling magnetic resonance detection of intracellular ultra-small iron oxide particles in vitro: Proof-of-concept

PURPOSE

Inflammation is central in disease pathophysiology and accurate methods for its detection and quantification are increasingly required to guide diagnosis and therapy. Here we explored the ability of Fast Field-Cycling Magnetic Resonance (FFC-MR) in quantifying the signal of ultra-small superparamagnetic iron oxide particles (USPIO) phagocytosed by J774 macrophage-like cells as a proof-of-principle.

METHODS

Relaxation rates were measured in suspensions of J774 macrophage-like cells loaded with USPIO (0-200 μg/ml Fe as ferumoxytol), using a 0.25 T FFC benchtop relaxometer and a human whole-body, in-house built 0.2 T FFC-MR prototype system with a custom test tube coil. Identical non-imaging, saturation recovery pulse sequence with 90° flip angle and 20 different evolution fields selected logarithmically between 80 μT and 0.2 T (3.4 kHz and 8.51 MHz proton Larmor frequency [PLF] respectively). Results were compared with imaging flow cytometry quantification of side scatter intensity and USPIO-occupied cell area. A reference colorimetric iron assay was used.

RESULTS

The T1 dispersion curves derived from FFC-MR were excellent in detecting USPIO at all concentrations examined (0-200 μg/ml Fe as ferumoxytol) vs. control cells, p ≤ 0.001. FFC-NMR was capable of reliably detecting cellular iron content as low as 1.12 ng/µg cell protein, validated using a colorimetric assay. FFC-MR was comparable to imaging flow cytometry quantification of side scatter intensity but superior to USPIO-occupied cell area, the latter being only sensitive at exposures ≥ 10 µg/ml USPIO.

CONCLUSIONS

We demonstrated for the first time that FFC-MR is capable of quantitative assessment of intra-cellular iron which will have important implications for the use of USPIO in a variety of biological applications, including the study of inflammation.

Myocardial and Systemic Inflammation in Acute Stress-Induced (Takotsubo) Cardiomyopathy

BACKGROUND

Acute stress-induced (takotsubo) cardiomyopathy can result in a heart failure phenotype with a prognosis comparable with that of myocardial infarction. In this study, we hypothesized that inflammation is central to the pathophysiology and natural history of takotsubo cardiomyopathy.

METHODS

In a multicenter study, we prospectively recruited 55 patients with takotsubo cardiomyopathy and 51 age-, sex-, and comorbidity-matched control subjects. During the index event and at the 5-month follow-up, patients with takotsubo cardiomyopathy underwent multiparametric cardiac magnetic resonance imaging, including ultrasmall superparamagnetic particles of iron oxide (USPIO) enhancement for detection of inflammatory macrophages in the myocardium. Blood monocyte subpopulations and serum cytokines were assessed as measures of systemic inflammation. Matched control subjects underwent investigation at a single time point.

RESULTS

Subjects were predominantly middle-aged (64±14 years) women (90%). Compared with control subjects, patients with takotsubo cardiomyopathy had greater USPIO enhancement (expressed as the difference between pre-USPIO and post-USPIO T2*) in both ballooning (14.3±0.6 milliseconds versus 10.5±0.9 milliseconds; P<0.001) and nonballooning (12.9±0.6 milliseconds versus 10.5±0.9 milliseconds; P=0.02) left ventricular myocardial segments. Serum interleukin-6 (23.1±4.5 pg/mL versus 6.5±5.8 pg/mL; P<0.001) and chemokine (C-X-C motif) ligand 1 (1903±168 pg/mL versus 1272±177 pg/mL; P=0.01) concentrations and classic CD14⁺⁺CD16^- monocytes (90±0.5% versus 87±0.9%; P=0.01) were also increased whereas intermediate CD14⁺⁺CD16⁺ (5.4±0.3% versus 6.9±0.6%; P=0.01) and nonclassic CD14⁺CD16⁺⁺ (2.7±0.3% versus 4.2±0.5%; P=0.006) monocytes were reduced in patients with takotsubo cardiomyopathy. At 5 months, USPIO enhancement was no longer detectable in the left ventricular myocardium, although persistent elevations in serum interleukin-6 concentrations ( P=0.009) and reductions in intermediate CD14⁺⁺CD16⁺ monocytes (5.6±0.4% versus 6.9±0.6%; P=0.01) remained.

CONCLUSIONS

We demonstrate for the first time that takotsubo cardiomyopathy is characterized by a myocardial macrophage inflammatory infiltrate, changes in the distribution of monocyte subsets, and an increase in systemic proinflammatory cytokines. Many of these changes persisted for at least 5 months, suggesting a low-grade chronic inflammatory state.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov . Unique identifier: NCT02897739.

Lifelong recurrent takotsubo cardiomyopathy: a case report

Background

Takotsubo cardiomyopathy is a transient left ventricular dysfunction with an established recurrence rate in populations, however, recurrences in the same individual have not been well described.

Case summary

We present a 76-year-old woman who had likely a total of six recurrent takotsubo cardiomyopathy episodes spanning over 33 years. Her diagnosis of takotsubo cardiomyopathy was first made in 2014 when she presented with chest pain, raised cardiac enzymes, and the presence of normal coronary arteries. Cardiac magnetic resonance was performed, ruling out any current or previous myocardial infarction. Subsequently, she had two further recurrences in 2015 and 2018. Stressors were identified on three occasions. She was diagnosed with ‘myocardial infarction’ in 1986, 1988, and 1998 when she presented with chest pain and electrocardiogram changes, despite demonstrating normal coronary arteries on each occasion.

Discussion

This case demonstrates three confirmed recurrent episodes of takotsubo in the same individual, showing three different left ventricular phenotypic morphologies on the background of three previous episodes of ‘myocardial infarction with normal coronary arteries’, which most likely might have been takotsubo episodes as well. Any myocardial infarction-type injury was definitely ruled out in the 2014 admission instigating a potential change in this patient’s past medical history and implicitly requirement for lifelong secondary prevention. It is notably difficult to make a confirmed diagnosis of takotsubo cardiomyopathy back in 1986, 1988, and 1998 due to the lack of awareness in this novel topic.

P6203Intramyocellular lipid saturation as a new metabolic biomarker

Background

Endurance trained athletic healthy volunteers (Athl-HV) and type 2 diabetes patients (T2D) have higher levels of lipids in their skeletal myocytes compared to healthy controls. Despite apparently similar metabolic storage, they are at opposite ends of insulin sensitivity and cardio-metabolic risk.

Purpose

We investigated if the degree of saturation of the IntraMyoCellular Lipids (IMCL) will differentiate Athl-HV from T2D; and explored if an exercise intervention will induce changes in the IMCL saturation.

Methods

Male, age matched Athl-HV and T2D were enrolled (n=25/group). Athl-HV had ≥5 years endurance training, T2D were sedentary. Subjects were studied at baseline and after an exercise intervention (4 week deconditioning in Athl-HV and supervised bike training at ≥65% of peakVO2, 5 hours/week x 8 weeks in T2D). All subjects underwent cardio-pulmonary exercise testing (CPET), blood sampling for insulin sensitivity (QUICKI*) and single voxel 1H-magnetic resonance spectroscopy (1H-MRS) of the right vastus lateralis. 1H-MRS was acquired on 3T Philips Achieva with a 16-channel coil, point-resolved spectroscopy, variable pulse power and optimized relaxation delay water suppression and analysed in LCModel. We derived fractional lipid mass (fLM) and fractions of saturated (fSL) and unsaturated (fUL) lipids. Data were analysed by t tests, shown as mean±SEM, statistical significance p<0.05.

Results

CPET and insulin sensitivity are presented in Table 1. T2D had higher fLM in the skeletal muscle compared to Athl-HV, at baseline (p=0.003) and after the exercise intervention (p=0.009), Figure 1A. At baseline, T2D had a different phenotype with a lower fSL and higher fUL compared to Athl-HV (82±3 vs 88±1% and 18±3 vs 12±1%, p=0.02 for both). Whilst deconditioning did not attract any significant changes in either fSL or fUL in Athl-HV (88±1 to 86±1% and 12±1 to 14±1, p=0.2), in contrast, with exercise training T2D significantly increased fSL (82±3 to 88±1%) and decreased their fUL (18±3 to 12±1%) (both p=0.01). Figure 1B and 1C.

CPET and insulin sensitivity results Athl-HV Baseline Athl-HV Deconditioning p value T2D Baseline T2D After Training p value VO2 peak, (mL/kg/min) 45.0±0.9† 41.7±0.9‡ <0.0001 23.6±0.6† 30.3±0.6‡ <0.0001 QUICKI* 0.346±0.002† 0.343±0.003‡ 0.2 0.308±0.004† 0.317±0.004‡ 0.02 *QUICKI: Quantitative Insulin Sensitivity Check Index; †Athl-HV vs T2D at baseline p≤0.001, ‡Athl-HV vs T2D after exercise intervention p≤0.001.

Figure 1

Conclusion

We demonstrate for the first time, in vivo, significant differences in the IMCL amount and saturation between Athl-HV and T2D. IMCL saturation was changed by exercise training in T2D to mirror the phenotype seen in Athl-HV uncovering a new, independent biomarker of improved cardio-metabolic health.

Acknowledgement/Funding

British Heart Foundation Project Grant no. PG/15/88/31780

4324Fast-field cycling magnetic resonance detection of intracellular iron in the nanomolar range - A pre-requisite for in-vivo study of inflammation

Background

Ultra-small superparamagnetic iron oxide (USPIO) nanoparticles are phagocytosed by macrophages and when subjected to magnetic resonance imaging (MRI) detect inflammation. We describe a novel MR technique where the magnetic field is rapidly cycled (Fast field-cycling MR, FFC-MR), assessing T1 dispersion over a range of low (100μT-0.2T) fields and offering superior T1-based iron quantification.

AIM

To quantify iron using the FFC-MR R1 (1/T1) dispersion profile and flow cytometry features of USPIO-laden cells, in comparison to colorimetric assays.

Methods

Murine J774 macrophage-like cells were incubated with 0–200μg/ml Fe as USPIO (ferumoxytol) for 16 hours, washed and suspended in 500μl PBS/2mM EDTA. Prussian blue staining confirmed USPIO phagocytosis. Relaxation was measured using a clinical, in-house built prototype 0.2T FFC-MR system with a custom test tube coil. R1 dispersion was derived from a saturation recovery sequence (Fig. 1A). R1 (s–1) values were calculated with a monoexponential curve fitting algorithm, R2 of fits were ≥0.999. R1 dispersion profiles were generated plotting R1 against the magnetic field (T). Quantification of side scatter (SCC) intensity and the USPIO-occupied fraction of total cell area was performed with imaging flow cytometry. A colorimetric assay provided validation of cell iron content. All data are mean±SEM, analysed with t-tests, Pearson correlation and linear regression; statistical significance set at p<0.05.

Results

Table 1 shows quantitative data derived by all 3 modalities with increasing USPIO exposure. FFC-MR detection of intracellular iron was excellent (p≤0.001 vs. control for all), with separation of average R1 dispersion profiles (Fig. 1B), strong correlation with colorimetry (r=0.993 p<0.001) and good fit on linear regression model (R2=0.9222, Fig 1C). Flow cytometry quantification of SCC was comparable (p≤0.001 for all), whereas USPIO-occupied area was only sensitive at exposures ≥10μg/ml USPIO (r=0.967 p<0.001 & r=0.983 p<0.001 vs. colorimetric respectively). FFC-MR detected iron at ≥1.12ng/μg protein.

USPIO exposure (μg/ml medium) 0 5 10 40 80 100 200 FFC-MR Mean R1 1x106 cell suspension (s–1) 0.308±0.014 0.356±0.013** 0.432±0.016** 0.706±0.021** 1.174±0.031** 1.239±0.033** 1.599±0.041** Flow cytometry USPIO area/cell area 0.034±0.001 0.036±0.001 0.037±0.001* 0.069±0.001** 0.085±0.001** 0.090±0.001** 0.097±0.001** Flow cytometry SSC intensity 26860 32815** 39573** 69285** 80967** 82693** 86373** Colorimetric assay Iron concentration 1x106 cells (ng/μg protein) 0.115±0.118 1.121±0.045** 2.074±0.084** 5.496±0.134** 8.421±0.269** 9.771±0.100** 12.398±0.233** SSC = side-scattered light; *p<0.05 vs. control; **p<0.001 vs. control.

Conclusion

Field-cycling MR is capable of highly accurate intracellular USPIO quantification, which has potential to non-invasively detect clinically relevant amounts of iron in inflammatory cardiovascular diseases.

Acknowledgement/Funding

NHS Grampian Endowment Fund

Metabolic changes in hypertrophic cardiomyopathies: scientific update from the Working Group of Myocardial Function of the European Society of Cardiology

Disturbed metabolism as a consequence of obesity and diabetes may cause cardiac diseases (recently highlighted in the cardiovascular research spotlight issue on metabolic cardiomyopathies).¹ In turn, the metabolism of the heart may also be disturbed in genetic and acquired forms of hypertrophic cardiac disease. Herein, we provide an overview of recent insights on metabolic changes in genetic hypertrophic cardiomyopathy and discuss several therapies, which may be explored to target disturbed metabolism and prevent onset of cardiac hypertrophy.

This article is part of the Mini Review Series from the Varenna 2017 meeting of the Working Group of Myocardial Function of the European Society of Cardiology.

Reference range determination for imaging biomarkers: Myocardial T1

BACKGROUND

Imaging biomarkers, such as the T₁ relaxation time of the myocardium using MRI, can be valuable in cardiac medicine if they are properly validated. Consensus statements recommend that for myocardial T₁ , each investigator should establish a reference range.

PURPOSE

To describe a statistically valid method for determining and reporting the reference range in each center, which simultaneously minimizes the twin risks of undersampling, leading to a uselessly uncertain range, and oversampling, which exposes volunteers to unnecessary scanning and wastes resources.

STUDY TYPE

Cohort.

POPULATION

In all, 278 normal human subjects without cardiac disease from two cardiac MR centers.

FIELD STRENGTH/SEQUENCE

1.5 T and 3 T; Modified Look-Locker Inversion recovery sequence.

ASSESSMENT

The T₁ relaxation time was estimated from multiple samples of tissue magnetization after inversion. A valid method for calculating a reference range was used.

STATISTICAL TESTS

Shapiro-Wilk test for normality; Tukey robust approach for identification of outliers; reference range calculation with confidence intervals.

RESULTS

Reference ranges for measurement of myocardial T₁ were calculated, with confidence intervals, enabling comparison with clinically important differences. At 3 T: 1129 to 1301 msec at site 1 (n = 21) and 1160 to 1309 msec at site 2 (n = 59), and at 1.5 T at site 2: 933 to 1020 msec (male, n = 130) and 965 to 1054 msec (female, n = 68). The 3 T reference range from site 1 was successfully benchmarked against the 3 T reference range at site 2.

DATA CONCLUSION

Myocardial T₁ reference ranges can be properly characterized, enabling clinical comparison to a valid reference range with known confidence intervals, using methodology similar to that described in this report.

LEVEL OF EVIDENCE

3 Technical Efficacy Stage: 3 J. Magn. Reson. Imaging 2019;50:771-778.

Characterization of the Myocardial Inflammatory Response in Acute Stress-Induced (Takotsubo) Cardiomyopathy

•

Takotsubo cardiomyopathy is an acute heart failure syndrome often triggered by emotional or physical stress, where no treatment currently exists, and exact pathogenic mechanisms are unclear.

•

Rats in which takotsubo-like cardiomyopathy was induced showed localized myocardial inflammatory changes, including progressive inflammatory infiltrates and myofiber atrophy, that persisted over the 14-day time course examined.

•

Early neutrophil infiltrates were followed by clusters of myocardial macrophages, typically of an M1 proinflammatory phenotype, with no switch to M2 resolving macrophages; individual M2 macrophage levels, however, correlated with recovery in cardiac function. Human post-mortem myocardial tissue shared features of the experimental model demonstrating M1 macrophage clusters.

•

The persistent clinical symptoms and long-term morbidity/mortality observed in takotsubo patients may, in part, relate to chronic nonresolving myocardial inflammation.

Takotsubo cardiomyopathy is an acute stress-induced heart failure syndrome for which the exact pathogenic mechanisms are unclear, and consequently, no specific treatment exists. In an experimental model of stress-induced takotsubo-like cardiomyopathy, the authors describe the temporal course of a chronic inflammatory response post-induction, with an initial early influx of neutrophils into myocardial tissue followed by macrophages that are typical of a proinflammatory M1 phenotype, and a nonsignificant increase in systemic inflammatory cytokines. Post-mortem myocardium from the more complex clinical takotsubo patients share features of the study’s experimental model. These findings suggest modulators of inflammation could be a potential therapeutic option.

Aortic stiffness in aortic stenosis assessed by cardiovascular MRI: a comparison between bicuspid and tricuspid valves

Objectives

To compare aortic size and stiffness parameters on MRI between bicuspid aortic valve (BAV) and tricuspid aortic valve (TAV) patients with aortic stenosis (AS).

Methods

MRI was performed in 174 patients with asymptomatic moderate-severe AS (mean AVAI 0.57 ± 0.14 cm²/m²) and 23 controls on 3T scanners. Valve morphology was available/analysable in 169 patients: 63 BAV (41 type-I, 22 type-II) and 106 TAV. Aortic cross-sectional areas were measured at the level of the pulmonary artery bifurcation. The ascending and descending aorta (AA, DA) distensibility, and pulse wave velocity (PWV) around the aortic arch were calculated.

Results

The AA and DA areas were lower in the controls, with no difference in DA distensibility or PWV, but slightly lower AA distensibility than in the patient group. With increasing age, there was a decrease in distensibility and an increase in PWV. After correcting for age, the AA maximum cross-sectional area was higher in bicuspid vs. tricuspid patients (12.97 [11.10, 15.59] vs. 10.06 [8.57, 12.04] cm², p < 0.001), but there were no significant differences in AA distensibility (p = 0.099), DA distensibility (p = 0.498) or PWV (p = 0.235). Patients with BAV type-II valves demonstrated a significantly higher AA distensibility and lower PWV compared to type-I, despite a trend towards higher AA area.

Conclusions

In patients with significant AS, BAV patients do not have increased aortic stiffness compared to those with TAV despite increased ascending aortic dimensions. Those with type-II BAV have less aortic stiffness despite greater dimensions. These results demonstrate a dissociation between aortic dilatation and stiffness and suggest that altered flow patterns may play a role.

Key Points

• Both cellular abnormalities secondary to genetic differences and abnormal flow patterns have been implicated in the pathophysiology of aortic dilatation and increased vascular complications associated with bicuspid aortic valves (BAV).

• We demonstrate an increased ascending aortic size in patients with BAV and moderate to severe AS compared to TAV and controls, but no difference in aortic stiffness parameters, therefore suggesting a dissociation between dilatation and stiffness.

• Sub-group analysis showed greater aortic size but lower stiffness parameters in those with BAV type-II AS compared to BAV type-I.

Electronic supplementary material

The online version of this article (10.1007/s00330-018-5775-6) contains supplementary material, which is available to authorized users.

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.

Persistent Long-Term Structural, Functional, and Metabolic Changes After Stress-Induced (Takotsubo) Cardiomyopathy

Supplemental Digital Content is available in the text.

Background:

Takotsubo cardiomyopathy is an increasingly recognized acute heart failure syndrome precipitated by intense emotional stress. Although there is an apparent rapid and spontaneous recovery of left ventricular ejection fraction, the long-term clinical and functional consequences of takotsubo cardiomyopathy are ill-defined.

Methods:

In an observational case-control study, we recruited 37 patients with prior (>12-month) takotsubo cardiomyopathy, and 37 age-, sex-, and comorbidity-matched control subjects. Patients completed the Minnesota Living with Heart Failure Questionnaire. All participants underwent detailed clinical phenotypic characterization, including serum biomarker analysis, cardiopulmonary exercise testing, echocardiography, and cardiac magnetic resonance including cardiac ³¹P-spectroscopy.

Results:

Participants were predominantly middle-age (64±11 years) women (97%). Although takotsubo cardiomyopathy occurred 20 (range 13–39) months before the study, the majority (88%) of patients had persisting symptoms compatible with heart failure (median of 13 [range 0–76] in the Minnesota Living with Heart Failure Questionnaire) and cardiac limitation on exercise testing (reduced peak oxygen consumption, 24±1.3 versus 31±1.3 mL/kg/min, P<0.001; increased VE/Vco₂ slope, 31±1 versus 26±1, P=0.002). Despite normal left ventricular ejection fraction and serum biomarkers, patients with prior takotsubo cardiomyopathy had impaired cardiac deformation indices (reduced apical circumferential strain, −16±1.0 versus −23±1.5%, P<0.001; global longitudinal strain, −17±1 versus −20±1%, P=0.006), increased native T1 mapping values (1264±10 versus 1184±10 ms, P<0.001), and impaired cardiac energetic status (phosphocreatine/γ-adenosine triphosphate ratio, 1.3±0.1 versus 1.9±0.1, P<0.001).

Conclusions:

In contrast to previous perceptions, takotsubo cardiomyopathy has long-lasting clinical consequences, including demonstrable symptomatic and functional impairment associated with persistent subclinical cardiac dysfunction. Taken together our findings demonstrate that after takotsubo cardiomyopathy, patients develop a persistent, long-term heart failure phenotype.

Clinical Trial Registration:

URL: https://clinicaltrials.gov. Unique identifier: NCT02989454.

Inorganic Nitrate in Angina Study: A Randomized Double-Blind Placebo-Controlled Trial

Background

In this double‐blind randomized placebo‐controlled crossover trial, we investigated whether oral sodium nitrate, when added to existing background medication, reduces exertional ischemia in patients with angina.

Methods and Results

Seventy patients with stable angina, positive electrocardiogram treadmill test, and either angiographic or functional test evidence of significant ischemic heart disease were randomized to receive oral treatment with either placebo or sodium nitrate (600 mg; 7 mmol) for 7 to 10 days, followed by a 2‐week washout period before crossing over to the other treatment (n=34 placebo‐nitrate, n=36 nitrate‐placebo). At baseline and at the end of each treatment, patients underwent modified Bruce electrocardiogram treadmill test, modified Seattle Questionnaire, and subgroups were investigated with dobutamine stress, echocardiogram, and blood tests. The primary outcome was time to 1 mm ST depression on electrocardiogram treadmill test. Compared with placebo, inorganic nitrate treatment tended to increase the primary outcome exercise time to 1 mm ST segment depression (645.6 [603.1, 688.0] seconds versus 661.2 [6183, 704.0] seconds, P=0.10) and significantly increased total exercise time (744.4 [702.4, 786.4] seconds versus 760.9 [719.5, 802.2] seconds, P=0.04; mean [95% confidence interval]). Nitrate treatment robustly increased plasma nitrate (18.3 [15.2, 21.5] versus 297.6 [218.4, 376.8] μmol/L, P<0.0001) and almost doubled circulating nitrite concentrations (346 [285, 405] versus 552 [398, 706] nmol/L, P=0.003; placebo versus nitrate treatment). Other secondary outcomes were not significantly altered by the intervention. Patients on antacid medication appeared to benefit less from nitrate supplementation.

Conclusions

Sodium nitrate treatment may confer a modest exercise capacity benefit in patients with chronic angina who are taking other background medication.

Clinical Trial Registration

URL: https://www.clinicaltrials.gov/. Unique identifier: NCT02078921. EudraCT number: 2012‐000196‐17.

Acute stress-induced (takotsubo) cardiomyopathy

Acute stress-induced (takotsubo) cardiomyopathy has a dramatic clinical presentation, mimicking an acute myocardial infarction and is triggered by intense emotional or physical stress. In this paper, we review the current state of knowledge of the mechanistic physiology underlying the left ventricular ballooning. The pathophysiology of the recovery from this acute heart failure syndrome is presented. The short-term and long-term outlook puts this new syndrome on a different perspective compared with recently held views. Current knowledge on susceptibility and predisposition already define distinctive characteristics of patients with takotsubo compared with myocardial infarction. Gaps in knowledge and future directions of research are identified in order to best direct efforts for identifying specific therapies for this condition, in the acute setting, to mitigate postacute symptoms or to prevent recurrences, none of which exist.

Comprehensive Echocardiographic and Cardiac Magnetic Resonance Evaluation Differentiates Among Heart Failure With Preserved Ejection Fraction Patients, Hypertensive Patients, and Healthy Control Subjects

OBJECTIVES

The aim of this study was to investigate the utility of a comprehensive imaging protocol including echocardiography and cardiac magnetic resonance in the diagnosis and differentiation of hypertensive heart disease and heart failure with preserved ejection fraction (HFpEF).

BACKGROUND

Hypertension is present in up to 90% of patients with HFpEF and is a major etiological component. Despite current recommendations and diagnostic criteria for HFpEF, no noninvasive imaging technique has as yet shown the ability to identify any structural differences between patients with hypertensive heart disease and HFpEF.

METHODS

We conducted a prospective cross-sectional study of 112 well-characterized patients (62 with HFpEF, 22 with hypertension, and 28 healthy control subjects). All patients underwent cardiopulmonary exercise and biomarker testing and an imaging protocol including echocardiography with speckle-tracking analysis and cardiac magnetic resonance including T₁ mapping pre- and post-contrast.

RESULTS

Echocardiographic global longitudinal strain (GLS) and extracellular volume (ECV) measured by cardiac magnetic resonance were the only variables able to independently stratify among the 3 groups of patients. ECV was the best technique for differentiation between hypertensive heart disease and HFpEF (ECV area under the curve: 0.88; GLS area under the curve: 0.78; p < 0.001 for both). Using ECV, an optimal cutoff of 31.2% gave 100% sensitivity and 75% specificity. ECV was significantly higher and GLS was significantly reduced in subjects with reduced exercise capacity (lower peak oxygen consumption and higher minute ventilation-carbon dioxide production) (p < 0.001 for both ECV and GLS).

CONCLUSIONS

Both GLS and ECV are able to independently discriminate between hypertensive heart disease and HFpEF and identify patients with prognostically significant functional limitation. ECV is the best diagnostic discriminatory marker of HFpEF and could be used as a surrogate endpoint for therapeutic studies.

A randomized double-blind placebo-controlled crossover trial of sodium nitrate in patients with stable angina INAS

In an aging western population, a significant number of patients continue to suffer from angina once all revascularization and optimal medical treatment options are exhausted. Under experimental conditions, oral supplementation with inorganic nitrate was shown to exhibit a blood pressure-lowering effect, and has also been shown to promote angiogenesis, improve endothelial dysfunction and mitochondrial efficiency in skeletal muscle. It is unknown whether similar changes occur in cardiac muscle. In the current study, we investigate whether oral sodium nitrate treatment will improve myocardial ischemia in patients with stable angina.

Right Ventricular Involvement and Recovery After Acute Stress-Induced (Tako-tsubo) Cardiomyopathy

Acute stress-induced (Tako-tsubo) cardiomyopathy is an increasingly recognized but insufficiently characterized syndrome. Here, we investigate the pathophysiology of right ventricular (RV) involvement in Tako-tsubo and its recovery time course. We prospectively recruited 31 patients with Tako-tsubo with predominantly ST-elevation electrocardiogram and 18 controls of similar gender, age, and co-morbidity distribution. Patients underwent echocardiography and cardiac magnetic resonance (CMR) imaging on a 3T Philips scanner in the acute phase (day 0 to 3 after presentation) and at 4-months follow-up. Visually, echocardiography was able to identify only 52% of patients who showed RV wall motion abnormalities on CMR. Only CMR-derived RV ejection fraction (p = 0.01) and echocardiography-estimated pulmonary artery pressure (p = 0.01) identify RV functional involvement in the acute phase. Although RV ejection fraction normalizes in most patients by 4 months, acutely there is RV myocardial edema in both functioning and malfunctioning segments, as measured by prolonged native T1 mapping (p = 0.02 for both vs controls), and this persists at 4 months in the acutely malfunctioning segments (p = 0.002 vs controls). The extracellular volume fraction was significantly increased acutely in all RV segments and remained increased at follow-up compared with controls (p = 0.004 for all). In conclusion, in a Tako-tsubo population presenting predominantly with ST-elevation electrocardiogram, we demonstrate that although RV functional involvement is seen in only half of the patients, RV myocardial edema is present acutely throughout the RV myocardium in all patients and results in microscopic fibrosis at 4-month follow-up.