Jonathan C Rodrigues

Comprehensive characterisation of hypertensive heart disease left ventricular phenotypes

Objective Myocardial intracellular/extracellular structure and aortic function were assessed among hypertensive left ventricular (LV) phenotypes using cardiovascular magnetic resonance (CMR). Methods An observational study from consecutive tertiary hypertension clinic patients referred for CMR (1.5 T) was performed. Four LV phenotypes were defined: (1) normal with normal indexed LV mass (LVM) and LVM to volume ratio (M/V), (2) concentric remodelling with normal LVM but elevated M/V, (3) concentric LV hypertrophy (LVH) with elevated LVM but normal indexed end-diastolic volume (EDV) or (4) eccentric LVH with elevated LVM and EDV. Extracellular volume fraction was measured using T1-mapping. Circumferential strain was calculated by voxel-tracking. Aortic distensibility was derived from high-resolution aortic cines and contemporaneous blood pressure measurements. Results 88 hypertensive patients (49±14 years, 57% men, systolic blood pressure (SBP): 167±30 mm Hg, diastolic blood pressure (DBP): 96±14 mm Hg) were compared with 29 age-matched/sex-matched controls (47±14 years, 59% men, SBP: 128±12 mm Hg, DBP: 79±10 mm Hg). LVH resulted from increased myocardial cell volume (eccentric LVH: 78±19 mL/m2 vs concentric LVH: 73±15 mL/m2 vs concentric remodelling: 55±9 mL/m2, p<0.05, respectively) and interstitial fibrosis (eccentric LVH: 33±10 mL/m2 vs concentric LVH: 30±10 mL/m2 vs concentricremodelling: 19±2 mL/m2, p<0.05, respectively). LVH had worst circumferential impairment (eccentric LVH: −12.8±4.6% vs concentric LVH: −15.5±3.1% vs concentric remodelling: –17.1±3.2%, p<0.05, respectively). Concentric remodelling was associated with reduced aortic distensibility, but not with large intracellular/interstitial expansion or myocardial dysfunction versus controls. Conclusions Myocardial interstitial fibrosis varies across hypertensive LV phenotypes with functional consequences. Eccentric LVH has the most fibrosis and systolic impairment. Concentric remodelling is only associated with abnormal aortic function. Understanding these differences may help tailor future antihypertensive treatments.

The Role of Cardiac MRI in Patients with Troponin-Positive Chest Pain and Unobstructed Coronary Arteries.

Acute coronary syndrome (ACS) still remains one of the leading causes of mortality and morbidity worldwide. Seven to fifteen percent of patients presenting with ACS have unobstructed coronary artery disease (CAD) on urgent angiography. Patients with ACS and unobstructed coronary arteries represent a clinical dilemma and their diagnosis and management is quite variable in current practice. Cardiovascular magnetic resonance imaging with its unique non-invasive myocardial tissue characterization property has the potential to identify underlying etiologies and reach a final diagnosis. These include acute and chronic myocarditis, embolic/spontaneous recanalization myocardial infarction, and Tako-Tsubo cardiomyopathy, and other conditions. Establishing a final diagnosis has a direct implication on patient’s management and prognosis. In this article, we have reviewed the current evidence on the diagnostic role of cardiac magnetic resonance (CMR) in patients with ACS and unobstructed coronary arteries. We have also highlighted the potential role of CMR as a risk stratification or prognostication tool for this patient population.

ECG strain pattern in hypertension is associated with myocardial cellular expansion and diffuse interstitial fibrosis: a multi-parametric cardiac magnetic resonance study

Aims In hypertension, the presence of left ventricular (LV) strain pattern on 12-lead electrocardiogram (ECG) carries adverse cardiovascular prognosis. The underlying mechanisms are poorly understood. We investigated whether hypertensive ECG strain is associated with myocardial interstitial fibrosis and impaired myocardial strain, assessed by multi-parametric cardiac magnetic resonance (CMR). Methods and results A total of 100 hypertensive patients [50 ± 14 years, male: 58%, office systolic blood pressure (SBP): 170 ± 30 mmHg, office diastolic blood pressure (DBP): 97 ± 14 mmHg) underwent ECG and 1.5T CMR and were compared with 25 normotensive controls (46 ± 14 years, 60% male, SBP: 124 ± 8 mmHg, DBP: 76 ± 7 mmHg). Native T1 and extracellular volume fraction (ECV) were calculated with the modified look-locker inversion-recovery sequence. Myocardial strain values were estimated with voxel-tracking software. ECG strain (n = 20) was associated with significantly higher indexed LV mass (LVM) (119 ± 32 vs. 80 ± 17 g/m2, P < 0.05) and ECV (30 ± 4 vs. 27 ± 3%, P < 0.05) compared with hypertensive subjects without ECG strain (n = 80). ECG strain subjects had significantly impaired circumferential strain compared with hypertensive subjects without ECG strain and controls (−15.2 ± 4.7 vs. −17.0 ± 3.3 vs. −17.3 ± 2.4%, P < 0.05, respectively). In subgroup analysis, comparing ECG strain subjects to hypertensive subjects with elevated LVM but no ECG strain, a significantly higher ECV (30 ± 4 vs. 28 ± 3%, P < 0.05) was still observed. Indexed LVM was the only variable independently associated with ECG strain in multivariate logistic regression analysis [odds ratio (95th confidence interval): 1.07 (1.02–1.12), P < 0.05). Conclusion In hypertension, ECG strain is a marker of advanced LVH associated with increased interstitial fibrosis and associated with significant myocardial circumferential strain impairment.

The Relationship Between Left Ventricular Wall Thickness, Myocardial Shortening, and Ejection Fraction in Hypertensive Heart Disease: Insights From Cardiac Magnetic Resonance Imaging

Hypertensive heart disease is often associated with a preserved left ventricular ejection fraction despite impaired myocardial shortening. The authors investigated this paradox in 55 hypertensive patients (52±13 years, 58% male) and 32 age‐ and sex‐matched normotensive control patients (49±11 years, 56% male) who underwent cardiac magnetic resonance imaging at 1.5T. Long‐axis shortening (R=0.62), midwall fractional shortening (R=0.68), and radial strain (R=0.48) all decreased (P<.001) as end‐diastolic wall thickness increased. However, absolute wall thickening (defined as end‐systolic minus end‐diastolic wall thickness) was maintained, despite the reduced myocardial shortening. Absolute wall thickening correlated with ejection fraction (R=0.70, P<.0001). In multiple linear regression analysis, increasing wall thickness by 1 mm independently increased ejection fraction by 3.43 percentage points (adjusted β‐coefficient: 3.43 [2.60–4.26], P<.0001). Increasing end‐diastolic wall thickness augments ejection fraction through preservation of absolute wall thickening. Left ventricular ejection fraction should not be used in patients with hypertensive heart disease without correction for degree of hypertrophy.

Hypertensive heart disease versus hypertrophic cardiomyopathy: multi-parametric cardiovascular magnetic resonance discriminators when end-diastolic wall thickness ≥ 15 mm

AbstractObjectivesEuropean guidelines state left ventricular (LV) end-diastolic wall thickness (EDWT) ≥15mm suggests hypertrophic cardiomyopathy (HCM), but distinguishing from hypertensive heart disease (HHD) is challenging. We identify cardiovascular magnetic resonance (CMR) predictors of HHD over HCM when EDWT ≥15mm.Methods2481 consecutive clinical CMRs between 2014 and 2015 were reviewed. 464 segments from 29 HCM subjects with EDWT ≥15mm but without other cardiac abnormality, hypertension or renal impairment were analyzed. 432 segments from 27 HHD subjects with EDWT ≥15mm but without concomitant cardiac pathology were analyzed. Magnitude and location of maximal EDWT, presence of late gadolinium enhancement (LGE), LV asymmetry (>1.5-fold opposing segment) and systolic anterior motion of the mitral valve (SAM) were measured. Multivariate logistic regression was performed. Significance was defined as p<0.05.ResultsHHD and HCM cohorts were age-/gender-matched. HHD had significantly increased indexed LV mass (110±27g/m2 vs. 91±31g/m2, p=0.016) but no difference in site or magnitude of maximal EDWT. Mid-wall LGE was significantly more prevalent in HCM. Elevated indexed LVM, mid-wall LGE and absence of SAM were significant multivariate predictors of HHD, but LV asymmetry was not.ConclusionsIncreased indexed LV mass, absence of mid-wall LGE and absence of SAM are better CMR discriminators of HHD from HCM than EDWT ≥15mm.Key Points• Hypertrophic cardiomyopathy (HCM) is often diagnosed with end-diastolic wall thickness ≥15mm. • Hypertensive heart disease (HHD) can be difficult to distinguish from HCM. • Retrospective case-control study showed that location and magnitude of EDWT are poor discriminators. • Increased left ventricular mass and midwall fibrosis are independent predictors of HHD. • Cardiovascular magnetic resonance parameters facilitate a better discrimination between HHD and HCM.

Myocardial Infarction With Nonobstructed Coronary Arteries: Impact of CMR Early After Presentation

Seven to 15% of patients with acute coronary syndrome (ACS) have nonobstructed coronary arteries, an entity that is known as myocardial infarction with nonobstructed coronary arteries (MINOCA) [(1)][1]. In these patients, cardiac magnetic resonance (CMR) can identify different underlying etiologies

The effect of obesity on electrocardiographic detection of hypertensive left ventricular hypertrophy: recalibration against cardiac magnetic resonance.

Electrocardiograph (ECG) criteria for left ventricular hypertrophy (LVH) are a widely used clinical tool. We recalibrated six ECG criteria for LVH against gold-standard cardiac magnetic resonance (CMR) and assessed the impact of obesity. One hundred and fifty consecutive tertiary hypertension clinic referrals for CMR (1.5 T) were reviewed. Patients with cardiac pathology potentially confounding hypertensive LVH were excluded (n=22). The final sample size was 128 (age: 51.0±15.2 years, 48% male). LVH was defined by CMR. From a 12-lead ECG, Sokolow–Lyon voltage and product, Cornell voltage and product, Gubner–Ungerleidger voltage and Romhilt–Estes score were evaluated, blinded to the CMR. ECG diagnostic performance was calculated. LVH by CMR was present in 37% and obesity in 51%. Obesity significantly reduced ECG sensitivity, because of significant attenuation in mean ECG values for Cornell voltage (22.2±5.7 vs 26.4±9.4 mm, P<0.05), Cornell product (2540±942 vs 3023±1185 mm • ms, P<0.05) and for Gubner–Ungerleider voltage (18.2±7.1 vs 23.3±1.2 mm, P<0.05). Obesity also significantly reduced ECG specificity, because of significantly higher prevalence of LV remodeling (no LVH but increased mass-to-volume ratio) in obese subjects without LVH (36% vs 16%, P<0.05), which correlated with higher mean ECG LVH criteria values. Obesity-specific partition values were generated at fixed 95% specificity; Cornell voltage had highest sensitivity in non-obese (56%) and Sokolow–Lyon product in obese patients (24%). Obesity significantly lowers ECG sensitivity at detecting LVH, by attenuating ECG LVH values, and lowers ECG specificity through changes associated with LV remodeling. Our obesity-specific ECG partition values could improve the diagnostic performance in obese patients with hypertension.

Out of hospital cardiac arrest survivors with inconclusive coronary angiogram: Impact of cardiovascular magnetic resonance on clinical management and decision-making☆

BACKGROUND Non-traumatic out of hospital cardiac arrest (OHCA) is the leading cause of death worldwide, mainly due to acute coronary syndromes. Urgent coronary angiography with view to revascularisation is recommended in patients with suspected acute coronary syndrome. Diagnosis and management of patients with inconclusive coronary angiogram (unobstructed coronaries or unidentified culprit lesion) is challenging. We sought to assess the role of Cardiovascular Magnetic Resonance (CMR) in the diagnosis and management of OHCA survivors with an inconclusive coronary angiogram. METHODS AND RESULTS This is a retrospective multicentre CMR registry analysis of OHCA survivors with an inconclusive angiogram. Clinical, ECG and multi-modality imaging data were analysed. Clinical impact of CMR was defined as a change in diagnosis or management. Out of 174 OHCA survivors referred for CMR, 110 patients (63%, 84 male, median age 58) had an inconclusive angiogram. CMR identified a pathologic substrate in 76/110 patients (69%): ischemic heart disease was found in 45 (41%) and non-ischemic heart disease in 31 (28%). A structurally normal heart was found in 25 patients (23%) and non-specific findings in 9 (8%). As compared to trans-thoracic echocardiogram, CMR proved to be superior in identifying a pathologic substrate (69% vs 54%, p=0.018). The CMR study carried a clinical impact in 70% of patients, determining a change in diagnosis in 25%, in management in 29% and a change in both in 16%. CONCLUSIONS CMR showed a promising role in the diagnostic work-up of OHCA survivors with inconclusive angiogram and its wider use should be considered.

Comprehensive First‐Line Magnetic Resonance Imaging in Hypertension: Experience From a Single‐Center Tertiary Referral Clinic

European guidelines recommend that patients with hypertension be assessed for asymptomatic organ damage and secondary causes. The authors propose that a single magnetic resonance imaging (MRI) scan can provide comprehensive first‐line imaging of patients assessed via a specialist hypertension clinic. A total of 200 patients (56% male, aged 51±15 years, office BP 168±30/96±16 mm Hg) underwent MRI of the heart, kidneys, renal arteries, adrenals and aorta. Comparisons were made with other imaging modalities where available. A total of 61% had left ventricular hypertrophy (LVH), 14% had reduced ejection fraction, and 15 patients had myocardial infarcts. Echocardiography overdiagnosed LVH in 15% of patients and missed LVH in 14%. Secondary causes were identified in 14.5% of patients: 12 adrenal masses, 10 renal artery stenoses, seven thyroid abnormalities, one aortic coarctation, one enlarged pituitary gland, one polycystic kidney disease, and one renal coloboma syndrome. This comprehensive MRI protocol is an effective method of screening for asymptomatic organ damage and secondary causes of hypertension.

Extra-cardiac findings in cardiovascular magnetic resonance: what the imaging cardiologist needs to know.

Cardiovascular magnetic resonance (CMR) is an established non-invasive technique to comprehensively assess cardiovascular structure and function in a variety of acquired and inherited cardiac conditions. A significant amount of the neck, thorax and upper abdomen are imaged at the time of routine clinical CMR, particularly in the initial multi-slice axial and coronal images. The discovery of unsuspected disease at the time of imaging has ethical, financial and medico-legal implications. Extra-cardiac findings at the time of CMR are common, can be important and can change clinical management. Certain patient groups undergoing CMR are at particular risk of important extra-cardiac findings as several of the cardiovascular risk factors for atherosclerosis are also risk factors for malignancy. Furthermore, the presence of certain extra-cardiac findings may contribute to the interpretation of the primary cardiac pathology as some cardiac conditions have multi-systemic extra-cardiac involvement. The aim of this review is to give an overview of the type of extra-cardiac findings that may become apparent on CMR, subdivided by anatomical location. We focus on normal variant anatomy that may mimic disease, common incidental extra-cardiac findings and important imaging signs that help distinguish sinister pathology from benign disease. We also aim to provide a framework to the approach and potential further diagnostic work-up of incidental extra-cardiac findings discovered at the time of CMR. However, it is beyond the scope of this review to discuss and determine the clinical significance of extracardiac findings at CMR.