Craig Bradbrook

Early and late changes in markers of aortic stiffness with breast cancer therapy

Anthracyclines and trastuzumab are well recognised to cause cardiac toxicity. Further to their effects on left ventricular (LV) function, anthracyclines in particular are considered to cause negative arterial remodelling. Whether these changes reverse is unknown. In addition, whether trastuzumab causes specific effects on arterial remodelling is yet undetermined.

Early effects of transcatheter aortic valve implantation and aortic valve replacement on myocardial function and aortic valve hemodynamics: Insights from cardiovascular magnetic resonance imaging

OBJECTIVES There remains a paucity of mechanistic data on the effect of transcatheter aortic valve implantation (TAVI) on early left and right ventricular function and quantitative aortic valve regurgitation. We sought to assess and compare the early effects on myocardial function and aortic valve hemodynamics of TAVI and aortic valve replacement (AVR) using serial cardiovascular magnetic resonance (CMR) imaging and echocardiography. METHODS A prospective comparison study of 47 patients with severe aortic stenosis undergoing either TAVI (n = 26) or high-risk AVR (n = 21). CMR (for left ventricle/right ventricle function, left ventricular mass, left atrial volume, and aortic regurgitation) was carried out before the procedure and early postprocedure (<14 days). RESULTS Groups were similar with respect to Society of Thoracic Surgeons score (TAVI, 7.7 vs AVR, 5.9; P = .11). Preoperative left ventricular (TAVI, 69% ± 13% vs AVR, 73% ± 10%; P = .10) and right ventricular (TAVI, 61% ± 11% vs AVR, 59% ± 8%; P = .5) ejection fractions were similar. Postoperative left ventricular ejection fraction was preserved in both groups. In contrast, decline in right ventricular ejection fraction was more significant in the TAVI group (61%-54% vs 59%-58%; P = .01). Postprocedure aortic regurgitant fraction was significantly greater in the TAVI group (16% vs 4%; P = .001), as was left atrial size (110 vs 84 mL; P = .02). Further analysis revealed a significant relationship between the increased aortic regurgitant fraction and greater left atrial size (P = .006), and a trend toward association between the decline in right ventricle dysfunction and increased postprocedure aortic regurgitation (P = .08). CONCLUSIONS There was no significant difference in early left ventricular systolic function between techniques. Whereas right ventricle systolic function was preserved in the AVR group, it was significantly impaired early after TAVI, possibly reflecting a clinically important pathophysiologic consequence of paravalvular aortic regurgitation.

Changes of left ventricular mechanics after trans-catheter aortic valve implantation and surgical aortic valve replacement for severe aortic stenosis: A tissue-tracking cardiac magnetic resonance study

BACKGROUND Left ventricular (LV) mechanics are impaired in patients with severe aortic stenosis (AS). The aim of the present study was to assess their changes early and late after trans-catheter aortic valve implantation (TAVI) and surgical aortic valve replacement (AVR) using cardiac magnetic resonance (CMR) tissue-tracking imaging. METHODS In 59 patients with severe AS undergoing either TAVI (n=35) or surgical AVR (n=24), CMR with late gadolinium enhancement (LGE) imaging was performed before and early post-procedure to evaluate LV function and mass, and presence/extent of LGE. A third CMR scan was performed in 29 patients after a mean follow-up of 15±4months. Tissue-tracking analysis was applied to cine CMR images, to assess LV global longitudinal (GLS), circumferential (GCS) and radial (GRS) strains. RESULTS The TAVI and surgical AVR groups were similar with respect to baseline (p=0.14) and early post-procedure (p=0.16) LV ejection fraction. However, baseline LV GLS was significantly impaired in TAVI patients compared to surgical AVR patients (p=0.025). Early post-procedure, TAVI resulted in a significant improvement of LV GLS (p=0.003), while a significant worsening of LV GLS was observed early after surgical AVR (p=0.012). At longer term follow-up, both TAVI and surgical AVR groups experienced a significant reduction of LV mass and a significant improvement of LV myocardial mechanics in all the three directions. CONCLUSIONS Treatment-specific differences in the changes of LV myocardial mechanics early after afterload release by TAVI and surgical AVR are present. Later, both interventions are associated with an improvement of LV myocardial deformation, alongside a regression of LV hypertrophy.

Preclinical alterations in cardiac energetics amongst sarcomere mutation carriers in hypertrophic cardiomyopathy

Background Hypertrophic cardiomyopathy (HCM) is characterised by reduced myocardial tissue oxygenation (assessed using blood oxygen level dependent (BOLD) CMR imaging) during stress, as well as reduced myocardial perfusion reserve (MPRI) due to coronary microvascular dysfunction. In HCM gene carriers without the HCM phenotype, it has been suggested that only oxygenation is impaired. [1] It remains unclear whether this relates to early cardiac remodelling/ diastolic dysfunction, or whether oxygen consumption is intrinsically altered with sarcomere mutations. We sought to assess the BOLD signal change during vasodilator stress in a homogenous group of MYPBC3 positive HCM patients (some with clinical HCM, and some with no phenotypic features of HCM), and normal controls.

Comparison of GLS via echocardiography and tissue tracking by Cardiac Magnetic Resonance imaging

Background Global longitudinal strain (GLS), has shown utility in detecting early subclinical LV dysfunction and has demonstrated significant efficacy in evaluating patients for chemotherapy cardiotoxicity. However, echocardiography is often reliant on operator experience and adequate quality windows for assessment. CMR is not subject to limitations of poor image quality due to its superior endocardial definition. We evaluated CMR derived strain by implementing a tissue tracking algorithm and compared it to GLS by 2D echocardiography in a prospective study of chemotherapy patients.

Early right ventricular dysfunction after transcatheter aortic valve replacement (TAVI): a prospective cardiac magnetic resonance study of open versus transcatheter aortic valve replacement

Background Recent published literature has validated the use of transcatheter aortic valve implantation (TAVI) in highrisk patients with aortic stenosis. These trials and registries have largely focused on combined morbidity and mortality outcomes with little focus given to impact on early myocardial function. We assessed effects on myocardial function, reversible and irreversible myocardial injury of both transcatheter and open aortic valve replacement utilizing multi-parametric CMR.

Myocardial perfusion is impaired in asymptomatic patients post renal transplantation

Background Cardiovascular disease is one of the commonest causes of mortality post-renal transplantation (RT), often in patients with no known cardiac disease. The cardiac phenotype in these patients is not clearly defined. Multi-parametric cardiovascular magnetic resonance (CMR) imaging enables concurrent assessment of myocardial function, perfusion and irreversible injury. We hypothesized that myocardial perfusion reserve would be impaired in asymptomatic post-renal transplant patients when compared with hypertensive controls. Methods Twenty-two asymptomatic R Tp atients (3 months to 5 years post-transplant) with, no known history of ischemic heart disease) and 12 hypertensive controls underwent

Myocardial perfusion is impaired in renal transplant and liver transplant patients

Methods We conducted a prospective study of 25 renal transplant (RT) recipients, 8 liver transplant (LT) recipients without previous CKD history and 7 controls with hypertension (HT). The transplant recipients were asymptomatic and had no previous ischaemic heart disease or revascularisation or systolic heart failure. The pre-transplant workup of the RT and LT were negative for haemodynamically significant epicardial coronary artery stenosis. Diabetes mellitus history between RT, LT and HT controls were not statistically different. Myocardial function, late-gadolinium enhancement and first-pass perfusion was assessed semiquantitatively at rest and under stress. The MPRI was calculated as the ratio of perfusion during adenosine-induced hyperemia to the rest perfusion. The RT and LT patients underwent whole-heart non-contrast magnetic resonance coronary angiography (MRCA) to assess the presence of proximal to mid epicardial coronary artery disease.

Myocardial oxygenation is impaired in advanced chronic kidney disease and renal transplant patients

Background Coronary artery disease (CAD) and left ventricular hypertrophy are prevalent in the chronic kidney disease (CKD) and renal transplant population. Advances in cardiovascular magnetic resonance (CMR) with the blood oxygen level-dependent (BOLD) technique provides unprecedented capability to assess myocardial oxygenation as a measure of ischaemia. We hypothesised that myocardial oxygenation would be reduced in advanced CKD and renal transplant patients and may provide a novel strategy for assessing myocardial ischaemia. Methods We prospectively studied 20 advanced CKD subjects (8 dialysis group with median eGFR 9.5 (range 5-37) ml/ min and 12 CKD group with median eGFR 14 (range 818) ml/min), 8 renal transplant (RT) recipients with median eGFR 74.5 (range 57-114) ml/min and 7 hypertensive (HT) controls with median eGFR 107 (range 57144) ml/min. All patients were asymptomatic for CAD and none had prior history of CAD. All groups had cine and BOLD CMR at 3T, and RT and HT groups also had late gadolinium CMR to assess infarction/replacement fibrosis. CKD group additionally underwent 2D echocardiography strain to assess fibrosis. Myocardial oxygenation was measured at rest and under stress with adenosine (140 µg/kg/min) using BOLD Signal Intensity (SI). Analyses were performed using linear mixed models. Results

Early effects of transcatheter aortic valve implantation and aortic valve replacement on myocardial function and injury: insights from Cardiovascular Magnetic Resonance

Background To assess the early effects on myocardial function, reversible and irreversible myocardial injury of both transcatheter (TAVI) and open aortic valve replacement (AVR) utilizing cardiovascular magnetic resonance (CMR) and biochemistry. Although recent studies have reported on clinical outcomes, there has been a paucity of mechanistic data on the effect of TAVI on ventricular function and irreversible myocardial injury.