Cardiovascular magnetic resonance in pulmonary hypertension

Pulmonary hypertension represents a group of conditions characterized by higher than normal pulmonary artery pressures. Despite improved treatments, outcomes in many instances remain poor. In recent years, there has been growing interest in the use of Cardiovascular Magnetic Resonance (CMR) in patients with pulmonary hypertension. This technique offers certain advantages over other imaging modalities since it is well suited to the assessment of the right ventricle and the proximal pulmonary arteries. Reflecting the relatively sparse evidence supporting its use, CMR is not routinely recommended for patients with pulmonary hypertension. However, it is particularly useful in patient with pulmonary arterial hypertension associated with congenital heart disease. Furthermore, it has proven informative in a number of ways; illustrating how right ventricular remodeling is favorably reversed by drug therapies and providing explicit confirmation of the importance of the right ventricle to clinical outcome. This review will discuss these aspects and practical considerations before speculating on future applications

Histology of a Marfan aorta four and a half years after personalised external aortic mesh support (PEARS)

In 2008 a 26 year old man had personalised external aortic root support (PEARS) with a macroporous mesh. He was the 16th of 46 patients to have this operation. He had a typical Marfan habitus. His mother died of this disease as did his brother, with an aortic dissection. The patient himself died suddenly four and a half years after his PEARS operation. At autopsy there was no blood in the pericardium. The coronary orifices and proximal arteries were normal. His bicuspid aortic valve was minimally regurgitant as it was prior to operation and remained throughout follow-up. Macroscopically the implanted mesh was embedded in the adventitia and not separable from the aortic wall. Microscopically it was fully incorporated with collagen fibres as has been seen in our animal studies. The unsupported aortic arch showed some focal fragmentation of elastic fibres and a mild increase in mucopolysaccharides consistent with Marfan syndrome. These appearances were not present in the supported aortic root which had the histological appearance of normal aorta. He was the first patient to die with an implant. The histological appearances suggest the possibility that the incorporated support of the aortic root allowed recovery of the microstructure of the media

External Aortic Root Support to Prevent Aortic Dilatation in Patients With Marfan Syndrome

Background: Personalized external aortic root support (PEARS) was introduced in 2004 for prevention of aortic root dilatation in Marfan patients. The individual's aortic root is replicated by 3-dimensional printing. A polymer mesh sleeve is manufactured, which is implanted with the aim to support and stabilize the aortic wall. / Objectives: The aim of this study was to assess effectiveness of PEARS for prevention of aortic root dilatation in Marfan patients. / Methods: A total of 24 consecutive Marfan patients operated 2004 to 2012 were prospectively monitored with magnetic resonance imaging. Following a pre-defined protocol, baseline and follow-up aorta measurements were made in a blinded random sequence. / Results: The mean age of the patients was 33 ± 13.3 years (range: 16 to 58 years), and the mean aortic root diameter was 45 ± 2.8 mm (range: 41 to 52 mm). Follow-up was 6.3 ± 2.6 years. There was no increase in the aortic root and ascending aorta diameters, but there was a tendency toward reduction: annulus diameter 28.9 ± 2.3 mm to 28.5 ± 2.4 mm (change −0.39 mm, 95% confidence interval [CI]: −1.05 to 0.27 mm), sinus of Valsalva diameter 44.9 ± 2.9 mm to 44.5 ± 3.0 mm (change −0.37 mm, 95% CI: −1.23 to 0.51 mm), and ascending aorta diameter 32.4 ± 3.6 mm to 32.3 ± 3.7 mm (change −0.10 mm, 95% CI: −0.92 to 0.74 mm). In the same period, the descending aorta diameter increased from 22.9 ± 2.4 mm to 24.2 ± 3.0 mm (change 1.32 mm, 95% CI: 0.70 to 1.94 mm; p < 0.001) with a tendency toward increase in aortic arch diameter 24.1 ± 2.0 mm to 24.5 ± 2.8 mm (change 0.41 mm, 95% CI: −0.56 to 1.37 mm). / Conclusions: PEARS is effective in stabilizing the aortic root and preventing its dilatation. It is a viable alternative for prevention of aortic root dissection in Marfan patients

Determination of Clinical Outcome in Mitral Regurgitation With Cardiovascular Magnetic Resonance Quantification

Background—Surgery for severe mitral regurgitation is indicated if symptoms or left ventricular dilation or dysfunction occur. However, prognosis is already reduced by this stage, and earlier surgery on asymptomatic patients has been advocated if valve repair is likely, but identifying suitable patients for early surgery is difficult. Quantifying the regurgitation may help, but evidence for its link with outcome is limited. Cardiovascular magnetic resonance (CMR) can accurately quantify mitral regurgitation, and we examined whether this was associated with the future need for surgery. Methods and Results—One hundred nine asymptomatic patients with echocardiographic moderate or severe mitral regurgitation had baseline CMR scans and were followed up for up to 8 years (mean, 2.5±1.9 years). CMR quantification accurately identified patients who progressed to symptoms or other indications for surgery: 91% of subjects with regurgitant volume ≤55 mL survived to 5 years without surgery compared with only 21% with regurgitant volume >55 mL (P40%. CMR-derived end-diastolic volume index showed a weaker association with outcome (proportions surviving without surgery at 5 years, 90% for left ventricular end-diastolic volume index <100 mL/m2 versus 48% for ≥100 mL/m2) and added little to the discriminatory power of regurgitant fraction/volume alone. Conclusions—CMR quantification of mitral regurgitation was associated with the development of symptoms or other indications for surgery and showed better discriminatory ability than the reference-standard CMR-derived ventricular volumes. CMR may be able to identify appropriate patients for early surgery, with the potential to change clinical practice, although the clinical benefits of early surgery require confirmation in a clinical trial

Right ventricular dysfunction is a predictor of non-response and clinical outcome following cardiac resynchronization therapy

<p>Abstract</p> <p>Background</p> <p>Cardiac resynchronization therapy (CRT) is an established treatment in advanced heart failure (HF). However, an important subset does not derive a significant benefit. Despite an established predictive role in HF, the significance of right ventricular (RV) dysfunction in predicting clinical benefit from CRT remains unclear. We investigated the role of RV function, assessed by cardiovascular magnetic resonance (CMR), in predicting response to and major adverse clinical events in HF patients undergoing CRT.</p> <p>Methods</p> <p>Sixty consecutive patients were evaluated with CMR prior to CRT implantation in a tertiary cardiac centre. The primary end-point was a composite of death from any cause or unplanned hospitalization for a major cardiovascular event. The secondary end-point was response to therapy, defined as improvement in left ventricular ejection fraction ≥ 5% on echocardiography at one year.</p> <p>Results</p> <p>Eighteen patients (30%) met the primary end-point over a median follow-up period of 26 months, and 27 out of 56 patients (48%) were considered responders to CRT. On time-to-event analysis, only atrial fibrillation (HR 2.6, 95% CI 1.02-6.84, p = 0.047) and RV dysfunction, either by a reduced right ventricular ejection fraction-RVEF (HR 0.96, 95% CI 0.94-0.99, p = 0.006) or tricuspid annular plane systolic excursion-TAPSE (HR 0.88, 95% CI, 0.80-0.96, p = 0.006), were significant predictors of adverse events. On logistic regression analysis, preserved RVEF (OR 1.05, 95% CI 1.01-1.09, p = 0.01) and myocardial scar burden (OR 0.90, 95% CI 0.83-0.96, p = 0.004) were the sole independent predictors of response to CRT. Patients with marked RV dysfunction (RVEF < 30%) had a particularly low response rate (18.2%) to CRT.</p> <p>Conclusions</p> <p>Right ventricular function is an important predictor of both response to CRT and long-term clinical outcome. Routine assessment of the right ventricle should be considered in the evaluation of patients for CRT.</p