Novel imaging strategies for the detection of prosthetic heart valve obstruction and endocarditis

Prosthetic heart valve (PHV) dysfunction remains difficult to recognise correctly by two-dimensional (2D) transthoracic and transoesophageal echocardiography (TTE/TEE). ECG-triggered multidetector-row computed tomography (MDCT), 18-fluorine-fluorodesoxyglucose positron emission tomography including low-dose CT (FDG-PET) and three-dimensional transoesophageal echocardiography (3D-TEE) may have additional value. This paper reviews the role of these novel imaging tools in the field of PHV obstruction and endocarditis.For acquired PHV obstruction, MDCT is of additional value in mechanical PHVs to differentiate pannus from thrombus as well as to dynamically study leaflet motion and opening/closing angles. For biological PHV obstruction, additional imaging is not beneficial as it does not change patient management. When performed on top of 2D-TTE/TEE, MDCT has additional value for the detection of both vegetations and pseudoaneurysms/abscesses in PHV endocarditis. FDG-PET has no complementary value for the detection of vegetations; however, it appears more sensitive in the early detection of pseudoaneurysms/abscesses. Furthermore, FDG-PET enables the detection of metastatic and primary extra-cardiac infections. Evidence for the additional value of 3D-TEE is scarce.As clinical implications are major, clinicians should have a low threshold to perform additional MDCT in acquired mechanical PHV obstruction. For suspected PHV endocarditis, both FDG-PET and MDCT have complementary value.     

Long-term prognostic value of CFVR and FFR versus perfusion scintigraphy in patients with multivessel disease

ObjectiveIn this multicentre study, we investigated the long-term prognostic value of intracoronary derived haemodynamic parameters compared with the results of myocardial perfusion scintigraphy (MPS). MethodsPatients (n=191) who were referred for angioplasty of a severe lesion in the presence of an intermediate lesion in another coronary artery were included. MPS was performed to determine the presence of reversible perfusion defects in the area of the intermediate lesion. Coronary flow velocity reserve (CFVR), and additionally fractional flow reserve (FFR; n=129), were determined distal to the intermediate lesion; CFVR ≥2.0 and FFR ≥0.75 were considered negative. ResultsIn total 67 events occurred in 49 patients (3 deaths, 9 MI, 9 CABG, 46 PTCA) during a mean of 793 days follow-up. Event-free survival was 63% for MPS, 79% for CFVR, and 79% for FFR if a negative test result was obtained. The relative risk was 1.2 (not significant) for MPS, 2.2 (p=0.001) for CFVR, and 2.4 (p=0.004) for FFR. ConclusionSelective evaluation of an intermediate lesion using CFVR or FFR allows more adequate risk stratification in patients with multivessel disease than MPS. A CFVR <2.0 or a FFR <0.75 was associated with a significant increase of the occurrence of cardiac events during long-term follow-up, predominantly associated with revascularisation. (Neth Heart J 2007;15:369-74.)     

Influence of hemodynamic conditions on fractional flow reserve: parametric analysis of underlying model

Pressure-based fractional flow reserve (FFR) is used clinically to evaluate the functional severity of a coronary stenosis, by predicting relative maximal coronary flow (Q(s)/Q(n)). It is considered to be independent of hemodynamic conditions, which seems unlikely because stenosis resistance is flow dependent. Using a resistive model of an epicardial stenosis (0-80% diameter reduction) in series with the coronary microcirculation at maximal vasodilation, we evaluated FFR for changes in coronary microvascular resistance (R(cor) = 0.2-0.6 mmHg. ml(-1). min), aortic pressure (P(a) = 70-130 mmHg), and coronary outflow pressure (P(b) = 0-15 mmHg). For a given stenosis, FFR increased with decreasing P(a) or increasing R(cor). The sensitivity of FFR to these hemodynamic changes was highest for stenoses of intermediate severity. For P(b) > 0, FFR progressively exceeded Q(s)/Q(n) with increasing stenosis severity unless P(b) was included in the calculation of FFR. Although the P(b)-corrected FFR equaled Q(s)/Q(n) for a given stenosis, both parameters remained equally dependent on hemodynamic conditions, through their direct relationship to both stenosis and coronary resistance.     

Haemodynamic and functional consequences of the iatrogenic atrial septal defect following Mitraclip therapy

Percutaneous MitraClip placement for treatment of severe mitral regurgitation in high surgical risk patients is a commonly performed procedure and requires a transseptal puncture to reach the left atrium. The resulting iatrogenic atrial septal defect (iASD) is not routinely closed, yet the haemodynamic and functional consequences of a persisting defect are not fully understood. Despite positive effects such as acute left atrial pressure relief, persisting iASDs are associated with negative consequences, namely significant bidirectional shunting and subsequent worse clinical outcome. Percutaneous closure of the iASD may therefore be desirable in selected cases. In this review we discuss the available literature on this matter.     

Carcinoid heart disease: a guide for screening and timing of surgical intervention

The cardiac manifestations of a neuroendocrine tumour are referred to as carcinoid heart disease (CaHD) and are associated with a poor prognosis. Surgical intervention is the only proven therapeutic option and may prolong survival and quality of life. No consensus has been reached internationally with regard to screening for CaHD and the optimal timing for surgery. Although limited evidence is available on this matter, a trend towards early surgery and subsequent reduced mortality has been observed. In this review we provide an overview of the current understanding and propose a protocol to guide cardiologists in the screening for CaHD and the timing of referral to a specialised surgical centre.     

Xenotransplantation of Human Cardiomyocyte Progenitor Cells Does Not Improve Cardiac Function in a Porcine Model of Chronic Ischemic Heart Failure. Results from a Randomized,Blinded, Placebo Controlled Trial

Background

Recently cardiomyocyte progenitor cells (CMPCs) were successfully isolated from fetal and adult human hearts. Direct intramyocardial injection of human CMPCs (hCMPCs) in experimental mouse models of acute myocardial infarction significantly improved cardiac function compared to controls.

Aim

Here, our aim was to investigate whether xenotransplantation via intracoronary infusion of fetal hCMPCs in a pig model of chronic myocardial infarction is safe and efficacious, in view of translation purposes.

Methods & Results

We performed a randomized, blinded, placebo controlled trial. Four weeks after ischemia/reperfusion injury by 90 minutes of percutaneous left anterior descending artery occlusion, pigs (n = 16, 68.5 ± 5.4 kg) received intracoronary infusion of 10 million fetal hCMPCs or placebo. All animals were immunosuppressed by cyclosporin (CsA). Four weeks after infusion, endpoint analysis by MRI displayed no difference in left ventricular ejection fraction, left ventricular end diastolic and left ventricular end systolic volumes between both groups. Serial pressure volume (PV-)loop and echocardiography showed no differences in functional parameters between groups at any timepoint. Infarct size at follow-up, measured by late gadolinium enhancement MRI showed no difference between groups. Intracoronary pressure and flow measurements showed no signs of coronary obstruction 30 minutes after cell infusion. No premature death occurred in cell treated animals.

Conclusion

Xenotransplantation via intracoronary infusion of hCMPCs is feasible and safe, but not associated with improved left ventricular performance and infarct size compared to placebo in a porcine model of chronic myocardial infarction.     

The role of exercise echocardiography in the management of mitral valve disease

Purpose

Exercise echocardiography can assess the dynamic component of mitral valve (MV) disease and may therefore be helpful for the clinical decision-making by the heart team. The purpose of this study is to determine the role of exercise echocardiography in the management of disproportionately symptomatic or otherwise atypical patients with mitral regurgitation (MR) and stenosis (MS) in clinical practice.

Methods

Data of 14 MR and 14 MS patients, including echocardiograms at rest, were presented retrospectively to an experienced heart team to determine treatment strategy. Subsequently, exercise echo data were provided whereupon once again the treatment strategy was determined. This resulted in: value of exercise echo by means of 1) alteration or 2) confirmation of treatment strategy or 3) no additional value.

Results

During exercise the echocardiographic severity of MV disease increased in 9 (64 %) MR and 8 (57 %) MS patients. Based upon alteration or confirmation of the treatment strategy, the value of exercise echocardiography in the management of MR and MS was 86 % and 57 %, respectively.

Conclusion

This study showed that physical exercise echo can have an important role in the clinical decision-making of challenging patients with MV disease. Exercise echocardiography had additional value to the treatment strategy in 71 % of these patients.     

Feasibility and potential benefit of pre-procedural CMR imaging in patients with ischaemic cardiomyopathy undergoing cardiac resynchronisation therapy

Netherlands Heart Journal - To determine the feasibility and potential benefit of a&nbsp;full cardiac magnetic resonance (CMR) work-up for assessing the location of scarred myocardium and the...     

Early mitral valve repair versus watchful waiting in patients with severe asymptomatic organic mitral regurgitation; rationale and design of the Dutch AMR trial, a multicenter, randomised trial

Background

Asymptomatic severe mitral valve (MV) regurgitation with preserved left ventricular function is a challenging clinical entity as data on the recommended treatment strategy for these patients are scarce and conflicting. For asymptomatic patients, no randomised trial has been performed for objectivising the best treatment strategy.

Methods

The Dutch AMR (Asymptomatic Mitral Regurgitation) trial is a multicenter, prospective, randomised trial comparing early MV repair versus watchful waiting in asymptomatic patients with severe organic MV regurgitation. A total of 250 asymptomatic patients (18–70 years) with preserved left ventricular function will be included. Intervention will be either watchful waiting or MV surgery. Follow-up will be 5 years. Primary outcome measures are all-cause mortality and a composite endpoint of cardiovascular mortality, congestive heart failure, and hospitalisation for non-fatal cardiovascular and cerebrovascular events. Secondary outcome measures are total costs, cost-effectiveness, quality of life, echocardiographic and cardiac magnetic resonance parameters, exercise tests, asymptomatic atrial fibrillation and brain natriuretic peptide levels. Additionally, the complication rate in the surgery group and rate of surgery in the watchful waiting group will be determined.

Implications

The Dutch AMR trial will be the first multicenter randomised trial on this topic. We anticipate that the results of this study are highly needed to elucidate the best treatment strategy and that this may prove to be an international landmark study.