Roberto Bellu

Current Clinical Applications of Transthoracic Three-Dimensional Echocardiography

The advent of three-dimensional echocardiography (3DE) has significantly improved the impact of non-invasive imaging on our understanding and management of cardiac diseases in clinical practice. Transthoracic 3DE enables an easier, more accurate and reproducible interpretation of the complex cardiac anatomy, overcoming the intrinsic limitations of conventional echocardiography. The availability of unprecedented views of cardiac structures from any perspective in the beating heart provides valuable clinical information and new levels of confidence in diagnosing heart disease. One major advantage of the third dimension is the improvement in the accuracy and reproducibility of chamber volume measurement by eliminating geometric assumptions and errors caused by foreshortened views. Another benefit of 3DE is the realistic en face views of heart valves, enabling a better appreciation of the severity and mechanisms of valve diseases in a unique, noninvasive manner. The purpose of this review is to provide readers with an update on the current clinical applications of transthoracic 3DE, emphasizing the incremental benefits of 3DE over conventional two-dimensional echocardiography.

Coronary Microvascular Dysfunction Induced by Primary Hyperparathyroidism is Restored After Parathyroidectomy

Background— Symptomatic primary hyperparathyroidism (PHPT) is associated with increased cardiovascular mortality. However, data on the association between asymptomatic PHPT and cardiovascular risk are lacking. We assessed coronary flow reserve (CFR) as a marker of coronary microvascular function in asymptomatic PHPT of recent onset. Methods and Results— We studied 100 PHPT patients (80 women; age, 58±12 years) without cardiovascular disease and 50 control subjects matched for age and sex. CFR in the left anterior descending coronary artery was detected by transthoracic Doppler echocardiography, at rest, and during adenosine infusion. CFR was the ratio of hyperemic to resting diastolic flow velocity. CFR was lower in PHPT patients than in control subjects (3.0±0.8 versus 3.8±0.7; P<0.0001) and was abnormal (⩽2.5) in 27 patients (27%) compared with control subjects (4%; P=0.0008). CFR was inversely related to parathyroid hormone (PTH) levels (r=−0.3, P<0.004). In patients with CFR ⩽2.5, PTH was higher (26.4 pmol/L [quartiles 1 and 3, 16 and 37 pmol/L] versus 18 [13–25] pmol/L; P<0.007), whereas calcium levels were similar (2.9±0.1 versus 2.8±0.3 mmol/L; P=0.2). In multivariable linear regression analysis, PTH, age, and heart rate were the only factors associated with CFR (P=0.04, P=0.01, and P=0.006, respectively). In multiple logistic regression analysis, only PTH increased the probability of CFR ⩽2.5 (P=0.03). In all PHPT patients with CFR ⩽2.5, parathyroidectomy normalized CFR (3.3±0.7 versus 2.1±0.5; P<0.0001). Conclusions— PHPT patients have coronary microvascular dysfunction that is completely restored after parathyroidectomy. PTH independently correlates with the coronary microvascular impairment, suggesting a crucial role of the hormone in explaining the increased cardiovascular risk in PHPT.

Transapical off-pump mitral valve repair with Neochord implantation: Early clinical results

BACKGROUND This prospective study aims to assess early clinical outcomes in patients undergoing Transapical Off-Pump Mitral Valve Intervention with Neochord Implantation (TOP-MINI). METHODS AND RESULTS Forty-nine patients with severe symptomatic degenerative mitral regurgitation (MR) were treated. Median age was 72 years (IQR 58-78) and median Euroscore-I was 3.26% (IQR 0.88-8.15). Forty-four patients (89.8%) presented with posterior leaflet prolapse (LP), 4 (8.2%) with anterior LP and 1 (2%) with combined disease. Acute procedure success (defined as successful placement of at least 3 neochords with reduction of residual MR to less than 2+) was achieved in all patients. In-hospital mortality was 2%. At 30 days major adverse events included one AMI (2%) successfully treated percutaneously and one sepsis (2%), no stroke or bleeding events occurred. At 3 months overall survival was 98%. MR was absent in 16 patients (33.4%), was grade 1+ in 15 (31.2%), and was grade 2+ in 12 (25%). Five patients (10.4%) developed recurrent severe MR due to anterior native chordae rupture. Four of them were successfully re-operated. At 3 months follow-up freedom from reoperation was 91.7 ± 4%. CONCLUSIONS Early results with Neochord procedure indicate that TOP-MINI is feasible and safe. Efficacy is maintained up to 3 months follow-up with significant clinical benefit for the patients.

Recent Developments on Coronary Microvasculopathy after Heart Transplantation:A New Target in the Therapy of Cardiac Allograft Vasculopathy

Heart transplantation (HTx) is the treatment of choice for patients with refractory end-stage heart diseases. Although the procedure is considered effective in extending and improving quality of life, the onset of cardiac allograft vasculopathy (CAV) continues to limit the long-term success of HTx. Emerging data indicate that the endothelium plays a significant role in the onset, progression and complication of this multifactorial disease, with both immunologic and nonimmunologic risk factors contributing to its development. Improving our understanding of the integral role of the coronary microcirculation in CAV is of crucial clinical interest since it could provide further insights into the related pathophysiological mechanisms and possible new strategies for CAV prevention and therapy. Assessment of coronary microvasculopathy has been shown to be of predictive value after HTx. Predominant allograft microvascular dysfunction is detectable in 15-20% of patients after HTx. Very recently, stenotic microvasculopathy (detected in biopsy samples) has been characterized as a prognostic factor for long-term survival after HTx. The ability to detect and distinguish changes in epicardial and microvascular function may aid in identifying modifiable factors that lead to CAV. Improved immunosuppressive drugs, including mycophenolate mofetil and proliferation signal inhibitors, as well as statins (in part via immunomodulation), may have a beneficial effect on coronary microcirculation after HTx, although there is still a need to confirm the impact of vasodilators in improving the prognosis of HTx patients. We review the role of coronary microvasculopathy in HTx, its prevention and new potential pharmacological interventions.

Transapical off-pump mitral valve repair with Neochord Implantation (TOP-MINI): step-by-step guide

A wide variety of surgical approaches for mitral valve repair (MVR) are available. Recent studies have demonstrated that the techniques which “respect rather than resect” the diseased portion of the mitral valve (MV) have comparable clinical outcomes and potentially superior results in terms of physiology (1). Artificial chordal implantation has received increased attention as an MVR strategy during the last few decades, especially when performed through a minimally invasive approach. The Transapical Off-Pump Mitral Valve Repair with Neochord Implantation (TOP-MINI) is a new MVR option that has been approved for patients presenting with severe mitral regurgitation (MR) due to leaflet(s) prolapse or flail (2-4). The procedure is performed using the NeoChord DS1000 system (NeoChord, Inc., Eden Praire, MN) under guidance of direct 2D and 3D transesophageal echocardiography (TEE) (5,6) for both implantation and tension adjustment of the neochordae. The aim of this article is to describe the TOP-MINI procedure in a step-by-step fashion.

Mitral valve anatomy and function: new insights from three-dimensional echocardiography.

Integrating volumetric rendering with motion in real-time, three-dimensional (3D) echocardiography is the most suitable imaging technique for assessing heart valves. Today, the rapidly advancing 3D technology allows us to perform a virtual ‘dissection’ of the heart intra vitam and to discover unprecedented, realistic views of cardiac valves in just a few minutes. The mitral valve is the cardiac structure easiest to visualize by transthoracic or transoesophageal approach. Three-dimensional echocardiography is able to display the non-planar valve leaflets and annulus, the complex subvalvular apparatus and their spatial relationships with the surrounding structures. The complementary use of 3D colour flow adds data about valve integrity and allows the quantitation of valvular diseases. Accumulating evidence suggests that 3D echocardiography is emerging as the reference technique to assess mitral valve morphology and function and guide valvular procedures of mounting complexity. The purpose of this review is to provide an update on the current clinical applications of 3D echocardiography for assessing mitral valves and to stress the incremental benefits of 3D echocardiography over conventional two-dimensional echocardiography.

Imaging-based right-atrial anatomy by computed tomography, magnetic resonance imaging, and three-dimensional transoesophageal echocardiography: correlations with anatomic specimens

Nowadays computed tomography, cardiac magnetic resonance imaging, and tridimensional transoesophageal echocardiography provide anatomic images of right-atrial structures with an impressive richness of anatomical details. It is therefore surprising that these techniques are not routinely used as complementary tools in teaching anatomy. This review aims to fill this gap showing the normal anatomy of right atrium as displayed by these sophisticated imaging techniques. A better understanding of right-atrial anatomy is crucial for the treatment of primary right-atrium electrical disorders as well as for catheter-based interventions for structural heart disease. The success of these procedures is, in fact, related to an accurate anatomical pre-procedural assessment. In this review, we describe the normal anatomy and variants of those right-atrial structures relevant for both ablationists and interventionalists.

Coronary Microvascular Dysfunction Correlates With the New Onset of Cardiac Allograft Vasculopathy in Heart Transplant Patients With Normal Coronary Angiography

Coronary microvascular dysfunction is emerging as a strong predictor of outcome in heart transplantation (HT). We assessed the validity of microvascular dysfunction, defined by means of a reduced coronary flow reserve (CFR), as a factor associated with new onset epicardial cardiac allograft vasculopathy (CAV) or death. We studied 105 patients at 4 ± 1 years post‐HT with a normal coronary angiography (CA). New onset CAV was assessed by CA. CFR was assessed in the left anterior descending (LAD) coronary artery by transthoracic Doppler echocardiography and calculated as the ratio of hyperaemic to basal blood flow velocity. A CFR ≤ 2.5 was considered abnormal. Epicardial CAV onset or death was assessed during a follow‐up of 10 years. New onset CAV was diagnosed in 30 patients (28.6%) (Group A), and the CA was normal in the remaining 75 patients (71.4%) (Group B). Group A had reduced CFR compared with group B (2.4 ± 0.6 vs. 3.2 ± 0.7, p < 0.0001). A CFR ≤ 2.5 was independently associated with a higher probability of new onset CAV (p < 0.0001) and a higher probability of death, regardless of CAV onset (p < 0.01). Microvascular dysfunction is independently associated with the onset of epicardial CAV, and associated with a higher risk of death, regardless of CAV onset.

Patient-Specific Ventricular Access Site Selection for the NeoChord Mitral Valve Repair Procedure

Selecting the ventricular access site on the basis of mitral valve anatomy improves the outcomes for a subgroup of patients undergoing the transapical echocardiographically guided NeoChord (NeoChord, Inc, St. Louis Park, MN) repair procedure to correct mitral regurgitation and who have a leaflet-to-annulus index lower than the recommended efficacy threshold of 1.25.

Ventricular Arrhythmias in Young Competitive Athletes: Prevalence, Determinants, and Underlying Substrate

Background Whether ventricular arrhythmias (VAs) represent a feature of the adaptive changes of the athletes heart remains elusive. We aimed to assess the prevalence, determinants, and underlying substrates of VAs in young competitive athletes. Method and Results We studied 288 competitive athletes (age range, 16–35 years; median age, 21 years) and 144 sedentary individuals matched for age and sex who underwent 12‐lead 24‐hour ambulatory electrocardiographic monitoring. VAs were evaluated in terms of number, complexity (ie, couplet, triplet, or nonsustained ventricular tachycardia), exercise inducibility, and morphologic features. Twenty‐eight athletes (10%) and 13 sedentary individuals (11%) showed >10 isolated premature ventricular beats (PVBs) or ≥1 complex VA (P=0.81). Athletes with >10 isolated PVBs or ≥1 complex VA were older (median age, 26 versus 20 years; P=0.008) but did not differ with regard to type of sport, hours of training, and years of activity compared with the remaining athletes. All athletes with >10 isolated PVBs or ≥1 complex VA had a normal echocardiographic examination; 17 of them showing >500 isolated PVBs, exercise‐induced PVBs, and/or complex VA underwent additional cardiac magnetic resonance, which demonstrated nonischemic left ventricular late gadolinium enhancement in 3 athletes with right bundle branch block PVBs morphologic features. Conclusions The prevalence of >10 isolated PVBs or ≥1 complex VA at 24‐hour ambulatory electrocardiographic monitoring did not differ between young competitive athletes and sedentary individuals and was unrelated to type, intensity, and years of sports practice. An underlying myocardial substrate was uncommon and distinctively associated with right bundle branch block VA morphologic features.