Mário Jorge Amorim

The TRIBECA study: (TRI)fecta (B)ioprosthesis (E)valuation versus (C)arpentier Magna-Ease in (A)ortic position

OBJECTIVE To determine whether the Trifecta bioprosthetic aortic valve produces postoperative haemodynamic results comparable with or better than those of the Magna Ease aortic valve bioprosthesis. METHODS We retrospectively reviewed the medical records of patients who had undergone aortic valve replacement with Trifecta or Magna Ease prostheses at eight European institutions between January 2011 and May 2013, and analysed early postoperative haemodynamic performance by means of echocardiography. RESULTS A total of 791 patients underwent aortic valve replacement (469 Magna Ease, 322 Trifecta). Haemodynamic variables were evaluated on discharge and during the follow-up (minimum 6 months, maximum 12 months). The mean gradient and the indexed effective orifice area (IEOA) were as follows: 10 mmHg [interquartile range (IQR): 8-13] and 1.10 cm(2)/m(2) (IQR: 0.95-1.27) for Trifecta; 16 mmHg (IQR: 11-22) and 0.96 cm(2)/m(2) (IQR: 0.77-1.13) for Magna Ease (P < 0.001). These significant differences were maintained across all valve sizes. Similar statistically significant differences were found when patients were matched and/or stratified for preoperative characteristics: body-surface area, ejection fraction, mean gradients and valve size. Severe prosthesis-patient mismatch (IEOA: <0.65 cm(2)/m(2)) was detected in 2 patients (0.6%) with Trifecta and 40 patients (8.5%) with Magna Ease (P < 0.001). CONCLUSIONS The haemodynamic performance of the Trifecta bioprosthesis was superior to that of the Magna Ease valve across all conventional prosthesis sizes, with almost no incidence of severe patient-prosthesis mismatch. The long-term follow-up is needed to determine whether these significant haemodynamic differences will persist, and influence clinical outcomes.

Correlation between plasma levels of apelin and myocardial hypertrophy in rats and humans: possible target for treatment?

Objective: To investigate the effects of left ventricular (LV) pressure overload and diabetes on the apelinergic system. Research design/methods: Pressure overload was established in rats by supra-renal aortic-banding. Six weeks later, diabetes was induced by streptozotocin (65 mg/kg, intraperitoneal), resulting in four groups: sham, banded (BA), diabetic (DM) and diabetic-banded (DM-BA). Twelve weeks later, LV function and structure were evaluated by echocardiography and biopsies and plasma samples collected. Furthermore, plasma samples and LV-endomyocardial biopsies were procured from aortic stenosis and mitral stenosis patients during surgery to evaluate myocardial expression of apelin and APJ-receptor and plasma levels of apelin. Results: Direct correlations between apelin plasma levels and LV-mass index and between apelin and APJ myocardial expression were observed both in humans and rats. Expression of apelin and APJ was not significantly altered by pressure-overload in humans, being downregulated by pressure overload and even more by diabetes in rats. Finally, an inverse correlation between apelin rat plasma levels and its myocardial expression was observed. Conclusions: While apelin/APJ myocardial expression decreases, apelin plasma levels increase in LV hypertrophy. Considering apelins positive inotropic and vasodilator properties, this elevation in apelin plasma levels may represent a compensatory mechanism to maintain inotropism and cardiac output during pressure-overload or diabetic cardiomyopathy.

Magnetic resonance imaging versus echocardiography to ascertain the regression of left ventricular hypertrophy after bioprosthetic aortic valve replacement: Results of the REST study

OBJECTIVES To compare the decrease in left ventricular mass index (LVMI) by magnetic resonance imaging (MRI) versus transthoracic echocardiography (TTE) after aortic valve replacement (AVR) for severe aortic stenosis with Epic and Epic Supra stented porcine bioprostheses (St Jude Medical, Inc, St Paul, Minn). METHODS This prospective multicenter study enrolled 149 patients who underwent AVR between January 2006 and February 2008. TTE and cardiac MRI measurements of LVMI were made at baseline and at 6 months of follow-up and were compared. Changes in mean pressure gradients were examined using TTE. RESULTS TTE measurements of LVMI were 48% to 63% higher than the MRI measurements. A decrease in LVMI from 137 ± 32 to 95 ± 16 g/m(2) with the Epic and from 139 ± 29 to 104 ± 28 g/m(2) with the Epic Supra valves (P < .0001 for both comparisons) was measured by TTE. Cardiac MRI revealed decreases in LVMI from 84 ± 20 to 64 ± 12 g/m(2) and from 86 ± 27 to 64 ± 17 g/m(2) with the Epic and Epic Supra valves, respectively (P < .0001 for both comparisons). TTE revealed a significant regression of mean pressure gradients from 51.6 ± 15.3 to 15.5 ± 5.2 mm Hg with the Epic and from 46.7 ± 19.4 to 17.9 ± 12.8 mm Hg with the Epic supra (P < .0001 for both comparisons). CONCLUSIONS A significant decrease in LVMI was measured after AVR with all sizes of both bioprosthetic models. Because of the overestimation of the decrease in LVMI by the Devereux formula, as well as the higher accuracy and reproducibility of cardiac MRI measurements, the latter should be preferred to TTE. An ultimate validation of this thesis could only be done comparing each of these modalities with pathologic examination.

Atrioventricular septal defect following blunt chest trauma

The authors describe an acquired atrioventricular septal defect that has resulted from a blunt chest trauma. Besides being an uncommon traumatic heart injury, this case has the particularities of the non-involvement of other adjacent anatomical structures and the long delay between the accident and the occurrence of the myocardial rupture.

Surgical treatment of atrial fibrillation: an updated review

The first Cox-maze procedure was performed in 1987, demonstrating the feasibility of a non-pharmacological treatment for atrial fibrillation (AF). Since then, surgery for AF has changed over time, in parallel with technological advances. Replacement of surgical incisions with linear ablation lines made a previously cumbersome procedure accessible to most surgeons, without compromising success. On the other hand, new ablation technologies paved the way for the development of minimally invasive surgery, which may potentially extend the scope of surgery to patients who would otherwise be deemed unsuitable. Nonetheless, literature on minimally invasive surgery is still scarce and randomized clinical trials currently under way are expected to shed light on some controversial issues. Moreover, successful AF treatment will probably rely on close collaboration between surgery and electrophysiology. Indeed, the hybrid procedure, though still in its very beginning, seems to combine the best of catheter and surgical ablation. However, further studies are warranted to determine the effectiveness of this promising strategy, especially in patients with persistent and longstanding persistent AF. Better understanding of AF pathophysiology as well as more accurate preoperative localization of AF triggers will bring about the possibility of tailoring specific lesion sets and ablation modalities to individual patients. This, in turn, will increase recovery and maintenance of sinus rhythm, with significant benefits in long-term outcomes.

Intraventricular pressure gradients throughout the cardiac cycle: effects of ischaemia and modulation by afterload

•  What is the central question of this study? The aim of the present study was to characterize the intraventricular pressure gradients (IVPGs) along the cardiac cycle, to correlate them with myocardial segmental asynchrony and to evaluate their response to regional myocardial ischaemia and ventricular afterload. •  What is the main finding and its importance? We showed the existence of diastolic and systolic IVPGs in the left ventricle (LV) and demonstrated for the first time that normal gradient pattern is related to physiological asynchrony between basal and apical myocardial segments. Moreover, we showed that IVPG, a marker of normal left ventricular function, can be attenuated, lost entirely, or even reversed after regional acute ischaemia and afterload elevations.

Ischemic rupture of the anterolateral papillary muscle

We describe the case of a 59-year-old man who presented with chest pain and ST-segment elevation in the inferior leads, R>S in V1 and ST depression in the anterior leads due to proximal occlusion of the first obtuse marginal. Primary coronary angioplasty and stenting of this artery were performed. Twelve hours later the patient became hemodynamically unstable and severe mitral regurgitation due to rupture of one of the heads of the anterolateral papillary muscle was diagnosed. Emergency surgery was performed (papillary muscle head reimplantation, mitral annuloplasty with a rigid ring, tricuspid annuloplasty and coronary artery bypass grafting). On surgical inspection, it was observed that the detached muscle head had become trapped in the left ventricle by a secondary cord attached to the other head. This case is unusual in presenting two uncommon features of ischemic papillary muscle: rupture of the anterolateral muscle in myocardial infarction involving the inferoposterior walls, and the fact that the ruptured muscle head did not prolapse because it had become trapped in the left ventricle by secondary cord attachment.

Rationale, design and methodology for Intraventricular Pressure Gradients Study: a novel approach for ventricular filling assessment in normal and falling hearts

AbstractBackgroundIntraventricular pressure gradients have been described between the base and the apex of the left ventricle during early diastolic ventricular filling, as well as, their increase after systolic and diastolic function improvement. Although, systolic gradients have also been observed, data are lacking on their magnitude and modulation during cardiac dysfunction. Furthermore, we know that segmental dysfunction interferes with the normal sequence of regional contraction and might be expected to alter the physiological intraventricular pressure gradients. The study hypothesis is that systolic and diastolic gradients, a marker of normal left ventricular function, may be related to physiological asynchrony between basal and apical myocardial segments and they can be attenuated, lost entirely, or even reversed when ventricular filling/emptying is impaired by regional acute ischemia or severe aortic stenosis.Methods/DesignAnimal Studies: Six rabbits will be completely instrumented to measuring apex to outflow-tract pressure gradient and apical and basal myocardial segments lengthening changes at basal, afterloaded and ischemic conditions. Afterload increase will be performed by abruptly narrowing or occluding the ascending aorta during the diastole and myocardial ischemia will be induced by left coronary artery ligation, after the first diagonal branch. Patient Studies: Patients between 65-80 years old (n = 12), both genders, with severe aortic stenosis referred for aortic valve replacement will be selected as eligible subjects. A high-fidelity pressure-volume catheter will be positioned through the ascending aorta across the aortic valve to measure apical and outflow-tract pressure before and after aortic valve replacement with a bioprosthesis. Peak and average intraventricular pressure gradients will be recorded as apical minus outflow-tract pressure and calculated during all diastolic and systolic phases of cardiac cycle.DiscussionWe expect to validate the application of our method to obtain intraventricular pressure gradients in animals and patients and to promote a methodology to better understand the ventricular relaxation and filling and their correlation with systolic function.

Load independent impairment of reverse remodeling after valve replacement in hypertensive aortic stenosis patients

BACKGROUND We evaluated the impact of hypertension on the left ventricular mass regression in aortic stenosis after aortic valve replacement. METHODS We prospectively studied 135 patients with severe aortic stenosis at baseline and 1 year after surgery. In 32 patients we analyzed myocardial gene expression of collagen types I and III, connective tissue growth factor, transforming growth factor-β1, metalloproteinase-2 and its tissue inhibitor and compared its levels vs controls. RESULTS Seventy-six patients (56.3%) had a history of hypertension. Hypertensive patients were older, had higher Euroscore-II and NYHA class, with no differences in stenosis severity. At 1 year follow-up there was a median decrease of mass index of 14.2% (P25-75: -4.3%-30.4%; p<0.001). Mass regression was significantly higher in patients without hypertension, with a median decrease of 25.9% (P25-75: 12.0%-38.7%) vs 5.4% (P25-75: -12.5%-20.1%; p=0.001), despite similar increase in effective orifice area and no differences in valvuloarterial impedance. After 1 year, higher baseline left ventricular mass index (p=0.005) and the absence of hypertension (p=0.002) or diabetes (p=0.041) were the only independent predictors of mass regression higher than the median. Comparing with controls, aortic stenosis patients had an increased expression of collagen types I and III, but only hypertensive patients had higher relative expression of collagen type I vs III. In hypertensive patients TIMP2 expression was up-regulated and correlated with higher baseline left ventricular mass index (r=0.61; p=0.020). CONCLUSIONS In aortic stenosis, hypertension impairs mass regression one year after valve replacement, independently of total afterload. Differences in the expression of extracellular matrix remodeling genes might contribute to this finding.

Unusual type A aortic dissection

A 66-year-old woman with hypertension and systemic lupus erythematosus presented with intermittent interscapular and chest pain, progressive dyspnea and presyncope episodes since the previous week. On physical examination she was hemodynamically stable, but jugular venous distension and diminished cardiac sounds were detected. Transthoracic echocardiography showed a pseudoaneurysm of the ascending aorta (Figure 1A, arrow) with an adjacent large mass compressing the right cardiac chambers (Figure 1B, arrow). Thoracic computed tomography confirmed aortic rupture (contrast extravasation suggestive of active rupture; Figure 1C, arrowed circle) associated with a large intramural hematoma (dimensions: 100×87×104 mm) extending inferiorly and compressing the right cardiac chambers (Figures 1D and E, arrow). Urgent surgery was