Contractile reserve induced with dobutamine echocardiography predicts outcome in patients with left ventricular dysfunction and mitral regurgitation.

BACKGROUND AND AIM OF THE STUDY: The appropriate management of patients with mitral regurgitation (MR) and left ventricular dysfunction (LVD) is controversial. The study aim was to determine whether the presence of contractile reserve (CR) assessed by dobutamine stress echocardiography (DSE) was associated with improved outcomes. METHODS: Death and heart transplantation were analyzed as the primary outcomes associated with the presence of CR. A total of 125 consecutive patients (96 males, 29 females; mean age 60 +/- 12 years) with left ventricular ejection fraction (LVEF) < or = 35% and hemodynamically significant MR underwent DSE between 1999 and 2005. CR was defined as an increase in LVEF of > or = 10% during dobutamine infusion. RESULTS: Among 125 patients, 55 (43.0%) showed evidence of CR. Within five years after DSE, 24 patients (34.3%) in the CR- group and seven (12.7%) in the CR+ group had died or required heart transplantation (p < 0.01, log rank). After adjusting for age, baseline LVEF, NYHA class and moderate/severe tricuspid regurgitation (TR), CR remained an independent predictor of time to death or heart transplantation (HR 0.34; 95% CI: 0.15-0.76, p < 0.01). Improvement in the degree of MR was present at one year in 85.0% of CR+ patients, and in 62.5% of CR- patients (p = 0.03). An improvement of 5% in LVEF was noted in the CR+ group, compared to 0% in the CR- group (p = 0.04). CONCLUSION: In patients with advanced LVD and severe MR, CR detected by DSE was associated with significant reductions in the risk of death and heart transplantation.

Impact of Donor Origin on Survival After Orthotopic Heart Transplantation.

Heart transplantation is the definitive management for select patients with end-stage heart failure. Owing to an ongoing organ donor shortage, organs are sometimes allocated from distant locales. These organs may be perceived as less desirable because of donor risk factors and ischemic times. We compared survival after heart transplantation by donors originating from British Columbia (BC), other Canadian provinces, and the United States. This retrospective cohort analysis included all patients transplanted in BC between December 1, 1988, and October 21, 2014, and excluded those with missing data or retransplantation. Among 382 patients, 297 (77.7%) recipients and 238 (62.3%) donors were male. The median recipient age was 54.6 years (interquartile range, 46.0-61.0 years) and the median donor age was 33 years (interquartile range, 22-46 years). Overall 10-year survival was 62.1% (95% confidence interval, 56.3-67.4). There was no difference in 10-year survival when comparing donors from BC, other Canadian provinces, and the United States despite significantly lower median ischemic times in donors from BC. Donor location was not predictive of mortality after controlling for recipient age, donor age, and cold ischemic time. Donor origin did not impact 10-year survival after heart transplantation despite increased ischemic time, suggesting that distant donors result in similar outcomes in BC.

Images in cardiovascular medicine: prosthetic aortic valve and conduit dehiscence with large periconduit cavity, ascending aortic aneurysm and severe mitral regurgitation.

Prosthetic aortic valve and conduit dehiscence with periconduit cavity and ascending aortic aneurysm is an uncommon complication of aortic root surgery. It is usually recognizable at echocardiography due to an abnormal position of the prosthetic valve and conduit in relation to the native aortic annulus in conjunction with an abnormal echolucent periconduit space that fills with color flow. Mitral regurgitation is an unusual complication of this condition. We present a patient with severe mitral regurgitation secondary to prosthetic aortic valve and conduit dehiscence with a large periconduit cavity and aneurysm of the intervalvular fibrosa. The mechanism of mitral regurgitation is secondary to functional involvement of the anterior mitral valve leaflet and intervalvular fibrosa with anterior mitral leaflet restriction in conjunction with mild left ventricular remodeling. Significant mitral regurgitation persisted post resection of the periconduit cavity and aortic valve replacement, requiring mitral valve replacement. This case study reports a new mechanism of mitral regurgitation in the setting of prosthetic aortic valve and conduit dehiscence.

Canadian guidelines for training in adult perioperative transesophageal echocardiography. Recommendations of the Cardiovascular Section of the Canadian Anesthesiologists' Society and the Canadian Society of Echocardiography.

PURPOSE: To establish Canadian guidelines for training in adult perioperative transesophageal echocardiography (TEE). METHODS: Guidelines were established by the Canadian Perioperative Echocardiography Group with the support of the cardiovascular section of the Canadian Anesthesiologists' Society in conjunction with the Canadian Society of Echocardiography. Guidelines for training in echocardiography by the American Society of Echocardiography, the American College of Cardiology and the Society of Cardiovascular Anesthesiologists were reviewed, modified and expanded to produce the 2003 Quebec expert consensus for training in perioperative echocardiography. The Quebec expert consensus and the 2005 guidelines for the provision of echocardiography in Canada formed the basis of the Canadian training guidelines in adult perioperative TEE. RESULTS: Basic, advanced and director levels of expertise were identified. The total number of echocardiographic examinations to achieve each level of expertise remains unchanged from the 2002 American Society of Echocardiography and the Society of Cardiovascular Anesthesiologists guidelines. The increased proportion of examinations personally performed at basic and advanced levels, as well as the level of autonomy at the basic level suggested by the Quebec expert consensus are retained. These examinations may be performed in a perioperative setting and are not limited to intraoperative TEE. Training 'on-the-job', the role of the perioperative TEE examination, the requirements for maintenance of competence and the duration of training are also discussed for each level of training. The components of a TEE report and comprehensive TEE examination are also outlined. CONCLUSION: The Canadian guidelines for training in adult perioperative TEE reflect the unique Canadian practice profile in perioperative TEE and address the training requirements to obtain expertise in this field.

Right Ventricular Assessment in Adult Congenital Heart Disease Patients with Right Ventricle-to-Pulmonary Artery Conduits.

BACKGROUND: There is little data on right ventricular (RV) remodeling patterns in complex congenital heart disease (CHD) patients with right ventricle to pulmonary artery (PA) conduits, and novel RV imaging modalities have not been explored in this population. Knowledge of the RV remodeling process is an important first step to future understanding and tracking of the RV response to pressure and volume overload in this diverse population. Three-dimensional knowledge-based reconstruction (3DKBR) derived from two-dimensional transthoracic echocardiography (TTE-3DKBR) is a novel approach to RV assessment. The aims of this study were twofold: (1) to assess the feasibility and accuracy of 3DKBR in patients with CHD with RV to PA conduits and (2) to characterize the three-dimensional shape of the RV across the spectrum of CHD with RV to PA conduits. METHODS: Seventeen patients with tetralogy of Fallot, pulmonary atresia with ventricular septal defect, or truncus arteriosus (mean age, 29 ± 8 years; 24% women) and a conduit referred for cardiac magnetic resonance imaging (CMR) were prospectively recruited and underwent TTE-3DKBR. TTE-3DKBR echocardiographic image acquisition was performed using a standard ultrasound scanner linked to a Ventripoint Medical Systems unit. The surface RV volumetric reconstruction was performed by transmitting two-dimensional data points to an online database and comparing these with a lesion-specific catalog to derive the RV reconstruction. Parameters analyzed were end-diastolic volume (EDV), end-systolic volume, and ejection fraction. Intertechnique agreement was assessed using Pearson's correlation analysis, coefficients of variation, and Bland-Altman analysis. Three-dimensional shape comparisons of RV surface reconstructions were performed via automated validation testing of CMRs from 43 patients (mean age, 30 ± 8 years; 32% women) with RV to PA conduits (tetralogy of Fallot, n = 15; pulmonary atresia, n = 19; and truncus arteriosus, n = 9) distinct from patients in the 3DKBR comparison. RESULTS: There was good correlation and agreement between the two modalities: EDV, R = 0.77, P = .0004; end-systolic volume, R = 0.93, P < .0001; ejection fraction, R = 0.75, P < .0005. On Bland-Altman analyses, CMR EDV was slightly larger TTE-3DKBR, while EF was slightly higher by 3DKBR. Qualitative and quantitative assessment both demonstrated RV shape diversity based on surface reconstructions. CONCLUSION: This study demonstrates that TTE-3DKBR is an alternative technology that can be used to assess the RV in patients with complex CHD with a conduit. A novel method was used to compare RV shapes in this important population, and our results draw specific attention to the fact that the RV both within and outside diagnostic groups has very different unpredictable shapes and should not be treated equally. Our findings should set into motion future work focused on indices of RV shape and their impact on overall RV function and clinical outcomes, hence defining optimal timing of conduit revision, which at the current time is very unclear.

Transesophageal echocardiography to guide pulmonary vein mapping and ablation for atrial fibrillation.

BACKGROUND: This study describes the use and outcomes of transesophageal echocardiography to guide atrial fibrillation (AF) ablation procedures. METHODS: Under general anesthesia, 25 patients with a history of AF underwent multiplane transesophageal echocardiography in conjunction with catheter placement under fluoroscopy. RESULTS: In this series, a combined fluoroscopic/echocardiographic approach obviated the need for angiographic imaging. Anatomic variation in pulmonary veins (PV) was common; the shortest distance between the ostia ranged from 2 to 11 mm. Individual PV diameters did not predict the presence of ectopic foci. The number of radiofrequency pulses delivered per vein was 2.6 +/- 2.3 (range: 0-10). Mean fluoroscopy time per procedure was 31 +/- 13 minutes and mean procedure time was 110 +/- 31 minutes. At follow-up, 68% of patients were free from AF. CONCLUSIONS: Transesophageal echocardiography enables identification and cannulation of the ostia and proximal branches of PV during AF ablation. Fluoroscopy, procedure times, and outcomes compare favorably with series using PV angiography and, as such, suggest that a controlled trial is warranted.

Edge-to-edge repair for functional mitral regurgitation: an echocardiographic study of the hemodynamic consequences.

BACKGROUND AND AIM OF THE STUDY: The study aim was to characterize changes in mitral valve area and flow, and left ventricular (LV) size and function, following edge-to-edge (E-E) repair for severe functional mitral regurgitation (MR). The possibility that preoperative dobutamine stress echocardiography (DSE) might be used to predict post-repair recovery in LV function was also examined. METHODS: Seventeen patients underwent preoperative transthoracic echocardiography (TTE) and DSE, intraoperative transesophageal echocardiography, and three-month postoperative TTE. RESULTS: After repair, mitral valve area was reduced from 8.5 +/- 1.9 cm2 to 3.8 +/- 0.9 cm2 by planimetry (p < 0.0001) and to 2.9 +/- 0.9 cm2 by pressure half-time. Valve area by pressure half-time correlated with the planimetered area (r = +0.55), but was consistently lower (p = 0.004). Sixxteen of 17 patients had mean transmitral gradients <5 mmHg. Postoperative LV end-diastolic diameter improved from 72 +/- 11 to 64 +/- 10 mm (p < 0.01), and end-systolic diameter from 56 +/- 14 to 46 +/- 12 mm (p < 0.05). Mean ejection fraction improved from 25 +/- 12% before repair to 38 +/- 17% after repair (p < 0.02) in patients with evidence of LV function improvement on DSE, but was unchanged (15 +/- 5% versus 17 +/- 5%, p = NS) in patients without evidence of improvement. Postoperatively, 13 patients had no or mild MR, and two patients had moderate MR. There was one perioperative death. CONCLUSION: E-E repair, in combination with ring annuloplasty, reduces LV cavity dimensions and functional MR severity, without causing significant valve stenosis. Improvement on DSE may predict those patients in whom EF will improve following repair.

Computed tomography-based sizing recommendations for transcatheter aortic valve replacement with balloon-expandable valves: Comparison with transesophageal echocardiography and rationale for implementation in a prospective trial.

BACKGROUND: Computed tomography (CT) annular measurements are predictive of paravalvular regurgitation after transcatheter aortic valve replacement (TAVR) which is a predictor of mortality and morbidity. OBJECTIVES: To demonstrate the rationale and potential implications of new CT sizing recommendations for TAVR. METHODS: The CT sizing recommendations aim to ensure routine transcatheter heart valve (THV) oversizing of the aortic annular area [(THV external area/systolic annular area - 1) × 100; range, 1%-20%; target, 10%-15%]. Consecutive patients (n = 120) underwent CT before TAVR with balloon-expandable valves sized by transesophageal echocardiography (TEE). Retrospectively, the CT-recommended THV size was compared with the actual size implanted. RESULTS: Compared with TEE, application of the newly developed CT-based sizing recommendations would have led to implantation of a larger valve in 33.3% (40/120), no change in valve size in 55.8% (67/120), and a smaller valve in 10.8% (13/120). In patients when CT recommended a larger valve, the incidence of at least moderate paravalvular regurgitation was 25% (10/40) compared with 4.5% (3/67; P < 0.01) when both TEE and CT recommendations were in agreement. Using diastolic versus systolic CT measurements results in 20% of patients receiving smaller THVs. TEE sizing resulted in 33.3% (40/120) of valves being undersized (THV area < CT systolic annular area) with a mean annular oversizing of 9.4% ± 17.4% (range: -21.5% to 65.9%) without annular rupture. In contrast, the CT sizing recommendations results in mean annular oversizing of 13.9% ± 8.0% (range, 1.3%-29.8%). CONCLUSION: These CT sizing recommendations enable standardized moderate overexpansion of the aortic annulus. Clinical outcomes from these recommendations are being prospectively assessed in a multicenter trial.

Off-pump implantation of the HeartWare HVAD left ventricular assist device through minimally invasive incisions.

Implantation of left ventricular assist devices through small incisions, avoiding cardiopulmonary bypass, may decrease the activation of the inflammatory and coagulation cascades and decrease bleeding and vasoplegia. One patient with severe, inotrope-dependant cardiomyopathy received the HeartWare left ventricular assist device (HeartWare Inc, Framingham, MA) through an upper ministernotomy and left minithoracotomy. The outflow graft was connected to the ascending aorta, and the inflow of the left ventricular assist device was attached through to the apex of the heart. The apical puncture was performed under rapid ventricular pacing, followed by insertion of the inflow of the pump. The patient was extubated rapidly and discharged home 14 days later.

Multisite infective endocarditis with widespread pulmonary and systemic embolization in the setting of overwhelming staphylococcal sepsis.

The presence of simultaneous left- and right-sided endocarditis affecting the cardiac structures is rare and information regarding clinical presentation, pathophysiologic mechanisms, and prognosis is limited. We report the case of a young woman who presented to our institution with severe staphylococcal peritonitis and generalized sepsis who had tricuspid valve and left ventricular (LV) mural endocarditis. Significant transpulmonary shunting was demonstrated using transesophageal imaging and saline contrast injection. In this case transesophageal echocardiography (TEE) provided enhanced imaging of an unusual form of right- and left-sided endocarditis. More importantly, the use of TEE and saline contrast injection suggested an interesting hypothesis that might ultimately contribute to an improved understanding of pathophysiologic mechanisms in infective endocarditis and severe sepsis.

Techniques for percutaneous closure of prosthetic paravalvular leaks.

Percutaneous transcatheter closure techniques are now routinely applied in the management of atrial and ventricular septal defects, patent ductus arteriosus, and other pathological cardiac and vascular communications. Recently, these same techniques have been applied to paravalvular defects. Reports are few; success variable and techniques vary widely. We review the current considerations and techniques of percutaneous transcatheter closure of paravalvular leaks.

Percutaneous closure of prosthetic paravalvular leaks: case series and review.

BACKGROUND: Paravalvular leaks (PVLs) are a well-recognized complication of prosthetic valve replacement. Most are asymptomatic and benign, but some may cause symptoms due to a large regurgitant volume or hemolysis. Medical therapy is palliative, while reoperation carries significant morbidity and mortality. Percutaneous transcatheter closure techniques, now routinely applied in the management of pathological cardiac and vascular communications, may be adaptable to PVL closure, potentially offer symptomatic relief. METHODS: We reviewed our experience with attempted percutaneous closure of PVLs, using data from medical and procedural records. RESULTS: Between 2001 and 2004, 14 procedures were performed in 10 patients, all under general anesthesia, with transesophageal and radiographic guidance. Mitral (9) and aortic (1) valve replacements were involved, both mechanical and bioprosthetic. A variety of devices were used, including atrial septal occluders, patent ductus arteriosus occluders, and coils (all of label use). Six had a single procedure, which was technically successful in four: in two, the PVL could not be crossed. Four underwent a second procedure, which was technically successful in three; in one the previously deployed device was dislodged necessitating urgent, but ultimately uneventful, surgical removal and leak repair. One patient had transient severe hemolysis, which resolved after 1 week. At 1-year follow-up (9/10 pts) three had died, five had sustained symptomatic improvement while 1 patient with a residual leak still required regular blood transfusions. CONCLUSIONS: Percutaneous closure of PVLs is time-consuming but feasible in selected patients, with a reasonable degree of technical and clinical success. A second procedure may be necessary and a variety of complications can occur.

Canadian guidelines for training in adult perioperative transesophageal echocardiography. Recommendations of the Cardiovascular Section of the Canadian Anesthesiologists' Society and the Canadian Society of Echocardiography.

PURPOSE: To establish Canadian guidelines for training in adult perioperative transesophageal echocardiography (TEE). METHODS: Guidelines were established by the Canadian Perioperative Echocardiography Group with the support of the cardiovascular section of the Canadian Anesthesiologists' Society (CAS) in conjunction with the Canadian Society of Echocardiography. Guidelines for training in echocardiography by the American Society of Echocardiography, the American College of Cardiology and the Society of Cardiovascular Anesthesiologists were reviewed, modified and expanded to produce the 2003 Quebec expert consensus for training in perioperative echocardiography. The Quebec expert consensus and the 2005 Guidelines for the provision of echocardiography in Canada formed the basis of the Canadian training guidelines in adult perioperative TEE. RESULTS: Basic, advanced and director levels of expertise were identified. The total number of echocardiographic examinations to achieve each level of expertise remains unchanged from the 2002 American Society of Echocardiography-Society of Cardiovascular Anesthesiologists guidelines. The increased proportion of examinations personally performed at basic and advanced levels, and the level of autonomy at the basic level suggested by the Quebec expert consensus are retained. These examinations can be performed in a perioperative setting and are not limited to intraoperative TEE. Training "on the job", the role of the perioperative transesophageal echocardiography examination, requirements for maintenance of competence, and duration of training are also discussed for each level of training. The components of a TEE report and comprehensive TEE examination are also outlined. CONCLUSION: The Canadian guidelines for training in adult perioperative TEE reflect the unique Canadian practice profile in perioperative TEE and address the training requirements to obtain expertise in this field.

Percutaneous stent-mounted valve for treatment of aortic or pulmonary valve disease.

The objective of this study was to develop a prosthetic cardiac valve designed for percutaneous transcatheter implantation. Percutaneous catheter-based therapies play a limited role in the management of cardiac valve disease. Surgical implantation of prosthetic valves usually requires thoracotomy and cardiopulmonary bypass. The stent-valve is constructed of a rolled sheet of heat-treated nitinol. Although malleable when cooled, once released from a restraining sheath at body temperature the stent unrolls, becomes rigid, and assumes its predetermined cylindrical conformation. A ratcheting lock-out mechanism prevents recoil and external protrusions facilitate anchoring. Valve leaflets are constructed of bovine pericardium. The feasibility of catheter implantation, prosthetic valve function, and survival were investigated in an animal model. In vitro and pulse duplicator testing documented valve durability. Endovascular delivery of the prototype stent-valve to the aortic or pulmonary position was feasible. Accurate positioning was required to ensure exclusion of the native valve leaflets and, in the case of the aortic valve, to avoid compromise of the coronary ostia or mitral apparatus. Oversizing of the stent in relation to the valve annulus was desirable to facilitate anchoring and prevent paravalvular insufficiency. Stent-valve implantation proved feasible and compatible with survival in an animal model. Transcatheter implantation of prosthetic valves is possible. Further evolution of this technology will involve lower-profile devices with design features that facilitate vascular delivery, visualization, positioning, deployment, and valvular function.