Multimodality Imaging in the Context of Transcatheter Mitral Valve Replacement: Establishing Consensus Among Modalities and Disciplines.

Transcatheter mitral valve implantation (TMVI) represents a promising approach to treating mitral valve regurgitation in patients at increased risk of perioperative mortality. Similar to transcatheter aortic valve replacement (TAVR), TMVI relies on pre- and periprocedural noninvasive imaging. Although these imaging modalities, namely echocardiography, computed tomography, and fluoroscopy, are well established in TAVR, TMVI has entirely different requirements. Approaches and nomenclature need to be standardized given the multiple disciplines involved. Herein we provide an overview of anatomical principles and definitions, a methodology for anatomical quantification, and perioperative guidance.

Transcatheter Aortic and Mitral Valve-in-Valve Implantation for Failed Surgical Bioprosthetic Valves: An 8-Year Single-Center Experience.

OBJECTIVES: We report our 8-year experience in transcatheter aortic and mitral valve-in-valve (VinV) implantation. BACKGROUND: Feasibility and good early outcomes associated with transcatheter aortic and mitral VinV implantation into failed surgical bioprostheses have been confirmed, but the mid-term and long-term outcomes of transcatheter aortic and mitral VinV is unknown. METHODS: A total of 73 patients with aortic (n = 42) and mitral (n = 31) bioprosthetic valve dysfunction underwent transcatheter VinV implantation between April 2007 and December 2013. Edwards balloon-expandable transcatheter valves (Edwards Lifesciences Inc., Irvine, California) were used. Median follow-up was 2.52 years with a maximum of 8 years. RESULTS: Seventy-two patients (mean age 79.7 ± 9.4 years, 32 women) underwent successful VinV implantation (success rate 98.6%). At 30 days, all-cause mortality was 1.4%, disabling stroke 1.4%, life-threatening bleeding 4.1%, acute kidney injury requiring hemodialysis 2.7%, and coronary artery obstruction requiring intervention 1.4%. No patient had greater than mild paravalvular leak. Estimated survival rates were 88.9%, 79.5%, 69.8%, 61.9%, and 40.5% at 1, 2, 3, 4, and 5 years, respectively. The small surgical valve size (19 and 21 mm) was an independent risk factor for reduced survival in aortic VinV patients. At 2-year follow-up, 82.8% of aortic and 100% of mitral VinV patients were in New York Heart Association functional class I or II. CONCLUSIONS: Transcatheter VinV for failed surgical bioprostheses can be performed safely with a high success rate and minimal early mortality and morbidity. Transcatheter VinV provides encouraging mid-term clinical outcomes in this high-risk elderly cohort of patients. Transcatheter VinV is an acceptable alternative therapy for failed aortic or mitral bioprostheses in selected high-risk patients.

A Strategy of Underexpansion and Ad Hoc Post-Dilation of Balloon-Expandable Transcatheter Aortic Valves in Patients at Risk of Annular Injury: Favorable Mid-Term Outcomes.

OBJECTIVES: The aim of this study was to evaluate a strategy of intentional underexpansion of excessively oversized balloon-expandable transcatheter heart valves (THVs) in terms of clinical outcomes, valve function, and frame durability at 1 year. BACKGROUND: Transcatheter aortic valve replacement requires the selection of an optimally sized THV to ensure paravalvular sealing and fixation without risking annular injury. However, some patients have "borderline" annular dimensions that require choosing between a THV that may be too small or another that may be too large. METHODS: We evaluated 47 patients at risk of annular injury who underwent transcatheter aortic valve replacement (TAVR) with an oversized, but deliberately underexpanded, THV followed by post-dilation if required. Clinical evaluation, echocardiography, and cardiac computed tomography were performed pre-TAVR, post-TAVR, and at 1 year. RESULTS: Deployment of oversized THVs with modest underfilling of the deployment balloon (<10% by volume) was not associated with significant annular injury. Paravalvular regurgitation was mild or less in 95.7% of patients, with post-dilation required in 10.7%. THV hemodynamic function was excellent and remained stable at 1 year. Computed tomography documented stent frame circularity in 87.5%. Underexpansion was greatest within the intra-annular THV inflow (stent frame area 85.8% of nominal). There was no evidence of stent frame recoil, deformation, or fracture at 1 year. CONCLUSIONS: In carefully selected patients with borderline annulus dimensions and in whom excessive oversizing of a balloon-expandable SAPIEN XT valve (Edwards Lifesciences, Inc., Irvine, California) is a concern, a strategy of deliberate underexpansion, with ad hoc post-dilation, if necessary, may reduce the risk of annular injury without compromising valve performance.

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.

Multidetector CT predictors of prosthesis-patient mismatch in transcatheter aortic valve replacement.

BACKGROUND: Prosthesis-patient mismatch (PPM) is a predictor of mortality after aortic valve replacement (AVR). OBJECTIVE: We examined whether accurate 3-dimensional annular sizing with multidetector CT (MDCT) is predictive of PPM after transcatheter AVR (TAVR). METHODS: One hundred twenty-eight patients underwent MDCT then TAVR. Moderate PPM was defined as an indexed effective orifice area ≤0.85 cm²/m² and severe ≤0.65 cm²/m². MDCT annular measurements (area, short and long axis) were compared with the size of the selected transcatheter heart valve (THV) to obtain (1) the difference between prosthesis size and CT-measured mean annular diameter and (2) the percentage of undersizing or oversizing (calculated as 100 × [MDCT annular area--THV nominal area]/THV nominal area). In addition, the MDCT annular area was indexed to body surface area. These measures were evaluated as potential PPM predictors. RESULTS: We found that 42.2% of patients had moderate PPM and 9.4% had severe PPM. Procedural characteristics and in-hospital outcomes were similar between patients with or without PPM. THV undersizing of the mean aortic annulus diameter was not predictive of PPM (odds ratio [OR], 0.84; 95% CI, 0.65-1.07; P = .16; area under the receiver-operating characteristic curve [AUC], 0.58). THV undersizing of annular area was not predictive of PPM (OR, 0.96; 95% CI, 0.80-1.16; P = .69; AUC, 0.52). Indexed MDCT annular area was, however, predictive of PPM (OR, 0.24; 95% CI, 0.10-0.59; P < .001; AUC, 0.66). CONCLUSIONS: PPM is frequent after TAVR. Appropriate annular oversizing does not reduce the rate or severity of PPM. Patient annulus size mismatch, identified by indexed MDCT annular area, is a significant predictor of PPM.

The impact of integration of a multidetector computed tomography annulus area sizing algorithm on outcomes of transcatheter aortic valve replacement: a prospective, multicenter, controlled trial.

OBJECTIVES: This study prospectively investigated the impact of integration of a multidetector computed tomography (MDCT) annular area sizing algorithm on transcatheter aortic valve replacement (TAVR) outcomes. BACKGROUND: Appreciation of the 3-dimensional, noncircular geometry of the aortic annulus is important for transcatheter heart valve (THV) sizing. METHODS: Patients being evaluated for TAVR in 4 centers underwent pre-procedural MDCT. Recommendations for balloon-expandable THV size selection were based on an MDCT sizing algorithm with an optimal goal of modest annulus area oversizing (5% to 10%). Consecutive patients who underwent TAVR with the algorithm (MDCT group) were compared with consecutive patients without the algorithm (control group). The primary endpoint was the incidence of more than mild paravalvular regurgitation (PAR), and the secondary endpoint was the composite of in-hospital death, aortic annulus rupture, and severe PAR. RESULTS: Of 266 patients, 133 consecutive patients underwent TAVR (SAPIEN XT THV) in the MDCT group and 133 consecutive patients were in the control group. More than mild PAR was present in 5.3% (7 of 133) of the MDCT group and in 12.8% (17 of 133) in the control group (p = 0.032). The combined secondary endpoint occurred in 3.8% (5 of 133) of the MDCT group and in 11.3% (15 of 133) of the control group (p = 0.02), driven by the difference of severe PAR. CONCLUSIONS: The implementation of an MDCT annulus area sizing algorithm for TAVR reduces PAR. Three-dimensional aortic annular assessment and annular area sizing should be considered for TAVR.

5-year outcome after transcatheter aortic valve implantation.

OBJECTIVES: The purpose of this study was to investigate the 5-year outcome following transcatheter aortic valve implantation (TAVI). BACKGROUND: Little is known about long-term outcomes following TAVI. METHODS: The 5-year outcomes following successful TAVI with a balloon-expandable valve were evaluated in 88 patients. Patients who died within 30 days after TAVI were excluded. RESULTS: Mean aortic valve gradient decreased from 46 ± 18 mm Hg to 10 ± 4.5 mm Hg after TAVI and 11.8 ± 5.7 mm Hg at 5 years (p for post-TAVI trend = 0.06). Mean aortic valve area increased from 0.62 ± 0.17 cm(2) to 1.67 ± 0.41 cm(2) after TAVI and 1.40 ± 0.25 cm(2) at 5 years (p for post-TAVI trend <0.01). At 5 years, 3 patients (3.4%) had moderate prosthetic valve dysfunction (moderate transvalvular regurgitation in 1, moderate stenosis in 1, and moderate mixed disease in 1). Survival rates at 1 to 5 years were 83%, 74%, 53%, 42%, and 35%, respectively. Median survival time after TAVI was 3.4 years (95% confidence interval [CI]: 2.6 to 4.3), and the risk of death was significantly increased in patients with chronic obstructive pulmonary disease (adjusted hazard ratio [HR]: 2.17; 95% CI: 1.28 to 3.70) and at least moderate paravalvular regurgitation (adjusted HR: 2.98; 95% CI: 1.44 to 6.17). CONCLUSIONS: Our study demonstrated favorable long-term outcomes after TAVI. Signs of moderate prosthetic valve failure were observed in 3.4% of patients. No patients developed severe prosthetic regurgitation or stenosis. Comorbidities, notably chronic lung disease and at least moderate paravalvular regurgitation, were associated with reduced long-term survival.

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.

Transcatheter closure of paravalvular defects using a purpose-specific occluder.

OBJECTIVES: This study sought to describe a method of paravalvular leak closure using a purpose-specific occlusion device. BACKGROUND: Transcatheter closure of paravalvular leaks has been hampered by technical challenges, the limitations of available imaging modalities, and the lack of closure devices specifically designed for this purpose. METHODS: Patients with severe symptomatic paravalvular regurgitation at high risk for repeat surgery underwent transcatheter leak closure. Both left ventricular puncture and retrograde transfemoral approaches were used with fluoroscopic and 3-dimensional transesophageal guidance. A purpose-specific occluder (Vascular Plug III, AGA Medical Corp., Plymouth, Minnesota) was used. RESULTS: Five patients with severe prosthetic mitral and aortic paravalvular leaks underwent attempted closure. Implantation of the device was successfully accomplished in all. In 1 patient, the plug interfered with closure of a mechanical valve leaflet and was removed and replaced with an alternate device. Complications included pericardial bleeding in 2 patients with a transapical approach. There was no procedural mortality. At a median follow-up of 191 days (interquartile range [IQR] 169 to 203 days) all patients were alive. New York Heart Association functional class fell from 4 (IQR 3 to 4) to 2 (IQR 2 to 3), hemoglobin rose from 89 g/l (IQR 87 to 108 g/l) to 115 g/l (IQR 104 to 118 g/l), creatinine fell from 109 micromol/l (IQR 106 to 132 micromol/l) to 89 micromol/l (IQR 89 to 126 micromol/l). Median echocardiographic follow-up at 58 days (IQR 56 to 70 days) reported residual regurgitation to be reduced from grade 4 to grade 2 (IQR 1.5 to 2.25). CONCLUSIONS: Closure of mitral and aortic prosthetic paravalvular leaks with the Vascular Plug III using either a transapical (mitral) or a retrograde (aortic) approach appears promising.

Transapical transcatheter aortic valve implantation: 1-year outcome in 26 patients.

BACKGROUND: We reported the first case of successful transapical transcatheter aortic valve implantation in a human subject in 2005 and have now completed a 12-month follow-up on our first 26 patients. This is, to date, the longest follow-up of patients undergoing transapical aortic valve implantation. METHODS: Between October 2005 and January 2007, 26 patients (13 female) underwent transcatheter transapical aortic valve implantation with either 23- or 26-mm Edwards Lifesciences transcatheter bioprostheses. All patients with symptomatic aortic stenosis were declined for conventional aortic valve replacement because of unacceptable operative risks and were not candidates for transfemoral aortic valve implantation because of poor arterial access. Clinical and echocardiographic follow-up was performed before discharge and at 1, 6, and 12 months. Data from the 17 patients who survived over 12 months were used for comparisons of the baseline and follow-up results. RESULTS: The mean age was 80 +/- 9 years, and the predicted operative mortality was 37% +/- 20% by using logistic EuroSCORE and 11% +/- 6% by using the Society of Thoracic Surgeons Risk Calculator. Valves were successfully implanted in all patients. Six patients died within 30 days (30-day mortality, 23%), and 3 patients died from noncardiovascular causes after 30 days (late mortality, 12%). Among patients who survived at least 30 days, 12-month survival was 85%. There were no late valve-related complications. New York Heart Association functional class improved significantly. The aortic valve area and mean gradient remained stable at 12 months (1.6 +/- 0.3 cm(2) and 9.6 +/- 4.8 mm Hg, respectively). CONCLUSION: Our 1-year clinical and echocardiographic outcomes suggest that transapical transcatheter aortic valve implantation is a viable alternative to conventional aortic valve replacement in selected high-risk patients.

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.

Role of echocardiography in percutaneous aortic valve implantation.

OBJECTIVES: This study was designed to investigate the usefulness and limitations of echocardiography in optimizing the outcome of percutaneous aortic valve implantation. BACKGROUND: Percutaneous aortic valve implantation is an emerging technique that has the potential to revolutionize the treatment of aortic valve disease. To date, however, the technique has been limited by technical constraints. Precise positioning of the valve is essential to minimize the potential for paravalvular regurgitation or device migration. Initial experience with device placement utilized fluoroscopic guidance only. METHODS: Candidates for percutaneous aortic valve implantation were evaluated with transthoracic echocardiography (TTE) to assess aortic annular dimension and aortic valve hemodynamics. Fifty consecutive patients were deemed suitable for percutaneous aortic valve implantation. Seventy-four percent (37 of 50) of patients underwent transesophageal echocardiography (TEE) during the procedure. RESULTS: Eighty-six percent (43 of 50) of patients had successful implantation, of which 77% (33 of 43) had TEE. Transthoracic echocardiography was used to determine annular dimension and was useful in guiding correct device sizing. Transesophageal echocardiography was able to successfully guide device implantation in 97% (33 of 34) of patients in whom the native valve was crossed with the percutaneous heart valve. Transesophageal echocardiography was used for the early detection of paravalvular aortic regurgitation (AR) and complemented fluoroscopy in the detection of complications. Additional balloon dilatation of the percutaneous heart valve was performed in 12 patients because of significant paravalvular AR, with 7 showing improvement in AR grade. After the procedure, early outcomes were evaluated using TTE. All patients in whom the device was successfully placed (43 of 50) had improvement in their aortic stenosis. Paravalvular AR, although present in many patients, is usually mild and has not emerged as a significant problem. CONCLUSIONS: Echocardiography has an important role in case selection, in guiding device placement, and in detecting complications of percutaneous aortic valve implantation.

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.

True versus reported waiting times for valvular aortic stenosis surgery.

OBJECTIVES: To produce a universally accepted waiting time definition for cardiovascular surgery, present the rationale for this definition, and compare data on current waiting times in British Columbia based on this definition versus the current definition in patients waiting for aortic stenosis surgery. STUDY DESIGN: The present study is a retrospective data analysis. SETTING: The fixed-dollar, single-payer health care delivery system in British Columbia. PATIENTS: All residents of British Columbia who were at least 22 years of age and who were placed on a waiting list for aortic valve surgery with the diagnosis of aortic stenosis between January 1, 1991, and December 31, 2000, were eligible for the present study. INTERVENTIONS: Dates of physician visits, procedures and surgery were obtained from the British Columbia Cardiac Registries and Medical Services Plan databases. True waiting times from physician visits to procedures and surgery were calculated. RESULTS: Of the 2516 patients booked for aortic valve surgery with a primary diagnosis of aortic stenosis, 2237 subjects (88.9%) were eligible for analysis after exclusions. The eligible patients ranged in age from 22 to 95 years, and 36.8% were female. The true median waiting time was 243 days (148 days [25th percentile], 397 days [75th percentile]), which was 3.2 times the interval currently reported as the waiting time (75 days [42, 127]). Thirty-nine patients died while waiting for surgery. Patients used more resources while waiting for surgery than after surgery. CONCLUSIONS: True waiting times for surgery for aortic stenosis in British Columbia are significantly longer than reported waiting times. The authors propose that the wait list time for cardiovascular surgery be redefined as "the time interval between the patient's first contact with a medical care provider with symptoms or signs which ultimately lead to cardiovascular surgery and the date of that surgery".

Outcome of mitral valve repair or replacement: a comparison by propensity score analysis.

BACKGROUND: There are no randomized trials comparing outcomes after mitral valve (MV) repair and replacement. Propensity scoring is a powerful tool that has the potential to reduce selection bias in nonrandomized studies. METHODS: From the BC Cardiac Registries, 2,060 patients presented for MV surgery, with or without CABG between 1991 and 2000. We then identified 322 MV repairs who were then matched by propensity score to an equal number of MV replacement patients. We compared survival and freedom from re-operation outcomes using Cox proportional hazards model analysis. Multivariable analysis was then used to compare outcomes in 358 MV repair patients with 352 MV replacement patients who had undergone chordal sparing surgery. RESULTS: The comparison groups generated using propensity scores were well balanced with respect to all collected baseline risk factors. Median follow-up time was 3.4 years. Patients undergoing MV repair had significantly improved survival (RR 0.46; 95% CI, 0.28 to 0.75) but a trend toward more re-operations (RR 2.11; 95% CI, 1.00 to 4.47) compared with patients undergoing replacement. Mitral valve repair patients still had better survival (RR 0.52; 95% CI, 0.32 to 0.85) compared with MV replacement patients who had undergone chordal sparing surgery. CONCLUSIONS: We used propensity score methods to reduce selection bias in a population-based cohort of patients undergoing MV repair/replacement. Repair was associated with better survival, but a trend to increased re-operation.