Alison Duncan

Transcatheter Aortic Valve Implantation in the United Kingdom Temporal Trends, Predictors of Outcome, and 6-Year Follow-Up: A Report From the UK Transcatheter Aortic Valve Implantation (TAVI) Registry, 2007 to 2012

Background— We assessed trends in the performance of transcatheter aortic valve implantation in the United Kingdom from the first case in 2007 to the end of 2012. We analyzed changes in case mix, complications, outcomes to 6 years, and predictors of mortality. Methods and Results— Annual cohorts were examined. Mortality outcomes were analyzed in the 92% of patients from England and Wales for whom independent mortality tracking was available. A total of 3980 transcatheter aortic valve implantation procedures were performed. In successive years, there was an increase in frequency of impaired left ventricular function, but there was no change in Logistic EuroSCORE. Overall 30-day mortality was 6.3%; it was highest in the first cohort (2007–2008), after which there were no further significant changes. One-year survival was 81.7%, falling to 37.3% at 6 years. Discharge by day 5 rose from 16.7% in 2007 and 2008 to 28% in 2012. The only multivariate preprocedural predictor of 30-day mortality was Logistic EuroSCORE ≥40. During long-term follow-up, multivariate predictors of mortality were preprocedural atrial fibrillation, chronic obstructive pulmonary disease, creatinine >200 μmol/L, diabetes mellitus, and coronary artery disease. The strongest independent procedural predictor of long-term mortality was periprocedural stroke (hazard ratio=3.00; P <0.0001). Nonfemoral access and postprocedural aortic regurgitation were also significant predictors of adverse outcome. Conclusions— We analyzed transcatheter aortic valve implantation in an entire country, with follow-up over 6 years. Although clinical profiles of enrolled patients remained unchanged, longer-term outcomes improved, and patients were discharged earlier. Periprocedural stroke, nonfemoral access, and postprocedural aortic regurgitation are predictors of adverse outcome, along with intrinsic patient risk factors. # CLINICAL PERSPECTIVE {#article-title-29}Background— We assessed trends in the performance of transcatheter aortic valve implantation in the United Kingdom from the first case in 2007 to the end of 2012. We analyzed changes in case mix, complications, outcomes to 6 years, and predictors of mortality. Methods and Results— Annual cohorts were examined. Mortality outcomes were analyzed in the 92% of patients from England and Wales for whom independent mortality tracking was available. A total of 3980 transcatheter aortic valve implantation procedures were performed. In successive years, there was an increase in frequency of impaired left ventricular function, but there was no change in Logistic EuroSCORE. Overall 30-day mortality was 6.3%; it was highest in the first cohort (2007–2008), after which there were no further significant changes. One-year survival was 81.7%, falling to 37.3% at 6 years. Discharge by day 5 rose from 16.7% in 2007 and 2008 to 28% in 2012. The only multivariate preprocedural predictor of 30-day mortality was Logistic EuroSCORE ≥40. During long-term follow-up, multivariate predictors of mortality were preprocedural atrial fibrillation, chronic obstructive pulmonary disease, creatinine >200 &mgr;mol/L, diabetes mellitus, and coronary artery disease. The strongest independent procedural predictor of long-term mortality was periprocedural stroke (hazard ratio=3.00; P<0.0001). Nonfemoral access and postprocedural aortic regurgitation were also significant predictors of adverse outcome. Conclusions— We analyzed transcatheter aortic valve implantation in an entire country, with follow-up over 6 years. Although clinical profiles of enrolled patients remained unchanged, longer-term outcomes improved, and patients were discharged earlier. Periprocedural stroke, nonfemoral access, and postprocedural aortic regurgitation are predictors of adverse outcome, along with intrinsic patient risk factors.

Relation of biventricular function quantified by stress echocardiography to cardiopulmonary exercise capacity in adults with Mustard (atrial switch) procedure for transposition of the great arteries.

Background—Mustard repair for transposition of the great arteries (TGA) is frequently associated with impaired systemic (right) ventricular function and sometimes exercise intolerance. We hypothesized that a simple quantitative measurement of ventricular function, during rest and pharmacological stress, could identify abnormalities and predict objective exercise capacity. Methods and Results—We quantified the performance of systemic and pulmonary (left) ventricles by using echocardiography, at rest and during dobutamine stress, in 27 adults who had undergone Mustard repair for TGA. Systolic and diastolic function of the systemic ventricle were markedly disturbed with respect to pulmonary ventricular function. We also measured exercise capacity by cardiopulmonary exercise testing for peak oxygen uptake. Exercise capacity was significantly predicted by systemic ventricular long-axis excursion both at rest (r=0.66, P<0.001) and at peak dobutamine stress (r=0.53, P=0.006) but not by pulmonary ventricular long-axis excursion at rest (r=0.04) or on stress (r=0.11). Exercise capacity was also predicted by the septal long-axis excursion at rest (r=0.61, P=0.001) but not pulmonary ventricular free wall excursion (P>0.05) or fractional shortening (P>0.05). Peak aortic velocity at maximum dobutamine stress correlated with exercise capacity (r=0.46, P=0.029) but not at rest (r=0.36). Multivariate analysis revealed systemic ventricular long-axis excursion to be the sole significant independent predictor of exercise capacity. Conclusions—Systemic ventricular function is depressed in most patients with Mustard repair. Quantitative echocardiographic evaluation shows systemic ventricular function to be a key determinant of exercise capacity.

Differentiation of Ischemic From Nonischemic Cardiomyopathy During Dobutamine Stress by Left Ventricular Long-Axis Function Additional Effect of Left Bundle-Branch Block

Background—Resting regional wall-motion abnormalities do not reliably distinguish ischemic from nonischemic cardiomyopathy. Dobutamine stress echocardiography with use of the wall-motion score index (WMSI) identifies coronary artery disease (CAD) in dilated cardiomyopathy (DCM), but the technique is subjective and further complicated by left bundle-branch block (LBBB). Long-axis motion is sensitive to ischemia and can be assessed quantitatively. We aimed to compare long-axis function with WMSI for detecting CAD in DCM with or without LBBB. Methods and Results—Seventy-three patients with DCM, 48 with CAD (16 with LBBB), and 25 without CAD (10 with LBBB) were studied. Long-axis M-mode, pulsed-wave tissue Doppler echograms (lateral, septal, and posterior walls), and WMSI were assessed at rest and at peak dobutamine stress. Failure to increase systolic amplitude (total amplitude minus postejection shortening) by 2 mm or early diastolic velocity by 1.1 cm/s was the best discriminator for CAD (systolic amplitude, sensitivity 85%, specificity 86%; lengthening velocity, 71% and 94%, respectively; P =NS). Both had greater predictive accuracy than did WMSI (sensitivity 67%, specificity 76%; P <0.001). The predictive accuracy of changes in septal long-axis function was similar to those of average long-axis function (systolic amplitude cutoff=1.5 mm, lengthening velocity cutoff=1.5 cm/s). However in LBBB, systolic amplitude proved to be the only significant discriminator for CAD, with sensitivity and specificity reaching 94% and 100%, respectively (P <0.01 versus early diastolic lengthening velocity). Conclusions—Quantified stress long-axis function identifies CAD in DCM with greater sensitivity and specificity than does standard WMSI, particularly in the presence of LBBB.

Limitation of cardiac output by total isovolumic time during pharmacologic stress in patients with dilated cardiomyopathy: Activation-mediated effects of leftbundle branch block and coronary artery disease

OBJECTIVES We sought to separate the effects of associated left bundle branch block (LBBB) and coronary artery disease (CAD) on peak cardiac output (CO) during dobutamine stress in patients with dilated cardiomyopathy (DCM). BACKGROUND The mechanisms limiting CO during stress in patients with DCM are unclear. Both LBBB and CAD may do so by prolonging the total isovolumic time (t-IVT). METHODS A total of 59 patients with DCM-34 with CAD (20 normal activation [NA], 14 LBBB) and 25 without CAD (15 NA, 10 LBBB)-were studied. The total IVT (s/min; calculated as: 60 - [total ejection time + total filling time] ) and CO were measured by Doppler echocardiography. RESULTS At rest, t-IVT was 8 s/min longer with LBBB (p < 0.001), was unaffected by CAD, and did not correlate with rest CO. During stress, CO correlated with t-IVT (r = -0.73, p < 0.001) in all four patient groups. In the absence of CAD, t-IVT became shortened (NA by 7 +/- 3 s/min; LBBB by 9 +/- 4 s/min) and correlated with a fall in the QRS duration (NA: r = 0.87; LBBB: r = 0.91), and CO increased with stress (NA by 4.7 +/- 2.7 l/min; LBBB by 4.0 +/- 2.3 l/min; all p < 0.001). With CAD, t-IVT did not shorten normally with stress. Instead, t-IVT was 5.6 s/min longer and CO was 3.3 l/min lower than in those without CAD (both p < 0.001), and t-IVT did not correlate with the QRS duration. CONCLUSIONS In patients with DCM, t-IVT during pharmacologic stress depends on changes in ventricular activation induced by LBBB or CAD and is, by itself, a major determinant of peak CO during stress.

Transcatheter Replacement of Failed Bioprosthetic Valves: Large Multicenter Assessment of the Effect of Implantation Depth on Hemodynamics After Aortic Valve-in-Valve

Background—Transcatheter valve implantation inside failed bioprosthetic surgical valves (valve-in-valve [ViV]) may offer an advantage over reoperation. Supra-annular transcatheter valve position may be advantageous in achieving better hemodynamics after ViV. Our objective was to define targets for implantation that would improve hemodynamics after ViV. Methods and Results—Cases from the Valve-in-Valve International Data (VIVID) registry were analyzed using centralized core laboratory assessment blinded to clinical events. Multivariate analysis was performed to identify independent predictors of elevated postprocedural gradients (mean ≥20 mm Hg). Optimal implantation depths were defined by receiver operating characteristic curve. A total of 292 consecutive patients (age, 78.9±8.7 years; 60.3% male; 157 CoreValve Evolut and 135 Sapien XT) were evaluated. High implantation was associated with significantly lower rates of elevated gradients in comparison with low implantation (CoreValve Evolut, 15% versus 34.2%; P=0.03 and Sapien XT, 18.5% versus 43.5%; P=0.03, respectively). Optimal implantation depths were defined: CoreValve Evolut, 0 to 5 mm; Sapien XT, 0 to 2 mm (0–10% frame height); sensitivities, 91.3% and 88.5%, respectively. The strongest independent correlate for elevated gradients after ViV was device position (high: odds ratio, 0.22; confidence interval, 0.1–0.52; P=0.001), in addition to type of device used (CoreValve Evolut: odds ratio, 0.5; confidence interval, 0.28–0.88; P=0.02) and surgical valve mechanism of failure (stenosis/mixed baseline failure: odds ratio, 3.12; confidence interval, 1.51–6.45; P=0.002). Conclusions—High implantation inside failed bioprosthetic valves is a strong independent correlate of lower postprocedural gradients in both self- and balloon-expandable transcatheter valves. These clinical evaluations support specific implantation targets to optimize hemodynamics after ViV.

Electromechanical interrelations during dobutamine stress in normal subjects and patients with coronary artery disease: comparison of changes in activation and inotropic state

OBJECTIVE To identify the effects of altered ventricular activation during dobutamine stress on left ventricular function in normal subjects and in patients with coronary artery disease, and to distinguish these from an inotropic response. DESIGN Prospective analysis of 12 lead ECG and echocardiogram at rest and at peak stress. SETTING Tertiary referral centre for cardiac disease equipped with non-invasive facilities for pharmacological stress testing. METHODS 22 patients with coronary artery disease were compared with 17 age matched controls. Left ventricular ejection and filling patterns were assessed using Doppler echocardiography. Activation effects were correlated with relative left ventricular ejection and filling times, and the Z ratio ([left ventricular ejection + filling times]/RR interval). Inotropic response was measured from peak aortic acceleration. RESULTS In controls, QRS shortened (by 4 ms, p < 0.001), and total ejection and filling periods lengthened (by 2 s/min, p < 0.01 and 5 s/min, p < 0.001, respectively). The Z ratio thus increased and correlated with QRS shortening (r 2 = 0.69). Peak aortic acceleration (PAA) increased by 135%, p < 0.001. In patients, QRS lengthened at peak stress (by 9 ms, p < 0.001). Total ejection and filling times did not change, but Z ratio fell, correlating with QRS prolongation (r 2 = 0.65). Nevertheless, PAA increased by 63%, p < 0.001. CONCLUSIONS Relative ejection and filling times reflect ventricular activation at rest and during stress independent of changes in inotropic state. By contrast, peak aortic acceleration reflects the positive inotropic effect of dobutamine on the myocardium, regardless of changes in activation.

Longitudinal study of the profile and predictors of left ventricular mass regression after stentless aortic valve replacement.

BACKGROUND The aim of this study was to evaluate the long-term profile and determine the factors that would influence the effect and rate of ventricular mass regression with time after aortic valve replacement with a stentless or a homograft valve. METHODS We studied 300 patients during a 10-year period with at least a year of follow-up with a total of 1,273 serial echocardiographic measurements. Left ventricular mass was calculated from M-mode recordings and indexed to body surface area. Longitudinal data analysis was performed using a linear mixed effects model. RESULTS The mean age (+/- standard deviation) was 65 (+/-14) years, consisting of 216 (72%) males. A stentless valve was implanted in 156 (52%), and a homograft in 144 (48%). The median time (interquartile range) to follow-up was 4.7 (2.8 to 6.6) years. The greatest rate of left ventricular mass regression occurred in the first year after surgery. On multivariable modeling, independent predictors of left ventricular mass were valve size (p = 0.011), left ventricular function (moderate impairment, p = 0.418; severe impairment, p = 0.011), and baseline left ventricular mass (middle tercile, p < 0.001; highest tercile, p < 0.001). Only baseline ventricular mass influenced the rate of subsequent left ventricular mass regression; the greatest rate of regression occurred in patients with the highest baseline values of ventricular mass (p < 0.001). CONCLUSIONS The greatest rate of left ventricular mass regression occurs in the first year with baseline left ventricular mass as the strongest predictor and the only identified variable that influenced the rate of left ventricular mass regression.

Valve-in-valve transcatheter aortic valve implantation for failing surgical aortic stentless bioprosthetic valves: A single-center experience

BACKGROUND Valve-in-valve (ViV) transcatheter aortic implantation (TAVI) is an alternative to redo surgery for patients with a failing aortic bioprosthesis. A lack of anatomic markers may complicate the procedure. This study reports procedural and midterm outcomes of patients undergoing ViV-TAVI for failing stentless bioprostheses, at a single institution. METHODS A total of 22 consecutive patients with failing homograft (n = 17), stented porcine valve (n = 3), aortic root bioprosthesis (n = 1), or native resuspended aortic valve (n = 1) (aged 74 ± 12 years; Society of Thoracic Surgeons 30-day predicted risk of mortality score: 14% ± 8%) were treated with ViV-TAVI, between 2007 and 2014. All had severe aortic regurgitation and were highly symptomatic before TAVI: 41% had chronic kidney disease; 32% had undergone previous coronary bypass grafts; 27% had previous percutaneous coronary intervention; 14% had severe pulmonary disease; 14% had had a stroke. All underwent TAVI with a self-expanding device. RESULTS The 30-day mortality was 0%. No cases occurred of myocardial infarction, tamponade, stroke, severe bleeding, acute kidney injury, or major vascular complications. Three instances of device migration, and 1 of device embolization, occurred. Permanent pacing was required in 14%. Paravalvular aortic regurgitation was absent or mild in 19, and mild to moderate in 3. Average hospital stay was 8 ± 3 days; all patients were discharged home. Six-month and 1-year mortality was 4.8% and 14.3%, respectively. Aortic valve area and paravalvular aortic regurgitation were unchanged at 1 year. CONCLUSIONS The ViV-TAVI procedure may be performed in high-risk patients with a degenerate stentless bioprosthesis with low 30-day mortality, and 1-year mortality of 14.3%. Although technically challenging, owing to a lack of anatomic markers, satisfactory positioning is possible in most cases, with excellent clinical and echocardiographic outcomes.

Transcatheter Mitral Valve Replacement for the Treatment of Mitral Regurgitation : In-Hospital Outcomes of an Apically Tethered Device

Mitral regurgitation (MR) is a leading cause of valvular heart disease. Although conventional mitral valve surgery is the gold standard, as many as 49% of patients with severe MR may not undergo conventional surgery [(1)][1]. Following on from the successful roll out of transcatheter aortic valve

Beta-blocker therapy for dynamic left-ventricular outflow tract obstruction.

BACKGROUND In a small but significant group of elderly patients who present with breathlessness, dynamic left-ventricular outflow tract obstruction (DLVOTO) may be responsible for symptom generation. The aim of our study was to investigate the effect of beta-blockade on ventricular physiology and symptoms in patients with DLVOTO. METHODS We performed a pilot study in 15 patients (age 76+/-10 years, mean+/-S.D., 14 female) with symptoms of exercise intolerance (New York Heart Association, NYHA, class 2.7+/-0.5). All patients had normal resting left ventricular (LV) systolic function together with DLVOTO based on the presence of basal septal hypertrophy and the development of high outflow tract velocities on stress echocardiography. All were commenced on oral atenolol (mean dose 45+/-19 mg), but this could not be tolerated in four patients due to a deterioration in clinical status. RESULTS In the remaining 11 patients who could tolerate atenolol therapy, the rate pressure product was significantly lower (23%, P=0.028) and there was a marked reduction in LV outflow tract velocity (23%, P=0.001) following beta-blockade. Patient symptoms improved significantly following atenolol therapy, with a reduction in mean NYHA class from 2.8+/-0.4 to 1.5+/-0.5 (P<0.0001). CONCLUSIONS Beta-blockade may represent a beneficial therapeutic approach in selected patients with DLVOTO as identified by stress echocardiography.