Inconsistency in aortic stenosis severity between CT and echocardiography: prevalence and insights into mechanistic differences using computational fluid dynamics.

Objectives: The aims of this study were to evaluate the inconsistency of aortic stenosis (AS) severity between CT aortic valve area (CT-AVA) and echocardiographic Doppler parameters, and to investigate potential underlying mechanisms using computational fluid dynamics (CFD). Methods: A total of 450 consecutive eligible patients undergoing transcatheter AV implantation assessment underwent CT cardiac angiography (CTCA) following echocardiography. CT-AVA derived by direct planimetry and echocardiographic parameters were used to assess severity. CFD simulation was performed in 46 CTCA cases to evaluate velocity profiles. Results: A CT-AVA>1 cm2 was present in 23% of patients with echocardiographic peak velocity≥4 m/s (r=-0.33) and in 15% patients with mean Doppler gradient≥40 mm Hg (r=-0.39). Patients with inconsistent severity grading between CT and echocardiography had higher stroke volume index (43 vs 38 mL/m2, p<0.003) and left ventricular outflow tract (LVOT) flow rate (235 vs 192 cm3/s, p<0.001). CFD simulation revealed high flow, either in isolation (p=0.01), or when associated with a skewed velocity profile (p=0.007), as the main cause for inconsistency between CT and echocardiography. Conclusion: Severe AS by Doppler criteria may be associated with a CT-AVA>1 cm2 in up to a quarter of patients. CFD demonstrates that haemodynamic severity may be exaggerated on Doppler analysis due to high LVOT flow rates, with or without skewed velocity profiles, across the valve orifice. These factors should be considered before making a firm diagnosis of severe AS and evaluation with CT can be helpful.

Right atrial and ventricular echocardiographic strain analysis predicts requirement for right ventricular support after left ventricular assist device implantation.

Aims: The need for right ventricular assist device (RVAD) support after left ventricular assist device (LVAD) therapy is associated with increased morbidity and mortality. We used 2D echocardiographic strain analysis to assess right atrial (RA) and right ventricular (RV) mechanics and predict the need for RV mechanical support after LVAD implantation. Methods and results: Seventy advanced chronic heart failure (ACHF) patients [59 male, age 47 ± 12 years, 79% dilated cardiomyopathy, left ventricular ejection fraction 23 ± 10%] received continuous-flow LVAD as a bridge to transplantation over an 18 month period. A retrospective analysis of RV and RA strain and right heart dyssynchrony was performed comparing those requiring RVAD (20%, n = 14) with those who did not (non-RVAD 80%, n = 56). One-year survival was significantly lower in the RVAD group (50% vs. 79%; P < 0.03). Independent predictors of RVAD support were: low peak RA longitudinal strain (RALS) [odds ratio (OR) 2.5, 95% confidence interval (95% CI) 1.37-2.0; P = 0.03], low RV free-wall longitudinal strain (RVFWLS) (OR 1.3, 95% CI 1.03-2.3; P = 0.04), and degree of intra-RV dyssynchrony (DRVFW-IVS, OR 1.3, 95% CI 1.02-1.3; P = 0.04). Conclusion: In LVAD recipients needing RVAD support, there was lower RALS and RVFWLS in addition to greater RV free-wall mechanical delay. We conclude that RA and RV strain and dyssynchrony analysis have the potential to add incremental value to the pre-VAD-implantation assessment made using conventional echo measurements.

Real-world comparison of the new 34 mm self-expandable transcatheter aortic prosthesis Evolut R to its 31 mm core valve predecessor.

OBJECTIVES: The aim of the present study was to compare the incidence of periprocedural complications and short-term outcomes between the second-generation recapturable 34 mm Evolut-R and its first-generation 31 mm predecessor. BACKGROUND: Although already in extensive clinical use in real world patients, the periprocedural complications and clinical outcomes of the new 34 mm device have not been investigated yet. METHODS: Consecutive patients who had undergone transcatheter aortic valve implantation in two centers with either a 31 mm CoreValve or a 34 mm Evolut-R device were retrospectively studied. Periprocedural complications of malpositioning, valve-in-valve implantation, conversion to full sternotomy or percutaneous coronary intervention and vascular complications were compared between the two groups. Short-term outcomes at discharge were compared using Valve Academic Research Consortium (VARC-2) criteria. RESULTS: The study group included 106 patients (35 Evolut-R 34 mm; 71 CoreValve 31 mm). Significantly lower rates of valve-in-valve implantation were demonstrated for the 34 mm group compared to the first-generation device (0% vs. 11.9%, respectively, P = 0.036). All other periprocedural complications were similar between groups. At discharge, the rates of new pacemaker implantation (5.7% vs. 26.8%, P = 0.037) and bleeding complications (2.9% vs. 19.6%, P = 0.025) were statistically significantly lower among the 34 mm group. With regards to VARC-2 defined combined endpoints, rates of early safety were significantly improved among the 34 mm group compared to 31 mm group (0% vs. 27.9%, respectively, P = 0.004). CONCLUSIONS: The recently introduced 34 mm Evolut-R seems to demonstrate an improved safety profile, as evidenced by the reduced bleeding rates, lower rates of valve-in-valve implantation and lower PPM rates compared to its 31 mm predecessor.

Effect of Aortic Valve Calcium Quantity on Outcome After Balloon Aortic Valvuloplasty for Severe Aortic Stenosis.

Balloon aortic valvuloplasty has a role in a select group of patients with severe aortic stenosis. Identifying those appropriate patients who will benefit most is key. Given previous evidence demonstrating that histologically the intervention involves a physical disrupting of the cusp's calcium we hypothesized that the quantity of calcium seen at CT will influence outcome. We examined our cohort of patients who had undergone balloon aortic valvuloplasty and CT-quantified aortic valve calcium (AVC) between July 2011 and April 2014. All patients underwent echocardiography pre- and post-procedure and for those patients managed medically, again at 6 months. A potential predictive AVC value for mortality was calculated using Youden's index. A total of 240 aortic valvuloplasties were performed in 206 patients (male = 124). Valvuloplasty caused a significant (pre 0.63 ± 0.21 vs post 0.77 ± 0.27 cm2, p <0.01, n = 240), but temporary (post 0.80 ± 0.27 vs 6 months: 0.64 ± 0.18 cm2, p <0.01, n = 88) increase in valve area. Those patients with a non-severe AVC (<1853.5 AU) had a larger increase in valve area after valvuloplasty compared with those with more calcium (0.10 [95% confidence interval {CI} 0.05 to 0.10] vs 0.15 [95%CI 0.10 to 0.22] cm2, p = 0.049). Multivariate analysis revealed severe AVC (Hazard ratio 2.79, 95% CI 1.18 to 6.63, p = 0.02) along with pulmonary artery pressure post-valvuloplasty (Hazard ratio 1.02, 95% CI 1.00 to 1.03, p = 0.03) to be predictive of survival. In conclusion, in patients with severe aortic stenosis the degree of AVC impacts on the success of valvuloplasty.

Imaging diagnoses and outcome in patients presenting for primary angioplasty but no obstructive coronary artery disease.

OBJECTIVE: A proportion of patients with suspected ST-elevation myocardial infarction (STEMI) presenting for primary percutaneous coronary intervention (PPCI) do not have obstructive coronary disease and other conditions may be responsible for their symptoms and ECG changes. In this study, we set out to determine the prevalence and aetiology of alternative diagnoses in a large PPCI cohort as determined with multimodality imaging and their outcome. METHODS: From 2009 to 2012, 5238 patients with suspected STEMI were referred for consideration of PPCI. Patients who underwent angiography but had no culprit artery for revascularisation and no previous history of coronary artery disease were included in the study. Troponin values, imaging findings and all-cause mortality were obtained from hospital and national databases. RESULTS: A total of 575 (13.0%) patients with a mean age of 58±15 years (69% men) fulfilled the inclusion criteria. A specific diagnosis based on imaging was made in 237 patients (41.2%) including cardiomyopathies (n=104, 18%), myopericarditis (n=48, 8.4%), myocardial infarction/other coronary abnormality (n=27, 4.9%) and severe valve disease (n=23, 4%). Pulmonary embolism and type A aortic dissection were identified in seven (1.2%) and four (0.7%) cases respectively. A total of 40 (7.0%) patients died over a mean follow-up of 42.6 months. CONCLUSIONS: A variety of cardiac and non-cardiac conditions are prevalent in patients presenting with suspected STEMI but culprit-free angiogram, some of which may have adverse outcomes. Further imaging of such patients could thus be useful to help in appropriate management and follow-up.

Does postoperative blood pressure influence development of aortic regurgitation following continuous-flow left ventricular assist device implantation?†.

OBJECTIVES: The true impact of postoperative blood pressure (BP) control on development of aortic regurgitation (AR) following continuous-flow left ventricular assist device (CF-LVAD) implantation remains uncertain. This study examines the influence of BP in patients with de novo AR following CF-LVAD implantation. METHODS: All patients with no or

Classification of Aortic Stenosis by Flow and Gradient Patterns Provides Insights into the Pathophysiology of Disease.

Different patterns of flow and valve gradients can lead to diagnostic uncertainty about the severity of aortic stenosis (AS). Consecutive patients with severe AS (valve area <1 cm(2)) underwent echocardiography and computed tomography. Patients were classified into 4 groups (high-gradient/normal flow [HGNF], high-gradient/low flow [HGLF], low-gradient/normal flow [LGNF], and low-gradient/low flow [LGLF]). Low flow was defined as stroke volume index <35 mL/m(2) and low gradient as a mean aortic gradient <40 mm Hg. Aortic valve calcification (AVC) was calculated using the Agatston score. Of 181 patients, 56, 30, 46, and 49 had HGNF, HGLF, LGNF and LGLF with median AVC of 2048, 2015, 1366, and 1178 AU/m(2) (P < .0001) and valvuloarterial impedance of 4.5, 6.4, 4.2, and 5.9, respectively (P < .0001). Among those with LGLF, AVC was lower in patients with preserved compared to reduced left ventricular ejection fraction (1018 vs 2550 AU/m(2); P < .0001), but valvuloarterial impedance was similar (P = .33). The LGLF AS with preserved ejection fraction is associated with lower AVC and may identify patients with less severe AS in association with an adaptive ventricular response to high afterload.

Preoperative predictors and outcomes of right ventricular assist device implantation after continuous-flow left ventricular assist device implantation.

OBJECTIVE: The outcomes of ventricular assist device therapy remain limited by right ventricular failure. We sought to define the predictors and evaluate the outcomes of right ventricular failure requiring right ventricular assist device support after long-term continuous-flow left ventricular assist device implantation. METHODS: Records of all continuous-flow left ventricular assist device recipients for the last 10 years were analyzed, including patients on preoperative intra-aortic balloon pump, extracorporeal membrane oxygenation, and short-term ventricular assist device support. Perioperative clinical, echocardiographic, hemodynamic, and laboratory data of continuous-flow left ventricular assist device recipients requiring right ventricular assist device support (right ventricular assist device group) were compared with the rest of the patient cohort (control group). RESULTS: Between July 2003 and June 2013, 152 patients underwent continuous-flow left ventricular assist device implantation as a bridge to transplantation. The overall postoperative incidence of right ventricular assist device support was 23.02% (n = 35). Right ventricular assist device implantation did not significantly affect eventual transplantation (P = .784) or longer-term survival (P = .870). Preoperative right ventricular diameter (P < .001), tricuspid annular plane systolic excursion (P < .001), previous sternotomy (P = .002), preoperative short-term mechanical support (P = .005), left atrial diameter (P = .014), female gender (P = .020), age (P = .027), and preoperative bilirubin levels (P = .031) were univariate predictors of right ventricular assist device implantation. Multivariate analysis revealed lesser tricuspid annular plane systolic excursion (P = .013; odds ratio, 0.613; 95% confidence interval, 0.417-0.901) and smaller left atrial diameter (P = .007; odds ratio, 0.818; 95% confidence interval, 0.707-0.947) as independent predictors of right ventricular assist device implantation. Receiver operating characteristic curve of tricuspid annular plane systolic excursion yielded an area under the curve of 0.85 (95% confidence interval, 0.781-0.923), with cutoff tricuspid annular plane systolic excursion less than 12.5 mm having 84% sensitivity and 75% specificity. CONCLUSIONS: Lesser tricuspid annular plane systolic excursion and smaller left atrial diameter are independent predictors of the need for right ventricular assist device support after continuous-flow left ventricular assist device implantation. Right ventricular assist device implantation does not adversely affect eventual transplantation or survival after continuous-flow left ventricular assist device implantation.

De novo aortic regurgitation after continuous-flow left ventricular assist device implantation.

BACKGROUND: Significant aortic regurgitation (AR) after continuous-flow left ventricular assist device (cf-LVAD) placement affects device performance and patient outcomes. This study examined the development of AR and long-term results after implantation of cf-LVADs. METHODS: The study included all patients with no or less than mild AR who underwent HeartMate II (58 [62%]; Thoratec Corp, Pleasanton, CA) or HeartWare (35 [38%]; HeartWare International, Framingham, MA) implantation at our institute from July 2006 to July 2012. Serial echocardiograms were obtained preoperatively, at 1, 3 and 6 months postoperatively, and then at a minimum of 4-month intervals in patients with longer-term support. Kaplan-Meier estimates for freedom from moderate or greater AR were generated. Logistic regression analysis was used to define independent predictors of AR after cf-LVAD implantation. RESULTS: Median duration of LVAD support was 527 days (25(th), 75(th): 289, 907; range, 60 to 2,433 days). Mild AR developed in 48 patients (51.6%) over a median duration of 126 days, with progression to moderate AR in 13 (14%) over 493 days and to severe AR in 2 (2.1%) over 1,231 days. The incidence of mild or greater AR was 43.1% in HeartMate II vs 65.7% in HeartWare recipients (p = 0.035). Overall freedom from moderate or greater AR was 94.7% ± 2.6% at 1 year, 86.9% ± 4.5% at 2 years, 82.8% ± 5.9% at 3 years, and 31% ± 16.9% at 4 years. Independent predictors of AR were duration of support (odds ratio, 1.002; 95% confidence interval, 1.000 to 1.004; p = 0.017) and a persistently closed aortic valve (odds ratio, 0.193; 95% confidence interval, 0.097 to 0.382; p < 0.001). CONCLUSIONS: AR is associated with longer cf-LVAD support duration and persistent aortic valve closure. Incidence of moderate or greater AR after cf-LVAD implantation increases significantly after 3 years. The clinical implications of these data may warrant consideration of prophylactic aortic valve replacement at the time of cf-LVAD implantation, particularly with expected longer duration of support and in patients with preexisting AR that is more than mild.

A randomized trial to assess catheter ablation versus rate control in the management of persistent atrial fibrillation in heart failure.

OBJECTIVES: This study sought to compare catheter ablation with rate control for persistent atrial fibrillation (AF) in heart failure (HF). BACKGROUND: The optimal therapy for AF in HF is unclear. Drug-based rhythm control has not proved clinically beneficial. Catheter ablation improves cardiac function in patients with HF, but impact on physiological performance has not been formally evaluated in a randomized trial. METHODS: In a randomized, open-label, blinded-endpoint clinical trial, adults with symptomatic HF, radionuclide left ventricular ejection fraction (EF) ≤35%, and persistent AF were assigned to undergo catheter ablation or rate control. Primary outcome was 12-month change in peak oxygen consumption. Secondary endpoints were quality of life, B-type natriuretic peptide, 6-min walk distance, and EF. Results were analyzed by intention-to-treat. RESULTS: Fifty-two patients (age 63 ± 9 years, EF 24 ± 8%) were randomized, 26 each to ablation and rate control. At 12 months, 88% of ablation patients maintained sinus rhythm (single-procedure success 68%). Under rate control, rate criteria were achieved in 96%. The primary endpoint, peak oxygen consumption, significantly increased in the ablation arm compared with rate control (difference +3.07 ml/kg/min, 95% confidence interval: 0.56 to 5.59, p = 0.018). The change was not evident at 3 months (+0.79 ml/kg/min, 95% confidence interval: -1.01 to 2.60, p = 0.38). Ablation improved Minnesota score (p = 0.019) and B-type natriuretic peptide (p = 0.045) and showed nonsignificant trends toward improved 6-min walk distance (p = 0.095) and EF (p = 0.055). CONCLUSIONS: This first randomized trial of ablation versus rate control to focus on objective exercise performance in AF and HF shows significant benefit from ablation, a strategy that also improves symptoms and neurohormonal status. The effects develop over 12 months, consistent with progressive amelioration of the HF syndrome. (A Randomised Trial to Assess Catheter Ablation Versus Rate Control in the Management of Persistent Atrial Fibrillation in Chronic Heart Failure; NCT00878384).

Coronary artery bypass surgery with or without mitral valve annuloplasty in moderate functional ischemic mitral regurgitation: final results of the Randomized Ischemic Mitral Evaluation (RIME) trial.

BACKGROUND: The role of mitral valve repair (MVR) during coronary artery bypass grafting (CABG) in patients with moderate ischemic mitral regurgitation (MR) is uncertain. We conducted a randomized, controlled trial to determine whether repairing the mitral valve during CABG may improve functional capacity and left ventricular reverse remodeling compared with CABG alone. METHODS AND RESULTS: Seventy-three patients referred for CABG with moderate ischemic MR and an ejection fraction >30% were randomized to receive CABG plus MVR (34 patients) or CABG only (39 patients). The study was stopped early after review of interim data. At 1 year, there was a greater improvement in the primary end point of peak oxygen consumption in the CABG plus MVR group compared with the CABG group (3.3 mL/kg/min versus 0.8 mL/kg/min; P<0.001). There was also a greater improvement in the secondary end points in the CABG plus MVR group compared with the CABG group: left ventricular end-systolic volume index, MR volume, and plasma B-type natriuretic peptide reduction of 22.2 mL/m(2), 28.2 mL/beat, and 557.4 pg/mL, respectively versus 4.4 mL/m(2) (P=0.002), 9.2 mL/beat (P=0.001), and 394.7 pg/mL (P=0.003), respectively. Operation duration, blood transfusion, intubation duration, and hospital stay duration were greater in the CABG plus MVR group. Deaths at 30 days and 1 year were similar in both groups: 3% and 9%, respectively in the CABG plus MVR group, versus 3% (P=1.00) and 5% (P=0.66), respectively in the CABG group. CONCLUSIONS: Adding mitral annuloplasty to CABG in patients with moderate ischemic MR may improve functional capacity, left ventricular reverse remodeling, MR severity, and B-type natriuretic peptide levels, compared with CABG alone. The impact of these benefits on longer term clinical outcomes remains to be defined.

Truly stentless autologous pericardial aortic valve replacement: an alternative to standard aortic valve replacement.

OBJECTIVE: The aim of this study was to determine the feasibility and durability of truly stentless aortic valve replacement using autologous pericardium sutured directly onto the aortic wall. METHODS: Eleven patients (mean age, 55.9 years) requiring aortic valve replacement were recruited. A circular piece of pericardium about 8 cm in diameter was harvested and treated in 0.6% glutaraldehyde for 10 minutes. The aortic valve was excised and, with the use of specially designed instruments (CardioMend LLC, Santa Barbara, Calif), the sinotubular junction was sized and the pericardium was tailored to the required size and shape and then sutured directly onto the aortic wall. The reconstructed valve was assessed directly and by echocardiography at the end of the operation; it was assessed by echocardiography and cardiac magnetic resonance imaging at 6 months and yearly. Computed tomographic scan of the aortic valve to assess for valve calcification was performed at last follow-up. RESULTS: Hospital mortality was 0%. Mean follow-up was 6.5 years (range, 5.3-7.5 years). Freedom from structural valve deterioration, thromboembolism, endocarditis and reoperation was 100%, 100%, 72.7%, and 63.6%, respectively. There were 4 reoperations at 4, 13, 15, and 46 months, 3 of them owing to endocarditis and 1 owing to technical failure noted at the time of surgery. The remaining 7 patients are alive and well with a mean New York Heart Association class of 1.3 and normally functioning aortic valves with no calcification. CONCLUSIONS: Truly stentless aortic valve replacement using autologous pericardium sutured directly onto the aortic wall is safe and feasible and has excellent durability up to 7.5 years with no calcification.

Towards comprehensive assessment of mitral regurgitation using cardiovascular magnetic resonance.

Cardiovascular magnetic resonance (CMR) is increasingly used to assess patients with mitral regurgitation. Its advantages include quantitative determination of ventricular volumes and function and the mitral regurgitant fraction, and in ischemic mitral regurgitation, regional myocardial function and viability. In addition to these, identification of leaflet prolapse or restriction is necessary when valve repair is contemplated. We describe a systematic approach to the evaluation of mitral regurgitation using CMR which we have used in 149 patients with varying etiologies and severity of regurgitation over a 15 month period. Following standard ventricular cine acquisitions, including 2, 3 and 4 chamber long axis views and a short axis stack for biventricular function, we image movements of all parts of the mitral leaflets using a contiguous stack of oblique long axis cines aligned orthogonal to the central part of the line of coaptation. The 8-10 slices in the stack, orientated approximately parallel to a 3-chamber view, are acquired sequentially from the superior (antero-lateral) mitral commissure to the inferior (postero-medial) commissure, visualising each apposing pair of anterior and posterior leaflet scallops in turn (A1-P1, A2-P2 and A3-P3). We use balanced steady state free precession imaging at 1.5 Tesla, slice thickness 5 mm, with no inter-slice gaps. Where the para-commissural coaptation lines curve relative to the central region, two further oblique cines are acquired orthogonal to the line of coaptation adjacent to each commissure. To quantify mitral regurgitation, we use phase contrast velocity mapping to measure aortic outflow, subtracting this from the left ventricular stroke volume to calculate the mitral regurgitant volume which, when divided by the left ventricular stroke volume, gives the mitral regurgitant fraction. In patients with ischemic mitral regurgitation, we further assess regional left ventricular function and, with late gadolinium enhancement, myocardial viability. Comprehensive assessment of mitral regurgitation using CMR is feasible and enables determination of mitral regurgitation severity, associated leaflet prolapse or restriction, ventricular function and viability in a single examination and is now routinely performed at our centre. The mitral valve stack of images is particularly useful and easy to acquire.