Ashley M. Lowry

Learning curves for transfemoral transcatheter aortic valve replacement in the PARTNER‐I trial: Success and safety

To identify number of cases needed to maximize device success and minimize adverse events after transfemoral transcatheter aortic valve replacement (TF‐TAVR), and determine if adverse events were linked to the technical performance learning curve.

Learning curves for transfemoral transcatheter aortic valve replacement in the PARTNER-I trial: Technical performance.

To assess technical performance learning curves of teams performing transfemoral transcatheter aortic valve replacement (TF‐TAVR).

Aortic Dissection in Patients With Bicuspid Aortic Valve-Associated Aneurysms.

BACKGROUND Data regarding the risk of aortic dissection in patients with bicuspid aortic valve and large ascending aortic diameter are limited, and appropriate timing of prophylactic ascending aortic replacement lacks consensus. Thus our objectives were to determine the risk of aortic dissection based on initial cross-sectional imaging data and clinical variables and to isolate predictors of aortic intervention in those initially prescribed serial surveillance imaging. METHODS From January 1995 to January 2014, 1,181 patients with bicuspid aortic valve underwent cross-sectional computed tomography (CT) or magnetic resonance imaging (MRI) to ascertain sinus or tubular ascending aortic diameter greater than or equal to 4.7 cm. Random Forest classification was used to identify risk factors for aortic dissection, and among patients undergoing surveillance, time-related analysis was used to identify risk factors for aortic intervention. RESULTS Prevalence of type A dissection that was detected by imaging or was found at operation or on follow-up was 5.3% (n = 63). Probability of type A dissection increased gradually at a sinus diameter of 5.0 cm--from 4.1% to 13% at 7.2 cm--and then increased steeply at an ascending aortic diameter of 5.3 cm--from 3.8% to 35% at 8.4 cm--corresponding to a cross-sectional area to height ratio of 10 cm(2)/m for sinuses of Valsalva and 13 cm(2)/m for the tubular ascending aorta. Cross-sectional area to height ratio was the best predictor of type A dissection (area under the curve [AUC] = 0.73). CONCLUSIONS Early prophylactic ascending aortic replacement in patients with bicuspid aortic valve should be considered at high-volume aortic centers to reduce the high risk of preventable type A dissection in those with aortas larger than approximately 5.0 cm or with a cross-sectional area to height ratio greater than approximately 10 cm(2)/m.

Beyond the Aortic Root: Staged Open and Endovascular Repair of Arch and Descending Aorta in Patients With Connective Tissue Disorders

BACKGROUND Improvements in care have prolonged survival of patients with connective tissue disorders (CTDs), but their entire native aorta remains at risk. Little data are available to guide treatment. Objectives were to characterize patients, describe repair methods, and assess outcomes. METHODS From 1996 to 2012, 527 patients with CTDs underwent cardiovascular operations. Beyond the root, arch and descending repair was performed in 121 patients (23%) for aneurysm (n = 17), acute complicated dissection (n= 5), or chronic dissection with aneurysmal degeneration (n = 99). CTD diagnoses included Marfan (n = 107), marfanoid (n = 7), Ehlers-Danlos (n = 4), and Loeys-Dietz (n = 3) syndromes. Eighty-seven (72%) had a previous ascending aorta repair, including 51 (57%) for type A dissection. Median interval to distal operation was 8.4 years. Index procedures for repair beyond the root were elephant trunk (ET) stage I (n = 63), open descending repair (n = 26), thoracoabdominal repair (n = 13), total arch replacement (n = 13), and stent-grafting (n = 6: frozen ET 3, thoracic endovascular aortic repair [TEVAR] 3). Median follow-up was 4.4 years. RESULTS Operative mortality was 2.5% (3 of 121). No paralysis occurred, but 3 patients (2.5%) had nonpermanent stroke, 4 (3.3%) required dialysis, 12 (10%) required tracheostomy, and 13 (11%) underwent reoperation for bleeding. During follow-up, 67 patients underwent 85 additional distal aortic procedures (58 open, 27 endovascular, 49 of which were stage II ET). By 10 years, probability of at least 1 reintervention was 61%. At 1, 5, and 10 years, estimated survival was 91%, 79%, and 62%, and event-free survival was 52%, 35%, and 24%, respectively. CONCLUSIONS Most patients with CTDs who require operations beyond the aortic root have aortic dissection and require multiple reinterventions. Staged repair strategies, including open repair in combination with TEVAR, are feasible, and benefits outweigh risks. These patients require lifelong imaging surveillance.

Early results of robotically assisted mitral valve surgery: Analysis of the first 1000 cases

Objective The study objective was to assess the technical and process improvement and clinical outcomes of robotic mitral valve surgery by examining the first 1000 cases performed in a tertiary care center. Methods We reviewed the first 1000 patients (mean age, 56 ± 10 years) undergoing robotic primary mitral valve surgery, including concomitant procedures (n = 185), from January 2006 to November 2013. Mitral valve disease cause was degenerative (n = 960, 96%), endocarditis (n = 26, 2.6%), rheumatic (n = 10, 1.0%), ischemic (n = 3, 0.3%), and fibroelastoma (n = 1, 0.1%). All procedures were performed via right chest access with femoral perfusion for cardiopulmonary bypass. Results Mitral valve repair was attempted in 997 patients (2 planned replacements and 1 resection of fibroelastoma), 992 (99.5%) of whom underwent valve repair, and 5 (0.5%) of whom underwent valve replacement. Intraoperative postrepair echocardiography showed that 99.7% of patients receiving repair (989/992) left the operating room with no or mild mitral regurgitation, and predischarge echocardiography showed that mitral regurgitation remained mild or less in 97.9% of patients (915/935). There was 1 hospital death (0.1%), and 14 patients (1.4%) experienced a stroke; stroke risk declined from 2% in the first 500 patients to 0.8% in the second 500 patients. Over the course of the experience, myocardial ischemic and cardiopulmonary bypass times (P < .0001), transfusion (P = .003), and intensive care unit and postoperative lengths of stay (P < .05) decreased. Conclusions Robotic mitral valve surgery is associated with a high likelihood of valve repair and low operative mortality and morbidity. The combination of algorithm‐driven patient selection and increased experience enhanced clinical outcomes and procedural efficiency.

Longitudinal Hemodynamics of Transcatheter and Surgical Aortic Valves in the PARTNER Trial

Importance Use of transcatheter aortic valve replacement (TAVR) for severe aortic stenosis is growing rapidly. However, to our knowledge, the durability of these prostheses is incompletely defined. Objective To determine the midterm hemodynamic performance of balloon-expandable transcatheter heart valves. Design, Setting, and Participants In this study, we analyzed core laboratory–generated data from echocardiograms of all patients enrolled in the Placement of Aortic Transcatheter Valves (PARTNER) 1 Trial with successful TAVR or surgical AVR (SAVR) obtained preimplantation and at 7 days, 1 and 6 months, and 1, 2, 3, 4, and 5 years postimplantation. Patients from continued access observational studies were included for comparison. Interventions Successful implantation after randomization to TAVR vs SAVR (PARTNER 1A; TAVR, n = 321; SAVR, n = 313), TAVR vs medical treatment (PARTNER 1B; TAVR, n = 165), and continued access (TAVR, n = 1996). Five-year echocardiogram data were available for 424 patients after TAVR and 49 after SAVR. Main Outcomes and Measures Death or reintervention for aortic valve structural indications, measured using aortic valve mean gradient, effective orifice area, Doppler velocity index, and evidence of hemodynamic deterioration by reintervention, adverse hemodynamics, or transvalvular regurgitation. Results Of 2795 included patients, the mean (SD) age was 84.5 (7.1) years, and 1313 (47.0%) were female. Population hemodynamic trends derived from nonlinear mixed-effects models showed small early favorable changes in the first few months post-TAVR, with a decrease of −2.9 mm Hg in aortic valve mean gradient, an increase of 0.028 in Doppler velocity index, and an increase of 0.09 cm2 in effective orifice area. There was relative stability at a median follow-up of 3.1 (maximum, 5) years. Moderate/severe transvalvular regurgitation was noted in 89 patients (3.7%) after TAVR and increased over time. Patients with SAVR showed no significant changes. In TAVR, death/reintervention was associated with lower ejection fraction, stroke volume index, and aortic valve mean gradient up to 3 years, with no association with Doppler velocity index or valve area. Reintervention occurred in 20 patients (0.8%) after TAVR and in 1 (0.3%) after SAVR and became less frequent over time. Reintervention was caused by structural deterioration of transcatheter heart valves in only 5 patients. Severely abnormal hemodynamics on echocardiograms were also infrequent and not associated with excess death or reintervention for either TAVR or SAVR. Conclusions and Relevance This large, core laboratory–based study of transcatheter heart valves revealed excellent durability of the transcatheter heart valves and SAVR. Abnormal findings in individual patients, suggestive of valve thrombosis or structural deterioration, were rare in this protocol-driven database and require further investigation. Trial Registration clinicaltrials.gov Identifier: NCT00530894

The Effect of Post-Exercise Ankle-Brachial Index on Lower Extremity Revascularization.

OBJECTIVES The purpose of this study was to investigate the effect of post-exercise ankle-brachial index (ABI) on the incidence of lower extremity (LE) revascularization, cardiovascular outcomes, and all-cause mortality in patients with normal and abnormal resting ABI. BACKGROUND The clinical and prognostic value of post-exercise ABI in the setting of normal or abnormal resting ABI remains uncertain. METHODS A total of 2,791 consecutive patients with ABI testing between September 2005 and January 2010 were classified into group 1: normal resting (NR)/normal post-exercise (NE); group 2: NR/abnormal post-exercise (AE); group 3: abnormal resting (AR)/NE; and group 4: AR/AE. Abnormal post-exercise ABI was defined as a drop of >20% from resting ABI as per the American College of Cardiology/American Heart Association guidelines. The primary endpoint was incidence of LE revascularization. Secondary endpoints were major adverse cardiovascular events (MACE) and all-cause mortality. Associations between post-exercise ABI and outcomes were adjusted using multivariable Cox proportional hazard and propensity analyses. RESULTS Compared with group 1 (NR/NE), group 2 (NR/AE) had increased LE revascularization (propensity-matched adjusted hazard ratio [HR]: 6.63, 95% confidence interval [CI]: 3.13 to 14.04; p < 0.001) but no differences in MACE or all-cause mortality. When resting ABI was abnormal, group 4 (AR/AE) compared with group 3 (AR/NE), abnormal post-exercise ABI was still associated with increased LE revascularization (adjusted HR: 1.59, 95% CI: 1.11 to 2.28; p = 0.01), which persisted after propensity matching (adjusted HR: 2.32, 95% CI: 1.52 to 3.54; p < 0.001). Compared with group 1 (NR/NE) and after propensity matching, group 4 (AR/AE) had a significant increase in MACE (adjusted HR: 1.44, 95% CI: 1.09 to 1.90; p = 0.009) and a trend toward increased all-cause mortality (adjusted HR: 1.37, 95% CI: 0.99 to 1.88; p = 0.052); however, group 3 (AR/NE) did not. CONCLUSIONS Post-exercise ABI appears to offer both clinical (lower extremity revascularization) and prognostic information in those with normal and abnormal resting ABI.

Tricuspid Regurgitation Associated With Ischemic Mitral Regurgitation: Characterization, Evolution After Mitral Surgery, and Value of Tricuspid Repair.

BACKGROUND Tricuspid regurgitation (TR) often accompanies ischemic mitral regurgitation and is generally assumed to be a secondary consequence of altered hemodynamics of the left-sided regurgitation. We hypothesized that it may also be a direct consequence of right-sided ischemic disease. Therefore, our objectives were to (1) characterize the nature of this TR and (2) describe its time course after mitral valve surgery for ischemic mitral regurgitation, with or without concomitant tricuspid valve repair. METHODS From 2001 to 2011, 568 patients with ischemic mitral regurgitation underwent mitral valve surgery. They had varying degrees of TR and altered right-side heart morphology and function; 131 had concomitant tricuspid valve repair. Postoperatively, 1,395 echocardiograms were available to assess residual and recurrent TR. RESULTS Greater severity of preoperative TR was accompanied by larger tricuspid valve diameter, greater leaflet tethering, worse right ventricular function, and higher right ventricular pressure (all p [trend] ≤ 0.002). Without tricuspid valve repair, 31% of patients with no preoperative TR had moderate or greater TR by 5 years, as did 62% with moderate TR. With tricuspid valve repair, 25% with moderate preoperative TR remained in that grade at 5 years, but 11% had severe TR. CONCLUSIONS Tricuspid regurgitation accompanying ischemic mitral regurgitation is associated with right-side heart remodeling and dysfunction often mirroring that occurring in the left side of the heart-ischemic TR. Tricuspid valve repair is effective initially, but as with mitral valve repair, TR progressively returns. Therefore, when the severity of TR and right-sided remodeling reaches the point of irreversibility, it may be an indication to eliminate the TR by replacing the tricuspid valve.

Robotic mitral valve repair for degenerative posterior leaflet prolapse

BACKGROUND Robotic mitral valve (MV) repair is the least invasive surgical approach to the MV and provides unparalleled access to the valve. We sought to assess technical aspects and clinical outcomes of robotic MV repair for isolated posterior leaflet prolapse by examining the first 623 such cases performed in a tertiary care center. METHODS We reviewed the first 623 patients (mean age 56±9.7 years) with isolated posterior leaflet prolapse who underwent robotic primary MV repair from 01/2006 to 11/2013. All procedures were performed via right chest access with femoral perfusion for cardiopulmonary bypass. RESULTS MV repair was attempted in all patients; 622 (99.8%) underwent MV repair and only 1 (0.2%) converted to replacement. After an initial attempt at robotic MV repair, 8 (1.3%) patients were converted to sternotomy as a result of management of residual mitral regurgitation (n=3), bleeding (n=1), difficulties with surgical exposure (n=2), aortic valve injury (n=1), and aortic dissection (n=1). Intraoperative post-repair echocardiography confirmed that all patients left the operating room with MR graded as mild or less, and pre-discharge echocardiography confirmed mild or less MR in 573 (99.1%). There was no hospital death, sternal wound infection, or renal failure. Seven (1.1%) patients suffered a stroke, 11 (1.8%) patients underwent re-exploration for bleeding, and 111 (19%) experienced new-onset atrial fibrillation. The mean intensive care unit length of stay and hospital length of stay were 29±17 hours and 4.6±1.6 days, respectively. CONCLUSIONS At a large tertiary care referral center, robotic MV repair for posterior prolapse is associated with zero mortality, infrequent operative morbidity, and near 100% successful repair. The combination of a patient selection algorithm and increased experience improved clinical outcomes and procedural efficiency.

Simple versus complex degenerative mitral valve disease

Objectives: At a center where surgeons favor mitral valve (MV) repair for all subsets of leaflet prolapse, we compared results of patients undergoing repair for simple versus complex degenerative MV disease. Methods: From January 1985 to January 2016, 6153 patients underwent primary isolated MV repair for degenerative disease, 3101 patients underwent primary isolated MV repair for simple disease (posterior prolapse), and 3052 patients underwent primary isolated MV repair for complex disease (anterior or bileaflet prolapse), based on preoperative echocardiographic images. Logistic regression analysis was used to generate propensity scores for risk‐adjusted comparisons (n = 2065 matched pairs). Durability was assessed by longitudinal recurrence of mitral regurgitation and reoperation. Results: Compared with patients with simple disease, those undergoing repair of complex pathology were more likely to be younger and female (both P values < .0001) but with similar symptoms (P = .3). The most common repair technique was ring/band annuloplasty (3055/99% simple vs 3000/98% complex; P = .5), followed by leaflet resection (2802/90% simple vs 2249/74% complex; P < .0001). Among propensity‐matched patients, recurrence of severe mitral regurgitation 10 years after repair was 6.2% for simple pathology versus 11% for complex pathology (P = .007), reoperation at 18 years was 6.3% for simple pathology versus 11% for complex pathology, and 20‐year survival was 62% for simple pathology versus 61% for complex pathology (P = .6). Conclusions: Early surgical intervention has become more common in patients with degenerative MV disease, regardless of valve prolapse complexity or symptom status. Valve repair was associated with similarly low operative risk and time‐related survival but less durability in complex disease. Lifelong annual echocardiographic surveillance after MV repair is recommended, particularly in patients with complex disease.