Faculty Bibliography

OBJECTIVES/OBJECTIVE:The recommended extent of surgical resection and reconstruction of the arch in acute DeBakey Type I aortic dissection is an ongoing controversy. However, several recent reports indicate a trend towards a more extensive arch operation in several institutions. We have analysed the recent data from the International Registry of Acute Aortic Dissection to assess the choice of procedure over time and to evaluate the surgical outcome in a 'real-world' database. Our aim was to compare short- and mid-term outcomes of limited repairs versus complete arch surgery. METHODS:Of the 1241 patients included in the 'Interventional Cohort' of the International Registry of Acute Aortic Dissection from March 1996 to March 2015, 907 underwent ascending aortic or hemiarch replacement (Group A) and 334 had extended arch replacement (Group B). An extended resection was a surgeon's 'judgement call'. Logistic regression analysis, propensity-adjusted multivariable comparisons and Kaplan-Meier curves were used for analyses. RESULTS:Overall in-hospital mortality was 14.2% with no difference between groups (Group A 13.1%, Group B 17.1%). Coma/altered consciousness (odds ratio 3.16, 95% confidence interval 1.60-6.25, P = 0.001), hypotension, tamponade or shock (2.03, 1.11-3.73, P = 0.022) and any pulse deficit (1.92, 1.04-3.54, P = 0.038) were predictors of in-hospital mortality in a propensity score-adjusted multivariable analysis. Overall 5-year survival was 69.4% in the ascending group and 73.1% in the total arch group (P = 0.83 by Kaplan-Meier analysis). For survivors of the index hospitalization, the 5-year freedom from death, aortic rupture and reintervention were 71.1% in Group A and 76.4% in Group B (P = 0.54 by Kaplan-Meier analysis). CONCLUSIONS:Selective, or 'surgeon's choice', extended arch replacement had no discernible acute downside compared with less extensive surgery. Whether extended arch replacement improves the prognosis beyond 5 years remains to be settled.

BACKGROUND:Despite rapidly increasing use of TAVR across institutions, limited data is available for the effect of procedural experience on TAVR outcomes. We investigate the relationship between institutional experience and TAVR outcomes. METHODS:1953 patients undergoing TAVR at 8 international sites were grouped into chronological quantiles (Q) to assess temporal changes on procedural and clinical outcomes and multivariate logistic regression performed to determine predictors of device success, early safety and all-cause mortality. RESULTS:The mean age of patients was 81±7years and 991 (51%) were female. The quantiles comprised of first 62 cases for Q1, 63-133 for Q2, 134 to 242 for Q3 and 243 to 476 for Q4. Device success increased from Q1 to Q4 (78% vs 89%, p<0.001) with significant improvement in the early safety endpoint (19% vs 10%, p<0.001). All cause mortality reduced by half in Q4 compared to Q1 (8% vs 4%, p=0.01) and rates of major vascular complications, major bleeding and valve embolization decreased with increasing experience. The multivariate analysis identified TAVR in Q3 and Q4 to be independently associated with higher device success and lower risk of complications. TAVR in Q4 was independently associated with lower mortality (OR 0.36 95% CI 0.19-0.70, p=0.002). CONCLUSIONS:Greater institutional experience with TAVR procedures improves device success and clinical outcomes. An experience of >242 cases is independently associated with lower mortality. These findings have important implications for defining minimum volume criteria for institutions and training standards for TAVR procedure.

PURPOSE/OBJECTIVE:Suprasternal transcatheter aortic valve replacement offers patients, with unsuitable femoral artery anatomy, an alternative to transapical, direct aortic, and subclavian approaches. DESCRIPTION/METHODS:The Transit System (Aegis Surgical, Galway, Ireland) enables transcatheter aortic valve replacement directly into the ascending aorta or innominate artery through a small, suprasternal incision. The valve introducer sheath is inserted through a standard pursestring suture, which facilitates secure arterial closure. The proximity to the aortic valve promotes precise control. EVALUATION/RESULTS:Proper patient selection and preoperative imaging is essential. A heart team working collaboratively in a hybrid operating room ensures procedural success. Using this approach, four different manufacturer's transcatheter valves have been used successfully. CONCLUSIONS:Suprasternal transcatheter aortic valve replacement is a safe and effective addition to the surgeon's armamentarium.

OBJECTIVE:Our objective was to evaluate sex-differences in outcomes after trans-catheter aortic valve replacement (TAVR) in a population-based cohort from Ontario, Canada. BACKGROUND:Prior studies comparing outcomes in men and women after TAVR have yielded divergent results. Some studies have suggested that women have better survival than men while others have not corroborated this finding. METHODS:A retrospective observational cohort study was conducted using chart abstraction data on all TAVR procedures performed between 2007 and 2013 in Ontario, Canada. Patients who had emergency TAVR procedures were excluded. The primary outcome was all-cause mortality at 30-days and 1-year. Secondary outcomes included mortality at last follow-up, cause-specific, and all-cause hospital readmission. Inverse probability of treatment weighting (IPTW) using propensity score was used to adjust for baseline differences between men and women. RESULTS:The final study cohort consisted of 453 women and 546 men with a mean follow-up of 3.5 years. Women were generally older and more frail but had less comorbid conditions. Women had lower unadjusted mean EuroScores (7% ± 5% vs 8% ± 7%; P = 0.008), but underwent significantly more trans-apical procedures (26.5% vs 19.2%; P = 0.006) than men. After IPTW, the groups were well balanced. Although mortality was numerically higher for women at 30-days (7.2% vs 5.4%), this was not statistically significant (P = 0.34). At 1-year, there was no difference in mortality (18.2% vs 19.2%; P = 0.85). There were no significant differences in all-cause readmission. CONCLUSION/CONCLUSIONS:In this population-based cohort including all patients undergoing TAVR, mortality or all-cause readmission were not significantly different between men and women. © 2017 Wiley Periodicals, Inc.

OBJECTIVES:This study sought to determine late (2-year) outcomes following transcatheter mitral valve replacement (TMVR) with the FORTIS valve (Edwards Lifesciences, Irvine, California). BACKGROUND:No data exist on long-term clinical outcomes following TMVR in patients with severe native mitral regurgitation (MR). METHODS:This multicenter registry included consecutive patients with severe MR who underwent TMVR with the FORTIS valve under a compassionate clinical use program. Clinical and echocardiographic data were collected at baseline, 30-day, and 1- and 2-year follow-up. RESULTS:Thirteen patients (71 ± 8 years, 10 men, logistic European System for Cardiac Operative Risk Evaluation score = 23.7 ± 12.1%) with severe MR were included. MR was of ischemic origin in most (76.9%) patients, and the mean left ventricular ejection fraction was 34 ± 9%. Technical success was achieved in 10 patients (76.9%), and 5 patients (38.5%) died within the 30 days following the procedure. At 30-day follow-up, mean transmitral gradient was 3 ± 1 mm Hg, and there were no cases of moderate-severe residual MR or left ventricular outflow tract obstruction. Two patients died during the follow-up period due to terminal heart failure, leading to an all-cause mortality rate of 54% at 2-year follow-up. At 2-year follow-up, all patients but 1 were in New York Heart Association functional class II, and there were no cases of valve malfunction (increasing gradients or MR recurrence). Computed tomography exams performed at 2-year follow-up in 3 patients showed no valve prosthesis fractures or displacement. CONCLUSIONS:TMVR with the FORTIS valve was feasible. MR reduction after TMVR was maintained at 2-year follow-up and no late device-related events were observed.

BACKGROUND:Frailty is a geriatric syndrome that diminishes the potential for functional recovery after a transcatheter aortic valve replacement (TAVR) or surgical aortic valve replacement (SAVR) procedure; however, its integration in clinical practice has been limited by a lack of consensus on how to measure it. OBJECTIVES/OBJECTIVE:This study sought to compare the incremental predictive value of 7 different frailty scales to predict poor outcomes following TAVR or SAVR. METHODS:A prospective cohort of older adults undergoing TAVR or SAVR was assembled at 14 centers in 3 countries from 2012 to 2016. The following frailty scales were compared: Fried, Fried+, Rockwood, Short Physical Performance Battery, Bern, Columbia, and the Essential Frailty Toolset (EFT). Outcomes of interest were all-cause mortality and disability 1 year after the procedure. RESULTS:The cohort was composed of 1,020 patients with a median age of 82 years. Depending on the scale used, the prevalence of frailty ranged from 26% to 68%. Frailty as measured by the EFT was the strongest predictor of death at 1 year (adjusted odds ratio [OR]: 3.72; 95% confidence interval [CI]: 2.54 to 5.45) with a C-statistic improvement of 0.071 (p < 0.001) and integrated discrimination improvement of 0.067 (p < 0.001). Moreover, the EFT was the strongest predictor of worsening disability at 1 year (adjusted OR: 2.13; 95% CI: 1.57 to 2.87) and death at 30 days (adjusted OR: 3.29; 95% CI: 1.73 to 6.26). CONCLUSIONS:Frailty is a risk factor for death and disability following TAVR and SAVR. A brief 4-item scale encompassing lower-extremity weakness, cognitive impairment, anemia, and hypoalbuminemia outperformed other frailty scales and is recommended for use in this setting. (Frailty Assessment Before Cardiac Surgery & Transcatheter Interventions; NCT01845207).

To provide data on the management and outcomes of patients with acute retrograde aortic dissection (AD) originating from a tear in the descending aorta with extension into the aortic arch or ascending aorta. All patients enrolled in the International Registry of Acute Aortic Dissection from 1996-2015 were reviewed. Retrograde AD was defined by primary tear in the descending aorta with proximal extension into the arch or ascending aorta. Primary end points were in-hospital management strategy and mortality. We identified 101 patients with retrograde AD (67 men; 63.2 ± 14.0 years). During index hospitalization, medical (MED), open surgical (SURG), and endovascular (ENDO) therapies were undertaken in 44, 33, and 22 patients, respectively. The SURG group presented with larger ascending aorta (P = 0.04) and more frequent ascending aortic involvement (81.8% [27/33] vs 22.7% [15/66], P < 0.001) compared with the MED and ENDO groups. Early mortality rate was 9.1% (4/44), 18.2% (6/33), and 13.6% (3/22), for the MED, SURG, and ENDO groups (P = 0.51), respectively. A favorable early mortality rate was observed in patients with retrograde extension limited to the arch (8.6% [5/58]) vs into the ascending aorta (18.6% [8/43], P = 0.14). Early mortality rate of patients with retrograde AD with primary tear in the descending aorta (12.9% [13/101]) was significantly lower than those with classic type A AD presenting with primary tear in the ascending aorta (20.0% [195/977], P = 0.001). A subset of patients with acute retrograde AD originating from primary tear in the descending aorta might be managed less invasively with acceptable early results, particularly among those with proximal extension limited to the arch.

INTRODUCTION:Neurological injury remains the major cause of morbidity and mortality following open aortic arch repair. Systemic hypothermia along with antegrade cerebral perfusion (ACP) is the accepted cerebral protection approach, with axillary artery cannulation being the most common technique used to establish ACP. More recently, innominate artery cannulation has been shown to be a safe and efficacious method for establishing ACP. Inasmuch as there is a lack of high-quality data comparing axillary and innominate artery ACP, we have designed a randomised, multi-centre clinical trial to compare both cerebral perfusion strategies with regards to brain morphological injury using diffusion-weighted MRI (DW-MRI). METHODS AND ANALYSIS:110 patients undergoing elective aortic surgery with repair of the proximal arch requiring an open distal anastamosis will be randomised to either the innominate artery or the axillary artery cannulation strategy for establishing unilateral ACP during systemic circulatory arrest with moderate levels of hypothermia. The primary safety endpoint of this trial is the proportion of patients with new radiologically significant ischaemic lesions found on postoperative DW-MRI compared with preoperative DW-MRI. The primary efficacy endpoint of this trial is the difference in total operative time between the innominate artery and the axillary artery cannulation group. ETHICS AND DISSEMINATION:The study protocol and consent forms have been approved by the participating local research ethics boards. Publication of the study results is anticipated in 2018 or 2019. If this study shows that the innominate artery cannulation technique is non-inferior to the axillary artery cannulation technique with regards to brain morphological injury, it will establish the innominate artery cannulation technique as a safe and potentially more efficient method of antegrade cerebral perfusion in aortic surgery. TRIAL REGISTRATION NUMBER:NCT02554032.

Transcatheter aortic valve implantation (TAVI) is the treatment of choice for inoperable and high-risk patients with severe aortic stenosis. Our objectives were to elucidate potential differences in clinical outcomes and safety between balloon-expandable versus self-expandable transcatheter heart valves (THV). We performed a retrospective cohort study of all transfemoral TAVI procedures in Ontario, Canada, from 2007 to 2013. Patients were categorized into either balloon-expandable or self-expandable THV groups. The primary outcomes were 30-day and 1-year death, with secondary outcomes of all-cause readmission. Safety outcomes included bleeding, permanent pacemaker implantation, need for a second THV device, postprocedural paravalvular aortic regurgitation, stroke, vascular access complication, and intensive care unit length of stay. Inverse probability of treatment-weighted regression analyses using a propensity score were used to account for differences in baseline confounders. Our cohort consisted of 714 patients, of whom 397 received a self-expandable THV, whereas 317 had a balloon-expandable THV system. There were no differences in death or all-cause readmission. In terms of safety, the self-expandable group was associated with significantly higher rates of inhospital stroke (p value <0.05), need for a second THV device (5.3% vs 2.7%; p value = 0.013), and permanent pacemaker (22.6% vs 8.9%; p value <0.001), whereas the balloon-expandable group had more vascular access site complications (23.1% vs 16.7%; p value = 0.002). Thus, we found similar clinical outcomes of death or readmission for patients who underwent transfemoral TAVI with either balloon-expandable or self-expandable THV systems. However, there were important differences in their safety profiles.