Faculty Bibliography

Acute type A aortic dissection is a life-threatening condition that confers significant early perioperative risk but is also associated with late aortic disease progression and the need for reintervention. Recent efforts to improve patient outcomes have focused on improving quality of care and extending treatment in the aortic root and arch to reduce late aortic events. The hybrid arch frozen elephant trunk technique facilitates a more aggressive distal aortic repair that may help mitigate the early and late deleterious effects of persistent false lumen perfusion. However, in the acute and emergency settings, management of the left subclavian artery remains a challenge. We present a step-by-step instructional guide on performing an emergency hybrid arch frozen elephant trunk procedure with emphasis on management of the difficult left subclavian artery. Our case report demonstrates a transthoracic aortoaxillary extra-anatomic bypass of the left axillary artery. We discuss the most important considerations when managing the left subclavian artery in an acute type A aortic dissection. Finally, we detail the benefits and limitations of the transthoracic aortoaxillary extra-anatomic technique and discuss other approaches to left subclavian artery reconstruction.

IMPORTANCE:Early data revealed a mortality rate of 1% to 2% per hour for type A acute aortic dissection (TAAAD) during the initial 48 hours. Despite advances in diagnostic testing and treatment, this mortality rate continues to be cited because of a lack of contemporary data characterizing early mortality and the effect of timely surgery. OBJECTIVE:To examine early mortality rates for patients with TAAAD in the contemporary era. DESIGN, SETTING, AND PARTICIPANTS:This cohort study examined data for patients with TAAAD in the International Registry of Acute Aortic Dissection between 1996 and 2018. Patients were grouped according to the mode of their intended treatment, surgical or medical. EXPOSURE:Surgical treatment. MAIN OUTCOMES AND MEASURES:Mortality was assessed in the initial 48 hours after hospital arrival using Kaplan-Meier curves. In-hospital complications were also evaluated. RESULTS:A total of 5611 patients with TAAAD were identified based on intended treatment: 5131 (91.4%) in the surgical group (3442 [67.1%] male; mean [SD] age, 60.4 [14.1] years) and 480 (8.6%) in the medical group (480 [52.5%] male; mean [SD] age, 70.9 [14.7] years). Reasons for medical management included advanced age (n = 141), comorbidities (n = 281), and patient preference (n = 81). Over the first 48 hours, the mortality for all patients in the study was 5.8%. Among patients who were medically managed, mortality was 0.5% per hour (23.7% at 48 hours). For those whose intended treatment was surgical, 48-hour mortality was 4.4%. In the surgical group, 51 patients (1%) died before the operation. CONCLUSIONS AND RELEVANCE:In this study, the overall mortality rate for TAAAD was 5.8% at 48 hours. For patients in the medical group, TAAAD had a mortality rate of 0.5% per hour (23.7% at 48 hours). However, among those in the surgical group, 48-hour mortality decreased to 4.4%.

BACKGROUND:Previous work has demonstrated that more than one-half of acute type A aortic dissections (ATADs) occur at a maximal aortic diameter (MAD) of <5.5 cm. However, no analysis has investigated whether ATAD risk at smaller MADs is more common with modest dilation of the aortic root (AR) or supracoronary ascending aorta (AA) in patients without genetically triggered aortopathy. OBJECTIVES:This study sought to determine if the segment of modest aortic dilation affects risk of ATAD. METHODS:Using the International Registry of Acute Aortic Dissection (IRAD) database from May 1996 to October 2016, we identified 667 ATAD patients with MAD <5.5 cm. Patients were stratified by location of the largest proximal aortic segment (AR or AA). Patients with known genetically triggered aortopathy were excluded. MADs at time of dissection were compared between AR and AA groups. Secondary outcomes included operation, postoperative outcomes, and long-term survival. RESULTS:Of patients with ATAD at an MAD <5.5 cm, 79.5% (n = 530) were in the AA group and 20.5% (n = 137) in the AR group. Modestly dilated ARs (median MAD 4.6 cm [IQR: 4.1-5.0 cm]) dissected at a significantly smaller diameter than modestly dilated AAs (median MAD 4.8 cm [IQR: 4.4-5.1 cm]) (P < 0.01). AR patients were significantly younger than AA patients (58.5 ± 13.0 years vs 63.2 ± 13.3 years; P < 0.01) and more commonly male (78% vs 65%; P < 0.01). Postoperative and long-term outcomes did not differ between groups. CONCLUSIONS:ATAD appears to occur at smaller diameters in patients with modest dilation in the AR vs the AA (4.6 vs 4.8 cm). These findings may have implications for future consensus guidelines regarding the management of patients with aortic disease.

AIMS:Transcatheter mitral valve implantation (TMVI) represents a novel treatment option for patients with mitral regurgitation (MR) unsuitable for established therapies. The CHOICE-MI registry aimed to investigate outcomes of patients undergoing screening for TMVI. METHODS AND RESULTS:From May 2014 to March 2021, patients with MR considered suboptimal candidates for transcatheter edge-to-edge repair (TEER) and at high risk for mitral valve surgery underwent TMVI screening at 26 centres. Characteristics and outcomes were investigated for patients undergoing TMVI and for TMVI-ineligible patients referred to bailout-TEER, high-risk surgery or medical therapy (MT). The primary composite endpoint was all-cause mortality or heart failure hospitalization after 1 year. Among 746 patients included (78.5 years, interquartile range [IQR] 72.0-83.0, EuroSCORE II 4.7% [IQR 2.7-9.7]), 229 patients (30.7%) underwent TMVI with 10 different dedicated devices. At 1 year, residual MR ≤1+ was present in 95.2% and the primary endpoint occurred in 39.2% of patients treated with TMVI. In TMVI-ineligible patients (n = 517, 69.3%), rates of residual MR ≤1+ were 37.2%, 100.0% and 2.4% after bailout-TEER, high-risk surgery and MT, respectively. The primary endpoint at 1 year occurred in 28.8% of patients referred to bailout-TEER, in 42.9% of patients undergoing high-risk surgery and in 47.9% of patients remaining on MT. CONCLUSION:This registry included the largest number of patients treated with TMVI to date. TMVI with 10 dedicated devices resulted in predictable MR elimination and sustained functional improvement at 1 year. In TMVI-ineligible patients, bailout-TEER and high-risk surgery represented reasonable alternatives, while MT was associated with poor clinical and functional outcomes.

OBJECTIVES/OBJECTIVE:Pulmonary homograft dysfunction is a limitation after the Ross procedure. Decellularized pulmonary homografts can potentially mitigate this complication. The aim of this study was to examine the incidence, predictors, progression, and morphology of pulmonary homograft dysfunction using data from the Canadian Ross Registry. METHODS:From 2011 to 2019, 466 consecutive patients (mean age: 47 ± 12 years, 73% male) underwent a Ross procedure using a decellularized cryopreserved pulmonary homograft (SynerGraft SG; CryoKife, Kennesaw, Ga). Pulmonary homograft dysfunction was defined as any of the following: peak pulmonary gradient ≥30 mm Hg, pulmonary regurgitation >2, or pulmonary homograft reintervention. Patients meeting ≥1 of these criteria (n = 30) were compared with the rest of the cohort (n = 436). Median follow-up is 2.2 years (maximum = 8.5 years) and 99% complete (1176 patient-years). RESULTS:The cumulative incidence of pulmonary homograft dysfunction was 11 ± 2% at 6 years. Pulmonary homograft stenosis was the most frequent presentation (n = 28 patients, 93%). Morphologically, stenosis occurred most often along the conduit (59%). Overall, 4 patients required homograft reintervention. At 6 years, the cumulative incidence of homograft reintervention was 3 ± 1%. The instantaneous risk was greatest in the first year after surgery (3.5%/year) and decreased to <1%/year thereafter. Patient age <45 years was the only independent risk factor associated with pulmonary homograft dysfunction (hazard ratio, 3.1, 95% confidence interval, 1.1-8.6, P = .03). CONCLUSIONS:The use of decellularized cryopreserved pulmonary homografts results in a low incidence of dysfunction and reintervention after the Ross procedure. The risk is greater in the first postoperative year. Younger age is the only independent risk factor for pulmonary homograft dysfunction.

OBJECTIVES:The aim of this study was to report the midterm outcomes at 1 year in the expanded first-in-human experience with the transfemoral EVOQUE system (Edwards Lifesciences) for tricuspid regurgitation (TR). BACKGROUND:Untreated TR is associated with excess mortality and morbidity. The first-in-human experience with the EVOQUE tricuspid valve replacement system reported favorable 30-day outcomes with no mortality in a compassionate use population. METHODS:Twenty-seven patients with severe TR were treated with the EVOQUE system in a compassionate use experience at 7 centers between May 2019 and July 2020. All patients had clinical right-sided heart failure (HF) and were deemed inoperable and unsuitable for transcatheter edge-to-edge repair by the institutional heart teams. The clinical outcomes collected included all-cause mortality, symptom status, TR severity, HF hospitalization, and major adverse cardiovascular events. RESULTS:At baseline, all patients (age: 77 ± 8 years, 89% female) were at high surgical risk (mean Society of Thoracic Surgeons score: 8.6% ± 5.5%), with 89% New York Heart Association functional class III/IV. TR was predominantly functional in etiology (19/27, 70%). At 1 year, mortality was 7% (2/27), 70% of patients were New York Heart Association functional class I/II, and 96% and 87% of patients had a TR grade ≤2+ and ≤1+, respectively. Between 30 days and 1 year, 2 patients experienced HF hospitalizations, and 1 patient required a new pacemaker implantation. CONCLUSIONS:In this early, compassionate use experience, the transfemoral transcatheter EVOQUE tricuspid valve replacement system demonstrated durable efficacy, persistent improvement in symptom status, and low rates of mortality and HF hospitalizations at a 1-year follow-up. Further studies are underway to validate its efficacy.

PURPOSE OF REVIEW:The purpose of this article is to review the contemporary evidence supporting valve-sparing aortic root replacement as the best option for patients with aortic root aneurysms and preservable aortic valves as well as to review the technical variations and modern adjuncts of these operations that impact both short and long-term durability. RECENT FINDINGS:In patients with an aortic root aneurysm, with or without aortic valve regurgitation, valve-sparing aortic root replacement provide excellent clinical outcomes and stable valve function over several decades. Successful execution of this operation depends on careful patient selection and a thorough understanding of the anatomical and physiological relationships between the various components of the aortic root. Echocardiography remains the mainstay of imaging to determine the feasibility of valve-sparing root replacement. SUMMARY:Valve-sparing aortic root replacement is an excellent alternative to composite valve graft replacement in nonelderly patients with aortic root aneurysms. Dedicated aortic root surgeons perform several technical variations of valve-sparing procedures aimed at matching the specific aortic root disorder with the optimal operation.