Twenty-five years of observations from the International Registry of Acute Aortic Dissection (IRAD) and its impact on the cardiovascular scientific community.

OBJECTIVE: The International Registry of Acute Aortic Dissection (IRAD) celebrated its 25th anniversary in January 2021. This study evaluated IRAD's role in promoting the understanding and management of acute aortic dissection (AD) over these years. METHODS: IRAD studies were identified, analyzed, and ranked according to their citations per year (c/y) to determine the most-cited IRAD studies and topics. A systematic search of the literature identified cardiovascular guidelines on the diagnosis and management of acute AD. Consequently, IRAD's presence and impact were quantified using these documents. RESULTS: Ninety-seven IRAD studies were identified, of which 82 obtained more than 10 cumulative citations. The median c/y index was 7.33 (25th-75th percentile, 4.01-16.65). Forty-two studies had a greater than median c/y index and were considered most impactful. Of these studies, most investigated both type A and type B AD (n = 17, 40.5%) and short-term outcomes (n = 26, 61.9%). Nineteen guideline documents were identified from 26 cardiovascular societies located in Northern America, Europe, and Japan. Sixty-nine IRAD studies were cited by these guidelines, including 38 of the 42 most-impactful IRAD studies. Among them, partial thrombosis of the false lumen as a predictor of postdischarge mortality and aortic diameters as a predictor of type A occurrence were determined as most-impactful specific IRAD topics by their c/y index. CONCLUSIONS: IRAD has had and continues to have an important role in providing observations, credible knowledge, and research questions to improve the outcomes of patients with acute AD.

Uncomplicated Type B Aortic Dissection: Challenges in Diagnosis and Categorization.

BACKGROUND: Acute type B aortic dissection (TBAD) is a rare disease that is likely under-diagnosed in the UK. As a progressive, dynamic clinical entity, many patients initially diagnosed with uncomplicated TBAD deteriorate, developing end-organ malperfusion and aortic rupture (complicated TBAD). An evaluation of the binary approach to the diagnosis and categorisation of TBAD is needed. METHODS: A narrative review of the risk factors predisposing patients to progression from unTBAD to coTBAD was undertaken. RESULTS: Key high-risk features predispose the development of complicated TBAD, such as maximal aortic diameter > 40 mm and partial false lumen thrombosis. CONCLUSION: An appreciation of the factors that predispose to complicated TBAD would aid clinical decision-making surrounding TBAD.

The genetic basis of thoracic aortic disease: The future of aneurysm classification?

The expansion in the repertoire of genes linked to thoracic aortic aneurysms (TAA) has revolutionised our understanding of the disease process. The clinical benefits of such progress are numerous, particularly helping our understanding of non-syndromic hereditary causes of TAA (HTAAD) and further refinement in the subclassification of disease. Furthermore, the understanding of aortic biomechanics and mechanical homeostasis has been significantly informed by the discovery of deleterious mutations and their effect on aortic phenotype. The drawbacks in genetic testing in TAA lie with the inability to translate genotype to accurate prognostication in the risk of thoracic aortic dissection (TAD), which is a life-threatening condition. Under current guidelines, there are no metrics by which those at risk for dissection with normal aortic diameters may undergo preventive surgery. Future research lies with more advanced genetic diagnosis of HTAAD and investigation of the diverse pathways involved in its pathophysiology, which will i) serve to improve our understanding of the underlying mechanisms, ii) improve guidelines for treatment and iii) prevent complications for HTAAD and sporadic aortopathies.

Current Understanding of Aortic Dissection.

The aorta is the largest artery in the body, delivering oxygenated blood from the left ventricle to all organs. Dissection of the aorta is a lethal condition caused by a tear in the intimal layer of the aorta, followed by blood loss within the aortic wall and separation of the layers to full dissection. The aorta can be affected by a wide range of causes including acute conditions such as trauma and mechanical damage; and genetic conditions such as arterial hypertension, dyslipidaemia, and connective tissue disorders; all increasing the risk of dissection. Both rapid diagnostic recognition and advanced multidisciplinary treatment are critical in managing aortic dissection patients. The treatment depends on the severity and location of the dissection. Open surgical repair is the gold standard of treatment for dissections located to the proximal part of the aorta and the arch, while endovascular interventions are recommended for most distal or type B aortic dissections. In this review article, we examine the epidemiology, pathophysiology, contemporary diagnoses, and management of aortic dissection.

Long-term outcomes of total arch replacement versus proximal aortic replacement in acute type A aortic dissection: Meta-analysis of Kaplan-Meier-derived individual patient data.

OBJECTIVES: To evaluate the long-term outcomes of a conservative approach (with proximal aortic replacement with or without hemiarch replacement) versus an aggressive approach (with total aortic arch replacement) in the treatment of acute type A aortic dissection (ATAAD). METHODS: We performed a pooled analysis of Kaplan-Meier-derived individual patient data from studies with follow-up comparing the aforementioned approaches to treat patients with ATAAD. RESULTS: Eighteen studies met our eligibility criteria, comprising 5243 patients with follow-up (Conservative: 3676 patients; Aggressive: 1567 patients). We observed a statistically significant difference in overall survival favoring the aggressive approach (hazard ratios [HR] 0.86, 95% confidence interval [CI] 0.76-0.98, p = .022), but no statistically significant difference in the risk of reoperation (HR 0.89, 95% CI 0.66-1.2, p = .439) in the overall follow-up. Landmark analyses revealed that, in the first 3 months after the procedure, mortality rates were comparable between conservative and aggressive approaches (HR 1.04, 95% CI 0.88-1.24, p = .627), but the results beyond 3 months showed improved survival in patients undergoing the aggressive surgical procedure (HR 0.71, 95% CI 0.59-0.85, p < .001). The landmark analyses also revealed that, in the first 7 years after the procedure, reoperation rates were comparable between the approaches (HR 1.03, 95% CI 0.76-1.40, p = .848), but the results beyond 7 years showed a lower risk of reoperation in patients undergoing the aggressive surgical procedure (HR 0.10, 95% CI 0.01-0.75, p = .025). CONCLUSION: The aggressive approach seems to confer better long-term survival and lower risk of the need for reoperation in the follow-up of patients treated for ATAAD.

Early Mortality in Type A Acute Aortic Dissection: Insights From the International Registry of Acute Aortic Dissection.

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%.

Transesophageal Ultrasound Guidance for Endovascular Interventions on the Aorta.

Aortic pathologies in general require a multidisciplinary approach and decision-making to integrate elements of clinical acuity, vascular pathology, individual comorbidity, and risk assessment; thus, ideally it is a center with access to multiple imaging modalities and expertise in all treatment options. Besides classic open surgical options, endovascular procedures have been accepted for a variety of aortic pathologies. More recently, novel transcatheter interventions even to the proximal aorta have been introduced, particularly for patients unfit for open surgery. Nevertheless, the role of transesophageal echocardiography to guide percutaneous aortic interventions is not well established, notwithstanding the growing potential as an ancillary tool to guide the procedure and document success.

Alternative management of proximal aortic dissection: concept and application.

Open surgery remains the mainstay of treatment for acute type A aortic dissection and should be offered to most patients. However, there are elderly patients in which surgical treatment may be deemed extremely high risk or futile. Endovascular treatment approaches have been applied to a small number of these patients and data are limited to case reports and small series. The application of endovascular therapies to ascending aorta is currently limited by anatomical and technical challenges posed by the dynamic motion of the ascending aorta and the proximity of vital structures to intended landing zones (aortic valve, coronary arteries, and supra-aortic branches) and lack of specially designed endografts to address these issues. While thoracic endovascular aortic repair (TEVAR) has replaced open aortic repair for a suitable lesion in distal aortic dissection, some selected patients with type A aortic dissection at high surgical may be candidates. Hence, there is potential because, in proximal (Stanford type A) dissections, 10-30% of patients are not accepted for surgery, and 30-50% are technically amenable for TEVAR. Recent experience has shown that carefully selected patients with favorable anatomical characteristics may be subject to endovascular stent-graft treatment as a last resort with mixed results. Technical improvement is necessary to offer. satisfactory endovascular options in non-surgical candidates.

Mid- and long-term outcomes of thoracic endovascular aortic repair in acute and subacute uncomplicated type B aortic dissection.

BACKGROUND: Uncomplicated type B aortic dissection (un-TBAD) has been managed conservatively with medical therapy to control the heart rate and blood pressure to limit disease progression, in addition to radiological follow-up. However, several trials and observational studies have investigated the use of thoracic endovascular aortic repair (TEVAR) in un-TBAD and suggested that TEVAR provides a survival benefit over medical therapy. Outcomes of TEVAR have also been linked with the timing of intervention. AIMS: The scope of this review is to collate and summarize all the evidence in the literature on the mid- and long-term outcomes of TEVAR in un-TBAD, confirming its superiority. We also aimed to investigate the relationship between the timing of TEVAR intervention and results. METHODS: We carried out a comprehensive literature search on multiple electronic databases including PubMed, Scopus, and EMBASE to collate and summarize all research evidence on the mid- and long-term outcomes of TEVAR in un-TBAD, as well as its relationship with intervention timing. RESULTS: TEVAR has proven to be a safe and effective tool in un-TBAD, offering superior mid- and long-term outcomes including all-cause and aorta-related mortality, aortic-specific adverse events, aortic remodeling, and need for reintervention. Additionally, performing TEVAR during the subacute phase of dissection seems to yield optimal results. CONCLUSION: The evidence demonstrating a survival advantage in favor TEVAR over medical therapy in un-TBAD means that with further research, particular trials and observational studies, TEVAR could become the gold-standard treatment option for un-TBAD patients.

Criteria for endovascular intervention in type B aortic dissection.

BACKGROUND: The use of thoracic endovascular aortic repair (TEVAR) for the management of uncomplicated type B aortic dissection (un-TBAD) remains controversial. There is a lack of consensus over whether pre-emptive TEVAR should be carried out in patients with un-TBAD at risk of progression to complicated TBAD. We present a review of current evidence and seek to suggest criteria where endovascular intervention in un-TBAD may prove beneficial relative to pharmacotherapy alone. METHODS AND MATERIALS: PubMed and Cochrane databases were searched using terms including: type B aortic dissection, risk factors, medical therapy, TEVAR, false lumen (FL) expansion, and mortality. Papers were selected based on title and abstract. RESULTS: Optimal medical therapy remains the mainstay treatment for patients with un-TBAD, however, patients with un-TBAD present with varying degrees of disease progression risk. Factors such as age, aortic morphology, history of connective tissue disorders, FL thrombosis, and aortic branch involvement may potentiate progression from un-TBAD to complicated TBAD. Short- and long-term outcomes associated with TEVAR for TBAD remain promising. CONCLUSION: Pre-emptive TEVAR may be beneficial in patients with un-TBAD presenting with the above factors, however, further prospective research into the optimal timing for TEVAR in un-TBAD is required.