Natural history of moderately dilated tubular ascending aorta: implications for determining the optimal imaging interval

ERS/ESTS/ESTRO/ESR/ESTI/EFOMP statement on management of incidental findings from low dose CT screening for lung cancer

BACKGROUND

Screening for lung cancer with low radiation dose computed tomography has a strong evidence base, is being introduced in several European countries and is recommended as a new targeted cancer screening programme. The imperative now is to ensure that implementation follows an evidence-based process that will ensure clinical and cost effectiveness. This European Respiratory Society (ERS) task force was formed to provide an expert consensus for the management of incidental findings which can be adapted and followed during implementation.

METHODS

A multi-European society collaborative group was convened. 23 topics were identified, primarily from an ERS statement on lung cancer screening, and a systematic review of the literature was conducted according to ERS standards. Initial review of abstracts was completed and full text was provided to members of the group for each topic. Sections were edited and the final document approved by all members and the ERS Science Council.

RESULTS

Nine topics considered most important and frequent were reviewed as standalone topics (interstitial lung abnormalities, emphysema, bronchiectasis, consolidation, coronary calcification, aortic valve disease, mediastinal mass, mediastinal lymph nodes and thyroid abnormalities). Other topics considered of lower importance or infrequent were grouped into generic categories, suitable for general statements.

CONCLUSIONS

This European collaborative group has produced an incidental findings statement that can be followed during lung cancer screening. It will ensure that an evidence-based approach is used for reporting and managing incidental findings, which will mean that harms are minimised and any programme is as cost-effective as possible.

ERS/ESTS/ESTRO/ESR/ESTI/EFOMP statement on management of incidental findings from low dose CT screening for lung cancer

BACKGROUND

Screening for lung cancer with low radiation dose computed tomography has a strong evidence base, is being introduced in several European countries and is recommended as a new targeted cancer screening programme. The imperative now is to ensure that implementation follows an evidence-based process that will ensure clinical and cost effectiveness. This European Respiratory Society (ERS) task force was formed to provide an expert consensus for the management of incidental findings which can be adapted and followed during implementation.

METHODS

A multi-European society collaborative group was convened. 23 topics were identified, primarily from an ERS statement on lung cancer screening, and a systematic review of the literature was conducted according to ERS standards. Initial review of abstracts was completed and full text was provided to members of the group for each topic. Sections were edited and the final document approved by all members and the ERS Science Council.

RESULTS

Nine topics considered most important and frequent were reviewed as standalone topics (interstitial lung abnormalities, emphysema, bronchiectasis, consolidation, coronary calcification, aortic valve disease, mediastinal mass, mediastinal lymph nodes and thyroid abnormalities). Other topics considered of lower importance or infrequent were grouped into generic categories, suitable for general statements.

CONCLUSIONS

This European collaborative group has produced an incidental findings statement that can be followed during lung cancer screening. It will ensure that an evidence-based approach is used for reporting and managing incidental findings, which will mean that harms are minimised and any programme is as cost-effective as possible.

Prevalence and determinants of dilated ascending aorta in a Swedish population: a case-control study

Aims

Dilation of the ascending aorta (AA) is often asymptomatic until a life-threatening dissection or rupture occurs. An overall increase in the use of thoracic imaging has enabled early and sometimes incidental identification of AA dilation. Still, the prevalence and determinants of AA dilation remain to be clarified. The aim was to identify and characterize persons with AA dilation in a middle-aged Swedish population.

Methods and results

We used the Swedish CardioPulmonary BioImage Study Linköping (n = 5058, age 50-65 years) to identify cases with AA diameter ≥ 40 mm on coronary computed tomography angiography (CCTA) or chest computed tomography. Age- and gender-matched individuals with AA diameter < 40 mm served as controls. Echocardiography, blood pressure (BP) measurements (office and home), pulse wave velocity (PWV), coronary artery calcification (CAC), CCTA-detected coronary atherosclerosis, and carotid ultrasound were used to characterize these subjects. We identified 70 cases (mean AA diameter 44 mm, 77% men) and matched these to 146 controls (mean AA diameter 34 mm). Bicuspid aortic valve and aortic valve dysfunction were more common in cases than in controls (8% vs. 0% and 39% vs. 11%, respectively). Both office and home BP levels were significantly higher among cases. Also, high PWV (>10 m/s) levels were more common in cases (33% vs. 17%). Neither CAC scores nor prevalence or burden of atherosclerosis in coronary and carotid arteries differed between groups.

Conclusion

The prevalence of dilated AA was 1.4% and showed positive associations with male gender, aortic valve pathology, and diastolic BP, though not with subclinical atherosclerosis.

Cost-effectiveness of Follow-up CT for Incidental Ascending Aortic Dilatation

Purpose

To evaluate the cost-effectiveness of CT follow-up strategies for incidental aortic dilatation.

Materials and Methods

In this cost-effectiveness analysis, a simulation model was developed with 1 000 000 adult patients aged 55-75 years with incidentally detected dilated aortas measuring 40-50 mm. Follow-up CT strategies were evaluated for various patient age- and aortic size-based cutoffs. Follow-up frequency ranged from 1 to 3 years, as well as a single follow-up CT examination at 1 year. Patient survival was determined by risk of aortic dissection or rupture and surgical- and age-based mortality. Costs and quality-adjusted life-years (QALYs) were calculated for each strategy within the simulated cohort. A probabilistic sensitivity analysis was performed by varying model parameters.

Results

The cost-effective strategy with the highest QALYs under a willingness-to-pay threshold of $100 000 per QALY was follow-up CT for patients younger than 60 years with aortas measuring at least 40 mm in diameter every 3 years (incremental cost-effectiveness ratio, $62 511; 95% CI: $52 168, $77 739). With this strategy, follow-up imaging was needed for only 17% of dilated aortas in the cohort. Probabilistic sensitivity analysis demonstrated that the cost-effective strategies at $100 000 per QALY threshold included the following: no follow-up for patients with aortas smaller than 50 mm (39% of simulations), follow-up every 3 years for patients younger than 55 years with aortas measuring at least 45 mm (21%), and follow-up every 3 years for patients older than 65 years with aortas measuring at least 40 mm (14%).

Conclusion

Follow-up CT for an incidentally detected dilated ascending aorta smaller than 50 mm is likely not cost-effective in patients older than 60-65 years.Keywords: CT, Thorax, Vascular, Aorta, Cost-Effectiveness, Cost-Benefit Analysis Supplemental material is available for this article. © RSNA, 2023See also commentary by Shen and Fleischmann in this issue.

The impact of prophylactic ascending aortic replacement on the long-term prognosis of hybrid arch repair

OBJECTIVES

To investigate the impact of prophylactic zone 0 replacement with prosthetic grafts on the long-term prognosis and perioperative safety of zone 0 hybrid arch repair (HAR) when zone 0 is neither dilated nor pathologic.

METHODS

115 patients whose zone 0 aorta was neither dilated nor pathologic and who underwent zone 0 HAR from January 2009 to December 2020 were retrospectively reviewed, and divided into two groups depending on whether zone 0 was replaced, with 46 patients in the no-replacement group and 69 patients in the replacement group. Inverse probability of treatment weighting (IPTW) was used to balance the baseline difference, and outcomes were compared after IPTW adjustment. The primary endpoints were overall survival and adverse aortic events (AAEs). The secondary endpoints were early composite adverse events and other perioperative complications. Subgroup analysis was performed by age, diagnosis, zone 0 maximum diameter and risk stratification.

RESULTS

The 5-year IPTW-adjusted overall survival rate was 84% in the no-replacement group, 90% in the replacement group, respectively (P=.61). With death as a competing risk, the IPTW-adjusted cumulative incidence of AAEs at 5 and 10 years was 23% and 41% in the no-replacement group, and 14% and 25% in the replacement group, respectively (sHR=0.56, 95%CI=0.23∼1.39; P=.23). Considering proximal complications alone, the replacement group exhibited lower 5-year (3% vs 18%) and 10-year (6% vs 36%) cumulative incidences of proximal complications (sHR=0.11, 95%CI=0.01∼0.91, P=.04) after IPTW adjustment. Subgroup analysis demonstrated that the benefits of zone 0 replacement in reducing AAEs were observed in the age≤60-year-old (sHR=0.15, 95%CI=0.03∼0.75, P=.02) and type B aortic dissection (TBAD) (sHR=0.24, 95%CI=0.07∼0.82, P=.02) subgroups. Additionally, zone 0 replacement did not increase early composite adverse event morbidity (9% vs 21%, P=.08) or early mortality (7% vs 6%, P=.87).

CONCLUSIONS

Although zone 0 was neither dilated nor pathologic, prophylactic zone 0 replacement in zone 0 HAR significantly reduced the incidence of proximal complications, without impairing perioperative safety. Additionally, this strategy was associated with benefits in reducing AAEs in younger and TBAD patients. Thus, prophylactic zone 0 replacement should be considered for reconstructing a stable proximal landing zone in zone 0 HAR.

Aortic Dilatation in Patients With Bicuspid Aortic Valve

Bicuspid aortic valve (BAV) is the most common congenital cardiac abnormality. BAV aortic dilatation is associated with an increased risk of adverse aortic events and represents a potentially lethal disease and hence a considerable medical burden. BAV with aortic dilatation warrants frequent monitoring, and elective surgical intervention is the only effective method to prevent dissection or rupture. The predictive value of the aortic diameter is known to be limited. The aortic diameter is presently still the main reference standard for surgical intervention owing to the lack of a comprehensive understanding of BAV aortopathy progression. This article provides a brief comprehensive review of the current knowledge on BAV aortopathy regarding clinical definitions, epidemiology, natural course, and pathophysiology, as well as hemodynamic and clinically significant aspects on the basis of the limited data available.

Determining the optimal interval for imaging surveillance of ascending aortic aneurysms

Background

Cardiovascular guidelines recommend (bi-)annual computed tomography (CT) or magnetic resonance imaging (MRI) for surveillance of the diameter of thoracic aortic aneurysms (TAAs). However, no previous study has demonstrated the necessity for this approach. The current study aims to provide patient-specific intervals for imaging follow-up of non-syndromic TAAs.

Methods

A total of 332 patients with non-syndromic ascending aortic aneurysms were followed over a median period of 6.7 years. Diameters were assessed using all available imaging techniques (echocardiography, CT and MRI). Growth rates were calculated from the differences between the first and last examinations. The diagnostic accuracy of follow-up protocols was calculated as the percentage of subjects requiring pre-emptive surgery in whom timely identification would have occurred.

Results

The mean growth rate in our population was 0.2 ± 0.4 mm/year. The highest recorded growth rate was 2.0 mm/year, while 40.6% of patients showed no diameter expansion during follow-up. Females exhibited significantly higher growth rates than men (0.3 ± 0.5 vs 0.2 ± 0.4 mm/year, p = 0.007). Conversely, a bicuspid aortic valve was not associated with more rapid aortic growth. The optimal imaging protocol comprises triennial imaging of aneurysms 40–49 mm in diameter and yearly imaging of those measuring 50–54 mm. This strategy is as accurate as annual follow-up, but reduces the number of imaging examinations by 29.9%.

Conclusions

In our population of patients with non-syndromic TAAs, we found aneurysm growth rates to be lower than those previously reported. Yearly imaging does not lead to changes in the management of small aneurysms. Thus, lower imaging frequencies might be a good alternative approach.

A "sneaky" symptom of aortic dissection. Brief literature review, physiopathology and diagnostic tools management

Aortic diseases cover a large spectrum of conditions, such as aortic aneurysm and acute aortic syndromes (i.e., dissections, intramural hematoma, penetrating atherosclerotic ulcer, traumatic aortic injuries, and pseudoaneurysms), genetic diseases (e.g., Marfan syndrome) and congenital abnormalities, such as coarctation of the aorta. These conditions may have an acute presentation; thus, if the acute aortic syndrome is the first sign of the disease, the prognosis is extremely poor. Prompt diagnosis and timely therapy are therefore mandatory. In this paper, we discuss a deceptive symptom of painless aortic dissection and its physiopathology. Furthermore, we briefly review the literature and discuss the management of diagnostic tools.

New indicators for systematic assessment of aortic morphology: a narrative review

In order to prevent the occurrence of aortic adverse events in ascending thoracic aortic aneurysm patients, preventive surgery is the sole option in case of large aneurysm. Identifying high-risk patients timely and accurately requires effective predictive indicators of aortic adverse events and accurate risk stratification thresholds. Absolute diameter measured after a single imaging examination, which has been used as the predictive indicator for decades, has been proved to be ineffective for risk stratification in moderately dilated aorta. Previously, new indicators combining absolute diameters with personalized parameters have been reported to show better predictive power of aortic adverse events than absolute diameters by correcting the effect of these parameters on the diameters. Meanwhile, combining three-dimensional parameters to formulate risk stratification thresholds not only may characterize the aortic risk morphology more precisely, but also predict aortic adverse events more accurately. These new indicators may provide more systematic assessment methods of patients’ risk, formulate more personalized intervention strategies for ascending thoracic aortic aneurysm patients, and also provide a basis for researchers to develop more accurate and effective risk thresholds. We also highlight that the algorithm obtained by combining multiple indicators may be a better choice compared with single indicator, but this still requires the support of more evidence. Due to the particularity of syndromic aortic disease, whether these new indicators can be used for its risk stratification is still uncertain. Therefore, the scope of this manuscript does not include this kind of disease.

Association of Mortality and Acute Aortic Events With Ascending Aortic Aneurysm: A Systematic Review and Meta-analysis

IMPORTANCE

The natural history of ascending aortic aneurysm (AsAA) is currently not well characterized.

OBJECTIVE

To summarize and analyze existing literature on the natural history of AsAA.

DATA SOURCES

A search of Ovid MEDLINE (January 1, 1946, to May 31, 2017) and Embase (January 1, 1974, to May 31, 2017) was conducted.

STUDY SELECTION

Studies including patients with AsAA were considered for inclusion; studies were excluded if they considered AsAA, arch, and descending thoracic aneurysm as 1 entity or only included descending aneurysms, patients with heritable or genetic-related aneurysms, patients with replaced bicuspid aortic valves, patients with acute aortic syndrome, or those with mean age less than 16 years. Two independent reviewers identified 20 studies from 7198 unique studies screened.

DATA EXTRACTION AND SYNTHESIS

Data extraction was performed according to the Meta-analysis of Observational Studies in Epidemiology (MOOSE) reporting guideline; 2 reviewers independently extracted the relevant data. Summary effect measures of the primary outcomes were obtained by logarithmically pooling the data with an inverse variance-weighted random-effects model. Metaregression was performed to assess the relationship between initial aneurysm size, etiology, and the primary outcomes.

MAIN OUTCOMES AND MEASURES

The primary composite outcome was incidence of all-cause mortality, aortic dissection, and aortic rupture. Secondary outcomes were growth rate, incidence of proximal aortic dissection or rupture, elective ascending aortic repair, and all-cause mortality.

RESULTS

Twenty studies consisting of 8800 patients (mean [SD] age, 57.75 [9.47] years; 6653 [75.6%] male) with a total follow-up time of 31 823 patient-years were included. The mean AsAA size at enrollment was 42.6 mm (range, 35.5-56.0 mm). The combined effect estimate of annual aneurysm growth rate was 0.61 mm/y (95% CI, 0.23-0.99 mm/y). The pooled incidence of elective aortic surgery was 13.82% (95% CI, 6.45%-21.41%) over a median (interquartile range) follow-up of 4.2 (2.9-15.0) years. The linearized mortality rate was 1.99% per patient-year (95% CI, 0.83%-3.15% per patient-year), and the linearized rate of the composite outcome of all-cause mortality, aortic dissection, and aortic rupture was 2.16% per patient-year (95% CI, 0.79%-3.55% per patient year). There was no significant relationship between year of study completion and the initial aneurysm size and primary outcomes.

CONCLUSIONS AND RELEVANCE

The growth rate of AsAA is slow and has implications for the interval of imaging follow-up. The data on the risk of dissection, rupture, and death of ascending aortic aneurysm are limited. A randomized clinical trial may be required to understand the benefit of surgical intervention compared with surveillance for patients with moderately dilated ascending aorta.