Asymptomatic stanford A aortic dissection in a patient with chronic kidney disease

Case report

Aortic diseases contribute to the wide spectrum of arterial disease: aortic aneurysm and acute aortic syndromes (AAS). The most common AAS is aortic dissection (AD) with an incidence estimated to be 5-30 cases per million per year. Most dissections occur in those between the ages of 50 and 70 years with a major incidence in men, even though patients with Marfan syndrome, Loeys–Dietz syndrome, and vascular Ehlers–Danlos syndrome, present at young ages^1,2. The chronic presentation of AD is very rare without prior acute AD (AAD) or well-established risk factors. These patients are underdiagnosed, and their treatment and follow-up continue as a challenge. We report a highly illustrative scenario in a patient with atypical risk factors and a short review of asymptomatic AD.

A 33-year-old woman with chronic kidney disease (CKD) and a long-standing history of hypertension presented for ambulatory transthoracic echocardiography (TTE) as part of her kidney transplant protocol. Her blood pressure (BP) was adequately controlled with candesartan/hydrochlorothiazide complemented with furosemide. She denies any episode of chest pain, diaphoresis, syncope, or near syncope episodes to direct history. Physical examination was unmarkable. The electrocardiogram showed sinus rhythm. NT-proBNP and C reactive protein were within normal limits. Echocardiography evidence dilated aortic root of 50 mm demonstrating a highly suggestive image of a flap (Fig. 1).

Figure 1.

Transthoracic echocardiography. Panel A parasternal short axis, Panel B parasternal long axis. The aortic flap is marked by the yellow arrows. AO: aorta; LV: left ventricle; LA: left atrium; RV: right ventricle.

Discussion

AD is a life-threatening disease that occurs when there is an intimal tear that allows the blood to pass through the tear and into the aortic media, splitting the intima in two longitudinally, creating a dissection flap that divides the true lumen from a newly formed false lumen. Chronic AD (CAD) is mostly found in AAD survivors (~60%) and can be divided into two categories. The first one is those who received medical, endovascular, or surgical treatment for AAD and survived 90 days. The second one consists of patients with a diagnosis of CAD for the 1^st time (asymptomatic in most of the cases)³.

There are several classifications used for AD based on the segment involvement such as the Stanford classification that only considers the extent of the dissection process; dividing the AD into groups A: any ascending dissection and B: any dissection without affection to the ascending aorta⁴.

The typical symptoms of acute dissection are severe, sharp, “tearing” back pain. Otherwise, in patients with CAD, the history must be carefully evaluated for previous AAD symptoms. Infrequently, symptoms related to the enlarging dissected aorta or chronic malperfusion may be seen. According to the International Registry of AAD, only 63 patients (6.4%) with AD are asymptomatic. These patients were older and, often presented a history of diabetes, aortic aneurysm, and prior cardiovascular surgery⁵.

The physiopathological principle of AD is an increased intra-aortic pressure that leads to the separation of the media layers which creates a false lumen within the aortic wall. The structural weakness of the aortic wall, and the increased wall tension are the two main factors related. It is important to note that the interaction between different factors, rather than individual factors, provides a satisfactory explanation for the onset of AD⁶. Although, CKD is a well-recognized contributor to cardiovascular disease and mortality, primarily through atherosclerosis and endothelial dysfunction both of which are linked to a chronic inflammatory state and increased aortic wall tension. In addition, CDK may be associated with AD through alterations in the renin-angiotensin-aldosterone system⁷. Oxidative stress also plays a critical role in the development of AD, as evidenced by elevated levels of uremic toxin and indoxyl-3-sulfate levels in patients with abdominal aortic aneurysms^8,9.

Marfan syndrome, smoking, hypertension, diabetes mellitus, cardiac failure, and atrial fibrillation are strongly related risk factors for AD. CKD carries an increased risk of mortality related to AD in the general population¹⁰. CKD is recognized as an additional risk factor, in addition to established risk factors, which may merit patient screening in patients in transplant programs¹⁰.

All the differential diagnoses include life-threatening conditions: myocardial infarction, aortic aneurysm, cardiac tamponade, esophageal rupture, spontaneous pneumothorax, pulmonary embolism, and stroke⁶.

Computed tomography angiography (CTA) is the gold standard for AD, providing excellent diagnostic performance, and anatomical evaluation to establish the extension, classify it accordingly, and decide optimal treatment. TTE is particularly useful in imaging the aortic root and ascending aorta¹. Laboratory studies in the future can be useful as D-dimers that could help to differentiate AD from coagulopathies other than pulmonary emboli. C-reactive protein can also predict long-term AD outcomes such as all-cause mortality, recurrence, or rupture⁶.

The evidence for medical treatment in patients with CAD is currently limited. Nevertheless, according to the latest guidelines, maintaining optimal BP control, with values below 130/80 mmHg, stands as a key recommendation. In addition, the prescription of beta-blockers for long-term prophylactic therapy has emerged as a prevalent approach to enhance overall survival. In the case of type B dissection, calcium channel blockers have demonstrated efficacy in improving survival, whereas angiotensin-1 antagonists present an appealing option to decelerate aortic enlargement in individuals with Marfan syndrome^1-5.

Although asymptomatic AD do not experience any discomfort the risk of aortic rupture or organ ischemia may lead to death. Surgical treatment is the gold standard for type A asymptomatic AD even when considered a high-risk procedure^1,4.

Patients with CAD require lifelong surveillance by imagining the entire aorta and the dissected part evaluation; the predischarge baseline scan is essential. The follow-up of surgically repaired AD after discharge should be followed up at 6 months, 12 months, and annually, after that. Medically managed AD must be scanned 1-3 months after the initial event, followed by 6-month, 12-month, and annual follow-up. Endovascular treatment needs scanning 1 month after the procedure and subsequent monitoring at 6 and 12 months. In all patients, even in stable ones, an annual follow-up is necessary^3,5.

Conclusion

AD may present without symptoms and in patients with atypical risk factors such as CKD; these patients could require specialized screening due to the presence of accelerated atherosclerosis and endothelial dysfunction, along with refractory systemic hypertension. Surgical or interventional management must be considered, even if the patients do not exhibit symptoms.

Patient outcome

After a CTA scan, a diagnosis of Stanford A, DeBakey II asymptomatic AD was confirmed, showing an intimal dissection that initiates in the right coronary Valsalva sinus just above the coronary artery with spiral extension to the left anterolateral wall (Fig. 2). The patient was admitted, and the heart team concluded that surgical intervention was essential. They performed a supracoronary aortic substitution procedure using a 20 mm Dacron tube graft. Histopathology reports extensive atherosclerosis of the intima and a prior split of the aortic media. The patient’s post-surgical recovery showed significant improvement, prompting their discharge for outpatient follow-up care.

Figure 2.

Sagittal plane in the CTA shows an intimal dissection that initiates in the right coronary Valsalva sinus just above the coronary artery with spiral extension to the left anterolateral wall marked by the yellow arrows.

Funding

None.

Conflicts of interest

None.

Ethical considerations

Protection of humans and animals. The authors declare that no experiments involving humans or animals were conducted for this research.

Confidentiality, informed consent, and ethical approval. The authors have followed their institution’s confidentiality protocols, obtained informed consent from patients, and received approval from the Ethics Committee. The SAGER guidelines were followed according to the nature of the study.

Declaration on the use of artificial intelligence. The authors declare that no generative artificial intelligence was used in the writing of this manuscript.