Will an aortic dissection result in elevated troponin levels, indicating cardiac injury?

From the Guidelines

An aortic dissection can cause elevated troponin levels, but this is not always the case, and the presence of elevated troponin should prompt further investigation for myocardial injury, as stated in the third universal definition of myocardial infarction 1. The mechanism of troponin elevation in aortic dissection involves either direct extension of the dissection into the coronary arteries, compression of coronary ostia by the false lumen, or general hypoperfusion causing secondary myocardial damage. According to the third universal definition of myocardial infarction, aortic dissection is one of the conditions that can cause elevation of cardiac troponin values due to myocardial injury, as seen in Table 1 of the study 1. Some key points to consider when evaluating troponin levels in the context of aortic dissection include:

• Troponin elevation is neither sensitive nor specific for diagnosing aortic dissection, and normal troponin levels do not rule out this condition, as noted in the study 1.
• Imaging studies such as CT angiography, transesophageal echocardiography, or MRI are essential for diagnosis rather than relying on cardiac biomarkers, as they can provide a more accurate diagnosis of aortic dissection.
• When evaluating chest pain, it's essential to consider aortic dissection in the differential diagnosis even with normal troponin levels, especially in patients with risk factors like hypertension, Marfan syndrome, or a family history of aortic disease, as mentioned in the study 1. The universal definition of myocardial infarction also notes that elevations of troponin can occur in the absence of overt ischemic heart disease, including conditions such as aortic dissection, as stated in the study 1. Therefore, it is crucial to consider aortic dissection in the differential diagnosis of chest pain, regardless of troponin levels, and to use imaging studies to confirm the diagnosis, as recommended in the third universal definition of myocardial infarction 1.

From the Research

Aortic Dissection and Troponin Levels

• An aortic dissection can have an elevated troponin level, as seen in a case report of a 36-year-old male with Type A aortic dissection, where the initial laboratory workup revealed an elevated troponin I level 2.
• A study of 119 consecutive patients with Type A acute aortic dissection found that cardiac troponin I was positive in 28 patients (23.5%) and above the myocardial infarction threshold in 12 (10%) 3.
• The elevation of troponin in aortic dissection may reflect a higher haemodynamic stress, but it does not necessarily indicate a negative prognosis 3.
• Coronary artery involvement in Type A aortic dissection can cause myocardial ischemia, leading to elevated troponin levels, and is often missed during diagnosis 4.

Incidence and Mechanism

• The incidence of coronary artery involvement in Type A aortic dissection is not well reported, but it is known to add to the already high mortality and morbidity associated with this disease 4.
• The mechanism of coronary artery involvement in Type A aortic dissection can be due to retrograde extension of the dissection flap into the coronaries or compression and/or blockage of these vessels by the dissection flap 4.

Diagnosis and Treatment

• Imaging methods, such as CT scans, are essential for diagnosing aortic dissection, and biomarkers like troponin can aid in detection 5.
• The choice of intervention for aortic dissection varies depending on the type of dissection, with open surgical repair remaining the choice for Type A dissections, and endovascular repair being explored as a viable option for Type B dissections 5.