Aspect of diagnosis
This patient presented with suspicious MINOCA in the second episode, and according to the working diagnosis of MINOCA , SC and CAS are the most likely diagnosis.
SC was diagnosed initially according to the revised Mayo Clinic criteria at that time, although a definite diagnosis could not be established then because of the uncertain reversible nature of the condition. Partial reversible nature of apical hypokinesis was observed in the echocardiogram during the follow-up. Moreover, the InterTAK diagnostic score is low (only 18 points of 100 points), which have been published as a new recommended diagnostic criteria recently . In other words, the diagnosis of SC during the second episode was still uncertain. However, contrast cardiac magnetic resonance imaging (CMRI) was not performed to detect edema (to confirm SC) at that time due to limited hospital resources.
As multivessel CAS was diagnosed definitely during the third episode, it could have occurred during the second episode as well. Retrospectively, the clinical manifestations are more consistent with the characteristics of CAS than with SC (chest pain occurred at rest in the early morning repeatedly without physical or emotional triggers). Moreover, CAS can diffusely involve the entire arteries and migrate from site to site, which may also cause severe apical hypokinesis with apical ballooning images ; multivessel spasm theory  also supports this possibility. However, the coronary images showed a wraparound left anterior descending branch, which contradicts this possibility. That it to say, CAS could not be the cause of the second episode. Unfortunately, we did not perform provocative tests, which are known as the key diagnostic criteria of CAS, during the second episode due to the insufficient evidence basis at that time. Recently, provocative tests for spasm have been confirmed to be safe and are recommended in the situation of rest angina without obstructive coronary artery disease .
Our understanding of both CAS and SC is still limited. CAS and SC share some predisposing factors and pathogenic mechanisms, such as emotional triggers and adrenergic hyperactivation, and some evidence suggests a potential pathogenic link between these two conditions . In other words, CAS and SC may be two expressions of the same disease, or rather two separate entities with overlapping mechanisms. In the present case, we could not draw the conclusion definitely because of the important limitation that CMRI and provocative tests were not performed.
Another important limitation is that left ventriculography was not performed during the third episode, which could also have been of great help to assess the appearance of a classic apical ballooning shape. However, we believe that both CAS and SC exist in this case, which is because this explanation is the most reasonable for this case as we have discussed earlier.
Furthermore, it is interesting that during the first episode, the patient’s ECG revealed poor R wave progression in V1–3 leads despite normal echocardiogram and CAG findings, which may have resulted due to small areas of prior myocardial infarction with silent manifestation caused by CAS. In addition, the first episode might point to microvascular endothelial dysfunction, and this microvascular dysfunction could be a risk factor for both CAS and SC .
In summary, the patient suffered silent CAS in the first episode, SC in the second episode, and severe multivessel CAS in the third episode. Alternate recurrent CAS and SC in the same individual as observed in this case has not been reported till date.
Aspect of treatment
During the second episode, the patient was discharged on dual antiplatelet therapy (DAPT). However, according to the latest recommendation, in the absence of CAD and in patients with TS or CAS, DAPT increases the risk of bleeding without an obvious benefit in this population, and even the role of aspirin at low doses has discussed over the years .
Moreover, beta-adrenergic blockers known as a risk factor for CAS were prescribed according to the treatment principles of SC , which may have been the trigger of the third episode. Therefore, beta-adrenergic blockers should be cautiously used before severe multivessel CAS has been completely excluded despite the typical scenarios of SC.
To our best knowledge, the unusual presentations as observed in this case have not been reported in the literature. Cardiologists should be aware of the possibility of alternate recurrent CAS and SC in the same individual. Provocative tests for spasm and cardiac magnetic resonance imaging might help gain more insights into this issue.