Acute thrombus formation is the pathophysiological substrate underlying several clinical conditions, such as acute coronary syndrome (ACS) and stroke. Activation of coagulation cascade is a key step of the thrombotic process: vessel injury results in exposure of the glycoprotein tissue factor (TF) to the flowing blood. Once exposed, TF binds factor VII/VIIa (FVII/FVIIa) and in presence of calcium ions, it forms a tertiary complex able to activate FX to FXa, FIX to FIXa, and FVIIa itself. The final step is thrombin formation at the site of vessel injury with subsequent platelet activation, fibrinogen to fibrin conversion and ultimately thrombus formation.Platelets are the key cells in primary hemostasis. For years they have been considered only as cell fragments participating to primary hemostasis and onto which coagulation factors are assembled in the process of thrombus formation. However, recent advances in platelets pathophysiology have shown that these cells are able to regulate their gene and protein expression, make de novo protein synthesis, and release different mediators with paracrine effects that may interfere with different cell functions.Pharmacological modulation of both side of thrombosis, coagulation cascade and platelet activation, is of great clinical importance. Several clinical trials have clearly shown the efficacy of anticoagulation and/or anti platelet aggregation in different thrombotic disorders. This article aims at reviewing the recent advancements on the two faces of thrombosis focusing on the emerging role of platelets not only as clot-forming components, but highlighting their involvement in the inflammatory-immune system, as well as in modulation of different cell functions.
We present the clinical case of a 67–year–old male. He was affected by hypertension, hypercholesterolemia; he was heavy smoker. He went to the ED for paresthesias and tremors in the left upper limb, which resolved spontaneously in a few minutes, to which there followed severe thoracic discomfort lasting more than 5 minutes, which resolved during the arrival at the hospital. Upon arrival, the ECG showed ST–segment elevation in leads V4 – V6. POCUS demonstrated akinesia of the apex in its entirety with hypercontractility of the basal segments and the EF was 35%. Blood tests showed an increase in cTI (0.89 ng/ml; vn < 0.16) and CK–MB (57 U/L; vn < 25 U/L). Complete blood count and PCR result in the norm. Coronary angiography showed <50% circumflex artery stenosis, not hemodynamically significant, not treated. Over the next few days the ECG showed marked changes in repolarization, up to T wave inversion; normalized blood tests. During the 3rd day of hospitalization, the patient presented an episode of sensorimotor epileptic seizure in the left upper limb, lasting about 3 minutes, which resolved spontaneously. He underwent a brain CT scan which revealed multiple, edematous brain lesions, probably of a repetitive nature. A whole body CT scan diagnosed lung malignancy. After the oncological evaluation, the patient started chemotherapy. Subsequent follow–ups documented recovery of apical movement at two months. The patient presented a clinical–instrumental picture compatible with the diagnosis of MINOCA. In particular, the echocardiography was suggestive of takotsubo syndrome (TTS). TTS affects 1–2% of patients presenting to ED with ACS and positive troponins or suspected STEMI. It mostly affects women and elderly patients. The exact pathophysiology of TTS is still unknown, but there are numerous determining factors, such as physical and/or emotional stress, that are responsible for sharp increases in levels of circulating catecholamines. Also neurological pathologies, such as ischemic and above all haemorrhagic stroke are implicated. Recent evidence suggests that about one in six TTS patients also have cancer. In conclusion, we described a case where the first clinical manifestation of a lung metastatic cancer was a SCA. In the TTS there can be a "theory of everything", capable of bringing together the various specialists (emergency physician, cardiologist, pulmonologist, general internist, oncologist, etc.) to reach a single outcome, the patient–care.
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