Coronary Artery Intervention after Cytostatics Treatment in Unstable Angina Patient with Essential Thrombocythemia. A Case Report and Literature Review
A 45-year-old male was admitted to our hospital due to substernal chest discomfort on mild exertion, which occurred three weeks prior to presentation. The frequency and severity of his angina increased over time and the patient described a squeezing chest pain with an onset three days prior to presentation. The past medical history included hypertension, diagnosed three years ago, and smoking history of ten pack-years. There was no family history of coronary artery or hematologic disease. At the time of admission he was on aspirin and anti-hypertensive medications. On physical examination, the blood pressure was 130/80 mmHg and the heart rate was 70 beats per minute. The heart sounds were unremarkable with normal S1 and S2 sounds. The lungs were clear on auscultation. The electrocardiogram showed no ST-segment change, T wave inversion or pathologic Q waves suggestive of myocardial ischemia. No abnormality was found on chest roentgenogram. On complete blood count, the hemoglobin was 13.9 g/dL, white blood cell count was 9,400/L, and the platelet count was 106×104/µL. Electrolytes, renal and liver function tests were not remarkable. Levels of CK-MB and Troponin-T were within normal range. Total serum cholesterol was 161 mg/dL, triglyceride was 95 mg/dL and high-density lipoprotein was 39 mg/dL. Serum homocystein level was 12.7 nmol/mL (reference range 5-15 nmol/mL), and hsCRP was 1.91 mg/L (reference range <3 mg/L). Prothrombin time, activated partial thromboplastin time and fibrinogen level were within normal range. The iron profile was not remarkable. Bone marrow study showed a hypercellular marrow with markedly increased megakaryocytes, and a normal myeloid/erythroid ratio (). Chromosomal analysis of bone marrow cells revealed a normal 46, XY karyotype with no evidence of bcr/abl rearrangement. Liver and spleen were not enlarged on sonogram images. An elective coronary angiography, two days after admission, showed total occlusion at the mid right coronary artery (RCA) with well-developed collaterals from proximal RCA to PD and PL branches. In addition, there was diffuse irregular, up to 70%, luminal narrowing with haziness noted at the proximal RCA. The left coronary angiography showed a 40% luminal narrowing at the mid left anterior descending artery (LAD). The echocardiography, performed three days after admission, showed no regional wall motion abnormality with about 60% of left ventricular ejection fraction. On color Doppler imaging, there was no significant valvular stenosis or regurgitation noted. There was a relaxational abnormality observed in the diastolic filling pattern. The patient was taking aspirin 100 mg/day, clopidogrel 75 mg/day, atenolol 25 mg/day, diltiazem 90 mg/day and nicorandil 15 mg/day from the day of admission. The chest pain was controlled by medical treatment; therefore, we decided to postpone coronary artery intervention until the platelet count reached a normal level. Treatment with hyroxyurea 500 mg/day and anagrelide HCl 1 mg/day was started as cytostatic therapy. The platelet count was normalized (23×104/µL) five weeks after initiation of cytostatic therapy, and coronary artery intervention was then performed. The totally occluded mid RCA lesion was thought to be a chronic total occlusion because of the presence of good collateral flow from the proximal RCA. We thought that the proximal RCA, stenotic lesion with haziness, resulted from a plaque rupture resulting in an occlusive thrombus, and caused the ischemic symptoms that the patient presented with. Two coronary stents were placed at the proximal and mid RCA. No residual stenosis was observed after the procedure (). The LAD lesion was not treated. The patient was discharged two days after the procedure without any hemorrhagic or thrombotic complication; he remained on aspirin, clopidogrel, hydroxyurea, and anagrelide. The patient was free of symptoms for six months during the follow-up period, and his platelet count remained within normal range.