Study on the Possibility of Emergency Percutaneous Coronary Intervention (PCI) in Myeloproliferative Neoplasms (MPNs) Patients with Acute Coronary Syndrome (ACS)

Myeloproliferative neoplasms (MPNs), particularly polycythemia vera (PV) and essential thrombocythemia (ET), are often associated with a high risk of acquired arterial and venous thrombosis. MPNs are also considered as vascular diseases that occur frequently in elderly patients, often accompanied by acute coronary syndrome (ACS).Very few studies have been made to estimate the risk after percutaneous coronary intervention (PCI) in MPNs with ACS patients. Moreover, the operative procedures or perioperative management procedures have not yet been fully established. The purpose of this study is to evaluate the risk factors and the effectiveness of PCI in MPNs with ACS.

Methods: From February 2001 through November 2018, a total of 215 patients were admitted to Beijing An Zhen Hospital with objectively proven ET (n=137) or PV (n=78). Among the 51 MPNs patients with ACS, 46 had undergone PCI therapy. Preoperative anticoagulation and perioperative antiplatelet therapy in all patients were similar to those in cardiovascular patients following the guideline. Patients with PCI were divided into two groups, the emergency PCI (<24h) and the elective PCI (>24h). Clinical data including medical history, age, gender, whole blood counts, JAK2v617F mutation, the type of ACS, vascular risk factors and target vessels disease and complications of PCI were retrospectively studied and the risk factors were analyzed using multivariate logistic regression analysis.

Results: Among the 46 patients with PCI, 37 were proven ET and 9 PV, including 27 cases of acute myocardial infarction (AMI) and 19 cases of unstable angina pectoris (UA). Their mean age is 58.22±12.10. Leukocyte and platelet count were higher than normal (WBC11.22±5.23╳109/L, HCT43.75±7.13%, PLT599.02±280.37╳109/L). The positive rate of JAK2V617F mutation was 61.11% (22/36), with 4 patients with CALR mutation. According to thrombosis risk stratification, 32.61% and 67.39% of the patients were classified as low risk and high risk thrombophilias respectively. 82.61% (38/46) of the patients had cardiovascular risk factor, while 52.61% showed two risk factors or above. 15 patients (32.61%) had a history of thrombosis. Nearly half of the patients (22 cases, or 47.83%) were diagnosed simultaneously with MPN because of ACS.

Coronary angiography showed 69 branch lesions, and left anterior descending artery(LAD)was the most common crime vessel (55.07%,38/69), followed by the right coronary artery (RCA) (24.64%, or 17/69). 29 cases (63.04%) were single vessel lesions. 11 (23.91%) cases were accompanied by coronary artery thrombus formation. Patients received a total of 61 stents (60 drug-eluting stents and 1 bare metal stents) implantation. There were 10 cases of complications in the perioperative period (21.74%), including 4 cases of postoperative stent thrombosis, 1 with ventricular fibrillation, 2 of re-infarction , 2 of arterial dissection, 1 of hemorrhagic local hematoma and 1 with low blood volume. Most complications of these cases occurred within 4 days after the operation, but no patients died.

Among patients treated with PCI therapy, 27 and 19 of the patients received emergency and elective surgery, respectively. There were no significant differences in the gender, MPNs type, vascular risk factors, thrombosis history, crime vessel, the number of stent implantation and complications between the two groups. The proportion of patients with WBC>10×109/L , single vessel lesions or WBC count was higher in patients with emergency surgery than that in patients with elective surgery.

Logistic regression analysis showed that thrombosis history (OR=27.235, P=0.034; 95%CI, 1.286-575.262) and coronary artery thrombus formation (OR=39.359, P=0.012; 95%CI, 2.223-696.778 ) were independent risk factors for complications of PCI in the perioperative period.

Conclusion: Our data show that PCI treatment, especially emergency surgery is not uncommon in MPN patients. Emergency PCI should be relatively safe and effective. Although there was a high occurrence of post-PCI complications and stent re-thrombosis, there were no fatal or serious complications. It is suggested that individualized cytoreduction therapy be given first, and once blood cells count decreases, PCI complications may significantly reduce. Previous thrombus history and coronary artery thrombus were independent risk factors for complications of PCI in the perioperative period.