Among patients hospitalized with acute myocardial infarction (AMI), those with myeloproliferative neoplasms (MPN) have an increased risk of in-hospital bleeding but a decreased risk of in-hospital death or cardiac arrest compared with patients without MPNs. This is according to a study published in JACC: CardioOncology.
“MPN poses a clinical conundrum. They are a heterogenous group of clonal hematopoietic neoplasms that portend a prognosis measured in years in some cases,” said Orly Leiva, MD, of the New York University Grossman School of Medicine. “The association between MPN and thrombosis has been well described. However, outcomes among patients with MPN who have had AMI have not been well studied.
“There are no current guidelines on specific treatment of AMI among patients with MPN. As such, current treatment of patients with MPN, including revascularization strategy and choice and duration of antithrombotic therapies, is usually made per current guidelines of the general population and on an individual basis based on the patient's perceived thrombotic and bleeding risks,” Dr. Leiva said. “Our study aimed to shed some light on describing the characteristics of patients with MPN admitted for AMI and outcomes compared to the general population and to encourage further study that may lead to a more refined and personalized approach to the management of AMI among patients with MPN.”
Between January 2006 and December 2018, 1,644,304 patients (mean age = 67.2 years; 61.1% male) admitted for AMI were identified using the National Inpatient Sample, which captures around 20% of hospitalizations in the U.S. Among the 5,374 patients (0.3%) with MPN, 48.8% had polycythemia vera (PV), 47.8% had essential thrombocythemia (ET), and 5.8% had primary myelofibrosis (MF). The procedures captured included left heart catheterization, percutaneous coronary intervention (PCI), mechanical circulatory support (MCS), and coronary artery bypass grafting (CABG). The researchers compared the in-hospital outcomes between patients with and without MPN. The primary outcome was in-hospital death or cardiac arrest, and the secondary outcome was major bleeding.
Baseline patient characteristics were adequately balanced between patients with and without MPN after propensity score weighting. Compared with patients without MPN, those with MPN had a lower risk of in-hospital death or cardiac arrest (odds ratio [OR] = 0.83; 95% CI 0.82-0.84) but a higher risk of major bleeding (OR=1.29; 95% CI 1.28-1.30). Patients without MPN had a decreasing temporal rate of in-hospital death or cardiac arrest and bleeding (ptrend<0.001 for both). However, patients with MPN had an increasing temporal rate of in-hospital death or cardiac arrest (ptrend<0.001) and a stable rate of major bleeding (ptrend=0.48). This was despite a similar reduction in ST-segment elevation myocardial infarction (STEMI) presentations between patients with and without MPN over time (ptrend for both < 0.001). The risk factors associated with an increased likelihood of death, cardiac arrest, or bleeding included peripheral vascular disease, anemia, STEMI presentation, and an ET and primary MF MPN phenotype.
Invasive management (left heart catheterization, PCI, or CABG) was lower, although not significantly so, in patients with MPN than in those without (68.8% vs. 71.6%; SMD = 0.06). Patients with MPN were less likely than those without MPN to undergo PCI (38.3% vs. 43.2%; standardized mean difference [SMD] = 0.10) but not CABG (8.9% vs. 8.8%; SMD = 0.002). For patients with and without MPN, use of MCS (5.5% vs. 5.0%; SMD = 0.018) and prevalence of cardiogenic shock (3.6% vs. 3.9%; SMD = 0.02) were similar.
“Our study suggested no increase in in-hospital mortality among patients with MPN compared with the general population. However, patients with MPN had increased rates of bleeding events, including gastrointestinal and procedure-related bleeding,” said Dr. Leiva. “Additionally, patients with MPN were less likely to be treated with PCI.”
Limitations to the study include its retrospective design. Further, the data in the National Inpatient Sample are abstracted from billing codes, which are prone to errors. Data on the treatment of MPN, blood counts, disease duration, and genetic testing (JAK2 mutation) are not reported and may affect cardiovascular outcomes.
“My hope is that our study spurs further research on the management of AMI among patients with MPN and other cancers to better understand bleeding and thrombotic risk and to develop therapeutic paradigms that better balance these competing risks,” Dr. Leiva said.
Any conflicts of interest declared by the authors can be found in the original article.
Leiva O, Xia Y, Siddiqui E, et al. Outcomes of patients with myeloproliferative neoplasms admitted with myocardial infarction: insights from National Inpatient Sample. JACC CardioOncol. 2023;5(4):457-468.