Accepted on 09 Jun 2020
Submitted on 09 Jun 2020
Myeloproliferative neoplasms (MPN) are characterized by clonal expansion of cells belonging to the erythroid and/or myeloid lineages. Concomitant platelet dysfunction and thrombocytosis predispose these patients to both arterial thromboses and bleeding, causing a high burden of morbidity and mortality. With advances in cancer therapeutics and improving survival, an increasing number of patients with MPN are presenting with acute coronary syndromes (ACS). However, data regarding in-hospital outcomes and revascularization strategies utilized in these patients is limited, due to lack of representation in trials and rarity of the disease.
We conducted a retrospective cohort study using the 2016 Nationwide Inpatient Sample (NIS), a large publicly available database in the United States. Adult patients with a primary diagnosis of ACS and a secondary diagnosis of MPN, including essential thrombocytosis, polycythemia vera, primary myelofibrosis or chronic myeloproliferative disorder, were identified using the International Classification of Diseases (ICD) 10th Revision codes. Main outcomes of interest such as in-hospital mortality, utilization of revascularization strategy and in-hospital complications, were compared between the patients with ACS and comorbid MPN and those without MPN, using a multivariate logistic regression model. Length of stay and total cost of hospitalization was also compared between cohorts.
Out of 677,304 patients admitted for ACS, 2,485 (0.37%) patients also had a secondary diagnosis of MPN. Patients with MPN were less frequently female and diabetic but were more likely to have heart failure. No statistical difference in race, smoking, obesity or peripheral arterial disease (PAD) was noted between the two cohorts. Also, there was no significant difference in the in-hospital mortality in ACS patients with or without MPN (5.83% vs 4.57% respectively, p = 0.59). In terms of revascularization, patients with MPN were less likely to undergo percutaneous coronary intervention (PCI), (adjusted odds ratio [aOR] 0.76, p = 0.01) and more likely to undergo coronary arterial bypass grafting (CABG), (aOR: 1.47, p = 0.007). In addition, patients with MPN had a higher risk of acute pulmonary embolism (aOR 2.31, p = 0.027), cardiogenic shock (aOR 1.54, p = 0.004), and acute kidney injury (aOR 1.36, 95% CI, p = 0.009) as well as increased length of stay and hospitalization costs (Table 1).
Table 1
Results.
| Parameter | ACS with MPN | ACS without MPN | Unadjusted OR | Adjusted OR | P value |
|---|---|---|---|---|---|
| Total patients (n = 677,304) | 2,485 | 674,819 | |||
| Demographics | |||||
| Age (years) | 67.9 (66.7–69.3) | 66.9 (66.7–66.9) | P = 0.085 | ||
| Female (%) | 38.4 % | 43.7% | P = 0.029 | ||
| Ethnicity (%) | |||||
| White | 74.79 | 73.98 | P = 0.5 | ||
| Black | 12.5 | 11.5 | |||
| Hispanic | 6.36 | 8.31 | |||
| Other | 6.35 | 6.21 | |||
| Clinical features | |||||
| Hypertension (%) | 81.09 | 80.43 | P = 0.71 | ||
| Chronic kidney disease (%) | 21.33 | 23.33 | P = 0.288 | ||
| Diabetes Mellitus (%) | 29.8 | 38.92 | P < 0.001 | ||
| Heart failure (%) | 36.62 | 27.17 | P < 0.001 | ||
| Smokers (%) | 49.9 | 45.42 | P = 0.052 | ||
| Obesity (%) | 13.1 | 15.1 | P = 0.21 | ||
| PAD (%) | 20.1 | 20.3 | P = 0.98 | ||
| Charlson Comorbidity Index (mean) | 1.54 | 1.47 | P = 0.07 | ||
| Outcomes | |||||
| In-hospital Mortality (%) | 5.83 | 4.57 | 1.29 (0.87–1.9) | 1.12 (0.73–1.71) | P = 0.59 |
| PCI for revascularization (%) | 38.43 | 46.02 | 0.73 (0.61–0.87) | 0.76 (0.63–0.93) | P = 0.01 |
| CABG for revascularization (%) | 12.45 | 8.75 | 1.54 (1.17–2.02) | 1.47 (1.11–1.96) | P = 0.007 |
| Acute pulmonary emboli (%) | 1.41 | 0.55 | 2.55 (1.21–5.35) | 2.31 (1.09–4.89) | P = 0.027 |
| Cardiogenic shock (%) | 7.04 | 3.26 | 2.24 (1.60–3.13) | 1.54 (1.14–2.08) | P = 0.004 |
| Acute kidney injury (%) | 24.29 | 18.63 | 1.40 (1.14–1.71) | 1.36 (1.08-1.73) | P = 0.009 |
| Length of stay (days) | 6.9 ± 0.027 | 4.3 ± 0.31 | P < 0.001 | ||
| Hospitalization total cost (×1,000 USD) | 121.7 ± 14.1 | 88.1 ± 77.2 | P < 0.001 | ||
In patients presenting with ACS and concomitant MPN, CABG was the preferred mode of revascularization over PCI, which might explain the longer length of stay and increased hospitalization cost. Although the in-hospital mortality was similar between the two groups, patients with MPN had higher risks of complications including pulmonary emboli, and cardiogenic shock.
