(HealthDay)—For patients with polycythemia vera, more intense treatment to achieve a hematocrit target of less than 45 percent correlates with a significantly lower rate of cardiovascular death and major thrombosis compared with a target of 45 to 50 percent, according to a study published online Dec. 8 in the New England Journal of Medicine to coincide with presentation at the annual meeting of the American Society of Hematology, held from Dec. 8 to 11 in Atlanta.
Roberto Marchioli, M.D., from the Consorzio Mario Negri Sud in Santa Maria Imbaro, Italy, and colleagues conducted a randomized controlled trial involving 365 adults with JAK2-positive polycythemia vera to compare more intensive treatment (target hematocrit less than 45 percent; low-hematocrit group) or less intensive treatment (target hematocrit 45 to 50 percent; high-hematocrit group) with phlebotomy, hydroxyurea, or both.
After a median follow-up of 31 months, the researchers found that the primary end point (time until death from cardiovascular causes or major thrombotic events) was reached by 2.7 percent of patients in the low-hematocrit group and 9.8 percent in the high-hematocrit group (hazard ratio in high-hematocrit group, 3.91). The primary end point plus superficial-vein thrombosis was reached by 4.4 and 10.9 percent, respectively (hazard ratio, 2.69). The rates of adverse events were similar between the groups.
"In conclusion, among patients with polycythemia vera, maintaining a hematocrit target of less than 45 percent, as compared with a target of 45 to 50 percent, was associated with a significantly lower rate of thrombotic complications without an increase in serious treatment complications," the authors write.
Several authors disclosed financial ties to the pharmaceutical industry.
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