Thrombin insensitive PAR1 transgenic mice demonstrate reduced doxorubicin-induced cardiac injury. (A) Plasma levels of cardiac troponin I were measured in Par1^+/+, Par1^-/-, Par1^R41Q and Par1^R46Q mice (n = 4-7/group) at baseline and 48 hours after administration of doxorubicin. (B) LV FS was assessed in Par1^+/+, Par1^-/-, Par1^R41Q, and Par1^R46Q mice at baseline and on day 5 in acute and day 35 in the chronic models of doxorubicin-induced cardiac injury by conscious echocardiography (n = 6-11/group). #P < .05 vs baseline of the respective genotype; ∗P < .05; ∗∗P < .01; ∗∗∗∗P < .0001; 2-way ANOVA with post hoc Holm-Sidak tests. Data are represented as individual values with mean and SEM.