Thrombolytic therapy of pulmonary embolism A meta-analysis

AbstractObjectivesWe sought to assess the efficacy and safety of thrombolytic therapy in patients with an acute pulmonary embolism (PE).BackgroundThrombolytic therapy is approved for the treatment of acute PE; however, the safety and efficacy of this therapy remain debated.MethodsA meta-analysis of randomized, controlled trials comparing thrombolytic agents with intravenous heparin in patients with acute PE was performed. Trials were identified through a combined search of the MEDLINE, EMBASE, and Current Contents databases. Three outcome measures were assessed: 1) mortality, 2) recurrence of PE, and 3) major hemorrhage.ResultsNine trials including 461 patients were identified. Compared with intravenous heparin, thrombolytic therapy had no significant effect on mortality (relative risk [RR] 0.63, 95% confidence interval [CI] 0.32 to 1.23) or the recurrence of PE (RR 0.59, 95% CI 0.30 to 1.18), but was associated with an increased risk of major hemorrhage (RR 1.76, 95% CI 1.04 to 2.98). These results were homogeneous and largely unaffected by the formulation of thrombolytic agent, the clinical severity of PE, the extent of vascular obstruction determined radiologically, or the methodologic quality of the included trials.ConclusionsCompared with intravenous heparin, thrombolytic therapy does not appear to have therapeutic benefit in unselected patients with acute PE, but it is associated with an increased risk of major hemorrhage. Given the small number of patients included in the randomized trials thus far, the negative results in terms of the efficacy outcomes should be interpreted with caution. Definitive evidence of the utility of thrombolytic therapy in this setting requires a large, randomized, controlled trial

Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum