A 68-year-old with pleuritic chest pain and dyspnea has a Wells score of 1.5 (low probability). A highly sensitive D-dimer (reported in FEU) returns 520 ng/mL. What is the best next step?AOrder CT pulmonary angiography because any D-dimer above 500 ng/mL is positive in older adults.BUse age-adjusted D-dimer (age × 10 ng/mL FEU); at a cutoff of 680 ng/mL, this result rules out PE without imaging.CStart full-dose anticoagulation while arranging imaging.DUse PERC to rule out PE and discharge.ERepeat the D-dimer in 24 hours.Check my answer