The study was conducted between September 2009 and December 2013 as part of the SWIss venous Thromboembolism COhort (SWITCO65+), a prospective, multicenter cohort study to assess long-term medical outcomes in elderly patients with acute symptomatic venous thromboembolism (VTE) from all five university and four high-volume non-university hospitals in Switzerland . Consecutive patients aged 65 years or older with objectively diagnosed, symptomatic VTE were identified in the in- and outpatient services of all participating study sites. For this study, we only considered patients with objectively diagnosed, acute symptomatic PE, defined as positive CTPA in patients with acute chest pain, new or worsening dyspnea, hemoptysis, or syncope . Patients with PE who did not undergo CTPA were excluded from the present analysis.