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Background: The aim of the study was to determine the incidence of acute pulmonary embolism (PE) in Sweden and any regional differences. To assess short-and long-term survival analysis after an episode of PE, before and after excluding patients with known malignancies, and to determine the most common comorbidities prior to the PE event. Methods: All in-hospital patients, including children, diagnosed with acute PE in 2005 were retrieved from the Swedish National Patient Registry (NPR) and incidence rates were calculated. All registered comorbidities from 1998 until the index events were collected and survival up to 4 years after the event were calculated and compared to matched controls. Results: There were 5793 patients of all ages diagnosed with acute PE in 2005 resulting in a national incidence of 0.6/1000/year. The mean age was 70 years and 52% were women. The most frequent comorbidities were cardiac-, vascular-, infectious-and gastrointestinal diseases, injuries and malignancies. The mortality rates were more than doubled in patients with recent PE compared to that in a matched control group (49.1% vs 21.9%), and the excess mortality remained after exclusion of deaths occurring within one year and after exclusion of patients with any malignancy prior to the event. Conclusions: PE is associated with high age as well as with multiple comorbidities, and with an increased shortand long-term mortality. This study highlights the importance of a proper follow-up after an acute PE.

Dyspnea is common after a pulmonary embolism. Often, but not always, the dyspnea can be explained by pre-existing comorbidities, and only rarely by chronic thromboembolic pulmonary hypertension (CTEPH). CTEPH is probably the extreme manifestation of a far more common condition, called the post-pulmonary embolism syndrome. The purpose of this retrospective study was to investigate the prevalence and predictors of dyspnea among Swedish patients that survived a pulmonary embolism, compared to the general population. All Swedish patients diagnosed with an acute pulmonary embolism in 2005 (n = 5793) were identified via the Swedish National Patient Registry. Patients that lived until 2007 (n = 3510) were invited to participate. Of these, 2105 patients responded to a questionnaire about dyspnea and comorbidities. Data from the general population (n = 1905) were acquired from the multinational MONItoring of trends and determinants in CArdiovascular disease health survey, conducted in 2004. Patients with pulmonary embolism had substantially higher prevalences of both exertional dyspnea (53.0% vs. 17.3%, odds ratio (OR): 5.40, 95% confidence intervals (CI): 4.61–6.32) and wake-up dyspnea (12.0% vs. 1.7%, OR: 7.7, 95% CI: 5.28–11.23) compared to control subjects. These differences remained after adjustments and were most pronounced among younger patients. The increased risk for exertional dyspnea and wake-up dyspnea remained after propensity score matching (OR (95% CI): 4.11 (3.14–5.38) and 3.44 (1.95–6.06), respectively). This population-based, nation-wide study demonstrated that self-reported dyspnea was common among patients with previous pulmonary embolism. This finding suggested that a post-pulmonary embolism syndrome might be present, which merits further investigation.

The Swedish National Inpatient Register (NPR) has near-complete coverage of in-hospital admissions and ICD codes in Sweden. Acute pulmonary embolism (PE) is a serious condition presenting challenges regarding diagnosis, treatment, and follow-up. Here we aimed to validate the accuracy of acute PE diagnosis in the NPR, investigational findings, antithrombotic treatment, and follow-up of PE patients in Sweden. From a nation-wide cohort of all patients with in-hospital diagnoses of acute PE (ICD-10-SE codes I26.0–I26.9) in 2005 (n = 5793), we selected those from two Swedish regions for thorough manual review of hospital records. We identified 599 patients with PE diagnoses according to the ICD-10 coding system. We excluded 58 patients with admissions related to previous PE (47; 8%) or incorrect ICD codes (11; 2%), leaving 501 patients with probable PE diagnoses. We confirmed the diagnosis in 441 (79%) cases, which was based on imaging (435 patients; 73%) or autopsy (6; 1%). In the remaining 60 (11%) cases, the PE diagnosis was based on clinical findings and can therefore not be confirmed. Of the surviving patients with PE, 231 (47%) were offered follow-up within 6 months after the acute event. At follow-up, 67 patients (29%) had symptoms requiring clinical attention (dyspnoea or reduced general condition). The Swedish NPR showed acceptable accuracy for PE diagnosis, and could be reliably used for register-based research regarding acute PE.