[Pulmonary thromboembolism: long term course and clinical epidemiology].

BACKGROUND

Long-term clinical course of pulmonary thromboembolism is not well-known. Our aim was to know the events which occur to in-patients diagnosed of pulmonary embolism.

METHODS AND PATIENTS

This is a prospective observational study from May-92 to December-2002 with all in-patients diagnosed of pulmonary thromboembolism at a clinical area of Internal Medicine. Main targets were to know survival, relapses, major hemorrhage rate (Defined as those episodes of bleeding which needed blood transfusion and readmission) and cancer associated rate (Previous and newly diagnosed cancer). Follow up were carried out with telephone contacts with patients and relatives in case of death, and with the computerized system of patients and clinical events of Health Service of Navarra.

RESULTS

One hundred and sixteen patients were included in the study (Mean age 72 SD 11 years male 54%). During index episode 4 (3.7%) patients dead. Ten patients were lost in follow up. The rest 102 patients were traced for 31.81 SD 31.23 months (Range 1-127). Relapse rate was 19.6% that occurred 22.64 SD 24.57 (Range 1-73) months after index episode (Twelve pulmonary embolisms, 5 deep venous thromboses and 3 sudden death with dyspnea). Major hemorrhage rate was 10.4%. During follow up 14 (13.7%) new cancers were diagnosed (Lung 4, prostate 2, bladder 2, and colorectal, ovary, breast, liver and kidney one each one). At all prevalence of cancer associated with pulmonary thromboembolism was 31%. Mortality rate was 37% (Men 25%, women 49%, p < 0.01). Main causes of death were cancer (32%) and relapse of pulmonary thromboembolism when joined with treatment complications 24%. Half of deaths occurred in the first year of follow up, showing a shortened survival those patients with cancer (p = 0.02) and patients with relapses of pulmonary embolism (p = 0.06). Beyond the first year, mortality declines to a rate of 10% per year mainly because of cardiovascular causes. Mortality associated factors were age > 75 years (p < 0.001) gender female (p < 0.01), a delayed admission and treatment from the beginning of symptoms (p < 0.05), higher LDH level (p < 0.01) and coexistence of cancer (p < 0.05). In logistic-regression analysis age, delayed admission and treatment and higher LDH levels were predictors of long-term death.

CONCLUSIONS

Patients with pulmonary embolism show a high mortality rate, with a critical period during the first year after index episode, being deaths associated to cancer and to a composite of relapse of venous thromboembolic disease and bleeding complications. Mortality rate beyond the first year declines, being deaths explained because of cardiovascular causes. An advanced age, a delayed diagnosis and treatment and serum LDH may predict long-term mortality.