Heart disease increases short-term risk for isolated pulmonary embolism
MedWire News: Patients with heart disease have an increased short-term risk for venous thromboembolism (VTE), particularly isolated pulmonary embolism (PE), compared with the general population, study findings indicate.
The risk was greatest with right-sided, rather than left-sided disease, the researchers remark.
It has previously been suggested that the heart itself may be a source of isolated PE, especially in cases of cardiac diseases that are associated with an increased risk for left-sided cardiac thromboses and subsequent embolic stroke, explain Henrik Sørensen (Aarhus University Hospital, Denmark) and colleagues.
To investigate the association further, Sørensen and team conducted a nationwide, population-based, case-control study in Denmark that included patients diagnosed with PE and/or deep venous thrombosis (DVT) between 1980 and 2007.
They evaluated whether common heart diseases that increase the risk for left-sided arterial embolism (such as heart failure, myocardial infarction, atrial fibrillation/flutter, and valvular heart disease) increased the risk for incident VTE.
The study included 45,282 patients with PE alone, 4680 with PE and DVT, 59,790 with DVT alone, and 541,561 age- and gender-matched controls selected from the Danish Civil Registration System.
The researchers report that the strength of the association between heart disease and VTE differed according to the time between hospitalization for heart disease and the VTE event. Specifically, they observed strong associations between heart disease hospitalizations in the 3 months before the VTE diagnosis date and VTE diagnosis, and almost no associations for patients who were hospitalized more than 3 months before VTE diagnosis.
Indeed, myocardial infarction and heart failure in the preceding 3 months conferred high risks for apparently isolated PE, at odds ratios (ORs) of 43.5 and 32.4, respectively. The corresponding risks for combined PE and DVT, and DVT alone were lower, at ORs of 19.7 and 22.1, and 9.6 and 12.7, respectively.
The differences in ORs among the three patient groups were less marked for incident atrial fibrillation/flutter and valvular disease, however, and ranged from 15.2 to 28.4 and from 5.5 to 11.1, respectively.
Of note, the risk for PE alone associated with right-sided valvular disease was substantially higher than that with left-sided valvular disease, with an OR of 74.6 versus 13.5.
When the researchers restricted their analysis to cases diagnosed after 2000 - when PE and DVT diagnostic accuracy improved with increased use of diagnostic imaging - the associations were attenuated, but still followed the same overall pattern.
Writing in the journal Circulation, Sørensen and co-authors conclude: "The remarkable increase in the risk of apparently isolated PE in the 3 months after incident heart disease suggests that several heart diseases may directly cause the development of symptomatic embolism without apparent peripheral thrombosis."
By Laura Dean