Abstract 14823: Prevalence and Natural History of Incidentally Diagnosed Pulmonary Embolism in Patients Undergoing Coronary Computed Tomography Angiography

Abstract

Introduction: Although clinically unsuspected pulmonary embolism (PE) can be detected in patients undergoing coronary computed tomography angiography (CTA), the natural history of these incidentally diagnosed PE remains unclear. The purpose of our study was to assess the prevalence of incidentally diagnosed PE, its clinical significance and its natural history.

Methods: We retrospectively reviewed coronary CTA performed in 1,296 consecutive cases (1,083 patients; 677 males, 406 females, mean 65.8 years) from March 2003 to June 2007. Coronary CTA was acquired using a 16-MDCT scanner with ECG-gating. The mean clinical follow up period was 1597 days.

Results: Thirty-two of 1,083 patients (3.0%) had incidentally diagnosed PE. Of these, 1 patient had died suddenly, and 1 patient had experienced recurrent PE. There was no significant difference in survival free from death and acute PE between patients with and without incidentally diagnosed PE (Kaplan-Meier estimate; Logrank test p=0.28).Fourteen of 32 patients with PE (44%) underwent open-heart surgery. Only 4 patients received therapeutic anticoagulant therapy (ACT), and the remaining 28 patients didn’t receive ACT. Coronary CTA were repeated in 16 of the 32 patients, and the thrombus disappeared regardless of its size and location in 12 patients, of which 11 patients did not receive ACT. The risk factor of incidentally diagnosed PE was the past open-heart surgery (14 of 213, 6.6%, p=0.0005), especially within 3 months (ten of 74, 13.5%, p=0.0029). In those patients who underwent coronary CTA within 3 months after open-heart surgery, not receiving ACT was an independent risk factor (p=0.019) of incidentally diagnosed PE. There was no significant difference between PE group and no PE group in BMI (p=0.087), the use of heart-lung machine (p=0.63), the durations of central venous catheterization (p=0.19), and the days of bed rest after surgery (p=0.90).

Conclusions: The prevalence of incidentally diagnosed PE by coronary CTA was not so low (3.0%) in our study. The risk factor of incidentally diagnosed PE was the past open-heart surgery, especially within 3 months, and no ACT. Long-term clinical outcomes of these patients were favorable even without therapeutic ACT.