Impact of higher detection rate of residual pulmonary thromboemboli one-year after acute pulmonary embolism: modified CT scan imaging method with modified CT obstruction index. (25th November 2020)

• Record Type: Journal Article
• Authors: Nakano, Y; Okumura, N; Imai, R; Yoshida, M; Shimokata, S; Adachi, S; Murohara, T; Kondo, T
• Is Part Of: European heart journal. Volume 41:(2020)Supplement 2
• Publication Date: 2020-11-25
• Subjects: Pulmonary Circulation, Pulmonary Embolism, Right Heart Failure - Epidemiology, Prognosis, Outcome; Cardiology -- Periodicals; Heart -- Diseases -- Periodicals; 616.12005
• DOI: 10.1093/ehjci/ehaa946.2242
• Languages: English
• ISSNs: 0195-668X

Abstract

Abstract: Background: Recently, post pulmonary embolism (PE) syndrome or chronic thromboembolic disease after acute PE, has been recognized as important long-term complications. Furthermore, patients may develop with chronic thromboembolic pulmonary hypertension. Purpose: We aimed to evaluate the frequency of residual pulmonary thromboemboli after acute PE by using our "higher"-resolution CT scan imaging method to detect residual thromboemboli down to sub-segmental pulmonary arteries. Methods: This study was a prospective multi-center observational study. We enrolled consecutive 34 patients with acute symptomatic PE whose informed consent was obtained, and followed up for one year. One year after the onset of acute PE, patients were referred to our hospital and multiple examination including CT scan, 6-minute walk test (6MWT), questionnaire of SF-36, echocardiography and laboratory testing were performed. Additionally, we have modified the CT obstruction index (CTOI) to quantitatively evaluate the thromboemboli down to sub-segmental pulmonary arteries. Results: Mean age was 60.5±15.8 years, and 56% were male. No patient was categorized as low recurrent VTE risk which was caused by transient factors, one patient was associated with active cancer, and 12% had known thrombophilia. In 85% of the patients, this onset was the first obvious episode of PE. At diagnosis, elevated B-type natriuretic peptide (BNP) (≥100 pg/ml) or N-terminal (NT)-proBNP (≥500 pg/ml) was observed in 45% of the patients. Median tricuspid regurgitation peak gradient (TRPG) by echocardiography was 30.9 (19.3–50.1) mmHg. Among all, 35% of the patients received single-drug approach with DOACs. At discharge, all of the patients except two were treated with DOACs. One year after the onset, 21% of the patient were in NYHA II and others were in NYHA I. It was notable that pulmonary thromboemboli was detected by our CT scan in 76% of the patients. Modified CTOI was median 11.9 (1.8–24.4) % as shown in the figure. In multiple regression analysis, TRPG at diagnosis and BNP at one month were significantly associated with mCTOI (β=0.536, p=0.002 and β=−0.482, p=0.003, respectively). Additionally, lowest SpO2 during 6MWT after one year from the onset, tended to inversely associate with mCTOI (β=−0.341, p=0.052). Conclusions: Using our modified CT scan imaging method and modified CTOI, residual pulmonary thromboemboli was able to be detected more frequently than the previous studies. Residual pulmonary thromboemboli could be one of the cause of the post PE syndrome and lead to exercise-induced desaturation. Funding Acknowledgement: Type of funding source: None