Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022 Feb;52(2):150-161.
doi: 10.4070/kcj.2021.0240. Epub 2021 Nov 26.

Ischemic Burden Assessment Using Single Photon Emission Computed Tomography in Single Vessel Chronic Total Occlusion of Coronary Artery

Affiliations

Ischemic Burden Assessment Using Single Photon Emission Computed Tomography in Single Vessel Chronic Total Occlusion of Coronary Artery

Yong-Hoon Yoon et al. Korean Circ J. 2022 Feb.

Abstract

Background and objectives: Studies evaluating the nature of ischemic burden of chronic total occlusion (CTO) vessels are still lacking.

Methods: A total of 165 patients with single vessel CTO >2.5 mm in an epicardial coronary artery who underwent single photon emission computed tomography (SPECT) were enrolled in the study. Ischemic burden was calculated with the use of semi-quantitative SPECT analysis, and was defined as the summed difference score (SDS) divided by the maximal limit of the score (=SDS/68).

Results: The mean age of the participants was 59.5 years and the CTO of the left anterior descending coronary artery (LAD), left circumplex coronary artery (LCX), and right coronary artery (RCA) accounted for 93 (56.4%), 18 (10.9%), and 54 (32.7%) patients, respectively. The median ischemic burden of the total population was 8.8%, and it was highest in the LAD CTO (10.3%) compared with the LCX (5.9%) and RCA CTO (5.9%, p<0.001). High-ischemic burden (ischemic burden >10%) was observed in 66 patients (40.0%), and in 47 patients (50.5%) of the LAD CTO. Ischemic burden was different according to the CTO location only in LAD CTO. The statistically significant predictors for high-ischemic burden were hypertension, baseline ejection fraction >45%, LAD CTO, proximal CTO location, and de novo CTO. Japanese-CTO score and Rentrop scale collateral grade were not associated with high-ischemic burden.

Conclusions: Only 40% of patients with single vessel CTO had ischemic burden >10%. For CTO vessels, measurement of ischemic burden using SPECT prior to revascularization may be helpful in identifying beneficial subjects.

Keywords: Chronic total occlusion; Ischemic burden; Single photon emission computed tomography.

PubMed Disclaimer

Conflict of interest statement

The authors have no financial conflicts of interest.

Figures

Figure 1
Figure 1. Box-Whisker plot of ischemic burden in each coronary vessel CTO.
CTO = chronic total occlusion; LAD = left anterior descending coronary artery; LCX = left circumflex coronary artery; RCA = right coronary artery
Figure 2
Figure 2. Box-Whisker plot of ischemic burden in each coronary vessel CTO according to CTO location or collateral grade. (A) Ischemic burden based on the location of CTO in each coronary vessel. (B) Ischemic burden based on Rentrop collateral grade in each coronary vessel.
CTO = chronic total occlusion; LAD = left anterior descending coronary artery; LCX = left circumflex coronary artery; RCA = right coronary artery.
Figure 3
Figure 3. Angiography and SPECT images of representative 2 cases. (A) The 65-year-old man presenting with stable chest pain started 4 months ago. An echocardiogram showed EF of 63%, and there was no regional wall motion abnormality. Angiography showed mid LAD CTO with collateral grade 3 via diagonal branch and septal-septal channels. The SPECT showed a low ischemic burden (SRS = 3, SSS = 4, SDS = 1, ischemic burden = 1.5%). (B) The 72-year-old man presenting with stable chest pain started 8 months ago. An echocardiogram showed EF of 47%, and there was regional wall motion abnormality in LAD territory. Angiography showed mid LAD CTO with collateral grade 2 via diagonal branch and septal-septal channels. The SPECT showed a high ischemic burden (SRS = 6, SSS = 20, SDS = 14, ischemic burden = 20.1%).
CTO = coronary total occlusion; EF = ejection fraction LAD = left anterior descending coronary artery; SDS = summed difference score; SPECT = single photon emission computed tomography; SRS = summed rest score; SSS = summed stress score.
Figure 4
Figure 4. Kaplan-Meier curves for long-term clinical outcomes according to high or low ischemic burden at baseline SPECT results.
HR = hazard ratio; MI = myocardial infarction.

References

    1. Lee PH, Lee SW, Park HS, et al. Successful recanalization of native coronary chronic total occlusion is not associated with improved long-term survival. JACC Cardiovasc Interv. 2016;9:530–538. - PubMed
    1. Christakopoulos GE, Christopoulos G, Carlino M, et al. Meta-analysis of clinical outcomes of patients who underwent percutaneous coronary interventions for chronic total occlusions. Am J Cardiol. 2015;115:1367–1375. - PubMed
    1. George S, Cockburn J, Clayton TC, et al. Long-term follow-up of elective chronic total coronary occlusion angioplasty: analysis from the U.K. Central Cardiac Audit Database. J Am Coll Cardiol. 2014;64:235–243. - PubMed
    1. Patel VG, Brayton KM, Tamayo A, et al. Angiographic success and procedural complications in patients undergoing percutaneous coronary chronic total occlusion interventions: a weighted meta-analysis of 18,061 patients from 65 studies. JACC Cardiovasc Interv. 2013;6:128–136. - PubMed
    1. Michael TT, Karmpaliotis D, Brilakis ES, et al. Procedural outcomes of revascularization of chronic total occlusion of native coronary arteries (from a multicenter United States registry) Am J Cardiol. 2013;112:488–492. - PubMed