Mielniczuk M; National Research Institute, Warsaw, Poland.
Krzesinski P; Uzieblo-Zyczkowska B; Kwiatkowski P; Kowal J;
Dziuk M; Wlochacz A; Maciorowska M; Malinowski M; Banak M; Surmacz E;
Gielerak G

Cardiology Journal. 33:e00226055, 2026.

BACKGROUND: Chronic total occlusion (CTO) is a common finding on coronary
angiograms of patients diagnosed with coronary artery disease, with an
incidence ranging from 15 to 25%. Despite its high incidence, this type of
coronary lesion is rarely treated with percutaneous coronary intervention.
The key to success appears to be appropriate qualification for
revascularization. Asymptomatic patients should be assessed for inducible
ischemia within the occluded vessel territory to detect patients with a
high ischemic burden, defined as inducible ischemia involving > 10% of the
myocardium. Single-photon emission computed tomography (SPECT) is a
well-established method of myocardial perfusion assessment; however, it is
not widely available, especially in less developed regions. The aim of the
study was to evaluate CTO patients to identify clinical parameters that
could predict the presence of relevant inducible ischemia measured by
SPECT.

METHODS: The study included 50 patients with a single-vessel CTO and
without any other significant coronary artery stenosis. Patients underwent
clinical examination, laboratory tests, echocardiography, 6-minute walk
test, cardiopulmonary exercise testing, exercise impedance cardiography,
and SPECT.

RESULTS: The only parameters associated with a high ischemic burden were
CTO location (in the left anterior descending artery and circumflex
artery) and one echocardiographic parameter: myocardial lateral wall
longitudinal strain.

CONCLUSIONS: Given the high incidence of CTO, there is an increasing need
to define non-invasive markers that could predict the presence of a high
ischemic burden and good clinical outcome after revascularization.
Echocardiographic longitudinal strains are worth further research in terms
of their utility in predicting inducible ischemia.