CARDIAC CATH LAB - Mount Sinai Hospital

Developing a well-designed
and well-supported
technique for clearing
CTOs has become the
last frontier in PCI.
Annapoorna S. Kini, MD
Associate Director, Cardiac
Cath Lab, on Percutaneous
Coronary Intervention for
Chronic Total Occlusion
A chronic total occlusion (CTO) is a complex
blockage of a coronary artery that has
lasted for more than three months. CTOs
are found in 15 to 20 percent of all patients
undergoing coronary angiography. This
subset of lesions has, up until now, proven
to be the least amenable to recanalization
through percutaneous coronary intervention
(PCI), especially when the blockage is calcified
or fibrotic and the obstruction is at an
angulated location, making access more
difficult. Consequently, the traditional
guideline for treating patients with CTO
remains coronary artery bypass surgery. But
because PCI is far less invasive and recovery
tends to be faster, developing a well-designed
and well-supported technique for clearing CTOs has become the
last frontier in percutaneous coronary intervention. Mount Sinai’s
cath lab, a tertiary referral center with special expertise in complex
coronary interventions, has been very much engaged in performing
this task successfully.
Before opening the blockage, we have to make sure that the heart
muscle serving it is still alive and capable of recovery once the
blockage is removed. A stress test or an MRI to check the viability
of myocardium (a gold standard) may be necessary. The remarkable
thing about chronic blockages that develop slowly (60 to 80 percent
and finally 100 percent) as opposed to acute blockages is that
during the gradual progression of a chronic blockage small-diameter
collaterals can develop to maintain sufficient myocardial function.
Often they do a good enough job that the patient is not even aware
of the blockage until it is complete. After the blockage is removed
the collaterals then regress and even wither away.
20 Mount Sinai Hospital Cardiac Cath Lab