Change in Exercise Capacity as Measured by Peak Oxygen Uptake After CTO PCI

PURPOSE: The purpose of this project is to objectively assess the change (improvement) in
exercise capacity in patients undergoing routine percutaneous coronary intervention (PCI)
for chronic total occlusion (CTO)

AIMS: The primary aim of this study is to identify any improvement in exercise capacity as
measured by peak oxygen uptake (VO2) and quality of life survey, for both symptomatic and
asymptomatic patients (each group will be analyzed separately). 2) The secondary aim is to
identify any cardiopulmonary exercise testing (CPX) predictors of exercise improvement that
may then be used for selecting optimal CTO PCI candidates

RATIONALE: Chronic Total Occlusion (CTO) of a coronary vessel is defined as 100% occlusion
of a coronary artery for more than 3 months. The prevalence of coronary CTO ranges from
18-34% in patients with coronary artery disease. Because of new developments in the
techniques and the available technology Chronic Total Occlusion Percutaneous Coronary
Intervention (CTO PCI) has been performed more frequently. The effects of successful CTO PCI
on the objective findings of CPX has never been studied before. Registry and retrospective
small studies have shown that successful CTO PCI decreases angina and ischemic burden,
improves left ventricular function, reduces the risk of arrhythmias, increases tolerance to
acute coronary syndromes, decreases the need for coronary artery by pass surgery, and
improves the patient quality of life. The American College of Cardiology - American Heart
Association PCI Guidelines give this procedure a Class IIa recommendation in specialized
centers with expertise in CTO PCI. The ultimate goal of coronary intervention is not only
improved survival and surrogate markers like left ventricular function, but improvement of
quality of life. While angina is a subjective marker of quality of life, the patient's
experience of angina will depend upon the degree to which the patient engages in exertion.
Many patients subconsciously or consciously adjust their routine activities and exercise
level to be below the threshold at which they experience angina, shortness of breath, or
fatigue. The investigators therefore aim to quantify the degree to which there is any change
in exercise capacity as measured by peak oxygen uptake (VO2) and a quality of life
questionnaire. This information may help future patients and physicians provide prognostic
information about the potential benefits of CTO PCI. Furthermore, as a secondary aim, the
investigators will evaluate any CPX predictors of post PCI improvement in exercise capacity.
This information may help establish algorithms for those patients who will most benefit from
CTO PCI. The investigators aim to 1- objectively quantify the negative effects of coronary
CTO on the CPX parameters (peak oxygen uptake), 2- demonstrate the effects of successful CTO
PCI on CPX parameters especially in asymptomatic patients 3- determine the patient and
procedural findings that determine improvement in CPX parameters.

Inclusion Criteria:

- Patients who present for percutaneous intervention of chronic total occlusion who are
able and willing to perform treadmill cardiopulmonary stress testing before and after
the intervention

Exclusion Criteria:

- Patients who present for percutaneous intervention of chronic total occlusion who are
unable or unwilling to perform treadmill cardiopulmonary stress testing before and
after the intervention