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

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)

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.

Eligibility Criteria:
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