Chronic total occlusion (CTO) recanalization and its effects on left ventricular function and patient outcomes has intrigued the interventional community over the last several years. Now that there is plenty of knowledge and experience on "how to treat" the lesion, another scientific effort should focus on "when to treat" the lesion. Physiologic assessment has altered the way we treat coronary artery stenosis to improve cardiovascular outcomes. We tend to assess the effects of CTO recanalization by evaluating resting parameters, although the effects of ischemia and concomitant left ventricular dysfunction manifest mainly during exercise. Physiologic assessment in CTOs by implementation of cardiopulmonary exercise testing, in order to indirectly assess the physiological effect of exercise-induced left ventricular dysfunction, could represent a novel approach to monitor the effects of CTO recanalization and hopefully to identify the responders after recanalization.
Keywords: cardiopulmonary exercise test; chronic total occlusion; physiology.