Chronic total improvement in ventricular function and survival

Coronary chronic total occlusions (CTOs) are defined as an occluded coronary segment with thrombolysis in myocardial infarction (TIMI) flow 0 for ≥3 months duration (1). According to EuroCTO club consensus, the occlusion duration could be divided into 3 levels of certainty: (I) “certain” (angiographically confirmed), in cases where a previous angiogram performed greater than 3 months ago, confirmed the presence of TIMI 0 flow; (II) “likely” (clinically confirmed), objective evidence of an acute myocardial infarction in the territory of the occluded artery without other possible culprit arteries of more than 3 months before the current angiogram; (III) “undetermined”, TIMI 0 flow and angiographic anatomy suggestive of long-standing occlusion with stable anginal symptoms unchanged in the last 3 months or evidence of silent ischemia (1). Coronary CTOs represent a frequent lesions’ subset observed in ~15% of patients undergoing coronary angiography, with a higher prevalence in those with previous coronary artery bypass grafting (CABG) (2,3). Previously considered to be an indication for surgical myocardial revascularization, the interest of interventional community in CTOs has exponentially grown during the last decade, particularly thanks to an important development in dedicated equipment and techniques (4), and has led to the achievement of high rates of success and low rates of complications by expert operators