Treatment Strategies for Coronary Artery Occlusion (CTO)

Treatment Strategies for Coronary Artery Occlusion (CTO)

Clinical presentations of CTO patients are diverse. Most CTO patients undergoing PCI have typical angina symptoms, while 11%–15% are asymptomatic. 42%–68% of CTO patients confirmed by coronary angiography have a history of myocardial infarction. CTO patients can be broadly divided into two categories based on their clinical presentation: one group presents with stable angina, resting myocardial ischemia, or ischemic heart failure; the other group presents with new-onset angina or acute coronary syndrome caused by other vessel occlusions. In the latter group, the discovery of CTO is purely accidental.

The treatment strategy for the first group is more challenging, especially when patients have multivessel disease. Surgical CABG is generally preferred for these patients to achieve complete revascularization, while PCI often fails to achieve complete revascularization due to the presence of CTO lesions. PCI can be considered as an alternative treatment option when the patient has no left main coronary artery disease and CABG is contraindicated. When performing PCI on patients with CTO (coronary artery lesions) and multivessel coronary artery disease (MCAD), a staged approach is recommended to avoid excessively long single procedures and high contrast agent doses. The decision of which vessel to intervene first, whether CTO or non-CTO, should be based on the assessment of the vessel's importance. If the CTO vessel is crucial and contains a large amount of viable myocardium, it should be intervened first. A successfully opened CTO vessel can also provide retrograde collateral blood supply to severely diseased collateral vessels. If the CTO vessel has poor collateral circulation or requires intervention via a retrograde route, the stenotic lesions in the collateral vessels should be addressed first.

In patients with acute coronary syndrome, treatment strategy development is relatively straightforward. We generally intervene first on the culprit vessel, and then intervene on the CTO and other diseased vessels based on the specific circumstances. Furthermore, because patients with acute coronary syndrome often require the use of glycoprotein IIb/IIIa receptor antagonists and direct thrombin inhibitors, simultaneous CTO-PCI is not appropriate. Furthermore, when determining a patient's treatment strategy, the patient's clinical and imaging characteristics, as well as their expected quality of life, should be considered as important factors. If the patient is relatively young, the necessity of revascularization is high; if the patient is older and has a low life expectancy and quality of life, relatively conservative drug therapy may be adopted. The length of occlusion time directly affects the success rate of CTO-PCI. The longer the occlusion time, the lower the success rate of PCI.