are taken 2-3 times per day and can be used to prevent angina. beta-blockers may also be used to reduce the incidence of chronic angina. beta-blockers prevent episodes of angina by reducing heart rate and reducing the strength of contraction of the heart, which lowers oxygen demand in the heart. coronary revascularization in individuals with symptoms that are not well controlled with medical and lifestyle therapy there are invasive options available including percutaneous coronary intervention (pci) and coronary artery bypass graft (cabg). pci involves placing a stent to relieve coronary artery blockages. cabg involves grafting new blood vessels to provide a new route for blood flow around the blocked vessel. choice of treatment is based on the number of coronary vessels with blockages, which vessels are effected, and the medical history of the patient. there is not sufficient evidence to suggest that pci or cabg provides a mortality benefit in individuals with stable coronary ischemia. more recently, research has been investigating the short- and long-term efficacy of hybrid coronary revascularization (hcr), a combination of both pci and cabg. some research supports that hcr is a stronger option compared to pci or cabg alone for multivessel coronary artery disease because hcr is better at lowering the risk of short-term adverse cardiac/vascular events. however, long-term prevalence and survival rates of major adverse events were less conclusive, yielding some opposing results. more research is being done in order to determine the long-term effectiveness of the hcr treatment method.