IVUS might be considered to determine the cause for in-stent restenosis and help guide treatment strategy. Interventionists may treat focal DES restenosis with balloon angioplasty and treat nonfocal DES restenosis with BMS, CABG, or repeat DES with the same or an alternative antiproliferative drug.848,849 Small, observational cohort studies have demon- strated angiographic restenosis rates of 25% to 30% with repeat DES either with the same or an alternative drug.495,849,850 There are no RCTs, and the most appropriate treatment of restenosis of DES remains unknown. 6.4. Clinical Follow-Up At the time of discharge, patients are instructed to contact their physician or seek immediate medical attention if symp- toms recur. Most physicians will give the patient instructions on return to work and timing of return to full activities. The importance of strict compliance with aspirin and P2Y12 inhibitor therapy is ideally emphasized to the patient at the time of discharge and during follow-up visits. Secondary prevention measures after PCI are an essential part of long-term therapy, reducing both future morbidity and mortality associated with CAD, and are discussed in Section 6.5. A follow-up visit after PCI is usually scheduled to assess the patient s clinical status, the patient s compliance with secondary prevention therapies, and the success of secondary prevention measures (eg, blood pressure control, low-density lipoprotein levels, smoking cessation). Routine, periodic stress testing of asymptomatic patients is not considered part of standard patient follow-up. 6.4.1. Exercise Testing: Recommendations Class IIa 1. In patients entering a formal cardiac rehabilitation program after PCI, treadmill exercise testing is reasonable. (Level of Evidence: C) Class III: NO BENEFIT 1. 