Noninvasive Testing in Known SIHD For any patients with known SIHD who have recurrent but stable symptoms after having been symptom free for a period of time on GDMT or after revascularization and who do not fall into any of the categories listed in the previous paragraph, the concepts underlying the recommendations for Noninva- sive Testing for Diagnosis of IHD from Section 2.2 gener- ally apply, with the modifications and special consideration discussed below. 6.3.1. Follow-Up Noninvasive Testing in Patients With Known SIHD: New, Recurrent, or Worsening Symptoms Not Consistent With Unstable Angina: Recommendations See Table 20 for a summary of recommendations from this section. 6.3.1.1. Patients Able to Exercise Class I 1. Standard exercise ECG testing is recommended in patients with known SIHD who have new or wors- ening symptoms not consistent with UA and who have a) at least moderate physical functioning and no disabling comorbidity and b) an interpretable ECG.114,145 147 (Level of Evidence: B) 2. Exercise with nuclear MPI or echocardiography is rec- ommended in patients with known SIHD who have new or worsening symptoms not consistent with UA and who have a) at least moderate physical functioning or no disabling comorbidity but b) an uninterpretable ECG.172,276,278,284,306,313,314,320,324,327 329,1237 1240 (Level of Evidence: B) Class IIa 1. Exercise with nuclear MPI or echocardiography is reasonable in patients with known SIHD who have new or worsening symptoms not consistent with UA and who have a) at least moderate physical function- ing and no disabling comorbidity, b) previously required imaging with exercise stress, or c) known multivessel disease or high risk for multivessel dis- ease.1241,1242 (Level of Evidence: B) Class III: No Benefit 1. 