Table 4: GRADE Quality of Studies.

Outcome	Design	Quality	Consistency	Directness	Overall Quality
Angina	1 RCT	Poor Unclear dropouts Subanalyses Patients/providers not blinded Greater adverse effects in EECP group.	Exercise duration not significantly different between arms. Authors’ results and conclusions not match.	Not all patients have severe, refractory stable angina. Large exclusion criteria.	Very Low
	Case series Registry studies	Uncontrolled.	Concomitant therapy in patients. Dropouts not accounted for.	Rationale for treatment unclear in some studies – e.g., patient “tune ups”.
Heart Failure	1 unpublished RCT (PEECH)	Poor Unclear dropouts Subanalyses Patients/providers not blinded	Conflicting co-primary endpoint results. Exacerbation of HF in some patients.	Large exclusion criteria.	Very Low
	Case series Registry studies	Uncontrolled.	Concomitant therapy in patients. Dropouts not accounted for.	Registry studies have patients enrolled for angina, not HF.