Prospective studies of EECP in patients with predominantly stable angina were eligible for inclusion. Studies had to report usable data on CCS angina class in the form of classes reported before and after 35 one-hour EECP sessions. Studies that reported data as mean baseline angina class before and after treatment were excluded. Studies from International EECP Patient Registry (IEPR) and EECP Consortium register were excluded to prevent double counting. Case series, case reports and abstracts were excluded.
The included trials studied 34 to 35 sessions of EECP over four to seven weeks in patients with chronic stable angina. Baseline CCS class varied from 1-4 to 3-4. Patient age, where reported, ranged from 61 to 68 years. The proportion of patients who had undergone previous percutaneous coronary intervention (PCI) ranged from 20% to 88%, undergone previous coronary artery bypass surgery (CABG) ranged from 41% to 91% and those with a previous myocardial infarction ranged from 30% to 79%.
The authors did not state how many reviewers performed study selection.