Efficacy of EECP Treatment

While EECP has been the standard of practice in China for some time, American cardiologists weren’t aware of its value until this paper came out in '92. Lawson and associates describe the short term benefits of EECP in 18 patients with refractory angina (persistent symptoms despite maximum medical therapy) in patients who are not felt to be good candidates for further bypass or angioplasty. As you would predict, this was an extremely ill, actually desperate group of patients. Eight had undergone a total of 19 angioplasty or bypass procedures; seven had sustained a total of 14 heart attacks. All three coronary arteries were blocked in 4, two vessels in 8, and three patients had single vessel disease.

Following an initial symptom limited nuclear stress test, all 18 patients received 35 one hour EECP treatments over a 7 week period. Anti-anginal medications were continued, but per the study protocol the doses could not be increased. Upon completion of EECP, the nuclear stress test was repeated, at the pre-treatment distance. (If the scan was done at 5 minutes of treadmill exercise pre-EECP, the post-EECP scan was carried out at 5 minutes. This way the investigators could see if EECP improved blood flow at a given level of exercise). A post-EECP symptom limited stress test was also carried out, to determine if treadmill time and exercise capacity would improve.

Angina improved substantially in all 18; 16 reported a complete absence of pain during their usual activities. The nuclear scan abnormality indicating ischemia (viable heart muscle with a compromised blood supply) fully resolved in 2/3rds of the patients, just as it would following a successful angioplasty or bypass. In 4 patients, the scan remained abnormal, while in 2 the scan improved without fully normalizing. Thus an objective improvement in blood flow to the heart muscle was demonstrated in 77% of the patients. Treadmill time increased by 1.6 min, or 20%, for the entire group, and by 1.9 min, or 22%, in the 14 patients whose flow scans improved. No side-effects were reported.