title: Cardiac shock wave therapy for chronic refractory angina pectoris. A prospective placebo-controlled randomized trial.
abstract: BACKGROUND
  Cardiac shock wave therapy (CSWT) delivered to the myocardium increases capillary density and regional myocardial blood flow in animal experiments. In addition, nonenzymatic nitric oxide production and the upregulation of vascular growth factor's mRNA by CSWT have been described. The aim of the study was therefore to test its potential to relieve symptoms in patients with chronic stable angina pectoris.
  
  
  METHODS
  Twenty-one patients (mean age 68.2 ± 8.3 years, 19 males) with chronic refractory angina pectoris and evidence of inducible myocardial ischemia during MIBI-SPECT imaging, were randomized into a treatment (n = 11) and a placebo arm (n = 10). The region of exercise-induced ischemia was treated with echocardiographic guidance during nine sessions over a period of 3 months. One session of CSWT consisted of 200 shots/spot (9--12 spots/session) with an energy intensity of 0.09 mJ/mm(2) . In the control group acoustic simulation was performed without energy application. Medication was kept unchanged during the whole treatment period.
  
  
  RESULTS
  In the treatment group, symptoms improved in 9/11 patients, and the ischemic threshold, determined by cardiopulmonary exercise stress testing, increased from 80 ± 28 to 95 ± 28 W (P= 0.036). In the placebo arm, only 2/10 patients reported an improvement and the ischemic threshold remained unchanged (98 ± 23 to 107 ± 23 W; P= 0.141). The items "physical functioning" (P= 0.043), "general health perception" (P= 0.046), and "vitality" (P= 0.035) of the SF-36 questionnaire significantly improved in the treatment arm, whereas in the placebo arm, no significant change was noted. Neither arrhythmias, troponin rise nor complications were observed during treatment.
  
  
  CONCLUSIONS
  This placebo controlled trial shows a significant improvement in symptoms, quality of life parameters and ischemic threshold during exercise in patients with chronic refractory angina pectoris treated with CSWT. Thus, CSWT represents a new option for the treatment of patients with refractory AP.
authors.affiliation: Division of Cardiology, Swiss Cardiovascular Center, Bern University Hospital, and University of Bern, Switzerland. jean-paul.schmid@insel.ch
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Schmid
authors.forename: Mauro
authors.initials: M
authors.lastname: Capoferri
authors.forename: Andreas
authors.initials: A
authors.lastname: Wahl
authors.forename: Parham
authors.initials: P
authors.lastname: Eshtehardi
authors.forename: Otto Martin
authors.initials: OM
authors.lastname: Hess
mesh_terms: D000368:Aged; D000787:Angina Pectoris / Q000523:psychology / Q000628:therapy*; D002908:Chronic Disease; D005080:Exercise Test; D005260:Female; D019220:High-Energy Shock Waves / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011788:Quality of Life