Release of cardiac biochemical markers after percutaneous myocardial laser or sham procedures

Background Percutaneous myocardial laser (PML) reduces symptoms in patients with intractable angina. PML leads to a certain loss of viable myocardium, we therefore assessed if troponin or cardiac markers release may explain the clinical effect, and furthermore assessed the markers release during percutaneous sham procedures. Methods Eighty-two patients with chronic refractory angina were randomized to either percutaneous myocardial laser or a true sham procedure. Cardiac markers were assessed before the procedure, and ½, 2, 4, 6, and 10–12 h postprocedure. Results Troponin I increased to median peak levels (range) of 4 (0.6–43) μg/L in the laser group vs. 1.5 (0.1–5.9) μg/L, p=0.001, and creatine kinase MB to 14 (6–357) μg/L vs. 11 (3–40) μg/L, p<0.05, within and between-group comparison, the rise of CK-MB occurred significantly earlier in the sham group, 3.8 vs. 2.5 h. A time-dependent between-group difference was only detected for troponin. 88% of sham and 100% of laser patients had marker levels above reference limits. There was no correlation between the number of laser/sham created channels, biomarker levels postprocedure, and changes in left ventricular ejection fraction or angina improvement during 12 months of follow-up. Conclusions The release of cardiac markers is not related to relief of angina after myocardial laser. The use of intracardiac catheters induces a considerable marker release, which is not caused by acute ischemia.