Noninvasive characterization of myocardium after transmyocardial laser revascularization.
OBJECTIVE
The therapeutic mechanism of transmyocardial revascularization (TMR) is not yet fully understood, and continues to be a subject of controversy and active research. Immediate direct laser channel flow, gradual angiogenesis, denervation, and perioperative infarction of the ischemic area have been all discussed, without clear evidence indicating superiority of individual factors.


METHODS
We utilized a prospective noninvasive physiologic dynamic method to assess laser-related myocardial injury. The study protocol included EKGs and echocardiograms, including intraoperative transesophageal echocardiograms (TEE) on consecutive TMR patients. CPK-MB was measured postoperatively, with 5 samples at 6-hour intervals.


RESULTS
Fifty male patients averaging 62 years old were enrolled in the study. Two patients experienced postoperative myocardial infarctions, from which 1 died. The average CPK-MB values were 12.8+/-1.28 immediately after surgery, 19.2+/-2.4 at 6 h, 15.2+/-2.3 at 12 h, 12.2+/-6.3 at 18 h, and 11.7+/-1.3 at 24 h. In only 5 patients were the CPK-MB values over 30 units at their peak. The intraoperative wall motion remained unchanged in the patients studied, both using TEE and transthoracic echography.


CONCLUSIONS
Significant myocardial injury after TMR appears unlikely, as indicated by CPK-MB and myocardial wall dynamics. Furthermore, TMR does not seem to aggravate baseline myocardial ischemia. We found no evidence to support a hypothesis that surgical myocardial injury constitutes the mechanism of therapeutic action in TMR.
Jones
J W
JW
Department of Surgery, University of Missouri-Columbia, MO 65212, USA. JonesJW@health.missouri.edu
Richman
B W
BW
Baldwin
J C
JC
Losanoff
J E
JE
D000328:Adult; D000368:Aged; D016342:Angioplasty, Laser / Q000009:adverse effects* / Q000379:methods; D003327:Coronary Disease / Q000175:diagnosis / Q000601:surgery*; D003402:Creatine Kinase / Q000032:analysis*; D052279:Creatine Kinase, MB Form; D017548:Echocardiography, Transesophageal / Q000379:methods*; D004562:Electrocardiography / Q000379:methods*; D006801:Humans; D007527:Isoenzymes / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000009:adverse effects / Q000379:methods; D017202:Myocardial Ischemia / Q000175:diagnosis / Q000401:mortality; D015428:Myocardial Reperfusion Injury / Q000175:diagnosis* / Q000401:mortality; D009204:Myocardial Revascularization / Q000009:adverse effects / Q000379:methods; D011379:Prognosis; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D015996:Survival Rate
D007527:Isoenzymes; D003402:Creatine Kinase; D052279:Creatine Kinase, MB Form