Intermediate-term clinical outcome following transmyocardial laser revascularization in patients with refractory angina pectoris.

BACKGROUND: This study was conducted to examine the intermediate-term clinical outcomes in patients with refractory angina pectoris treated with transmyocardial laser revascularization (TMR) at our institution. TMR is an alternative surgical technique for the treatment of myocardial ischemia and angina pectoris not amenable to conventional percutaneous or surgical revascularization. Limited data exist evaluating the natural history and duration of clinical improvement in angina pectoris following TMR. METHODS AND RESULTS: Thirty-four patients with severe coronary artery disease unsuitable for treatment with standard revascularization techniques underwent TMR in myocardial regions determined to be ischemic by preoperative SPECT (201)Tl perfusion imaging following dipyridamole stress. Patients were assessed postoperatively at 3, 6, and 12 months for clinical outcomes including death, myocardial infarction, functional class of angina pectoris, and hospitalizations for unstable angina. Myocardial perfusion imaging by (201)Tl scintigraphy was also assessed at these temporal end points. Overall mortality at 1 year was 14.7% (n=5). Nonfatal myocardial infarction occurred in 3 patients (8.8%). Among the patients with complete 12-month follow-up (n =27), mean anginal class improved from 3.5+/-0. 5 pre-TMR to 2.8+/-0.7 and 2.5+/-0.7 at 3 and 6 months, respectively, and 2.8+/-0.9 at 12 months. Overall improvement in angina pectoris was sustained at 1 year by at least one functional class in 50% of patients. Mean hospitalizations per year for unstable angina declined from 2.4+/-1.6 pre-TMR to 1.7+/-2.0 post-TMR (P=0.01). There was no significant improvement in perfusion by SPECT (201)Tl imaging at any temporal end point post-TMR. CONCLUSIONS: Despite the lack of demonstrable improvement in perfusion by SPECT (201)Tl imaging, TMR improved the functional class of angina pectoris in patients with end stage coronary artery disease to a modest degree. Although the maximal benefit in symptoms occurred at 6 months post-TMR, mild sustained clinical improvement above baseline was evident in 50% of patients at 1 year.

Diagnosis, incidence, and clinical significance of early postoperative ischemia after transmyocardial laser revascularization.

BACKGROUND: Clinical improvement after transmyocardial laser revascularization (TMR) is typically delayed, and patients therefore remain at risk for ischemic events after the procedure. The purpose of this study was to define the range of creatine phosphokinase (CPK) and CPK-MB enzyme elevation after TMR and to assess the incidence of early postoperative ischemic events. METHODS: Twenty-one patients undergoing isolated TMR were evaluated for 48 hours after surgery with serial CPK and CPK-MB enzymes and 12-lead electrocardiograms for evidence of myocardial ischemia or injury. Clinically evident postoperative ischemic events including angina pectoris, myocardial infarction (MI), and cardiac death were recorded as well. RESULTS: Eleven patients (52.4%) had ischemic electrocardiographic changes in the first 48 hours after TMR. Ischemia was clinically silent in 7 (63.6%) of these 11 patients. Cardiac death occurred in 1 patient (4.8%) as a result of acute MI. Nonfatal MI occurred in an additional 4 patients (19.0%). Of the 5 patients with MI, 4 had angina pectoris versus no angina in the 16 patients without MI (P =.02). All patients had elevated CPK and CPK-MB levels after TMR: however, peak CPK (P =.02) and CPK-MB (P =. 005) levels were significantly higher for patients suffering postoperative MI compared with those without MI. CONCLUSIONS: Transient ischemia occurs frequently after TMR and is clinically silent in the majority of patients. Patients with postoperative MI are more likely to have symptomatic ischemia as well as significant cardiac enzyme elevation. The combination of 12-lead electrocardiogram and cardiac enzymes appears to have significant merit for the diagnosis of myocardial ischemia and infarction after TMR. These studies should be obtained in all patients undergoing TMR for the first 48 hours after surgery.

Perioperative morbidity and mortality after transmyocardial laser revascularization: incidence and risk factors for adverse events.

OBJECTIVES: The purpose of this study was to describe the incidence and spectrum of perioperative cardiac and noncardiac morbidity and mortality after transmyocardial laser revascularization (TMR) and to identify predictors of these adverse clinical events. BACKGROUND: Clinical studies have demonstrated the efficacy of TMR for relieving angina pectoris, although no study to date has specifically addressed the associated perioperative morbidity and mortality. METHODS: Between October 1995 and August 1997, 34 consecutive patients with end-stage coronary artery disease (CAD) underwent isolated TMR. The majority of patients (94%) had class III or IV angina pectoris, and two patients (6%) had unstable symptoms preoperatively. Patient records were reviewed for fatal and nonfatal adverse cardiac and noncardiac events. RESULTS: Perioperative death occurred in two patients (5.9%) due to cardiogenic shock complicating acute myocardial infarction. Perioperative cardiac morbidity occurred in 16 patients (47.1%); noncardiac morbidity was seen in 12 patients (35.3%). Preoperative unstable angina was the only variable predictive of perioperative death (p = 0.005). Cardiac (p = 0.005) and noncardiac (p < 0.001) morbidity rates were significantly higher for the initial 15 patients undergoing the procedure. Other predictors of perioperative complications included lack of postoperative treatment with a furosemide infusion (p < or = 0.04) and preoperative unstable angina (p = 0.05). CONCLUSIONS: Perioperative mortality in patients undergoing isolated TMR is low. Transmyocardial laser revascularization patients are at higher risk for adverse perioperative cardiac and noncardiac events, likely reflecting the lack of immediate benefit from the procedure in the setting of severe CAD. These patients merit vigilant surveillance for adverse events and aggressive medical management in the perioperative period.

Improvement in inducible ischemia during dobutamine stress echocardiography after transmyocardial laser revascularization in patients with refractory angina pectoris.

OBJECTIVES: The purpose of this ongoing study is to determine whether transmyocardial laser revascularization (TMLR) can lessen inducible ischemia and improve contractile reserve in patients with refractory angina pectoris. BACKGROUND: TMLR is an emerging surgical technique for the treatment of myocardial ischemia and angina pectoris not amenable to conventional percutaneous or surgical revascularization. Objective data documentating a reduction in ischemia during noninvasive stress testing after TMLR are rare. METHODS: Fifteen patients with severe coronary artery disease unsuitable for treatment with standard revascularization techniques were studied with dobutamine stress echocardiography (DSE) before TMLR. Of the 12 patients who underwent TMLR, DSE was repeated at 3 months postoperatively in 11 patients and at 6 months in 9 patients. Stress echocardiograms were analyzed for inducible ischemia, with calculation of the wall motion score index (WMSI). Heart rate and dobutamine dose achieved at peak stress were also assessed as indexes of stress tolerance. RESULTS: Compared with that before TMLR, wall motion at rest for all myocardial segments did not change significantly after TMLR, although there was a mild improvement in the WMSI of the lased myocardial regions ([mean +/- SD] 1.64 +/- 0.34 after vs. 1.78 +/- 0.34 before TMLR, p < 0.05). Overall WMSI at peak stress improved markedly after TMLR (1.70 +/- 0.30 after vs. 2.06 +/- 0.31 before TMLR, p < 0.002), with the improvement in WMSI limited to the lased segments only (1.47 +/- 0.31 after vs. 2.15 +/- 0.34 before TMLR, p < 0.0004). The improvement in WMSI with stress resulted primarily from a decrease in the percentage of ischemic segments (47% before vs. 23% after TMLR, p < 0.0008), with no change in the percentage of infarcted segments (23% before vs. 26% after TMLR). Heart rate (83 +/- 5 beats/min before vs. 102 +/- 21 beats/min after TMLR, p = 0.01) and dobutamine infusion rate (26 +/- 9 micrograms/kg body weight per min before vs. 34 +/- 9 micrograms/kg per min after TMLR) achieved at peak stress also increased postoperatively, consistent with improved stress tolerance. The reduction in ischemic wall motion abnormalities and improved stress tolerance persisted at 6 months, without evidence of further improvement or deterioration of function over time. CONCLUSIONS: TMLR performed in patients with refractory angina pectoris reduces ischemic wall motion abnormalities and improves stress-induced tolerance during dobutamine echocardiography. These beneficial effects persist up to 6 months postoperatively.