Background: Chronic angina and advanced forms of coronary disease are increasingly more frequent. Although the improved efficacy of available revascularization treatments, a subgroup of patients present with refractory angina. Transmyocardial laser revascularization (TMLR) has been proposed to improve the clinical situation of these patients.
Objectives: To assess the efficacy and safety of TMLR versus optimal medical treatment in patients with refractory angina in alleviating the severity of angina and improving survivorship and heart function.
Search strategy: We searched the Cochrane Central Register of Controlled Trials on The Cochrane Library (Issue 2 2007), MEDLINE (January 2006 to June 2007), EMBASE ( 2004 to June 2007) and ongoing studies were sought using the metaRegister of Controlled Trials database (mRCT) and ClinicalTrials.gov databases. No languages restrictions were applied. Reference lists of relevant papers were also checked.
Selection criteria: Studies were selected if they fulfilled the following criteria: randomized controlled trials of TMLR, by thoracotomy, in patients with angina grade III-IV who were excluded from other revascularization procedures. From a total of 181 references, 20 papers were selected, reporting data from seven studies.
Data collection and analysis: Two reviewers abstracted data from selected papers; . The reviewers performed independently both quality assessment and data extraction. Selected studies present methodological weaknesses. None of them fulfilled all the quality criteria.
Main results: Seven studies (1137 participants of which 559 randomized to TMLR) were included. Overall, 43.8 % of patients in the treatment group decreased two angina classes as compared with 14.8 % in the control group, odds ratio (OR) of 4.63 (95% confidence interval (CI) 3.43 to 6.25), and heterogeneity was statistically significant. Mortality by intention-to-treat analysis at both 30 days (4.0 % in the TMLR group and 3.5 % in the control group) and 1 year (12.2 % in the TMLR group and 11.9 % in the control group) was similar in both groups. The 30-days mortality as treated was 6.8% in TMLR group and 0.8% in the control group, showing a statistically significant difference. The pooled OR was 3.76 (95% CI 1.63 to 8.66), because of the higher mortality in patients crossing from standard treatment to TMLR.
Authors' conclusions: There is insufficient evidence to conclude that the clinical benefits of TMLR outweigh the potential risks. The procedure is associated with a significant early mortality.