ArticlesTransmyocardial laser revascularisation in patients with refractory angina: a randomised controlled trial
Introduction
Most patients with angina due to coronary artery disease respond adequately to treatment with antianginal medication, coronary angioplasty with or without stenting, or coronary-artery bypass surgery. Some patients, however, present with angina that is refractory to such treatments, generally because the coronary disease is diffuse and in the distal part of their coronary circulation. Transmyocardial laser revascularisation (TMLR) is a new technique that uses laser ablation to create transmural channels in ischaemic myocardium. Animal studies have shown improvements in mortality, decreases in infarct size, and preservation of contractile function.1, 2, 3 Early results of TMLR in human beings, sometimes used in combination with coronary-artery bypass surgery, have been encouraging.4, 5, 6
The effectiveness of TMLR remains largely unproven, although a multicentre uncontrolled trial in the USA7 has suggested improvements in anginal symptoms and myocardial perfusion. A subsequent US randomised controlled trial is yet to publish its findings, but its results have led the Food and Drug Administration to approve the technology.8 We undertook a randomised controlled single-centre trial to assess the effectiveness and costs of TMLR in terms of exercise capacity, angina, myocardial perfusion, health-related quality of life, mortality, and resource use.
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Patients
All patients who were referred for recruitment were assessed at the trial centre. Refractory angina was generally due to diffuse and distal distribution of disease. Eligible patients were required to have reversible ischaemia seen on radionuclide myocardial perfusion scan. Patients were excluded if they were unable to do treadmill exercise testing, had a left-ventricular ejection fraction of less than 30%, were suitable for conventional revascularisation, were on intravenous therapy to control
Results
188 (60·3%) of 312 patients were enrolled (figure 1). 124 patients were excluded: 57 had no evidence of reversible ischaemia; 29 underwent conventional revascularisation procedures; nine had a left-ventricular ejection fraction of less than 30%; two were unable to participate in treadmill testing; 17 refused to participate; six patients had other contraindications; one died before making a decision; and three did not complete their assessment.
At initial assessment, the medical-management and
Discussion
Our trial showed no clinically important difference between groups in treadmill exercise time or 12 min walking distance. Angina symptoms did, however, improve significantly, albeit less than in previous studies: 34% of TMLR patients improved by two Canadian Cardiovascular Society score for angina classes at 3 months, compared with 75% in a US report7 and 47% in the international registry.15 Scoring of physician-rated angina is variable between centres. Patients” reports of perceived angina
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