Elsevier

The Lancet

Volume 353, Issue 9152, 13 February 1999, Pages 519-524
The Lancet

Articles
Transmyocardial laser revascularisation in patients with refractory angina: a randomised controlled trial

https://doi.org/10.1016/S0140-6736(98)11478-2Get rights and content

Summary

Background

Transmyocardial laser revascularisation (TMLR) is used to treat patients with refractory angina due to severe coronary artery disease, not suitable for conventional revascularisation. We aimed in a randomised controlled trial to assess the effectiveness of TMLR compared with medical management.

Methods

188 patients with refractory angina were randomly assigned TMLR plus normal medication or medical management alone. At 3 months, 6 months, and 12 months after surgery (TMLR) or initial assessment (medical management) we assessed exercise capacity with the treadmill test and the 12 min walk.

Findings

Mean treadmill exercise time, adjusted for baseline values, was 40 s (95% CI-15 to 94) longer in the TMLR group than in the medical-management group at 12 months (p=0·152). Mean 12 min walk distance was 33 m (-7 to 74) further in TMLR patients than medical-management patients (p=0·108) at 12 months. The differences were not significant or clinically important. Perioperative mortality was 5%. Survival at 12 months was 89% (83-96) in the TMLR group and 96% (92-100) in the medical-management group (p=0·14). Canadian Cardiovascular Society score for angina had decreased by at least two classes in 25% of TMLR and 4% of medical-management patients at 12 months (p<0·001).

Interpretation

Our findings show that the adoption of TMLR cannot be advocated. Further research may be appropriate to assess any potential benefit for sicker patients.

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.

Section snippets

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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