Transmyocardial laser revascularisation for refractory angina pectoris(interventional procedures consultation)

NATIONAL INSTITUTE FOR HEALTH AND CLINICAL EXCELLENCE

Interventional procedure consultation document

Laser transmyocardial revascularisation for refractory angina pectoris

Patients with refractory angina pectoris have chest pain (because of insufficient oxygen delivery to their heart muscle) that cannot be controlled by optimal medical or surgical management. Transmyocardial laser revascularisation involves open heart surgery to drill holes on the heart muscle using a laser beam, with the aim of enabling blood flow from the heart chambers into the heart muscle, to relieve myocardial ischaemia and reduce chest pain.

 

The National Institute for Health and Clinical Excellence (NICE) is examining interventional procedure overview of laser transmyocardial revascularisation for refractory angina pectoris and will publish guidance on its safety and efficacy to the NHS in England, Wales, Scotland and Northern Ireland. NICE's Interventional Procedures Advisory Committee has considered the available evidence and the views of Specialist Advisers, who are consultants with knowledge of the procedure. The Advisory Committee has made provisional recommendations about laser transmyocardial revascularisation for refractory angina pectoris.

This document summarises the procedure and sets out the provisional recommendations made by the Advisory Committee. It has been prepared for public consultation. The Advisory Committee particularly welcomes:

  • comments on the provisional recommendations
  • the identification of factual inaccuracies
  • additional relevant evidence, with bibliographic references where possible.

Note that this document is not NICE's formal guidance on this procedure. The recommendations are provisional and may change after consultation.

The process that NICE will follow after the consultation period ends is as follows.

  • The Advisory Committee will meet again to consider the original evidence and its provisional recommendations in the light of the comments received during consultation.
  • The Advisory Committee will then prepare draft guidance which will be the basis for NICE's guidance on the use of the procedure in the NHS in England, Wales, Scotland and Northern Ireland.

For further details, see the Interventional Procedures Programme manual, which is available from the NICE website (www.nice.org.uk/ipprogrammemanual).

NICE is committed to promoting through its guidance race and disability equality and equality between men and women, and to eliminating all forms of discrimination. One of the ways we do this is by trying to involve as wide a range of people and interest groups as possible in the development of our guidance on interventional procedures. In particular, we aim to encourage people and organisations from groups in the population who might not normally comment on our guidance to do so. We also ask consultees to highlight any ways in which draft guidance fails to promote equality or tackle discrimination and give suggestions for how it might be improved. NICE reserves the right to summarise and edit comments received during consultations, or not to publish them at all, where in the reasonable opinion of NICE, the comments are voluminous, publication would be unlawful or publication would otherwise be inappropriate.

Closing date for comments: 24 February 2009

Target date for publication of guidance: May 2009

 

1 Provisional recommendations
1.1 Current evidence on transmyocardial laser revascularisation (TMLR) for refractory angina pectoris shows no efficacy, based on objective measurements of myocardial function or survival.  Evidence on safety suggests that the procedure may pose unacceptable risks. Therefore, this procedure should not be used.

 

2 The procedure
2.1 Indications and current treatments
2.1.1 Angina pectoris is chest discomfort, often described as pressure or pain, typically occurring on exertion. It is caused by inadequate delivery of oxygen to the heart muscle, usually because of coronary artery disease. Refractory angina is a severe form of angina that cannot be controlled by normal medical or surgical treatment.
2.1.2 The treatment and management of angina depends on patient characteristics and coronary angiography findings. Treatments include anti-anginal medication and interventions to improve blood flow (coronary angioplasty, stenting, or coronary artery bypass surgery). For patients with refractory angina, these treatments have either failed or are not clinically suitable, so other treatment options include transcutaneous nerve and spinal cord stimulation.

 

2.2 Outline of the procedure
2.2.1 Transmyocardial laser revascularisation for refractory angina pectoris is carried out under general anaesthesia. A thoracotomy is performed and the pericardium opened. Echocardiography or a myocardial perfusion scan is used to identify myocardium that needs revascularisation, and laser ablation is used to create a number of parallel channels in the myocardium.
2.2.2 A number of different devices can be used for this procedure.

 

A systematic review of the published evidence on the use of the efficacy and safety of transmyocardial and percutaneous laser revascularisation for refractory angina pectoris  was commissioned by NICE. Sections 2.3 and 2.4 describe efficacy and safety outcomes from the systematic review that the Committee considered as part of the evidence about this procedure. For more detailed information on the evidence, see the systematic review, available at www.nice.org.uk/IP374review.

 

2.3 Efficacy
2.3.1 Meta-analysis of 10 randomised controlled trials (RCTs) including a total of 1359 patients indicated that there was no difference in mortality rates at 12-month follow-up between TMLR-treated patients and those in the control groups (who were treated either medically or with coronary artery bypass grafting [CABG]) (odds ratio [OR] 0.89; 95% confidence interval [CI] 0.5 to 1.8). Nor was there any difference in mortality between groups when those studies comparing TMLR plus CABG against CABG alone were excluded from the analysis (OR 0.8; 95% CI 0.5 to 1.2).
2.3.2 An RCT of 100 patients treated with either TMLR or medically reported that wall motion index (examined by dobutamine stress echocardiology or single photon emission computed tomography [SPECT] scan, lower value indicating worse function) was significantly lower in TMLR-treated patients (1.49 ± 0.44) than in patients treated medically (1.56 ± 0.47) at 12-month follow-up (p < 0.05). In the same study the number of non-viable myocardial segments was significantly higher in the TMLR group (89%) than in the medical management group (62%) at 12 months (p < 0.01). Six other RCTs found no significant difference in myocardial perfusion (examined with stress testing or perfusion scanning) in patients treated with TMLR, compared with patients treated medically.Meta-analysis of four RCTs (including a total of 323 patients) reported that the mean improvement (from baseline) in total exercise time was greater in TMLR-treated patients compared with those treated medically at 6‑month follow‑up (pooled mean difference: 120.1 seconds; 95% CI 4.5 to 235.7).
2.3.3 Meta-analysis of three studies (including a total of 135 patients) showed that there was an improvement from baseline in angina score (measured using the Canadian Cardiovascular Society Angina Score or the New York Heart Association Score four-point scales) in TMLR-treated patients compared with those treated medically, with a reduction in the mean difference in angina score between TMLR and non-TMLR treatment groups of –1.8 (95% CI –2.4 to –1.1) at 6‑month follow‑up. The mean difference in angina score between TMLR and non-TMLR treatment groups reduced further at 12‑month follow-up (–1.0; 95% CI –1.7 to –0.3).
2.3.4 Five RCTs measured quality of life. Different instruments were used across the studies, including the Duke Activity Status Index, Seattle Angina Questionnaire, SF 30 and EuroQol questionnaire. One RCT showed no significant difference between patients treated with TMLR and patients treated with thoracic sympathectomy, while the other four RCTs found significant improvements in quality of life for TMLR-treated patients compared with those treated medically (level of significance not stated). Patients were not blinded to their treatment group in any of these studies.
2.3.5 Specialist Advisers considered that key efficacy outcomes included improvement in angina and exercise capacity, reduced medicine use and increased quality of life.

 

2.4 Safety
2.4.1 Meta-analysis of 10 RCTs indicated no difference in perioperative mortality between TMLR-treated patients and patients in control arms treated medically or with CABG (pooled OR 0.78; 95% CI 0.34 to 1.7). However, when two trials comparing TMLR plus CABG against CABG alone were excluded, perioperative mortality was greater in TMLR-treated patients than patients in the control groups (OR 0.35; 95% CI 0.13 to 0.93).
2.4.2 In seven RCTS the overall rate of subsequent myocardial infarction was higher in patients treated with TMLR than in patients in the control groups (6% [41/633] compared with 2% [11/651]; follow-up period 12 months, level of significance not stated).
2.4.3 An RCT of 100 patients reported that postoperative heart failure occurred more frequently in TMLR-treated patients (34% [17/50]) than in patients treated medically (0% [0/50]; level of significance not stated). An RCT of 182 patients reported that thromboembolic events occurred more frequently in TMLR-treated patients (10% [(9/92]) than those treated medically (3% [3/90]; level of significance and follow-up not stated).
2.4.4 A case series of 169 TMLR-treated patients reported that 14% (23/169) developed acute non-inflammatory pericarditis following the procedure (sequelae not reported). In a case series of 20 TMLR-treated patients, acute mitral regurgitation was reported in 5% (1/20). An international multicentre case series of 932 patients reported cardiac tamponade in < 1% (5/932) of patients.
2.4.5 A retrospective non-randomised controlled trial of 255 patients reported that neurologic complications occurred more frequently after TMLR plus CABG (3% [1/36]) than after CABG alone (1% [3/219]; level of significance and follow-up not stated).
2.4.6 Specialist Advisers stated that adverse events reported in the literature included death, myocardial infarct, heart failure, arrhythmias, and wound and other infections.

 

2.5 Other comments
2.5.1 The Committee noted that some studies showed improvements in symptoms and quality of life, but considered that these were likely to be placebo responses, in the light of evidence which showed no objective benefits.
2.5.2 The Committee considered evidence on TMLR alone for refractory angina pectoris, and also on TMLR performed concomitantly with CABG.

 

Bruce Campbell

Chairman, Interventional Procedures Advisory Committee

December, 2008

 

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This page was last updated: 30 March 2010