Percutaneous laser coronary angioplasty

Coronary artery disease (CAD) refers to the narrowing and occlusion of the coronary arteries as a result of atherosclerosis. This can cause angina, myocardial infarction and heart failure.

Treatment options for patients with CAD with severe stenosis or occlusion include thrombolysis, percutaneous balloon angioplasty, stent placement, percutaneous cutting balloon or coronary artery bypass grafting.

Percutaneous laser coronary angioplasty has been used for CAD with severe stenosis or atherosclerotic occlusion, when standard techniques for recannalisation are unlikely to succeed or have failed.

Percutaneous laser coronary angioplasty aims to penetrate plaque within coronary arteries that is not amenable to standard techniques such as balloon angioplasty or stenting alone.

A thin, flexible fibre-optic catheter connected to a laser-generating source outside the body is introduced via the femoral artery. The catheter is advanced over a guidewire through the artery to the blockage in the coronary artery, under fluoroscopic guidance. The tip of the catheter system emits pulses of laser light to vaporise the plaque while being slowly advanced across the lesion.

Percutaneous laser coronary angioplasty has also been done using a laser guidewire system but that method is not now in regular use.

This procedure is often used with adjunctive balloon angioplasty and followed by angiography to document the results.

A randomised controlled trial (RCT) of 303 patients treated with laser guidewire or mechanical guidewire reported procedural success (defined as the ability to cross the target lesion at the first attempt) in 53% (76 out of 144) and 47% (75 out of 159) of patients respectively (p=0.33). A non-randomised controlled study of 3,733 procedures reported that 'lesion success' assessed angiographically was achieved in 89% and 94% of native vessels treated with laser angioplasty using 2 different laser devices, and in 91% and 95% of saphenous vein grafts for which laser treatment was attempted (absolute figures not stated). A case series of 958 patients reported that among 55 patients who underwent immediate postoperative angiographic assessment, coronary stenosis (assessed by the percentage of artery diameter blocked) decreased from 83% at baseline to 49% following laser angioplasty and to 38% following adjunctive balloon angioplasty (absolute figures not stated).

The RCT of 303 patients treated with laser guidewire or mechanical guidewire reported no major adverse cardiac events in 54% (78 out of 144) and 67% (106 out of 159) of patients respectively at 400-day follow-up (p=0.026).

Major adverse cardiac events (death, myocardial infarction or revascularisation) were more frequent after laser angioplasty compared with balloon angioplasty in the meta-analysis of 9,222 patients at up to 1‑year follow-up (odds ratio [OR] 1.32; 95% confidence interval [CI] 1.01 to 1.73).

A case series of 1,862 patients reported that 71% of patients had an improvement in their angina symptoms, 13% had unchanged symptoms and 16% had worse symptoms at 6-month median follow-up (absolute figures not stated).

A meta-analysis of 16 studies including a total of 9,222 patients reported that angiographically measured restenosis occurred more frequently after laser angioplasty than after balloon angioplasty (OR 1.55; 95% CI 1.09 to 2.20) at follow-up of between 3 months and 1 year. An RCT of 96 patients treated by laser angioplasty and adjunctive balloon angioplasty or by balloon angioplasty alone reported restenosis in 52% and 47% of patients respectively at 163 days median follow-up (p=not significant; absolute figures not stated).

The case series of 1,862 patients reported restenosis greater than 50% of the artery diameter in 54% (434 out of 797) of eligible patients undergoing angiographic assessment at 6-month median follow-up. A case series of 495 stenosed saphenous vein grafts treated by laser angioplasty reported restenosis in 55% of the 161 patients who had angiographic assessment at 6-month follow-up (absolute figures not stated).

The Specialist Advisers listed key efficacy outcomes as procedural success, angiographic success, quality-of-life scores, target vessel revascularisation and cardiac enzyme level post procedure.

The meta-analysis of 9,222 patients treated by laser angioplasty or balloon angioplasty reported no difference between the groups in the rate of myocardial infarction at 30-day follow-up (OR 1.39; 95% CI 0.69 to 2.82). A meta-analysis of 3,012 patients being treated for in-stent restenosis reported that the pooled mean rate of major adverse cardiac events was 35% for laser angioplasty, 29% for balloon angioplasty and 31% for stent-in-stent treatment (absolute figures not stated).

A non-randomised controlled study of 8,932 procedures reported that the rate of arterial perforation was 2% (5 out of 242) for laser angioplasty, less than 1% (11 out of 7,905) for balloon angioplasty and 0% (0 out of 116) for mechanical rotational atherectomy.

The Specialist Advisers listed theoretical adverse events as death, coronary dissection, abrupt vessel closure, thermal damage to the vessel and restenosis.