Cardiac revascularization--a need for independent decision-makers
Authors: L. C H John
Journal: Journal of the Royal Society of Medicine (2005)

Cardiac surgeons are noticing two trends. The first is a decline in the number of cases referred for coronary surgery. The second is that an increasing number of patients so referred have previously received stents. Some of these have received multiple stents to the extent that a suitable site to graft is difficult to find. Surgeons speculate as to whether these patients have received the best treatment. They have needed to undergo multiple interventions, they have possibly sustained myocardial damage following stent occlusion and the siting of their coronary grafts sometimes has to be suboptimal.

It is cardiologists who usually decide which intervention is most appropriate—angioplasty or surgery—and there is little information to guide their choice. Few clinical trials have reached firm conclusions as to the relative merits of these treatments. The RITA-1 study (Randomised Intervention Treatment of Angina), with a median follow-up of 6.5 years, indicated significantly more angina and reintervention with angioplasty.1 The BARI study (Bypass Angioplasty Revascularization Investigation) reported that 7-year survival was greater in the surgical group (84.4% v 80.9% [P=0.043]) although this difference was principally amongst diabetic patients (76.4% v 55.7%).2 In addition, reintervention rates were greater in the angioplasty group (59.7% v 13.1%). A meta-analysis of randomized trials comparing angioplasty alone with surgery3 revealed, in addition to less angina and reintervention, a 1.9% absolute survival advantage favouring surgery over angioplasty for all trials at 5 years. Angioplasty is now usually accompanied by stent insertion. The SOS trial (Stent Or Surgery) showed more reintervention (21% v 6%) and a greater mortality (5% v 2%) for stenting than for surgery at a median follow-up of 2 years.4

Despite the verdict of many trialists that surgery gives more favourable results, few have emphasized its superiority. These are several reasons for this. Some believe the lower cost of angioplasty is an important advantage to set against the better clinical results with surgery;5 however, the increased need for reintervention evens out the longterm cost.1 Another reason is the complication rate, but the mortality of routine surgery is similar to that of routine angioplasty and there are no differences in cognitive function 5 years later.6 Some suggest that patients prefer the less invasive approach of angioplasty; however, in a study of patient preferences the most important consideration was avoidance of the need for reintervention.7

The high incidence of restenosis following angioplasty was once described as its Achilles' heel but some cardiac surgeons now compare interventional cardiology with the Hydra, who, when decapitated, grows another head. This may prove to be true of drug-eluting stents. Although these have a much lower rate of restenosis than conventional stents they do not completely prevent it,9,10 and long-term follow-up may reveal cases of late thrombosis as well as aneurysm formation.11

The range of available interventions for coronary artery disease is large. It includes coronary artery bypass grafts (CABG) with a mixture of venous and arterial grafts, CABG with total arterial revascularization, off-pump CABG, minimal-access CABG, robotic CABG, hybrid CABG with angioplasty, angioplasty, rotablation, various stents, and irradiation (brachytherapy). With such a range of techniques the optimum treatment for an individual can be very hard to decide—what is the balance between the risks and the short and long term aims? The best intervention for an 85-year-old person who hopes for symptomatic relief is unlikely to be the same as that for a 45-year-old person whose interest is in maximum long-term benefit and survival. In the past an important consideration was the length of the respective waiting lists, usually longer for surgery than for angioplasty. However, surgical waiting lists have lately come down dramatically and in some units patients now wait longer for angioplasty.

Who can best advise the patient on what treatment to have? Inevitably, a specialist in one technique will be biased towards that technique simply by having greater knowledge of its application. In one study of appropriateness for coronary revascularization, surgeons' ratings for angioplasty indications were significantly lower and for bypass indications significantly higher than those of cardiologists.12 The investigators therefore argued for decision-making by a multispecialty panel, but this is hardly a practical option for the large number of patients concerned. Sometimes cardiologists and cardiac surgeons meet to review angiograms and decide jointly on the intervention, but these meetings capture only a proportion of patients and the decisions are based principally upon angiographic appearance together with an abbreviated clinical history. Such an assessment lacks the perspective of knowing the individual patient and applying the often subtle balance between individual risks and aims together with a full knowledge of the available techniques. The alternative I suggest here is that within each unit there should be at least one 'coronary artery disease specialist'. This would be someone who is skilled not only in the interventional techniques but also in the different forms of cardiac surgery—thus free from bias towards a particular intervention. Patients would then be channelled to the other relevant specialists within the unit. Who would best fulfil the role of a coronary artery disease specialist? Cardiologists might undertake further training in cardiac surgery, or cardiac surgeons might train in interventional cardiology. At present there is a substantial mismatch between the number of cardiac surgical specialist registrars who will shortly be accredited and the predicted number of consultant posts. Now might be a good time for some of them to train in interventional cardiology and equip themselves to assist with these difficult judgments across the specialties.