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the first year.
Late outcome, however, may not always be as satisfactory as was originally believed. Surgical graft
attrition occurs steadily, and 10 per cent, 20 per cent and 40 per cent of saphenous grafts occluded by one,
five and ten years, respectively, in the pre-statin era. Early recurrence of symptoms is likely to be due to
graft attrition, and late recurrence to progression of disease in the native circulation. Aggressive lipid
management improves the outcome whilst the robust performance of the internal mammary artery conduit
is well known - a 93 per cent ten-year survival in patients in whom an internal mammary artery conduit
ICAO Preliminary Unedited Version — October 2008 III-1-18
was implanted into the left anterior descending coronary artery. The ejection fraction was an important
predictor of outcome.
Coronary artery bypass grafting has a low risk of MACE once rehabilitation has taken place. Actuarial
survival following saphenous vein bypass grafting in one group of 428 patients with a mean age of 52.6
years at 5, 10 and 15 years was 94.2 per cent, 82.4 per cent and 63 per cent, respectively. This was in the
pre-statin era. The cumulative probability of event-free survival for cardiac death, acute myocardial
infarction, re-intervention and angina pectoris at 5, 10 and 15 years was as follows:
Cardiac death — 97.8 %, 90.1 % and 74.4 %;
Acute myocardial infarction — 98.5 %, 89.0 % and 77.4 %;
Re-intervention — 97.0 %, 83.0 % and 62.1 %;
Angina pectoris — 77.8 %, 52.1 % and 26.8 %.
Left ventricular function and the number of vessels involved are independently predictive of survival. For
certificatory purposes these figures are reassuring only for the early years after intervention.
Percutaneous transluminal coronary angioplasty (PTCA) and intracoronary stenting
PTCA has been established since the 1980s. The technique has the advantage that an early return to full
activity is usual but with the disadvantage that the subsequent trajectory is often not unblemished. The
original technique employed a balloon inserted via a guide-wire which was inflated across the obstructing
lesion. More recently, the insertion of a stent — a small wire basket — has been shown to improve the
prognosis, while more recently still, stent performance has been enhanced by the elution of drugs (antimitotic
agents such as paclitaxel) from its surface, although long-term data are not yet available. See
Appendix 3, panels A & B.
In the context of aviation, medical certification following PTCA requires both freedom from symptoms
and complete revascularization. PTCA is good for the former but less easy to achieve for the latter. In the
BARI trial1, complete revascularization in the presence of multi-vessel coronary artery disease was
achieved in only 57 per cent of PTCA patients but in 91 per cent of those undergoing CABG. In contrast
to the results of surgery, no survival advantage over medical treatment has been demonstrated for PTCA.
Indeed, in one study, the group treated with high-dose (80mg) atorvastatin had a 36 per cent lower event
rate than the PTCA group. Similar results were seen in the RITA-2 study2. Death was significantly more
common in the angioplasty group versus the medically treated group after three years whilst at seven
years there was no difference in mortality between the two groups. Symptoms were fewer in the
angioplasty group.
Diabetic patients fared significantly worse following PTCA when compared with CABG in terms of
survival (65.5 per cent versus 80.6 per cent at five years) in the BARI study, while the Coronary
Angioplasty versus Bypass Revascularization Investigation (CABRI) study3 confirmed a more favourable
1 BARI trial: Bypass Angioplasty Revascularization Investigation trial, in which 1 829 patients with symptomatic
multivessel coronary artery disease requiring revascularization were randomly assigned to undergo either CABG or
PTCA between 1988 and 1991. In 1995 the US National Heart Lung and Blood Institute (NHLBI) issued an alert
warning about the poorer outcome following angioplasty in diabetic patients
2 RITA-2 study: the second Randomised Intervention Treatment of Angina. Coronary angioplasty versus medical
therapy for angina; the trial ran for seven years.
3 CABRI study: A randomized study of 1054 patients from 26 European centres, all with symptomatic, multivessel
coronary disease who underwent either CABG or PTCA (1988-1992)
ICAO Preliminary Unedited Version — October 2008 III-1-19
surgical outcome. Likewise, saphenous vein graft angioplasty has a poor outcome. In the Arterial
Revascularization Therapy Study (ARTS)3, the MACE difference between surgery and angioplasty (on
average 30 to 40 per cent) was reduced to 14 per cent with stenting at one year — still not impressive in
　
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