Every piece is important to build a puzzle. What can we learn from early experiences with balloon PTCA?

Percutaneous transluminal coronary angioplasty (PTCA) was introduced into clinical practice more than 20 years ago, for the treatment of very selected anatomical and clinical situations. The procedure quickly became accepted as an alternative to the medical and surgical treatment of coronary artery disease. Progress made over the years has been tremendous and was unimaginable when PTCA was first used. Progress has also been quick, in spite of the reduced number of prospective randomized clinical trials comparing PTCA to medical or surgical treatment, for single or multivessel disease, with or without stents. Guidelines have been written, but they soon become, like clinical trials, outdated, because they might not represent the ‘state of the art’ of existing treatment modalities. In order for the clinician to decide what is best for his patient, every single publication is important. We should not forget, however, that all available treatments for coronary artery disease are palliative, and that the decision to revascularize, often made on the spot, should aim first to improve symptoms and quality of life and, ultimately, improve prognosis, by altering the natural history of the disease. The paper by van Domburg et al., reports on the longest follow-up (17 years), ever published, of balloon angioplasty performed in a single reputed centre. The data probably represent the worst possible scenario after PTCA, if we compare the conditions available in 1980–1985 with those existing today. It could also be considered as the natural history of balloon PTCA, if we ignore the fact that this type of revascularization was being applied to coronary artery disease patients. What can we learn from this early experience with PTCA? Several aspects regarding the natural history of coronary artery disease, when the first option of revascularization was balloon angioplasty, can be discussed. The population selected at the time had a mean age of 56 years (6% more than 70 years), 47% had unstable angina or acute coronary syndromes and patients had predominantly single vessel disease (37% with 2–3 vessels disease) and good ventricular function (17% with an ejection fraction <50%). Information that came to the fore initially was that the four most important independent predictors of long-term mortality were advanced age (>60 years), diabetes, multivessel disease and impaired left ventricular function (ejection fraction <55%). Mortality at 17 years was 42% and event-free survival 19%. There was an impressive difference between survival in single-vessel disease with good ventricular function (75%) compared to multivessel disease with impaired function at 15 years (28%). Diabetics had a worse outcome with survival curves diverging in the first 7 years and a 15% benefit for non-diabetics. The authors, however, in selecting a group of patients (26% of the total population) aged less than 60 years who were, non-diabetic, with single vessel disease and good ventricular function, found the prognosis to be similar to the general Dutch population. The second piece of important information is that, although 59% of patients required reinterventions (34% repeat PTCA, 42% surgery, 24% PTCA+ surgery), 32% of the new revascularizations occurred within the first year. Afterwards, the annual coronary reintervention incidence was 2–3% and stable, beyond the 10 years. Of the 87% of patients who do not require a reintervention in the first year, only 24% had further interventions in the follow-up. Finally, and somewhat surprisingly, is the fact that the prognosis of patients with failed PTCA (59% survival at 15 years) is similar to those in whom it succeeds (64%). The lack of further information in the paper would make any discussion speculative. Increased age is expected to have a strong impact on survival, the bigger the group of patients followed, particularly as a result of co-morbidities and ageing. Multivessel disease and impaired left ventricular function helped to favour coronary surgery in the randomized trials of the 1970s, comparing surgery to medical treatment. The risk of future events should increase with the extent of atherosclerosis present at the time of revascularization, particularly if we do not control adequately the ongoing atherosclerosis process. In the paper of van Domburg et al., cholesterol-lowering drugs were given in only 18% of patients at hospital discharge. Reduced ventricular function, the consequence of previous infarctions or the extent of the disease, has been always recognized as important for survival. Diabetes, however, only recently became an important marker of accelerated atherosclerosis with implications for the choice of revascularization type. In the study, only 12% of patients were diabetic, but the finding that diabetes