Since percutaneous transluminal coronary angioplasty (PTCA) was first introduced in 1977 by Gruentzig as a treatment for proximal short-segmental, non-calcified, concentric isolated coronary stenosis¹⁾, it has been used with increasing frequency in patients of symptomatic coronary artery disease with broader indications, including multi-vessel disease, unstable angina, acute myocardial infarction and totally occluded coronary arteries. Among these, total coronary occlusion constitutes a subdivision with specific features that require separate evaluation. The purpose of this study was to determine the initial results of PTCA for total coronary occlusion.

Table 1 summarizes the patient characteristics. They were 28 men and 7 women with a mean age of 55±10 years. Twenty patients (57.1%) were acute myocardial infarction, 7 old myocardial infraction (20%) and 8 unstable angina.

Twenty-eight patients had one or more major atherosclerosis risk factors and 10 patients had two or more major atherosclerosis risk factors (Table 2).

Attempted lesions were the left anterior descending artery in 19 (51.4%), the right coronary artery 14 (40%), left circumflex artery 2 (5.7%), and protected left main one. Twenty two patients (63%) had single-vessel disease and 12 patients had multi-vessel disease and one had left main disease (Table 3).

In 21 patients with a duration of occlusion less than 2 weeks, the success rate was 71% (15 of 21), while in patients with duration of occlusion from 2 to 12 weeks, the success rate was 63% (5 of 8) and the success rate was 50% in 6 patients with duration of occlusion longer than 12 weeks (3 of 6) (Table 4).

The outcome of coronary angioplasty was not significantly influenced by the age and sex of the patients, associated risk factors and the number of involved vessels, but the procedural success rate was higher on the RCA than on the LAD (p<0.05) (Table 5).

The mean percentage of stenosis decreased from 100% to 20.5% in left anterior descending artery, 19.1% in right coronary artery and 17.0% in left circumflex artery (Table 6).

The most common reason of the procedural failure was inability to cross the lesion with the wire in 9 patients and inability to follow the wire across the lesion with balloon catheter in 3 (Table 7).

Distal embolization was observed in 2 patients with successful PTCA. Other complication included spiral intimal dissection in one, acute reocclusion in one and prolonged chest pain in one (Table 8).

Since PTCA of total coronary occlusion was first reported by Savage et al²⁾, many study groups have reported the initial and late results of PTCA of this disease. The reported overall initial success rate ranged from 63% to 72%^3–10). Our primary success rate without significant residual stenosis was 66%. This result is similar to initial success rates previously reported. Many study groups have reported that the main factor that determines the outcome of PTCA for occlusion is duration of occlusion^5,7,9) i. e the age of the lesion. Thus, older lesions are less likely to be crossed with the guidewire. In the present study, the success rate was 71% in patients with a duration of occlusion less than 2 weeks, but it was 50% in patients with duration of occlusion longer than 12 weeks. The reports from Stone et al³⁾ identified the bridging collateral vessels and the tapered occlusion morphology as independent factors of procedural outcome. Other variables, including the estimated duration of occlusion, lesion length and location and extent of disease, were unrelated to success.

With present technique and sufficient operator experience, 70% to 80% of total occlusion could be successfully recanalized by coronary angioplasty with a lower complication rate³⁾.

Careful case selection, with attention to angiographic variables related to procedural success, may be expected to improve procedural outcome. Holmes et al⁴⁾ suggested that certain precautions should be taken with dilatation of completely occluded arteries. First, perfusion of the myocardium in the distribution of the occluded vessel relies on the remaining coronary vessels. Care must be taken to avoid trauma to the nondilating segments that supply these vessels. Second, it is important to visualize the course of the distal vessel and thus determine the proper route for the dilating catheter. This may be possible by reviewing films before the time of complete occlusion or by visualizing the distal vessel by way of collateral channels.

This study suggested that PTCA of total coronary artery occlusion can be performed safely and effectively in selected cases and might be more successful in the lesion with shorter duration of occlusion. But total coronary occlusion is the main limiting factor of PTCA with guide wire technique. New technique has been developed to achieve the higher success rate for the recanalization of chronically occluded coronary arteries, such as low-speed rotational angioplasty or laser angioplasty^11–12). And the long-term clinical and angiographic follow-up in patients having successful recanalization of an occluded coronary vessel should be done to determine the long-term benefit of the procedure.