The primary success rate of PTCA is very high, exceeding 90%. Except for the puncture site, the patient has no wound to heal and is virtually immediately free of symptoms and able to perform better. This can already be seen in the stress ECG the day after the examination.
The downside of the comparatively simple procedure is the high recurrence rate: in about one-third of patients, dilatation lasts only a few months despite drug support, and PTCA must be repeated.
Tears in the vessel wall
To check the long-term results of PTCA, a cardiac catheterization is performed again after about six months. A possible complication of the procedure is tearing of the inner vessel wall as a result of the dilatation. Smaller tears are often unavoidable and insignificant, but larger ones can affect blood flow. The physician tries to repair them with the help of a new dilatation or with a stent. If this remains unsuccessful, bypass surgery is usually indicated.
Risk of a blood clot
In addition, a blood clot may form and debris may become dislodged, which then travels with the bloodstream, completely blocking the vessel at a narrower site and thus leading to a heart attack. This, too, can possibly be prevented by re-expansion and a stent, and medications can dissolve the clot.
If unsuccessful, immediate emergency bypass surgery is inevitable, although this is the case in less than 2 out of 1000 patients. In addition, the entrained material can also cause occlusion of the pulmonary vessels (pulmonary embolism) or cerebral vessels (stroke).
Allergic reactions
Other rare but potentially life-threatening complications – as with cardiac catheterization – include cardiac arrhythmias, allergic reactions, or thyroid dysfunction because of the contrast material.
High risk of injury
Somewhat more common are skin, soft tissue, or nerve injuries at the puncture site, bleeding, inflammation, circulatory problems, and injury to the punctured vessel.
A fatal outcome occurs with an average frequency of about 0.05% of cases – although the risk also depends on preexisting conditions and age.
PTCA with stent or bypass surgery?
In a study of 3000 patients in Europe and the United States (Syntax study, 2008), dilatation with stenting was compared with bypass surgery. Results: PTCA is gentler, and patients appear to suffer fewer strokes afterward. However, compared with bypass surgery, it usually has to be repeated because of the high recurrence rate. Interestingly, neither procedure was superior in terms of mortality and myocardial infarction rates.
