Recent progress in coronary interventions--assessment by quantitative coronary angiography

Coronary balloon angioplasty is now well accepted as an effective therapy for patients with significant coronary artery stenosis. However, a number of deficiencies, including short-term complications, long-term restenosis, and limited application to complex morphologic lesions, restrict the widespread use of this technique. The precise lesion measurement provided by quantitative coronary angiography and intracoronary ultrasonography is a prerequisite for the optimization of balloon dilation or stent implantation. The short-term outcome may be improved by stent implantation, as this can prevent acute closure by acting as a scaffold for the disrupted vessel wall. The indications for percutaneous revascularization have been extended to chronic total occlusion by using a special guidewire, a laser wire and a coronary stent. Local drug delivery techniques to distribute agents to target revascularization sites may play a role in reducing the restenosis rate. Although the limitations of balloon angioplasty have led to the introduction of new devices, it remains to be seen whether these new devices can demonstrate, in a scientific manner, their safety, feasibility and superiority over conventional balloon angioplasty. Percutaneous coronary revascularization therapy may be an acceptable alternative to coronary bypass surgery in the future. However, to confirm this, a large multicenter randomized study is necessary to compare new percutaneous coronary interventional devices with bypass surgery. Additionally, further studies are required to demonstrate the most effective device for treating specific lesions in each individual patient.