Chronic stable angina revascularization percutaneous coronary intervention indications


 * Associate Editor(s)-In-Chief: Lakshmi Gopalakrishnan, M.B.B.S.

Indications

 * PCI has been shown to reduce the frequency of anginal symptoms and improve exercise tolerance in patients with single and double-vessel coronary artery disease.


 * In patients with objective large ischemia associated with severe angina, PCI has shown to significantly reduce mortality and provide greater symptomatic improvement. However, on the contrary, patients with mild symptoms do not benefit from PCI.


 * Despite the high rates of restenosis associated with PCI, it may be beneficial for chronic total occlusions only in cases where the distal lumen could be accessed and favorable results could be obtained with stent implantation.


 * In patients with refractory ischemia and severe LV dysfunction with ejection fraction less than 35% may benefit from PCI in comparison to CABG.


 * In patients with unprotected left main disease associated with high peri-operative risk for CABG, PCI with stent implantation may be considered as an revascularization option.

Supportive Trial Data

 * The ACIP study, a randomized study of 558 patients with increased cardiac events, compared the 12-week efficacy of three treatment strategies such as medical therapy, medical therapy plus ambulatory ECG monitoring or revascularization to suppress cardiac ischemia. The goal of the study was to assess the feasibility of a prognosis trial in patients with asymptomatic cardiac ischemia, demonstrated both stress-inducible ischemia and two or more ischemic episodes on holter monitoring. Two years after randomization (1997), the total mortality was significantly reduced from 6.6% in the angina-guided strategy to 4.4% in the ischemia-guided strategy and 1.1% in the revascularization strategy (p=less than 0.02). The rate of composite primary end-points was also significantly reduced from 41.8% in the angina-guided strategy to 38.5% in the ischemia-guided strategy and 23.1% in the revascularization strategy (p=less than 0.001). Researchers concluded that a strategy of initial revascularization appeared to improve the prognosis but longer-term study was needed to further establish this relationship.


 * The TIME study (2004) assessed the long-term survival and quality of life in 276 elderly patients with CCS class II or greater angina receiving atleast two anti-anginal medication at baseline. The study demonstrated similar long-term survival benefits observed in both the groups; however, freedom from major cardiovascular events remained higher in invasive therapy group versus the medical therapy group (39% versus 20%, p=less than 0.0001). Irrespective of whether patients were catheterized initially or only after failure to respond to medical therapy, their survival rates were better if they were revascularized within the first year.


 * The GISSOC trial (2003) studied the benefit of stent implantation over balloon PTCA for the treatment of chronic total coronary occlusions in six-year clinical follow-up patients. The study demonstrated a significant reduction in the major adverse cardiovascular events observed in the stent group during a 6-year follow-up (76.1% in the stent group versus 60.4% in the PTCA group; p=0.055) and attributed this reduction secondary to the target lesion revascularization free-survival rate (85.1% in the stent group versus 65.5% in the PTCA group; p=0.0165). However, in most cases, restenosis of the study occlusion was evident at nine-month angiography. Thus, the study concluded stent implantation was superior to balloon PTCA in chronic total occlusions that can be recanalized percutaneously and is a valuable long-term therapeutic option; however, at nine-month follow-up both the stent and PTCA results appear to remain stable.


 * Similar benefits with stent implantation for chronic total occlusion were reported in few other studies such as:
 * The SICCO trial (1996) reported a significant reduction in the target lesion revascularization (22% in the stent group versus 42% in the PTCA group; p=0.025) and restenosis (32% patients with stent and 74% patients with PTCA only; p=0.025) noted in the stent implantation group.
 * The TOSCA study (1999) demonstrated stent implantation significantly improved late patency and reduced the rates of restenosis (70% in the PTCA group versus 55% in the stent group; p=less than 0.01) and target-vessel revascularization (15.4% in the PTCA group versus 8.4% in the stent group; p=0.03). Hence, the study concluded stent implantation being superior to PTCA for non-acute coronary occlusions.
 * The SARECCO trial (1999) demonstrated a significant event free survival in the stent group observed during a 2-year follow-up (26% in the group that received angioplasty alone versus 52% in the stent group; p=less than 0.05).
 * The SPACTO trial (1999) demonstrated significant reduction in the rates of restenosis (29% in the stent group versus 72% in the PTCA group; p=less than 0.01) and reocclusion (3% in the stent group versus 24% in the PTCA group) observed in the stent group. At follow-up,there was also a significant reduction in cardiac events (p=less than 0.03) and marked improvement in the anginal class (p=less than 0.01) reported in the stent group.
 * The STOP study (2000) demonstrated significant reduction in the rate of restenosis (42.1% in the stent group versus 70.9% in the PTCA group; p=0.034) and reocclusion (7.9% in the stent group versus 16.1% in the PTCA group) observed with the stent implantation. However, stent group was associated with more a diffuse in-stent restenosis in comparison to a focal re-stenosis in the PTCA group that occurred at the point of total obstruction (within 5mm).
 * The PRISON study (2004) demonstrated a statistically significant reduction in the need for target lesion revascularization (29% in the PTCA group versus 13% in the stent group; p=less than 0.0001) and a non-significant rate of restenosis was observed (33% in the PTCA group versus 22% in the stent group; p=0.137).


 * In the PACTO study (2004), 48 consecutive patients received paclitaxel-eluting stent implantation after successful recanalization of a chronic total occlusion, researchers assessed the efficacy of drug-eluting stent in comparison to bare metal stent for the treatment of chronic total coronary occlusions. At 1-year follow-up, the incidence of major adverse cardiovascular events was significantly reduced in the paclitaxel group (12.5% in the Taxus group and 47.9% in the BMS group; p=less than 0.001) which was secondary to reduced need for repeat revascularization. The secondary end-points included the rate of restenosis (8.3% in the Taxus group and 51.1% in the BMS group; p=less than 0.001) and reocclusion (2.1% in the Taxus group and 23.4% in the BMS group; p=less than 0.005) which was also significantly reduced in the paclitaxel group. Thus, the study concluded, paclitaxel-eluting stent drastically reduced the incidence of major cardiovascular events and restenosis, and almost eliminated reocclusion, frequently observed with bare metal stents when used for chronic total occlusion.


 * The AWESOME trial and registry (2004) demonstrated the benefit of PCI over CABG in patients with refractory ischemia and who are at increased risk of adverse events, which may also be applicable to patients with left ventricular dysfunction.


 * In a sub-study (2002) of patients with prior CABG, the three-year survival rate between CABG and PCI groups did not differ significantly: 73% in the CABG group and 76% in the PCI group (p=NS). However, the patient choice registry reported that the patients with prior-CABG preferred PCI over repeat CABG.