PERCUTANEOUS CORONARY INTERVENTION FOR TOTAL CORONARY OCCLUSION
Mohamed Z. El Ramly, Mohamed Abdel Ghany, Reda Diab, Hossam El Hossary, Mohamed Abdel Fattah and Khaled Sorour
Cardiology Department, Faculty of Medicine, Cairo University
Background: Total coronary occlusion is still considered to be a challenge for the interventional cardiologist, it accounts for 30% of electively performed coronary angiographic procedures. The success rate for re-canalization of chronic total occlusion (CTO) ranges from 42-72% depending on duration of occlusion versus 80% for acute total occlusion. The encountered difficulties in attempts to open total occlusion are the high failure rate in crossing the lesion, emergency bypass surgery, asystole, bradycardia including heart block, sustained hypotension, myocardial infarction (MI). The approach is further compromised by compound restenosis and reocclusion rates between 40-45%.
Objective: To estimate the success rate in cases of total coronary occlusion treated by percutaneous coronary intervention (PCI) and to determine the predictors of success.
Methods: This is a prospective unicenter study which included all patients with native total coronary artery occlusions who were scheduled for PCI, during the period of June 2002 till June 2004. The study included 170 patient divided into two groups; group A (83 patients) (patients with successful PCI to total coronary artery occlusion) and group B (87 patients) (patients with non successful PCI).
Results: In this study we found that the success rate was 48.8%. The clinical variables of successful PCI of total coronary artery occlusion were recent MI in 14.4% (p < 0.001). The coronary occlusion of acute duration (≤ 1 month) was successfully opened in 37.4% (p < 0.001), while patients whose occlusions were estimated to be > 1 month duration were successfully dilated in 27.7% of patients (p < 0.2). The success rate in the presence of functional occlusion was 100% (p < 0.001), while that in absolute occlusion (TIMI 0) was 62.58% (p < 0.06). Successful PCI with a tapered morphology at the point of coronary occlusion has been shown in 22.8% of patients as opposed to an abrupt morphology which showed a success rate of 11.4% (p< 0.0001). In our study success was achieved in 7 patients (7.2%) with the presence of a side branch, while failure occurred in 13 patients (14.9%) (p < 0.001). The presence of bridging collaterals was associated with failed PCI in 2 patients (P<0.06). The mean length of the lesion for successful PCI was less than 10.9±0.46 mm (P<0.001). The use of balloons to support the wire and facilitate its passage through totally occluded lesion was 48.1% (p < 0.001), the use of Shinobi wire showed (100%) success rate in 6 patients (p < 0.001). The use of Tirofiban in addition to Ticlopidine or Clopidogrel increased the success rate in 61.4% (P<0.001). Multivariate analysis showed that short duration of occlusion (≤ 1 month) (p < 0.001) was the most important independent predictor of successful PCI to total coronary artery occlusion. In this study the incidence of adverse clinical outcome was 2.93% (mortality rate was 1.17%, MI occurred in 1.76% and emergency CABG surgery was not performed). The incidence of adverse angiographic outcome was 14.5% (dissection occurred in 6.4%, perforation in 1.1%, no reflow in 2.9%, side branch loss in 4.1% and no cases with abrupt vessel closure.
Conclusion: Successful PCI to total coronary occlusion was achieved in 48.8% of patients, predictors of successful PCI to total coronary occlusions were, normal contractility, recent MI, duration of occlusion < 1 month, functional total occlusion, tapering morphology, mean length of the lesion < 10.9±0.46 mm, absence of side branch at the site of occlusion, the presence of retrograde flow, and the use of IIb/IIIa inhibitors in addition to Clopidogrel or Ticlopidine. However, duration of total occlusion< 1 month was the most important independent predictor of successful PCI to total coronary occlusion.