Predictors of improvement in left ventricular function after initially successful angioplasty of unprotected left main coronary artery stenoses.

BACKGROUND: Percutaneous coronary intervention (PCI) has been increasingly applied to unprotected left main coronary artery (LMCA) lesions, with varied procedural success and clinical outcomes. However, the effect of PCI on left ventricular performance is still unclear, and there are no clinical studies assessing factors that influence left ventricular ejection fraction (LVEF) in these cases. METHODS: Between April 1986 and August 2002, de novo PCI was performed for unprotected LMCA stenoses in 199 patients. Close clinical and angiographic follow-up were conducted after the procedure. RESULTS: One hundred eighty patients survived over six months and analysis of paired left ventriculography was possible in 175 patients. Improvement in LVEF was observed in the entire population (52.9 +/- 15.7% to 56.1 +/- 14.3%, p = 0.048). The LVEF change was 6.7 +/- 9.5% (p < 0.01) in group with baseline LVEF < or = 50% and 0.7 +/- 6.7 % (p = NS) in group with LVEF > 50%. There was significant intergroup difference (p < 0.001). Patients with baseline diameter stenosis > or = 60% had an improvement of 5.3 +/- 8.3% (p < 0.05) whereas those with stenosis < 60% had no improvement (2.0 +/- 8.4%, p = NS). CK-MB elevation > or = 3 times normal after PCI had a significant inverse association with improvement in LVEF (p < 0.05). Multivariate analysis revealed baseline LVEF < or = 50% was the only independent predictor of improvement in LVEF (standard estimate = 3.509, 95% CI: 2.164-4.854, p < 0.001). CONCLUSIONS: Successful PCI procedure is associated with significant improvement in LVEF, especially in patients with depressed left ventricular function.

Intravascular ultrasound-guided directional coronary atherectomy for unprotected left main coronary stenoses with distal bifurcation involvement.

Stent implantation in unprotected left main coronary artery (LMCA) bifurcation lesions may improve procedural and late clinical outcomes. However, concerns regarding stent-related complications, such as stent jail, subacute thrombosis, and in-stent restenosis remain. Optimal debulking by directional coronary atherectomy (DCA) with intravascular ultrasound (IVUS) guidance may be effective in this complex lesion subset, but this strategy has not yet been established. Our objective was to evaluate the safety and efficacy of IVUS-guided DCA for unprotected LMCA stenoses with distal bifurcation involvement. A total of 67 consecutive patients were included in this study and procedural success was achieved in all cases. Two cardiac deaths (2.9%) were noted and 3 patients (4.5%) underwent repeat angioplasty during hospitalization. There was no Q-wave myocardial infarction or emergency bypass surgery. Non-Q-wave myocardial infarction (creatine kinase-MB >3 times normal) occurred in 13.4% of patients. Stent implantation was necessary in 17 cases (25.4%) to achieve an optimal result. IVUS showed an improved lumen cross-sectional area and a low plaque burden in the LMCA after intervention. All-cause mortality, angiographic restenosis, and the target lesion revascularization rates at 6 months were 7.4%, 23.8%, and 20.0%, respectively. With IVUS guidance, aggressive DCA can be performed safely in unprotected LMCA bifurcation lesions, and optimal angiographic and IVUS results can be achieved with low residual plaque burden, which leads to a low restenosis rate. Optimal lesion debulking by DCA does not necessarily need adjunctive stenting in this specific anatomic subset.