Percutaneous Coronary Intervention of Coronary Chronic Total Occlusions Improves Peak Oxygen Uptake during Cardiopulmonary Exercise Testing

OBJECTIVES: Although coronary chronic total occlusions (CTOs) are treated with percutaneous coronary intervention (PCI) to improve symptoms, studies demonstrating symptom improvement have been mostly limited to questionnaire responses. The current study assessed for changes in peak oxygen uptake [VO₂] during cardiopulmonary exercise testing after CTO-PCI. METHODS: Patients with heart failure or angina symptoms referred for CTO-PCI were prospectively enrolled. The primary outcome of the study was improvement in peak VO₂ during cardiopulmonary exercise (CPX) testing 5 months after CTO-PCI. Secondary outcomes included improvement in physical capacity, angina, and self perception of health as assessed by questionnaires, and in plasma brain natriuretic peptide (BNP) levels. RESULTS: CTO-PCI was attempted in 32 men (mean age, 62 ± 6 years; CTO vessel: 47% right coronary, 44% left anterior descending). CTO-PCI was unsuccessful in 1 patient, and 3 patients had restenosis of their CTO vessel at follow-up. In the 28 patients with patent CTO vessel at follow-up, significant improvements were noted in self-reported physical capacity, angina, and several aspects of health perception. In the 25 patients who underwent baseline and follow-up CPX testing, peak VO₂ significantly improved from 17.7 ± 4.3 mL/kg/min to 19.1 ± 4.0 mL/kg/min (P=.02). Plasma BNP levels significantly decreased from 143 ± 138 pg/mL to 102 ± 123 pg/mL (P=.01). CONCLUSIONS: CTO-PCI in symptomatic patients was associated with improvements in cardiovascular exercise capacity, as assessed by peak VO₂. These results suggest that in symptomatic patients with CTOs, PCI appears clinically beneficial.