J Invasive Cardiol. 2017 Mar;29(3):83-91.
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 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
oxygen uptake 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 oxygen uptake 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 oxygen uptake. These
results suggest that in symptomatic patients with CTOs, PCI appears clinically