Long-term clinical outcome in patients with isolated chronic total occlusion treated percutaneously or pharmacologically
Authors: Frynas K , Krecki R , Kasprzak J D 
Published: October 2022

Abstract

Purpose
Chronic Total Coronary Occlusion (CTO) is defined as the total obstruction of coronary blood flow for at least 3 months duration. The aim of this study was to compare the long-term clinical outcome in patients with stable angina (CCS I-III) and isolated CTO treated with successful percutaneous coronary intervention (PCI) or conservative management (a priori pharmacologically or after failed PCI) and to detect potential risk factors of unsuccessful PCI.

Methods
The inclusion criteria were: isolated CTO of one CA, previously confirmed viability of myocardium in the area of occluded CA, stable coronary disease, absence of significant valve disease resulting in predicted survival below 1 year. Choice of management was based on individualized risk/benefit analysis encompassing ischemia assessment and angiographic considerations. Clinical follow-up of 24 months duration was conducted with regard to occurrence of major adverse cardiac events (MACE) including death, acute myocardial infarction (MI), need for repeat revascularization (surgical or PCI), major bleeding and hospitalization for angina.

Results
The study group consisted of 119 pts with isolated CTO (88 males, mean age 60.7±9.6 years)– 75 (63%) in the right CA, 28 (23,5%) in the left anterior descending CA, 16 (13,5%) in the circumflex CA. The history of MI was revealed in 37 pts in medically treated group, 10 pts in PCI group and 7 pts after failed PCI. Successful PCI was performed in 39 (33%) pts while 80 (67%) pts were treated pharmacologically (16 after failed PCI). Over a mean 24-months follow-up there were 58 MACE in all groups, including: 2 cardiac deaths (1 in medically treated group and 1 in PCI group), hospitalization due to angina in 17 pts (10 in medically treated group, 6 in PCI group, 1 after failed PCI), 4 repeated revascularizations (1 in PCI group, 3 after failed PCI), 33 pts developed unstable angina (25 medically treated, 6 in PCI group, 2 after failed PCI), major bleeding occurred in 2 pts in medically treated group. The risk of MACE was lower in pts after successful PCI comparing both with patients treated medically as well as those with failed PCI (p=0.05 for both). Univariate analysis showed that left ventricular endsystolic (p=0.001) and enddiastolic diameter (p=0.01), left ventricular ejection fraction (p=0.03), higher NYHA class (p=0.002) and duration of angina (p=0.05) were significant predictors of MACE. Multivariate analysis identified two independent predictors of MACE: absence of effective PCI (as an intention-to-treat and per protocol) (OR 3.6, 95% CI 1.6–8.3) and larger left ventricular systolic diameter (OR=1.16, 95% CI 1.04–1.29). The independent negative predictors of procedural success were severity of calcification (p=0.001) and length of occlusion (p=0.02).

Conclusions
Successful PCI of CTO leads to a significant reduction in MACE in 24 months follow-up. Failed PCI is predicted by the occlusion length and extent of calcification.

Funding Acknowledgement
Type of funding sources: None.