Percutaneous Coronary Intervention for Chronic Total Occlusion-The Michigan Experience: Insights From the BMC2 Registry

Abstract

Objectives: The aim of this study was to describe the performance and outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) in Michigan.

Background: CTO PCI has been associated with reduction in angina, but previous registry analyses showed a higher rate of major adverse cardiac events with this procedure.

Methods: To study uptake and outcomes of CTO PCI in Michigan, patients enrolled in the BMC2 (Blue Cross Blue Shield of Michigan Cardiovascular Consortium) registry (2010 to 2017) were evaluated. CTO PCI was defined as intervention in a 100% occluded coronary artery ≥3 months old.

Results: Among 210,172 patients enrolled in the registry, 7,389 CTO PCIs (3.5%) were attempted, with 4,614 (58.3%) achieving post-procedural TIMI (Thrombolysis In Myocardial Infarction) flow grade 3. The proportion of PCIs performed on CTOs increased over the study period (from 2.67% in 2010 to 4.48% in 2017). Thirty of 47 hospitals performed >50 CTO interventions in 2017. Pre-procedural angina class ≤2 was present in one-quarter, and functional assessment for ischemia was performed in 46.6% of patients. Major complications occurred in 245 patients (3.3%) and included death (1.4%), post-procedural stroke (0.4%), cardiac tamponade (0.5%), and urgent coronary artery bypass graft surgery (1.3%). Procedural success improved modestly from 44.5% in 2010 to 54.9% in 2017 (p for trend < 0.001). Rates of in-hospital mortality (p for trend = 0.247) and major adverse cardiac event (p for trend = 0.859) for CTO PCI remained unchanged over the study period.

Conclusions: The rate of CTO PCI in Michigan increased over the study period. Although the success rate of CTO PCI has increased modestly in contemporary practice, it remained far below the >80% reported by select high-volume CTO operators. The rate of periprocedural major adverse cardiac events or death remained unchanged over time. These data suggest room for improvement in the selection and functional assessment of CTO lesions before subjecting patients to the increased procedural risk associated with CTO PCI.

Keywords: CTO; PCI; outcomes.