‘Enabling Strategies’ Improve Success of Chronic Total Occlusion PCI

Operators should be aware of the “tools and tricks” that can increase the chances of success in these complex patients, the author says.

‘Enabling Strategies’ Improve Success of Chronic Total Occlusion PCI

SAN DIEGO, CA—Use of enabling strategies during chronic total occlusion (CTO) PCI significantly improves the procedural success rate, despite the increase in complex patients and disease seen over 9-year time span, according to registry data presented this week at TCT 2018.

“Our results demonstrated that a number of factors appear to increase CTO procedural success. These include study year (ie, better success in later years), operator volume (the more, the better), and use of a number of what we termed ‘enabling strategies,’” Tim Kinnaird, MD (University of Wales, Cardiff), told TCT Daily via email. These strategies, he explained, are the tools and tricks that CTO operators can use to increase procedural success.

Kinnaird and colleagues examined all stable angina CTO PCI procedures performed in England and Wales between 2006 and 2014 from the British Cardiovascular Society dataset (n = 28,050). Procedures were categorized into one of four groups, depending on the number of enabling strategies used: zero, one, two, or three or more. Enabling strategies included IVUS, rotational/laser atherectomy, dual arterial access, and use of microcatheters, penetration catheters, or CrossBoss (Boston Scientific), with procedural success defined as < 50% residual stenosis with antegrade TIMI flow grade 3 at the end of the procedure.

Over time, there were significant increases in annualized use of each enabling strategy, as well as a steady and significant decrease in CTO PCI cases performed without use of an enabling strategy (P < 0.001 for all trends).

The rate of CTO PCI success rose from 55.4% in 2006 to 66.9% in 2014 (P < 0.001). Despite more complex patients and procedures, procedural success increased when the number of enabling strategies was higher (56.8% with zero vs 83.8% with three or more; P < 0.001).

On multivariate analysis, several factors were independently associated with increased CTO PCI success.

Factors Independently Associated With CTO PCI Success


OR (95% CI)

P Value

Operator CTO Volume (per case)

1.004 (1.003-1.005)

< 0.001

Year of Procedure (per year)

1.092 (1.027-1.161)


Two vs Zero Enabling Strategies

1.43 (1.24-1.66)

< 0.001

Three vs Zero Enabling Strategies

1.95 (1.55-2.45)

< 0.001

Four or More vs Zero Enabling Strategies

4.52 (2.22-9.20)

< 0.001

Left Main CTO

1.48 (1.13-1.94)


Left Anterior Descending CTO

1.24 (1.11-1.39)

< 0.001

After adjustment for baseline differences, the following procedural complications were associated with increased enabling strategy use: arterial complications (P < 0.001), in-hospital bleeding (P < 0.001), in-hospital mortality (P = 0.040), and in-hospital MACE (P = 0.018).

“Operators, as well as [those] being trained to use the CTO kit and techniques, must be prepared for things to go wrong and be able to deal with such complications,” Kinnaird said.

Notably, 30-day mortality did not significantly differ between the four enabling-strategy groups.

“The data would support the concept of CTO operators and CTO centers; this would mean that the case volumes, experience, and skill set should be focused into a small group of operators in a center or geographical region, and developing a CTO service in this fashion would optimize procedural success and patient outcomes,” Kinnaird said. “These data very much oppose the concept of a lot of small-volume operators using the ‘poke-and-hope’ approach, as this appears to lead to lower CTO success rates and is not offering patients their best chance of success.”