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Long-term Survival After PCI for CTO Linked with Procedural Success, Completeness of Revascularization

By Yael L. Maxwell

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Survival in patients undergoing percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) hinges on both procedural success and complete revascularization of all vessels, according to data from large United Kingdom-based registry published in the July 22, 2014, issue of the Journal of the American College of Cardiology. 

In fact, “if you can’t achieve complete revascularization percutaneously in complex disease, then you should be strongly thinking about another option,” Jeffrey W. Moses, MD, of Columbia University Medical Center/Weill Cornell Medical Center (New York, NY), told TCTMD in a telephone interview. 

Methods
Sudhakar George, MD, of Brighton and Sussex University Hospitals (Brighton, England), and colleagues analyzed 13,443 stable patients in the UK Central Cardiac Audit Database who underwent 14,439 elective CTO PCIs from 2005 to 2009. Mean patient age was 63.5 years, and 78.8% were men.
Most patients had a single procedure (93.3%), while 6.07% had 2 and a handful of patients had 3 (0.56%) or 4 (0.07%) procedures. DES were implanted in 82.2% of lesions, while BMS were used in 3.9%.


Predicting Failure

Procedural success (< 50% residual stenosis with TIMI flow grade 3 antegrade) was 70.6%, and mortality was 5.6% during the median follow-up period of 2.65 years, amounting to 20.4 deaths per 1,000 person-years. Multivariate analysis identified the following predictors of failed CTO intervention:

  • Older age
  • Angina
  • Current smoker status
  • Higher BMI
  • Previous CABG
  • Peripheral vascular disease
  • Previous MI

On multivariate analysis, successful revascularization of at least 1 CTO and preprocedural angina decreased mortality, while older age, higher NYHA class, insulin-treated diabetes, current smoker status, higher LVEF, and renal disease increased mortality risk (table 1). 

Table 1. Independent Predictors of Mortality

 

HR

95% CI

Successful Revascularization

0.72

0.62-0.83

Age 
60 to < 70 
70 to < 80 
≥ 80


 2.28
3.94
9.28

 
1.59-3.28
2.74-5.66
6.31-13.67

Preprocedural Angina Grade 4

0.50

0.30-0.84

Preprocedural NYHA IV

2.45

1.46-4.12

Insulin-Treated Diabetes

1.84

1.38-2.45

Current Smoker

1.67

1.30-2.14

LVEF < 30%

2.24

1.68-2.97

Renal Disease

3.05

2.26-4.13 

Propensity matching confirmed the link between successful revascularization and mortality (HR 0.66; 95% CI 0.54-0.80). 

Mortality declined proportionally with increasing completeness of revascularization (P < .001 for trend). Risk was lower in patients who had complete revascularization of all vessels than for those whose procedures were partial (adjusted HR 0.70; 95% CI 0.56-0.87; P = .002) or failed (adjusted HR 0.61; 95% CI 0.50-0.74; P < .001).

Compared with the RCA, revascularization was more likely to be successful in the LCX or LAD (P < .001 for both), but the association between successful revascularization of a single CTO with reduced mortality did not differ according to the epicardial vessel treated (P for interaction = .52). 

A New Perspective on ‘Completeness’  

Because this was not a randomized trial, the observed relationship between revascularization and reduced mortality cannot be considered causal, the authors caution. Nonetheless, they add, “Patients may have much to gain from CTO PCI.”

In an editorial accompanying the paper, Ehtisham Mahmud, MD, of the University of California, San Diego (La Jolla, CA), says the results match those of previous studies, although the “association between mortality reduction and single-vessel CTO revascularization… remains puzzling.” 

Dr. Moses said that, in addition to being much more “robust” than past studies, the current analysis adds to the literature by investigating the relationship between completeness of PCI and mortality.

Success Rates Rise Amid Caution  

CTO practice has changed since the study period, which ended in 2009, Dr. Moses observed. Today, he said, many more patients are being treated successfully, with contemporary rates reaching well into the 90% range. 

Dr. Mahmud agrees in his editorial that there have been major shifts. However, he cautions, newer “techniques are not widely mastered and are associated with higher rates of complications.” 

There is a “golden opportunity for the field of interventional cardiology with the improvements in the technique of CTO PCI and proliferation of dedicated CTO devices to treat a larger population percutaneously,” Dr. Mahmud concludes, adding that both randomized trials and large prospective multicenter registries will continue to advance the field.

 

Sources: 
1. George S, Cockburn J, Clayton TC, et al. Long-term follow-up of elective chronic total occlusion angioplasty: analysis from the U.K. Central Cardiac Audit Database. J Am Coll Cardiol. 2014;64:235-243.

2. Mahmud E. Chronic total occlusion revascularization: Achilles’ heel or golden opportunity for PCI [editorial]? J Am Coll Cardiol. 2014;64:244-246.

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Disclosures
  • Dr. George reports no relevant conflicts of interest.
  • Dr. Mahmud reports receiving clinical trial support from Boston Scientific and Corindus and consulting fees from Corindus and The Medicines Company and serving on speakers bureaus for Abbott Vascular and Medtronic.
  • Dr. Moses reports consulting for Boston Scientific.

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