CTOs Relatively Frequent in Patients Without Previously Known CAD

Chronic total occlusions (CTOs) are “not uncommon” in patients undergoing coronary CT angiography for suspected CAD, according to a registry study published online June 15, 2015, ahead of print in Heart.

James K. Min, MD, of NewYork-Presbyterian Hospital/Weill Cornell Medical College (New York, NY), and colleagues analyzed data from the CONFIRM registry on 23,745 patients (mean age 57.3 years; 54.4% men) who underwent noninvasive imaging at 17 centers worldwide between 2005 and 2010 for suspected—but not proven—CAD. Patients with congenital heart disease were excluded.

Overall, the prevalence of CTOs was 1.4% (n = 342), but among the 5,559 patients whose lesions had at least 50% stenosis, the prevalence was 6.2%.

On multivariate analysis, the researchers identified several factors associated with a greater likelihood of patients having a CTO (table 1). In addition, there was an inverse association between LVEF and the odds of CTO (OR 0.96; 95% CI 0.95-0.98).

CTOs were most commonly found in the RCA (50.3%), followed by the LAD (33.3%) and LCX (27.4%).

Most patients with CTOs (61%) received medical therapy alone, while the remainder underwent revascularization (39%). Among the patients with at least 1 severe coronary stenosis (≥ 70%), those with a CTO had higher rates of referral for CABG and lower rates of referral for PCI compared with patients without a CTO.

Advances to Come in CTO Detection, Treatment

In an email with TCTMD, Farouc Jaffer, MD, PhD, of Massachusetts General Hospital (Boston, MA), said it was surprising that CTOs were such a major predictor for surgical revascularization rather than PCI. “This [will likely] change due to advances in contemporary CTO PCI, where success rates can approach 90%,” he added.

Dr. Min and coauthor Maksymilian P. Opolski, MD, PhD, of the Cardinal Wyszynski National Institute of Cardiology (Warsaw, Poland), told TCTMD in an email that although CTO patients in the registry “tended to be older and sicker than the general population, the majority (79%) presented with a low-to-intermediate probability of obstructive CAD.”

Dr. Jaffer said it was “remarkable that even in a low-risk population, the prevalence of a CTO in CAD patients was 6%.” The discovery of a CTO “should prompt clinicians to evaluate the patient for limiting exertional symptoms, both angina and dyspnea, and motivate the initiation of aggressive secondary prevention therapies,” he added.

According to the study coauthors, there is much room to grow in understanding CTOs.

“The discrepancy between the CTO revascularization rates and the incidence of patients’ symptoms as well as normal LV function suggests that a substantial proportion of CTO patients with indirect evidence of myocardial viability are not undergoing some form of revascularization,” they wrote in the email. “To clarify this issue, future studies with objective assessment of myocardial viability in the CTO territory should define the most optimal treatment strategies (medical therapy vs coronary revascularization) for [the blockage].”

In addition, Drs. Min and Opolski said they anticipated that, in the future, a model would be developed to better predict which patients undergoing CT angiography are likely to have a CTO.

Note: Dr. Min is a faculty member of the Cardiovascular Research Foundation, which owns and operates TCTMD.

Source:

Opolski MP, ó Hartaigh B, Berman DS, et al. Current trends in patients with chronic total occlusions undergoing coronary CT angiography. Heart. 2015;Epub ahead of print.

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