Author + information
- Maksymilian P. Opolski, MD∗ (, )
- Paul Knaapen, MD,
- Adam Witkowski, MD and
- James K. Min, MD
- ↵∗Department of Interventional Cardiology and Angiology, Institute of Cardiology, Alpejska 42, 04-628 Warsaw, Poland
We read with interest the paper by Fujino et al. (1) evaluating the accuracy of the computed tomography angiography (CTA)–derived J-CTO (Multicenter CTO Registry of Japan) score for predicting successful percutaneous coronary intervention (PCI) for chronic total occlusion (CTO). We congratulate the authors on their elegant study; however, several aspects of the presented results need more in-depth reflection before major implications can be conveyed to the clinical community.
First, it is important to note that there are 2 distinct ways to obtain CTA before PCI for CTO (2). Specifically, CTA may be performed for better characterization of CTO when the decision to perform PCI is already made or is at least considered. In this scenario, the referral patterns for CTA usually include CTO with previously failed PCI or challenging visualization in invasive coronary angiography (ICA) (e.g., ambiguous proximal cap, poor distal target, long occlusion). Alternatively, CTO may be initially identified on diagnostic CTA in patients with suspected coronary artery disease, and these patients may be subsequently scheduled for percutaneous recanalization attempts (2). Whereas the latter scenario should favor relatively “straightforward” CTO lesions, the former is usually associated with difficult occlusions resisting effortless guidewire (GW) crossing. Thus outstanding questions informing the most accurate use of coronary CTA to predict successful PCI for CTO will likely require better-defined patient populations in future clinical trials.
Second, that coronary CTA outweighs ICA in visualization and characterization of CTO has been consistently established in several clinical trials (2,3). Importantly, the more complex the appearance of the CTO lesion in ICA, the more valuable is the information that can be derived from the noninvasive CTA scan. Conversely, with a median J-CTO score of 1 (and less than one-third of lesions with calcification, bending, and occlusion length >20 mm), the sample included in the study by Fujino et al. (1) represents a rather simple CTO population, particularly when compared with the prior J-CTO and CT-RECTOR (Computed Tomography Registry of Chronic Total Occlusion Revascularization) registries (3,4). As such, the true diagnostic yield of CTA over ICA in more complex CTO lesions may have been underestimated, and yet it gains momentum to be fully elucidated in future clinical trials.
Third, although one may be impressed with the overall high success rate of PCI for CTO (almost 83%) reported by Fujino et al. (1), the relatively low percentage of 30-min GW crossing (29%) in essentially noncomplex CTO is surprising. This finding contrasts with prior studies (with 30-min GW crossing rates ranging from 47% to 55%) (3,4), and it may represent a function of differing PCI techniques as well as a wide variability between operators’ speed and control of GW manipulations. Thus, until the results of Fujino et al. (1) are replicated in a prospective trial with a refined GW crossing rate, the clinical utility of the noninvasive J-CTO score should be viewed with caution.
Finally, in 2015 the CT-RECTOR score was introduced as a robust and easy-to-remember CTA-based calculator to predict 30-min GW crossing through CTO (3). It was derived from 240 consecutive CTO lesions from 4 European centers by assigning 1 point for each of the independent predictors (multiple occlusions, blunt stump, calcification ≥50% of the vessel cross-section, bending ≥45°, CTO age ≥12 months, previously failed PCI). Contrary to the J-CTO score, the CT-RECTOR score is a 6-grade classification system with multiple occlusions (instead of the lesion length) and CTO duration. By relevance, multiple occlusion sites are clearly seen on CTA but are usually missed with ICA, and they have the potential to exceed the discriminatory accuracy of the lesion length for predicting GW passage (3). Hence a head-to-head comparison between CTA-derived J-CTO score and CT-RECTOR score makes intuitive sense to establish the most accurate noninvasive prediction rule for time-efficient GW crossing through a CTO.
To sum up, clinicians may find the CTA-derived scores particularly useful to better estimate the time and resources required for the interventional treatment of CTO when compared with the angiographic J-CTO score (3). Whether coronary CTA will build on the optimal approach to the interventional treatment of CTO remains to be observed, but what is certain is that it is already a “moving target” that is too good to ignore.
Please note: Dr. Min has reported equity interest in MDDX; has a research agreement of GE Healthcare; and is on the advisory board of Arineta. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- 2017 American College of Cardiology Foundation
- Fujino A.,
- Otsuji S.,
- Hasegawa K.,
- et al.
- Opolski M.P.,
- Achenbach S.
- Opolski M.P.,
- Achenbach S.,
- Schuhbäck A.,
- et al.
- Morino Y.,
- Abe M.,
- Morimoto T.,
- et al.