Distal Reference Segment Luminal Gain Following Percutaneous Coronary Intervention for Chronic Total Occlusion

Abstract

SummaryPercutaneous coronary intervention (PCI) for chronic total occlusion (CTO) increases forward blood flow, possibly resulting in an increase in lumen diameter. We investigated the determinants of luminal gain at the distal reference segment following PCI for CTO. Forty-eight consecutive patients who underwent PCI for CTO were included in this study. Clinical and angiographic data were obtained at baseline and follow-up (mean follow-up period: 251 ± 73.6 days). Overall, the reference lumen diameter was 2.53 ± 0.38 mm at post-procedure and 2.38 ± 0.84 mm at follow-up. The distal reference lumen diameter (segment 5 mm distal to the stent) was larger at follow-up than at post-procedure (1.64 ± 0.64 and 1.38 ± 0.51 mm, respectively, P < 0.05). Luminal gain (LG), in the distal reference segment, defined as an increase in lumen diameter from post-procedure to follow-up, was observed in 33 of 48 patients (69%). Univariate and multivariate logistic regression analyses were performed to identify the clinical and angiographic predictors of LG. Minimum lumen diameter and left ventricular ejection fraction at baseline were both significant predictors of LG in univariate and multivariate logistic regression analyses. Luminal gain was observed at the distal reference segment following PCI for CTO. Left ventricular ejection fraction may have an impact on the lumen diameter distal to lesions responsible for CTO. (Int Heart J 2011; 52: 270-273) Key words: Coronary intervention, Chronic total occlusion, Luminal gain C hronic total occlusion (CTO) of coronary artery was observed in approximately 30% of patients with coronary artery disease who underwent diagnostic coronary angiography.1) Furthermore, percutaneous coronary intervention (PCI) for CTO has been challenging because of high restenosis and reocclusion rates.2-4) The introduction of drugeluting stents (DES) has been shown to significantly reduce the restenosis rate.5-7) The successful recanalization of CTO results in improvement of mid-term clinical outcomes 8,9) and left ventricular function.10,11) Chronic changes in blood flow affect blood vessel architecture with normalization of vessel wall shear stress in response to hemodynamic changes. 12,13) PCI for CTO increases forward blood flow, possibly resulting in an increase in lumen diameter. We investigated the determinants of luminal gain at the distal reference segment following PCI for CTO. MethodsStudy population and follow-up: Consecutive 89 patients with CTO were treated by successful PCI at our institution from January 2005 to March 2007. A lesion with CTO was defined as an obstruction of a coronary artery with TIMI (Thrombolysis In Myocardial Infarction) flow grade 0 that was at least 3 months old. The duration of chronic occlusion was estimated by clinical information or the results of previous angiography. 5)Out of the 89 patients, follow-up coronary angiography (at least 6 months after PCI) was performed in 49 patients. The median period between the date of PCI and the date of restudy was 253 days. Acute r...

Novel predictors of late lumen enlargement in distal reference segments after successful recanalization of coronary chronic total occlusion

“…The present study also showed a significant negative linear correlation between LD at distal reference at post‐PCI and %LG (r = −0.57, p < 0.001), in the similar magnitude as previously reported (r = −0.5, p < 0.001) . Several factors are reported to be associated with greater late lumen enlargement such as lower low‐density lipoprotein cholesterol level, longer total occlusion duration, poor collateral flow grade, statin use, no resting hypokinesis in the territory supplied by the CTO, PHB on IVUS, and smaller LD at the distal reference . However, the predictors are not established yet except for the small distal reference at post‐PCI.…”

“…In the present study, cases without resting segmental hypokinesis tended to be more frequently observed in LAD than non‐LAD group (26 vs. 15%, p = 0.13), and LD at distal reference was significantly smaller in the LAD compared to the counterpart (1.83 ± 0.54 mm vs. 2.18 ± 0.63 mm, p = 0.002) at post‐PCI. These factors have been reported as predictors of late lumen enlargement, possibly affecting our results. However, multivariable analysis showed the CTO in the LAD as independent predictors.…”

“…Intracoronary isosorbide dinitrate was administered before each angiogram. Three coronary segments were analyzed by a program automatically: in‐stent segment, the segment 5 mm proximal to the implanted stent, and the segment 5 mm distal to the stent . Late lumen loss was calculated as the difference in minimal lumen diameter (LD) within stent between post‐PCI and follow‐up.…”

Prediction of Chronic Vessel Enlargement by a Novel Intravascular Ultrasound Finding

“…Second, lesions with restenosis or re-occlusion were excluded, so it is uncertain whether the Park et al 1 and Ogita et al 16 reported clinical or angiographic predictors of LLG, but we did not find similar findings. Recent pathological studies have suggested a possible role of the IEM and media in coronary arterial lesions with spasm or vessel shrinkage.…”

“…It is well known that the lumen size of the reference segments distal to the chronically occluded or severely stenotic lesion may increase late after successful PCI of the culprit lesion. 1,15,16 A recent serial IVUS observational study, 1 as well as an angiographic follow-up study, 16 demonstrated that the lumen area of the distal reference segments increases in 69% of the patients with successful recanalization of CTO at 6-month follow-up. Our results showing that LLG was detected in 59% of lesions are concordant with that.…”