Diagnostic accuracy of intraluminal blood speckle intensity on intravascular ultrasound for physiological assessment of coronary artery stenosis

Novel predictor of target vessel revascularization after coronary stent implantation: Intraluminal intensity of blood speckle on intravascular ultrasound

BACKGROUND

The difference in intraluminal intensity of blood speckle (IBS) on integrated backscatter-intravascular ultrasound (IB-IVUS) across the coronary artery stenosis (i.e., ΔIBS) has been reported to negatively correlate with fractional flow reserve. Fractional flow reserve after coronary stenting is known as a predictor of target vessel revascularization (TVR). However, the relation between ΔIBS and TVR is unclear.

METHODS

Seven hundred and three vessels which underwent percutaneous coronary intervention with stents were screened. Vessels without IVUS-guidance and follow-up information were excluded. Intraluminal IBS values were measured using IB-IVUS in cross-sections at the ostium of the target vessel and at the distal reference of implanted stent. ΔIBS was calculated as (distal IBS) - (ostium IBS).

RESULTS

A total of 393 vessels were included. Mean ΔIBS at postprocedure was 6.22 ± 5.65. During the follow-up period (11.2 ± 3.1 months), 24 cases (6.1%) had TVR. ΔIBS was significantly greater in the vessels with TVR than in those without (11.10 ± 5.93 vs. 5.90 ± 5.49, P <0.001). In receiver operating characteristic curve analysis, ΔIBS significantly predicted TVR (AUC 0.74, best cut-off value 8.24, P < 0.001). Multiple logistic regression analysis showed use of drug eluting stent and ΔIBS ≥ 8.24 as independent predictors of TVR.

CONCLUSIONS

ΔIBS at postprocedure was significantly associated with TVR. IVUS may be able to predict TVR by physiological assessment with measurement of ΔIBS.

Intraluminal Intensity of Blood Speckle on Intravascular Ultrasound, a Novel Predictor of Periprocedural Myocardial Injury After Coronary Stenting

The difference in the intraluminal intensity of blood speckle (IBS) on integrated backscatter-intravascular ultrasound (IB-IVUS) across a coronary artery stenosis (i.e., ΔIBS) has previously shown a negative correlation with fractional flow reserve, reflecting an impaired coronary blood flow. Periprocedural myocardial injury (PMI) after coronary stenting has also been associated with coronary circulatory dysfunction. The aim of this study was to investigate the relation between ΔIBS after coronary stenting and PMI. A total of 180 patients who underwent elective coronary stenting under IVUS guidance for a single lesion were included. Intraluminal IBS was measured using IB-IVUS in cross sections at the ostium of the target vessel and at the distal reference of the stent. ΔIBS was calculated as (distal IBS value) - (ostium IBS value). PMI was defined as an elevation of troponin I >5 times the 99th percentile upper reference limit (>0.45 ng/ml) within 24 hours after the procedure. The mean ΔIBS after coronary stenting was 6.52 ± 5.71. There was a significantly greater use of the rotational atherectomy, the number of stents, the total stent length, and ΔIBS in patients with PMI than those without. In the receiver operating characteristic curve analysis, ΔIBS significantly predicted PMI (area under the curve 0.64, best cut-off value 7.88, p = 0.001). Multiple logistic regression analysis determined that the total stent length, the use of rotational atherectomy, and ΔIBS were independent predictors of PMI. In conclusion, greater ΔIBS assessed by IB-IVUS was significantly associated with PMI after coronary stenting in patients with a stable coronary artery disease.