Incidence and prognostic impact of the calcified nodule in coronary artery disease patients with end-stage renal disease on dialysis.

Coronary artery calcification is frequently observed in coronary artery disease (CAD) patients with end-stage renal disease (ESRD). Calcified nodule (CN) is recognized as one of the vulnerable plaque characteristics responsible for acute coronary syndrome (ACS). Although CN is a cause of ACS in only 10%, its prevalence may be higher in elderly patients and/or ESRD. The aim of this study is to investigate incidence, clinical characteristics, and prognostic impact of CN in CAD patients with ESRD on dialysis. A total of 51 vessels from 49 CAD patients with ESRD on dialysis were enrolled in this study. CN was defined as a high-backscattering mass protruding into the lumen with a strong signal attenuation and an irregular surface by optical coherence tomography. Incidence, clinical characteristics and prognosis of patients with CN were studied. Major adverse cardiac events (MACE) were defined as a composite of all-cause death, non-fatal myocardial infarction, target vessel revascularization (TVR) and stroke. CNs were observed in 30 vessels from 29 patients (59.2%). Duration of dialysis was significantly longer in CN group than in non-CN group (P = 0.03). Overall, all-cause death, cardiac death, TVR and MACE occurred in 7 (14.3%), 3 (6.1%), 11 (22.4%) and 16 (32.7%) patients during follow-up (median 826 days), respectively. Kaplan-Meier survival analysis revealed that MACE-free survival was significantly lower in patients with CN compared with those without CN (Log-rank, P = 0.036).In conclusion, CN was observed in about 60% of the CAD patients with ESRD and was associated with duration of dialysis and worse prognosis.

Detection of myocardial bridge by optical coherence tomography.

Myocardial bridge (MB) is less commonly documented by angiography than autopsy. Optical coherence tomography (OCT) may be useful to detect angiographically undetectable MB. To investigate OCT characteristics of MB, 86 LAD vessels were imaged by OCT. MB was defined as presence of intermediate optical intensity, "fine" layer surrounding coronary artery by OCT. Frequency and characteristics of the angio-detectable and angio-undetectable but OCT-detectable MB were investigated. In a subset of patients with angio-detectable MB, cyclic changes in coronary arterial dimensions were analyzed. OCT detected MB in 44 of 86 (51%). Arc of the MB was significantly larger (334.8 ± 58.5° vs. 268.4 ± 92.1°, P = 0.008) and length was significantly longer (22.6 ± 11.7 mm vs. 14.5 ± 8.1 mm, P = 0.014) in angio-detectable MB than OCT-detectable but angio-undetectable MB. Both vessel (6.8 ± 1.5 to 5.3 ± 1.0 mm2, P = 0.035) and lumen area (4.4 ± 1.5 to 3.1 ± 0.7 mm2, P = 0.040) decreased significantly from diastole to systole. Adventitial (0.08 ± 0.03 to 0.08 ± 0.02 mm, P = 0.828) and intima + plaque thickness (0.12 ± 0.05 to 0.10 ± 0.03 mm, P = 0.398) did not change significantly during cardiac cycle. On the other hand, medial thickness increased significantly from diastole to systole (0.08 ± 0.03 to 0.12 ± 0.03 mm, P = 0.022). In conclusion, MB is frequently detected as intermediate intensity, fine layer by OCT. During systole, vessel and lumen size decrease with increased medial thickness. Therefore, we should be careful for OCT interpretation of the coronary arteries with MB.

Incidence and Characteristics of Incomplete Stent Apposition in Calcified Lesions: An Optical Coherence Tomography Study.

BACKGROUND: Persistent or late acquired incomplete stent apposition (ISA) may be associated with late or very late stent thrombosis following drug-eluting stent implantation. Presence of calcium at the target lesion may increase the risk of ISA even after rotational atherectomy (RA) followed by stenting with high pressure balloon inflation. The aim of this study is to examine the incidence and characteristics of ISA in heavily calcified lesions. METHODS: A total of 52 heavily calcified coronary artery lesions requiring RA plus stenting were selected and studied. After successful ablation followed by stent implantation, optical coherence tomography (OCT) was performed to assess stent expansion and apposition. Presence or absence of ISA was examined and maximal stent strut to vessel wall distance (max SV distance) was measured. In lesions with repeated OCT at follow-up, serial changes in ISA were investigated. RESULTS: ISA was documented in 51 of 52 (98%) lesions. Mean max SV distance was 713 ± 371 µm. In lesions with serial OCT images (n = 11), max SV distance decreased significantly (692.1 ± 420.2 to 462.5 ± 387.0 µm, P < 0.01) but persisted in all but 2 lesions (82%). CONCLUSIONS: ISA is frequently documented in heavily calcified lesions requiring RA. Significant ISA still persisted with minimal improvement in SV distance at follow-up. Prognostic impact of the persistent ISA in such calcified lesions needs further investigations.

Clinical Impact of Irregular Protrusion Angle After Coronary Stenting at Culprit Lesions With ST-Elevation Myocardial Infarction　- An Intravascular Optical Coherence Tomography Study.

Background: A recent optical coherence tomography (OCT) registry showed that the presence of irregular protrusion (IP) after coronary stenting was a predictor of worse 1-year cardiovascular events. This study evaluated the clinical impact of OCT-detected IP after coronary stenting at ST-elevation myocardial infarction (STEMI) culprit lesions. Methods and Results: In all, 139 consecutive STEMI patients with OCT-detected IP after stenting were analyzed retrospectively. The maximum IP angles were measured and patients with IP were divided into 2 groups (large IP, maximum IP angle ≥180°; small IP, 0°

Prognostic Impact of Calcified Plaque Morphology After Drug Eluting Stent Implantation　- An Optical Coherence Tomography Study.

BACKGROUND: Optical coherence tomography (OCT) has the potential to characterize the detailed morphology of calcified coronary plaques. This study examined the prognostic impact of calcified plaque morphology in patients with coronary artery calcification (CAC) who underwent newer-generation drug-eluting stent (DES) implantation.Methods and Results:In all, 251 patients with moderate to severe CAC who underwent OCT-guided DES implantation were reviewed retrospectively and divided into 3 groups according to OCT findings of the target lesion: 25 patients (10.0%) with calcified nodules (CN), 69 patients (27.5%) with calcified protrusion (CP) without CN, and 157 patients (62.5%) with superficial calcific sheet (SC) without CN and CP. The primary endpoint was major adverse cardiac events (MACE), defined as a composite of cardiac death, myocardial infarction, and target lesion revascularization (TLR). Kaplan-Meier survival analysis revealed that, among the 3 groups, the rates of MACE-free survival (log-rank test, P=0.0117), myocardial infarction (log-rank test, P=0.0103), and TLR (log-rank test, P=0.0455) were significantly worse in patients with CN. Multivariate Cox proportional hazards analysis demonstrated that CN was an independent predictor of MACE (hazard ratio 4.41; 95% confidence interval 1.63-10.8; P=0.0047). CONCLUSIONS: Target lesion CN was associated with higher cardiac event rates in patients who underwent newer-generation DES implantation for lesions with moderate to severe CAC.

Post-Stent Optical Coherence Tomography Findings at Index Percutaneous Coronary Intervention　- Characteristics Related to Subsequent Stent Thrombosis.

BACKGROUND: The association between unfavorable post-stent optical coherence tomography (OCT) findings and subsequent stent thrombosis (ST) remains unclear. This study investigated the ST-related characteristics of post-stent OCT findings at index percutaneous coronary intervention (PCI).Methods and Results:Fifteen patients with ST onset after OCT-guided PCI (ST group) were retrospectively enrolled. Post-stent OCT findings in the ST group were compared with those in 70 consecutive patients (reference group) without acute coronary syndrome onset for at least 5 years after OCT-guided PCI. The incidence of acute myocardial infarction (AMI) was higher in the ST than reference group (60.0% vs. 17.1%, respectively; P=0.0005). The incidence of incomplete stent apposition (93.3% vs. 55.7%; P=0.0064), irregular protrusion (IP; 93.3% vs. 62.8%; P=0.0214), and thrombus (93.3% vs. 51.4%; P=0.0028) was significantly higher in the ST than reference group. The maximum median (interquartile range) IP arc was significantly larger in the ST than reference group (265° [217°-360°] vs. 128° [81.4°-212°], respectively; P<0.0001). In AMI patients, the incidence of a maximum IP arc >180° was significantly higher in the ST than reference group (100% vs. 58.3%, respectively; P=0.0265). CONCLUSIONS: IP with a large arc was a significant feature on post-stent OCT in patients with ST.

Usefulness of longitudinal reconstructed optical coherence tomography images for predicting the need for the reverse wire technique during coronary bifurcation interventions.

OBJECTIVES: The aim is to investigate the usefulness of longitudinal reconstructed optical coherence tomography (OCT) images in selecting the reverse wire (RW) technique for inserting a guidewire into a side branch (SB). BACKGROUND: It is sometimes necessary to protect the SB with a guidewire to prevent SB complications in PCI for bifurcation lesions. The RW is a novel method for guidewire insertion into an extremely angulated SB when the standard antegrade wire (AW) approach is difficult. METHODS: This retrospective study included 46 consecutive patients who underwent OCT-guided PCI in bifurcation lesions with significant SB stenosis. Patients were divided into two groups: 36 patients with successful guidewire crossing using the AW (AW group) and 10 patients with unsuccessful AW but successful RW guidewire crossing (RW group). SB angle and branch point (BP) slope, defined as the angle between the line connecting the proximal and distal BPs and the vertical, were measured using longitudinal reconstructed OCT images. RESULTS: The RW group had a significantly larger SB angle and higher BP slope than the AW group (108.7 ± 11.4° vs. 76.2 ± 14.9°; P < 0.0001, 128.7 ± 31.6° vs. 82.9 ± 33.6°; P = 0.0004, respectively). Receiver operating characteristic curve analysis indicated that SB angle ≥ 100° and BP slope ≥ 120° are optimal cutoff values for predicting the need for RW (area under the curve 0.97, sensitivity 90.0%, specificity 91.7%; area under the curve 0.83, sensitivity 80.0%, specificity 86.1%, respectively). CONCLUSIONS: Longitudinal reconstructed OCT is useful for selecting the wiring technique for bifurcation lesions.