Accurate placement of coronary stents in left anterior descending artery (LAD) ostial locations (Medina 0,1,0) poses technical challenges because of the ambiguity in angiographic ostial separation and issues related to stent movement before deployment. Harding et al developed a novel technique for accurate ostial stenting. This method uses real-time intravascular ultrasound (IVUS) guidance to achieve precise ostial stent placement, accurate identification of the ostial location, improved stability of the stent delivery system, and reduced stent motion before deployment. This study aimed to investigate the feasibility and accuracy of real-time IVUS guidance compared with angiographic guidance for LAD ostial stenting.
This was a single-center, retrospective, observational study. We enrolled 19 consecutive patients for real-time IVUS guidance and 41 for angiographic guidance as historical controls, who underwent LAD ostial stenting with a Medina 0,1,0 lesion at Miyazaki Prefectural Nobeoka Hospital. In both groups, lesion assessment and modification before stenting and stent optimization were performed with IVUS guidance, along with the 2023 expert consensus document on IVUS published by the Japanese Association of Cardiovascular Intervention and Therapeutics. In the real-time IVUS-guided stenting group, an Altaview 60 MHz IVUS catheter system (Terumo, Tokyo, Japan) was introduced using a second coronary guidewire in the nontarget branch (e.g., the left circumflex artery [LCX] or ramus branch), and its position was adjusted to provide a clear view of the ostium ( Figure 1 ). The drug-eluting stent was placed under real-time IVUS guidance, and the IVUS catheter was moved back and forth to confirm that the proximal edge of the stent ( Figure 1 ) was correctly positioned at the ostium of the LAD. In the angiography-guided group, the drug-eluting stent was placed under fluoroscopic and angiographic guidance. The IVUS marking technique, involving aligning the IVUS probe with the LAD ostium and performing angiography at the same angle as the stent placement, was used according to the operator’s preference. IVUS images were analyzed using EchoPlaque software (INDEC Medical Systems, Mountain View, California), along with expert consensus reports. All statistical analyses were conducted using IBM SPSS Statistics for Windows, version 20 (IBM Corp., Armonk, New York). This study was designed and conducted in accordance with the ethical guidelines of the Declaration of Helsinki, established by the World Medical Association, and the “Ethical Principles in Clinical Studies,” published by the Ministry of Health, Labour, and Welfare in Japan. This study was approved by the institutional review board of Miyazaki Prefectural Nobeoka Hospital (No. 20191004-1).
No significant differences in baseline patient and lesion characteristics and procedural characteristics were observed between the 2 groups, except for the guiding catheter size, frequency of IVUS marking, and number of coronary angiographies required for stent placement ( Table 1 ). In the real-time IVUS guidance group, the bifurcation of the LAD and LCX and the proximal edge of the stent were clearly visualized and confirmed on IVUS images during stent placement in all cases. The %plaque area (%PA) at the LAD ostium, excluding directional coronary atherectomy cases, was 54.3% (47.4% to 61.6%), whereas the %PA at 1, 2, and 3 mm from the ostium increased significantly to 65.2% (56.1% to 73.7%) (p <0.001), 70.8% (62.7% to 78.6%) (p <0.001), and 74.6% (66.9% to 80.0%) (p <0.001), respectively (p <0.001 overall for trend). Based on this result, we defined precise stenting zones to prevent geographic miss, specifying a stent proximal edge <1 mm from the LAD ostium, because the cut-off value of %PA for the stent proximal landing zone was set at approximately 55%. Compared with the angiography-guided group, the stent proximal edge in the real-time IVUS-guided group resulted in a significantly shorter absolute distance from the carina (0.26 [0 to 0.47] vs 0.82 [0.24 to 1.56] mm, p = 0.009) ( Figure 1 ). The overall incidence of precise stenting was 94.7% and 56.1% in the real-time IVUS and angiographic guidance groups, respectively (p = 0.003) ( Figure 1 ).
Real-time IVUS guidance (n=19) | Angiographic guidance (n=41) | P value | |
---|---|---|---|
Age, y | 71 (59, 80) | 72 (60, 81) | 0.80 |
Male, n (%) | 14 (73.7) | 34 (82.9) | 0.31 |
Body mass index, kg/m 2 | 24.4 (21.1, 26.5) | 22.3 (20.0, 25.2) | 0.11 |
Acute coronary syndrome, n (%) | 4 (21.1) | 14 (34.1) | 0.30 |
Hypertension, n (%) | 13 (68.4) | 32 (78.1) | 0.31 |
Diabetes mellitus, n (%) | 9 (47.4) | 12 (29.3) | 0.17 |
Dyslipidemia, n (%) | 13 (68.4) | 32 (78.1) | 0.31 |
Current smoking, n (%) | 4 (21.1) | 10 (24.4) | 0.53 |
Family history of CAD, n (%) | 1 (5.3) | 2 (4.9) | 0.69 |
History of MI, n (%) | 7 (36.8) | 10 (24.4) | 0.32 |
History of CABG, n (%) | 0 (0.0) | 1 (2.4) | 0.68 |
History of CHF, n (%) | 2 (10.5) | 8 (19.5) | 0.32 |
eGFR, mL/min/1.73 m 2 | 57.1 (40.3, 75.0) | 60.3 (46.0, 72.3) | 0.70 |
Hemodialysis, n (%) | 2 (10.5) | 2 (4.9) | 0.38 |
LVEF, % | 55.9 (45.1, 62.8) | 53.5 (46.5, 60.0) | 0.86 |
Moderate-severe calcification, n (%) | 10 (52.6) | 14 (34.1) | 0.17 |
LMT-LAD angle, degree | 43.3 (24.4, 57.3) | 38.6 (28.5, 47.3) | 0.74 |
LAD-LCX angle, degree | 104.4 (78.2, 134.8) | 102.9 (87.9, 126.4) | 0.94 |
Angiographic separation of the LAD ostium, n (%) | 10 (52.6) | 30 (73.2) | 0.12 |
Syntax score, pts | 11.0 (8.0, 22.5) | 12.0 (9.0, 19.3) | 0.74 |
%Plaque area at LAD ostium | 50.9 (47.6, 55.0) | 55.4 (46.9, 62.3) | 0.73 |
Radial artery approach, n (%) | 12 (63.2) | 28 (68.3) | 0.40 |
Guiding catheter size, Fr | 7 (7, 8) | 7 (6, 8) | 0.04 |
Ad-hoc, n (%) | 7 (36.8) | 18 (43.9) | 0.61 |
DCA, n (%) | 6 (31.6) | 7 (17.1) | 0.18 |
Rotational atherectomy, n (%) | 4 (21.1) | 8 (19.5) | 0.57 |
Stent diameter, mm | 3.5 (2.75, 3.5) | 3.0 (2.75, 3.5) | 0.26 |
Stent length, mm | 20 (15, 34) | 23 (21, 33) | 0.43 |
Pre dilatation, n (%) | 17 (89.5) | 35 (85.4) | 0.51 |
Post dilatation, n (%) | 6 (31.6) | 17 (17.1) | 0.46 |
Maximum balloon size, mm | 4.0 (3.0, 4.0) | 3.5 (3.0, 3.5) | 0.29 |
Maximum balloon pressure, atm | 12 (11, 14) | 12 (12, 16) | 0.17 |
Number of CAG needed for stent placement, n | 0 (0, 1) | 4 (3, 4) | <0.001 |
IVUS marking, n (%) | 4 (21.1) | 40 (97.6) | <0.001 |
Procedure time, min | 80 (54, 111) | 79 (47, 108) | 0.69 |
Contrast volume, ml | 105 (70, 146) | 121 (82, 149) | 0.61 |
Radiation dose, mGy | 1030 (831, 1954) | 1092 (832, 1789) | 0.96 |
%Plaque area at stent proximal edge, % | 50.8 (47.6, 56.1) | 52.9 (48.9, 58.9) | 0.11 |
Proximal stent area, mm 2 | 8.08 (6.23, 10.2) | 6.76 (6.08, 8.0) | 0.15 |
Stent proximal edge dissection, n (%) | 1 (5.3) | 10 (24.4) | 0.11 |
Procedural success, n (%) | 19 (100) | 41 (100) | – |
Periprocedural MACE, n (%) | 1 (5.3) | 0 (0) | 0.32 |
MACE at 30 days, n (%) | 1 (5.3) | 1 (2.4) | 0.44 |